Tag Archives: Agriculture

Extreme drought and fire risk may double by 2060

Climate change may soon double the impact of extreme drought and fire. And it’s a two-way traffic.

LONDON, 25 January, 2021 − As climate change threatens a doubling of the impact of extreme drought and fire within a generation, researchers are uncovering the influence of human activity on both these growing risks.

One study has found that human numbers exposed to the hazard of extreme drought are likely to double in the decades to come, as global heating bakes away the groundwater and limits annual snowfall.

Another team of researchers says the risks of extreme wildfire could also rise twofold in the next 40 years in the Mediterranean, southern Africa, eastern North America and the Amazon. In those places already severely scorched by frequent fire − western North America, equatorial Africa, south-east Asia and Australia − hazards could rise by 50%.

And a third, separate study warns that global temperature rise will shift the patterns of rainfall around the tropics − with the consequent risks to tropical crop harvests and to equatorial ecosystems such as rainforest and savannah.

All three studies are reminders of the intricacies of the planetary climate system and the impact of human action in the last hundred years.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this will affect food security and escalate human migration and conflict.”

An international research team reports in the journal Nature Climate Change that it looked at the simple problem of global terrestrial water storage: all the moisture in the canopies of forest trees, in the mountain snows and ice, in the lakes, rivers, wetlands, and in the soil itself.

This wealth of stored water is a big player in the patterns of global flooding and drought in the monsoon climates and the arid lands alike. But, the researchers say, there has so far been no study of the potential impact of global climate change on global terrestrial water storage overall.

So researchers from the US, China, Japan and Europe began modelling tomorrow’s world. And they found that, while 3% of the planet’s people were vulnerable to extreme drought in the timespan from 1976 to 2005, later in the century this proportion could increase to 7% or even 8%.

“More and more people will suffer from extreme droughts if a medium-to-high level of global warming continues and water management is maintained in its present state,” warned Yadu Pokhrel, an engineer at Michigan State University, who led the research.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this increase in water scarcity will affect food security and escalate human migration and conflict.”

Fire chances increased

Australia is a southern hemisphere country that knows about water scarcity: its wildfires in 2019 broke all records and sent a vast cloud of smoke to an altitude of 35 kms.

And, on the evidence of a new study in the journal Nature Communications, it won’t be the last such extreme event. Californian scientists, struck by the scale and intensity of Californian wildfires in 2017 and 2018, report that they took a closer look at the way greenhouse gas emissions and human land use change have played into the risks of extreme fire weather.

The simple act of setting forests afire to clear land for farm use has amplified the risk of extreme blazes in the Amazon and North America by 30% in the last century. Fires create aerosols that could, by absorbing sunlight, help cool the terrain beneath them − in some zones. But they could also affect rainfall levels and raise the chances of fire. The nature of such impacts varies from place to place.

“South-east Asia relies on the monsoon, but aerosols cause so much cooling on land that they can actually suppress a monsoon,” said Danielle Touma of the University of California at Santa Barbara. “It’s not just whether you have aerosols or not, it’s the way the regional climate interacts with aerosols.”

Aerosols − with other forces − cannot just suppress a monsoon, they can shift rain patterns permanently. The tropics, too, have begun to feel the heat of the moment.

Drought stress rises

The footprint of extreme drought and fire is massive. Californian researchers report in Nature Climate Change that, across two thirds of the globe, the tropical rainbelt is likely to shift north over eastern Africa and the Indian Ocean to cause more drought stress in south-eastern Africa and Madagascar and intensified flooding in south Asia.

In the western hemisphere, however, as the Gulf Stream current and the North Atlantic deep water formation weaken, the rain belt could move south to bring greater drought stress to Central America.

And once again, climate change driven by global heating is at work with other human influences to alter what had for most of human history been a stable pattern of climate.

“In Asia, projected reductions in aerosol emissions, glacier melting in the Himalayas and loss of snow cover in northern areas brought on by climate change will cause the atmosphere to heat up faster than in other regions,” said James Randerson of the University of California, Irvine, one of the authors.

“We know the rainbelt shifts towards this heating, and that its northward movement in the eastern hemisphere is consistent with these expected impacts of climate change.” − Climate News Network

Climate change may soon double the impact of extreme drought and fire. And it’s a two-way traffic.

LONDON, 25 January, 2021 − As climate change threatens a doubling of the impact of extreme drought and fire within a generation, researchers are uncovering the influence of human activity on both these growing risks.

One study has found that human numbers exposed to the hazard of extreme drought are likely to double in the decades to come, as global heating bakes away the groundwater and limits annual snowfall.

Another team of researchers says the risks of extreme wildfire could also rise twofold in the next 40 years in the Mediterranean, southern Africa, eastern North America and the Amazon. In those places already severely scorched by frequent fire − western North America, equatorial Africa, south-east Asia and Australia − hazards could rise by 50%.

And a third, separate study warns that global temperature rise will shift the patterns of rainfall around the tropics − with the consequent risks to tropical crop harvests and to equatorial ecosystems such as rainforest and savannah.

All three studies are reminders of the intricacies of the planetary climate system and the impact of human action in the last hundred years.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this will affect food security and escalate human migration and conflict.”

An international research team reports in the journal Nature Climate Change that it looked at the simple problem of global terrestrial water storage: all the moisture in the canopies of forest trees, in the mountain snows and ice, in the lakes, rivers, wetlands, and in the soil itself.

This wealth of stored water is a big player in the patterns of global flooding and drought in the monsoon climates and the arid lands alike. But, the researchers say, there has so far been no study of the potential impact of global climate change on global terrestrial water storage overall.

So researchers from the US, China, Japan and Europe began modelling tomorrow’s world. And they found that, while 3% of the planet’s people were vulnerable to extreme drought in the timespan from 1976 to 2005, later in the century this proportion could increase to 7% or even 8%.

“More and more people will suffer from extreme droughts if a medium-to-high level of global warming continues and water management is maintained in its present state,” warned Yadu Pokhrel, an engineer at Michigan State University, who led the research.

“Areas of the southern hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this increase in water scarcity will affect food security and escalate human migration and conflict.”

Fire chances increased

Australia is a southern hemisphere country that knows about water scarcity: its wildfires in 2019 broke all records and sent a vast cloud of smoke to an altitude of 35 kms.

And, on the evidence of a new study in the journal Nature Communications, it won’t be the last such extreme event. Californian scientists, struck by the scale and intensity of Californian wildfires in 2017 and 2018, report that they took a closer look at the way greenhouse gas emissions and human land use change have played into the risks of extreme fire weather.

The simple act of setting forests afire to clear land for farm use has amplified the risk of extreme blazes in the Amazon and North America by 30% in the last century. Fires create aerosols that could, by absorbing sunlight, help cool the terrain beneath them − in some zones. But they could also affect rainfall levels and raise the chances of fire. The nature of such impacts varies from place to place.

“South-east Asia relies on the monsoon, but aerosols cause so much cooling on land that they can actually suppress a monsoon,” said Danielle Touma of the University of California at Santa Barbara. “It’s not just whether you have aerosols or not, it’s the way the regional climate interacts with aerosols.”

Aerosols − with other forces − cannot just suppress a monsoon, they can shift rain patterns permanently. The tropics, too, have begun to feel the heat of the moment.

Drought stress rises

The footprint of extreme drought and fire is massive. Californian researchers report in Nature Climate Change that, across two thirds of the globe, the tropical rainbelt is likely to shift north over eastern Africa and the Indian Ocean to cause more drought stress in south-eastern Africa and Madagascar and intensified flooding in south Asia.

In the western hemisphere, however, as the Gulf Stream current and the North Atlantic deep water formation weaken, the rain belt could move south to bring greater drought stress to Central America.

And once again, climate change driven by global heating is at work with other human influences to alter what had for most of human history been a stable pattern of climate.

“In Asia, projected reductions in aerosol emissions, glacier melting in the Himalayas and loss of snow cover in northern areas brought on by climate change will cause the atmosphere to heat up faster than in other regions,” said James Randerson of the University of California, Irvine, one of the authors.

“We know the rainbelt shifts towards this heating, and that its northward movement in the eastern hemisphere is consistent with these expected impacts of climate change.” − Climate News Network

Overheated Earth can slow plants’ carbon storage

For vast tracts of forest and savannah, the heat could rise too far for plants’ carbon storage abilities to go on working.

LONDON, 15 January, 2020 − Climate change could be about to slowly shut down the planet’s most vital life-support ability: the functioning of plants’ carbon storage system, which protects the Earth by absorbing the greenhouse gas before it can enter the atmosphere.

Green things driven by photosynthesis right now soak up around one-third of all the greenhouse gas emitted from vehicle exhausts and power station chimneys. But in the next two or three decades, their capacity to do this could be halved, because rapidly rising atmospheric temperatures will set a limit.

At that limiting point, the ability of forests, grasslands and even crops to capture and hold atmospheric carbon, the nourishment for all life on Earth, will start to diminish.

For one important group of plants − these include rice, soy, pulses, grasses, oaks, pines and so on − photosynthesis happens at a peak rate at 18°C. At higher temperatures, the process becomes less efficient and the plant begins to respire: that is, gulp oxygen and breathe out carbon dioxide.

For a second, smaller group − one that includes maize and sugar cane and just one group of trees − that temperature tipping point is 28°C. And researchers report in the journal Science Advances that, by 2050, temperatures will have risen in ways that will limit the efficiency of photosynthesis by around 45%.

“The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years”

The finding is based not just on computer simulation and theoretical models, but on direct observation. Researchers used directly measured data of sunlight, water and carbon dioxide action from 1991 to 2015 at a network of scientific instruments placed in every major ecosystem around the globe to identify these temperature tipping points.

And they warn that the mean or average temperature for the warmest three months of the year had already passed the thermal maximum for photosynthesis “some time in the last decade.”

Right now, only about a tenth of the forests and grasslands are exposed to temperatures beyond such thresholds, and then only for a short period. But greenhouse gas emissions continue to rise and global temperatures continue to soar. In time, half the planet could start to experience such temperatures.

The scientists warn that if humans go on clearing natural forests and burning fossil fuels at the present rates − climate scientists call this the “business-as-usual scenario” − then the capacity of the vegetable world to absorb atmospheric carbon could be almost halved as early as 2040.

Researchers have repeatedly warned that climate change in one way or another was likely to compromise the capacity of some natural ecosystems to go on doing what they have done for the last 10,000 years. But this study is one of the first to consider the green world as a whole.

Capacity halved

“The Earth has a steadily growing fever and, much like the human body, we know every biological process has a range of temperatures at which it performs optimally, and ones above which function deteriorates,” said Katharyn Duffy, of Northern Arizona University, who led the study. “So, we wanted to ask, how much can plants withstand?”

The US scientists and colleagues from New Zealand give their answer to the conundrum of plants’ carbon storage with a clarity and simplicity rare in scientific papers. “The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years,” they warn.

“Without mitigating warming, we will cross the temperature threshold of the most productive biomes by mid-century, after which the land sink will degrade.”

And if the plant world does not adapt, the capacity of the land to absorb surplus atmospheric carbon will drop to around 50% of its present range. And, the scientists warn, the process may not be a smooth, barely-perceptible decline: disturbance in a lot of landscapes could be rapid and precipitous.

They conclude: “Failure to implement agreements that meet or exceed limits in the Paris Accord could quantitatively alter the large and persistent terrestrial carbon sink, on which we currently depend to mitigate anthropogenic emissions of CO2 and therefore global environmental change.” − Climate News Network

For vast tracts of forest and savannah, the heat could rise too far for plants’ carbon storage abilities to go on working.

LONDON, 15 January, 2020 − Climate change could be about to slowly shut down the planet’s most vital life-support ability: the functioning of plants’ carbon storage system, which protects the Earth by absorbing the greenhouse gas before it can enter the atmosphere.

Green things driven by photosynthesis right now soak up around one-third of all the greenhouse gas emitted from vehicle exhausts and power station chimneys. But in the next two or three decades, their capacity to do this could be halved, because rapidly rising atmospheric temperatures will set a limit.

At that limiting point, the ability of forests, grasslands and even crops to capture and hold atmospheric carbon, the nourishment for all life on Earth, will start to diminish.

For one important group of plants − these include rice, soy, pulses, grasses, oaks, pines and so on − photosynthesis happens at a peak rate at 18°C. At higher temperatures, the process becomes less efficient and the plant begins to respire: that is, gulp oxygen and breathe out carbon dioxide.

For a second, smaller group − one that includes maize and sugar cane and just one group of trees − that temperature tipping point is 28°C. And researchers report in the journal Science Advances that, by 2050, temperatures will have risen in ways that will limit the efficiency of photosynthesis by around 45%.

“The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years”

The finding is based not just on computer simulation and theoretical models, but on direct observation. Researchers used directly measured data of sunlight, water and carbon dioxide action from 1991 to 2015 at a network of scientific instruments placed in every major ecosystem around the globe to identify these temperature tipping points.

And they warn that the mean or average temperature for the warmest three months of the year had already passed the thermal maximum for photosynthesis “some time in the last decade.”

Right now, only about a tenth of the forests and grasslands are exposed to temperatures beyond such thresholds, and then only for a short period. But greenhouse gas emissions continue to rise and global temperatures continue to soar. In time, half the planet could start to experience such temperatures.

The scientists warn that if humans go on clearing natural forests and burning fossil fuels at the present rates − climate scientists call this the “business-as-usual scenario” − then the capacity of the vegetable world to absorb atmospheric carbon could be almost halved as early as 2040.

Researchers have repeatedly warned that climate change in one way or another was likely to compromise the capacity of some natural ecosystems to go on doing what they have done for the last 10,000 years. But this study is one of the first to consider the green world as a whole.

Capacity halved

“The Earth has a steadily growing fever and, much like the human body, we know every biological process has a range of temperatures at which it performs optimally, and ones above which function deteriorates,” said Katharyn Duffy, of Northern Arizona University, who led the study. “So, we wanted to ask, how much can plants withstand?”

The US scientists and colleagues from New Zealand give their answer to the conundrum of plants’ carbon storage with a clarity and simplicity rare in scientific papers. “The temperature tipping point of the terrestrial biosphere lies not at the end of the century or beyond, but within the next 20 to 30 years,” they warn.

“Without mitigating warming, we will cross the temperature threshold of the most productive biomes by mid-century, after which the land sink will degrade.”

And if the plant world does not adapt, the capacity of the land to absorb surplus atmospheric carbon will drop to around 50% of its present range. And, the scientists warn, the process may not be a smooth, barely-perceptible decline: disturbance in a lot of landscapes could be rapid and precipitous.

They conclude: “Failure to implement agreements that meet or exceed limits in the Paris Accord could quantitatively alter the large and persistent terrestrial carbon sink, on which we currently depend to mitigate anthropogenic emissions of CO2 and therefore global environmental change.” − Climate News Network

Caspian Sea loss puts Asian water supplies at risk

The Caspian Sea’s decline means a climate-led water crisis for at least five Asian nations as inland seas dry up.

LONDON, 7 January, 2021 − The Caspian Sea − the world’s largest lake − is about to go down in the world. And with it could go the fortunes of some of the people of at least five nations. New research suggests that the Caspian Sea, already getting lower at the rate of several centimetres a year, is to go into even faster decline: later this century, it could be nine metres lower than it is now. Or even 18 metres lower.

In the paradoxical world of climate change, sea levels will rise to threaten coastal settlements, but many of the great inland lakes could be doomed to dwindle.

Dutch and German scientists report in the journal Communications Earth & Environment that because more water will evaporate each summer, and less ice will form each winter, the area of the Caspian − it covers 371,000 square kilometres, an area greater than Japan, or Germany − is doomed to shrink at an accelerating rate.

Lakeside communities, ports and industries in Azerbaijan, Russia, Iran, Turkmenistan and Kazakhstan, all of which border the Caspian, could be left high and dry.

Change required

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded. Fishing boats and container giants alike would struggle, and all the countries of the North Sea would have a huge problem,” said Frank Wesselingh, of the University of Utrecht in the Netherlands, one of the authors. “Here we are talking about a decrease of no less than nine metres, in the best case scenario.”

His co-author Matthias Prange of the University of Bremen in Germany warned that what happens to the Caspian could and will happen to the great land-locked lakes on other continents. “This has to change. We need more studies and a better understanding of the consequences of global warming in this region.”

This is not the first such warning: although much of the world’s concern has been with the dramatic loss of water from the Aral Sea, researchers have worried about the impact of evaporation on the Caspian too. It may be salty, but it is one of the world’s great inland reservoirs of water for industry, agriculture and human settlement.

It is also host to a vast range of species, including the Caspian seal, an endangered creature that depends on winter ice to protect and rear its pups. Its shallow waters provide food for migrating birds, and serve as spawning grounds for its fish, including the sturgeon endemic to the region.

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded, and all the countries of the North Sea would have a huge problem”

The Caspian Sea’s chief source of water is the Volga River: it has no connection with the ocean. So its water levels depend entirely on rainfall, evaporation and inflow. And in a world of global heating, evaporation is on the increase.

The level of rainfall, on the other hand, is likely to decline: in a world of climate change, those already semi-arid regions can expect to become more parched.

The authors expect these challenges will confront not only the dwellers by the Caspian Sea but also those hundreds of millions who live by, and depend upon, other lakes in Asia, and in Africa and North America. The consequences for these people could be just as devastating as global sea level rise will be for others. They call for higher levels of awareness, and an international task force to help address the problem.

“Immediate and co-ordinated action is needed to make up for valuable time lost,” they write. “The shrinking Caspian Sea might serve as a poster child that will help galvanise such actions.” − Climate News Network

The Caspian Sea’s decline means a climate-led water crisis for at least five Asian nations as inland seas dry up.

LONDON, 7 January, 2021 − The Caspian Sea − the world’s largest lake − is about to go down in the world. And with it could go the fortunes of some of the people of at least five nations. New research suggests that the Caspian Sea, already getting lower at the rate of several centimetres a year, is to go into even faster decline: later this century, it could be nine metres lower than it is now. Or even 18 metres lower.

In the paradoxical world of climate change, sea levels will rise to threaten coastal settlements, but many of the great inland lakes could be doomed to dwindle.

Dutch and German scientists report in the journal Communications Earth & Environment that because more water will evaporate each summer, and less ice will form each winter, the area of the Caspian − it covers 371,000 square kilometres, an area greater than Japan, or Germany − is doomed to shrink at an accelerating rate.

Lakeside communities, ports and industries in Azerbaijan, Russia, Iran, Turkmenistan and Kazakhstan, all of which border the Caspian, could be left high and dry.

Change required

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded. Fishing boats and container giants alike would struggle, and all the countries of the North Sea would have a huge problem,” said Frank Wesselingh, of the University of Utrecht in the Netherlands, one of the authors. “Here we are talking about a decrease of no less than nine metres, in the best case scenario.”

His co-author Matthias Prange of the University of Bremen in Germany warned that what happens to the Caspian could and will happen to the great land-locked lakes on other continents. “This has to change. We need more studies and a better understanding of the consequences of global warming in this region.”

This is not the first such warning: although much of the world’s concern has been with the dramatic loss of water from the Aral Sea, researchers have worried about the impact of evaporation on the Caspian too. It may be salty, but it is one of the world’s great inland reservoirs of water for industry, agriculture and human settlement.

It is also host to a vast range of species, including the Caspian seal, an endangered creature that depends on winter ice to protect and rear its pups. Its shallow waters provide food for migrating birds, and serve as spawning grounds for its fish, including the sturgeon endemic to the region.

“If the North Sea were to drop two or three metres, access to ports like Rotterdam, Hamburg and London would be impeded, and all the countries of the North Sea would have a huge problem”

The Caspian Sea’s chief source of water is the Volga River: it has no connection with the ocean. So its water levels depend entirely on rainfall, evaporation and inflow. And in a world of global heating, evaporation is on the increase.

The level of rainfall, on the other hand, is likely to decline: in a world of climate change, those already semi-arid regions can expect to become more parched.

The authors expect these challenges will confront not only the dwellers by the Caspian Sea but also those hundreds of millions who live by, and depend upon, other lakes in Asia, and in Africa and North America. The consequences for these people could be just as devastating as global sea level rise will be for others. They call for higher levels of awareness, and an international task force to help address the problem.

“Immediate and co-ordinated action is needed to make up for valuable time lost,” they write. “The shrinking Caspian Sea might serve as a poster child that will help galvanise such actions.” − Climate News Network

Human handiwork’s mass exceeds world lifeforms

Human handiwork, all we’ve produced, now outweighs the plants and animals evolved over 3 billion years: a global takeover.

LONDON, 10 December, 2020 − Our domination of the planet may have just reached a new level: human handiwork now probably surpasses all that evolution has placed on the Earth. The mass of all the things made by humans − cities, roads, factories, houses, cars, trains, machines, bricks, concrete, steel, glass, tile, asphalt and so on − may have just overtaken the mass of all the living things on the planet.

Among those living things now being outweighed by buildings and roads are all seven billion-plus people on the planet and all their livestock, their cornfields and rice paddies, orchards and gardens.

This conclusion − open to challenge and difficult to establish with immediate certainty − is a fresh and startling measure of the scale of human change to the planet, and of the speed at which it has happened.

At the beginning of the 20th century, the mass of human-produced infrastructure probably added up to just 3% of the mass of the planet’s living tissue: its forests and savannahs, wetlands and scrub, its mammals, fish, reptiles, amphibians, birds, insects and microbes.

But in the course of little more than a century, says a new study in the journal Nature, two things happened. The human population increased fourfold, and with those numbers so did human demand for manufactured things and built objects.

Forests erased

Humans’ demand for farmland has cleared the wilderness and reduced the overall mass of planetary foliage by about half.

Even though humans use ever more land for crops, the mass of those crops is vastly outweighed by the mass of trees and other forest plants cleared to make room for soy, or maize.

Once the planet was home to 2 trillion tonnes, or 2 teratonnes, of natural vegetable life. Now the tally of the green wilderness has been reduced to about 1 teratonne, according to researchers who have embarked on this global accounting of human profit and natural loss.

But the burden of human-fashioned hardware has been growing at around 30 billion tonnes a year, doubled in mass every 20 years or so, and is now estimated at 1.1 teratonnes.

In effect, a species that now numbers about 7.7 bn, and still adds up to only about 0.01% of global biomass, has quarried, mined, and built over so much of the planet that its infrastructure weighs more than the rest of living creation.

“If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes [3tn tonnes] by 2040 − almost triple the dry biomass on Earth”

Even the output of the plastics industries, at eight billion tonnes, adds up to more than twice the mass of all the planet’s animals.

Conclusions of this kind rest on how measurements are arrived at. And there is room for error. Ron Milo of the Weizmann Institute for Science in Israel and his colleagues settled for estimates of the dry weight of living things − that is, tissue as if without water − and this skews the raw figures, because humans and other animals are around 60% water by weight. If the same estimates were made with wet tissue, then the outcome would be different, but not very different.

If so, Professor Milo and his fellow authors suggest that the great crossover could be happening now, or in the next few years. But equally, human handiwork might already have reached its zenith in the last decade.

Either way, the broad conclusion remains the same. The scale of the takeover of the planet by one species is almost complete, and could be devastating to the rest of the natural world.

“The study provides a sort of ‘big picture’ snapshot of the planet in 2020. This overview can provide a crucial understanding of our major role in shaping the face of the Earth in the current age of the Anthropocene,” Professor Milo said.

“The message to both the policy makers and the general public is that we cannot dismiss our role as a tiny one in comparison to the huge Earth. We are already a major player and I think with that comes a shared responsibility.”

Rollcall of devastation

This study is yet another in a long series that demonstrates the now-overwhelming impact of human handiwork upon the environment in which they evolved. Two years ago Professor Milo and colleagues made estimates of the mass of all things living on planet Earth, and confirmed that humans probably outweighed by a factor of ten the mass of all other living wild mammals.

Another team tried to calculate the mass of the human technosphere − once again, all the things humans have ever made − and reached a figure of 30 trillion tonnes.

In the course of the last century or so, profligate human use of fossil fuels may have precipitated a new climate regime, halted the cycle of Ice Ages and reversed a 50 million-year cooling trend.

Geologists who argue that human handiwork has now shifted the planet into a new geological epoch − one still unofficially known as the Anthropocene − have compiled a devastating catalogue of change to the natural world. Other groups have also highlighted the human appropriation of the planet’s land and water, and its toll upon millions of other species with which humanity shares the sunlight.

Professor Milo and his colleagues settled for a more simple illustration. They reckon that for the last five years, humans have been accumulating anthropogenic mass − roads and buildings − at the rate of 30 billion tonnes a year. This is as if every person on the planet produced more than his or her own bodyweight in tarmac and bricks, cement and steel, every week.

They warn: “If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes by 2040 − almost triple the dry biomass on Earth.” − Climate News Network

Human handiwork, all we’ve produced, now outweighs the plants and animals evolved over 3 billion years: a global takeover.

LONDON, 10 December, 2020 − Our domination of the planet may have just reached a new level: human handiwork now probably surpasses all that evolution has placed on the Earth. The mass of all the things made by humans − cities, roads, factories, houses, cars, trains, machines, bricks, concrete, steel, glass, tile, asphalt and so on − may have just overtaken the mass of all the living things on the planet.

Among those living things now being outweighed by buildings and roads are all seven billion-plus people on the planet and all their livestock, their cornfields and rice paddies, orchards and gardens.

This conclusion − open to challenge and difficult to establish with immediate certainty − is a fresh and startling measure of the scale of human change to the planet, and of the speed at which it has happened.

At the beginning of the 20th century, the mass of human-produced infrastructure probably added up to just 3% of the mass of the planet’s living tissue: its forests and savannahs, wetlands and scrub, its mammals, fish, reptiles, amphibians, birds, insects and microbes.

But in the course of little more than a century, says a new study in the journal Nature, two things happened. The human population increased fourfold, and with those numbers so did human demand for manufactured things and built objects.

Forests erased

Humans’ demand for farmland has cleared the wilderness and reduced the overall mass of planetary foliage by about half.

Even though humans use ever more land for crops, the mass of those crops is vastly outweighed by the mass of trees and other forest plants cleared to make room for soy, or maize.

Once the planet was home to 2 trillion tonnes, or 2 teratonnes, of natural vegetable life. Now the tally of the green wilderness has been reduced to about 1 teratonne, according to researchers who have embarked on this global accounting of human profit and natural loss.

But the burden of human-fashioned hardware has been growing at around 30 billion tonnes a year, doubled in mass every 20 years or so, and is now estimated at 1.1 teratonnes.

In effect, a species that now numbers about 7.7 bn, and still adds up to only about 0.01% of global biomass, has quarried, mined, and built over so much of the planet that its infrastructure weighs more than the rest of living creation.

“If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes [3tn tonnes] by 2040 − almost triple the dry biomass on Earth”

Even the output of the plastics industries, at eight billion tonnes, adds up to more than twice the mass of all the planet’s animals.

Conclusions of this kind rest on how measurements are arrived at. And there is room for error. Ron Milo of the Weizmann Institute for Science in Israel and his colleagues settled for estimates of the dry weight of living things − that is, tissue as if without water − and this skews the raw figures, because humans and other animals are around 60% water by weight. If the same estimates were made with wet tissue, then the outcome would be different, but not very different.

If so, Professor Milo and his fellow authors suggest that the great crossover could be happening now, or in the next few years. But equally, human handiwork might already have reached its zenith in the last decade.

Either way, the broad conclusion remains the same. The scale of the takeover of the planet by one species is almost complete, and could be devastating to the rest of the natural world.

“The study provides a sort of ‘big picture’ snapshot of the planet in 2020. This overview can provide a crucial understanding of our major role in shaping the face of the Earth in the current age of the Anthropocene,” Professor Milo said.

“The message to both the policy makers and the general public is that we cannot dismiss our role as a tiny one in comparison to the huge Earth. We are already a major player and I think with that comes a shared responsibility.”

Rollcall of devastation

This study is yet another in a long series that demonstrates the now-overwhelming impact of human handiwork upon the environment in which they evolved. Two years ago Professor Milo and colleagues made estimates of the mass of all things living on planet Earth, and confirmed that humans probably outweighed by a factor of ten the mass of all other living wild mammals.

Another team tried to calculate the mass of the human technosphere − once again, all the things humans have ever made − and reached a figure of 30 trillion tonnes.

In the course of the last century or so, profligate human use of fossil fuels may have precipitated a new climate regime, halted the cycle of Ice Ages and reversed a 50 million-year cooling trend.

Geologists who argue that human handiwork has now shifted the planet into a new geological epoch − one still unofficially known as the Anthropocene − have compiled a devastating catalogue of change to the natural world. Other groups have also highlighted the human appropriation of the planet’s land and water, and its toll upon millions of other species with which humanity shares the sunlight.

Professor Milo and his colleagues settled for a more simple illustration. They reckon that for the last five years, humans have been accumulating anthropogenic mass − roads and buildings − at the rate of 30 billion tonnes a year. This is as if every person on the planet produced more than his or her own bodyweight in tarmac and bricks, cement and steel, every week.

They warn: “If current trends continue, anthropogenic mass, including waste, is expected to exceed 3 teratonnes by 2040 − almost triple the dry biomass on Earth.” − Climate News Network

Mixed farming beats intensive agriculture methods

It sounds like the conservationist’s dream. But a return to traditional mixed farming ways could pay off for farmers too.

LONDON, 23 November, 2020 − Once again, researchers have shown that it should be possible to feed the human race and leave enough space for the rest of creation, simply by going back to centuries-old mixed farming practices.

That would mean an end to highly intensively-farmed landscapes composed of vast fields that were home to just one crop, and a return to a number of once-traditional husbandry methods. It sounds counter-intuitive, but European researchers are convinced that it could be good value.

They report in the journal Science Advances that they looked at more than 5,000 studies that made more than 40,000 comparisons between what they term diversified and simplified agriculture.

And they found that crop yield in general either kept to the same level or even increased when farmers adopted what they called diversified practices of the kind that sustained subsistence farmers for many centuries.

These include intercropping − different crops side by side − and multiple crops in rotation, strips of flowers to encourage pollinating insects, lower levels of disturbance of the soil and hedges, and forested shelter belts to encourage wildlife alongside farmland.

“Most often, diversification practices resulted in win-win support of services and crop yields”

The payoff? Better ecosystem services such as pollination, the regulation of crop pests by natural enemies, a more efficient turnover of nutrients, higher water quality, and in many cases better storage of carbon in ways that could mitigate climate change.

This, of course, is not how big agribusiness delivers much of the world’s food.

“The trend is that we are simplifying major cropping systems worldwide,” said Giovanni Tamburini, an ecologist at the Swedish University of Agricultural Sciences in Uppsala, who led the study.

“We grow monoculture on enlarged fields in homogenised landscapes. According to our study, diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself.”

It’s an old argument. Is it better for a farmer to invest all in one vast crop of maize or wheat or soy, regularly nourished by commercial fertilisers, routinely sprayed to suppress pests, moulds and mildews, with the land ploughed and harrowed after harvest for the next crop, and always at risk of frost or flood, locust swarms, drought or blight?

All-round winners

Or would it be better in the long run for the farmer to spread the risk by changing and multiplying the crops, and to rely more on undisturbed soils and local habitats for birds and insects that would demolish some of the pests (and of course take some of the crop)?

Researchers have repeatedly argued that both to contain climate change and to preserve the natural world from which all human nourishment and almost all human wealth ultimately derive, farming practices must change, and so must human appetite. The argument remains: what is the best way to set about change down on the farm itself?

There have already been a large number of studies of this question. There have also been meta-analyses, or studies of collected studies. Dr Tamburini and his colleagues identified 41,946 comparisons embedded in 5,160 original studies. They also found 98 meta-analyses. And they took a fresh look at the whole lot to identify what could be win-win, trade-off and lose-lose outcomes.

They found that diversification is better for biodiversity, pollination, pest control, nutrient cycling, soil fertility and water regulation at least 63% of the time. “Most often, diversification practices resulted in win-win support of services and crop yields,” they report.

“Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.” − Climate News Network

It sounds like the conservationist’s dream. But a return to traditional mixed farming ways could pay off for farmers too.

LONDON, 23 November, 2020 − Once again, researchers have shown that it should be possible to feed the human race and leave enough space for the rest of creation, simply by going back to centuries-old mixed farming practices.

That would mean an end to highly intensively-farmed landscapes composed of vast fields that were home to just one crop, and a return to a number of once-traditional husbandry methods. It sounds counter-intuitive, but European researchers are convinced that it could be good value.

They report in the journal Science Advances that they looked at more than 5,000 studies that made more than 40,000 comparisons between what they term diversified and simplified agriculture.

And they found that crop yield in general either kept to the same level or even increased when farmers adopted what they called diversified practices of the kind that sustained subsistence farmers for many centuries.

These include intercropping − different crops side by side − and multiple crops in rotation, strips of flowers to encourage pollinating insects, lower levels of disturbance of the soil and hedges, and forested shelter belts to encourage wildlife alongside farmland.

“Most often, diversification practices resulted in win-win support of services and crop yields”

The payoff? Better ecosystem services such as pollination, the regulation of crop pests by natural enemies, a more efficient turnover of nutrients, higher water quality, and in many cases better storage of carbon in ways that could mitigate climate change.

This, of course, is not how big agribusiness delivers much of the world’s food.

“The trend is that we are simplifying major cropping systems worldwide,” said Giovanni Tamburini, an ecologist at the Swedish University of Agricultural Sciences in Uppsala, who led the study.

“We grow monoculture on enlarged fields in homogenised landscapes. According to our study, diversification can reverse the negative impacts that we observe in simplified forms of cropping on the environment and on production itself.”

It’s an old argument. Is it better for a farmer to invest all in one vast crop of maize or wheat or soy, regularly nourished by commercial fertilisers, routinely sprayed to suppress pests, moulds and mildews, with the land ploughed and harrowed after harvest for the next crop, and always at risk of frost or flood, locust swarms, drought or blight?

All-round winners

Or would it be better in the long run for the farmer to spread the risk by changing and multiplying the crops, and to rely more on undisturbed soils and local habitats for birds and insects that would demolish some of the pests (and of course take some of the crop)?

Researchers have repeatedly argued that both to contain climate change and to preserve the natural world from which all human nourishment and almost all human wealth ultimately derive, farming practices must change, and so must human appetite. The argument remains: what is the best way to set about change down on the farm itself?

There have already been a large number of studies of this question. There have also been meta-analyses, or studies of collected studies. Dr Tamburini and his colleagues identified 41,946 comparisons embedded in 5,160 original studies. They also found 98 meta-analyses. And they took a fresh look at the whole lot to identify what could be win-win, trade-off and lose-lose outcomes.

They found that diversification is better for biodiversity, pollination, pest control, nutrient cycling, soil fertility and water regulation at least 63% of the time. “Most often, diversification practices resulted in win-win support of services and crop yields,” they report.

“Widespread adoption of diversification practices shows promise to contribute to biodiversity conservation and food security from local to global scales.” − Climate News Network

Food system causes one third of greenhouse gases

How we eat causes dangerous climate heating. It’s time to change not only our diet, but the entire global food system.

LONDON, 13 November, 2020 − If the nations of the world really want to limit climate change to the level agreed five years ago, it will not be enough to immediately abandon fossil fuels as the principal source of energy: the global food system demands radical overhaul.

Humans will have to make dramatic changes to every aspect of agriculture worldwide, to planetary diet and to much else besides.

That is because the global food system − everything from clearing land and felling forests for cattle ranches to the arrival of meat and two vegetables on a suburban family dinner plate − accounts for 30% of the world’s greenhouse gas emissions. And to contain global heating later this century to no more than 1.5°C above the levels that existed before the Industrial Revolution, urgent action is needed.

In Paris in 2015, 195 nations undertook to limit the planetary thermometer rise to “well below” 2°C. The undeclared target was 1.5°C. In the last century, the global temperature has already risen by 1°C, and at the present rate it’s heading for a potentially catastrophic 3°C or more rise by around 2100.

“Food is a much greater contributor to climate change than is widely known”

British and US scientists report in the journal Science that they looked at the challenge of feeding a global population that has almost trebled in one human lifetime, and could reach 9bn or even 10bn later this century.

They found that the greenhouse gas emissions from food production alone would by 2050 take the world to the 1.5°C target, and to 2°C by the end of the century.

In just the five years that separated 2010 from 2017, the global food system accounted for an average of 16 billion tonnes of carbon dioxide equivalent in emissions each year. If humans go on pursuing business as usual, then the cumulative emissions from the food system could add up to 1,365 billion tonnes.

Emissions on that scale from the food system alone would take the planet past the preferred 1.5°C limit some time between 2051 and 2063, and reach the 2°C limit by 2100.

Remedies at hand

“Food is a much greater contributor to climate change than is widely known,” said Jason Hill, of the University of Minnesota, and one of the authors. “Fortunately, we can fix this problem by using fertiliser more efficiently, by eating less meat and more fruits, vegetables, whole grains and nuts, and by making other important changes to our food system.”

The finding should come as no great surprise: global heating is driven by more than simply the return of carbon dioxide fossilised 300 million years ago as coal, oil and natural gas to the atmosphere with every touch of the accelerator, with every jet plane take-off, with every ignition of the electric light, the air conditioning system and the heating, and every turn of industrial machinery around the planet.

It is also fuelled by the devastating clearance of natural forest, grassland and marsh for grazing land or plantation, and the conversion of natural canopy to fodder crops to nourish the world’s domestic cattle and sheep.

Researchers have repeatedly pointed out that even a relatively simple shift to greater reliance on a plant diet could save on carbon emissions, protect the million or so species threatened with imminent extinction, and improve global health, all at the same time.

Multiple benefits

So the latest study offers a new way of spelling out the scale of the problem − a global challenge that could be resolved by concerted and coherent international action.

The researchers identified five strategies that, they believe, could both help limit climate change and improve human health, enhance air quality, reduce water pollution, slow extinction rates and make farms more profitable.

The challenge is to increase crop yields per hectare, reduce food waste, improve farm efficiency and switch to healthy calorie supplies based increasingly on plant crops.

“Even partially adopting several of these five changes would solve this problem as long as we start right now,” said David Tilman, another author, and an ecologist at the university’s College of Biological Sciences. − Climate News Network

How we eat causes dangerous climate heating. It’s time to change not only our diet, but the entire global food system.

LONDON, 13 November, 2020 − If the nations of the world really want to limit climate change to the level agreed five years ago, it will not be enough to immediately abandon fossil fuels as the principal source of energy: the global food system demands radical overhaul.

Humans will have to make dramatic changes to every aspect of agriculture worldwide, to planetary diet and to much else besides.

That is because the global food system − everything from clearing land and felling forests for cattle ranches to the arrival of meat and two vegetables on a suburban family dinner plate − accounts for 30% of the world’s greenhouse gas emissions. And to contain global heating later this century to no more than 1.5°C above the levels that existed before the Industrial Revolution, urgent action is needed.

In Paris in 2015, 195 nations undertook to limit the planetary thermometer rise to “well below” 2°C. The undeclared target was 1.5°C. In the last century, the global temperature has already risen by 1°C, and at the present rate it’s heading for a potentially catastrophic 3°C or more rise by around 2100.

“Food is a much greater contributor to climate change than is widely known”

British and US scientists report in the journal Science that they looked at the challenge of feeding a global population that has almost trebled in one human lifetime, and could reach 9bn or even 10bn later this century.

They found that the greenhouse gas emissions from food production alone would by 2050 take the world to the 1.5°C target, and to 2°C by the end of the century.

In just the five years that separated 2010 from 2017, the global food system accounted for an average of 16 billion tonnes of carbon dioxide equivalent in emissions each year. If humans go on pursuing business as usual, then the cumulative emissions from the food system could add up to 1,365 billion tonnes.

Emissions on that scale from the food system alone would take the planet past the preferred 1.5°C limit some time between 2051 and 2063, and reach the 2°C limit by 2100.

Remedies at hand

“Food is a much greater contributor to climate change than is widely known,” said Jason Hill, of the University of Minnesota, and one of the authors. “Fortunately, we can fix this problem by using fertiliser more efficiently, by eating less meat and more fruits, vegetables, whole grains and nuts, and by making other important changes to our food system.”

The finding should come as no great surprise: global heating is driven by more than simply the return of carbon dioxide fossilised 300 million years ago as coal, oil and natural gas to the atmosphere with every touch of the accelerator, with every jet plane take-off, with every ignition of the electric light, the air conditioning system and the heating, and every turn of industrial machinery around the planet.

It is also fuelled by the devastating clearance of natural forest, grassland and marsh for grazing land or plantation, and the conversion of natural canopy to fodder crops to nourish the world’s domestic cattle and sheep.

Researchers have repeatedly pointed out that even a relatively simple shift to greater reliance on a plant diet could save on carbon emissions, protect the million or so species threatened with imminent extinction, and improve global health, all at the same time.

Multiple benefits

So the latest study offers a new way of spelling out the scale of the problem − a global challenge that could be resolved by concerted and coherent international action.

The researchers identified five strategies that, they believe, could both help limit climate change and improve human health, enhance air quality, reduce water pollution, slow extinction rates and make farms more profitable.

The challenge is to increase crop yields per hectare, reduce food waste, improve farm efficiency and switch to healthy calorie supplies based increasingly on plant crops.

“Even partially adopting several of these five changes would solve this problem as long as we start right now,” said David Tilman, another author, and an ecologist at the university’s College of Biological Sciences. − Climate News Network

More avoidable pandemics await a heedless world

There will be more avoidable pandemics, more devastating and lethal, as humans intrude further upon the planet’s forests.

LONDON, 11 November, 2020 − Once again, naturalists have warned that the invasion of wilderness can seriously damage human health: avoidable pandemics − Covid-19 is an instance of a disease transferred from wild mammals to humans − threaten to arrive more often, spread more rapidly, do more damage to the global economy, and kill more people.

That’s because the odds on even more fearful infections remain very high: the world’s wild mammals could between them be hosts to 1.7 million viruses that have yet to be identified and named. If only a third of them them could infect humans, that’s 540,000 new diseases waiting to happen.

The number could be higher: perhaps 850,000 potential infections lie so far undisturbed, waiting to happen.

A new report by a team of 22 global experts warns that Covid-19 is at least the sixth global health pandemic since the Great Influenza Epidemic of 1918: all had their origins in microbes carried by animals, and all were awakened and spread by human interaction with the wilderness.

By July 2020, the coronavirus linked to a market in wild animals in Wuhan in China had spread around the planet at a cost of between US$8 trillion and $16tn. The world has already seen the Ebola virus devastating West African communities, the HIV/Aids epidemic, Zika, and many others claiming lives in the last century.

Wilderness no more

The arrival of new zoonotic diseases − infections caught from other creatures − has been counted at roughly two a year since 1918. The number could increase to as many as five a year. And most of them will be linked to increasing human impact upon what had once been largely undisturbed wilderness.

“There is no great mystery about the cause of the Covid-19 pandemic − or of any modern pandemic”, said Peter Daszak, president of EcoHealth Alliance and chair of a workshop of the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES for short) that assembled the research.

“The same human activities that drive climate change and biodiversity loss also drive pandemic risk through their impacts on our environment. Changes in the way we use land; the expansion and intensification of agriculture; and unsustainable trade, production and consumption disrupt nature and increase contact between wildlife, livestock, pathogens and people. This is the path to pandemics.”

All living things are host to viruses and other microbes: in most cases host and parasite adapt to live peaceably with each other. The danger comes when a microbe transfers to a new host that is entirely unprepared for the invader.

“We still rely on attempts to contain and control diseases after they emerge. We can escape the era of pandemics, but this requires a greater focus on prevention”

What became known as the human immuno-deficiency virus HIV-1 is believed to have emerged first in West or Central Africa from the remains of chimpanzees hunted and sold for bushmeat. It spread around the planet within a decade, to claim millions of lives as the disease AIDS. Ebola infects both primates and humans: in an outbreak among humans, it has been known to kill 90% of all infected people.

Researchers have consistently linked epidemic and pandemic outbreaks to climate change, to the destruction and degradation of the wilderness, and to the traffic in wild creatures as objects of value or commerce.

And all are consequences ultimately of exponential growth in human numbers in the last century, a growth that puts ever greater pressure on what had once been largely undisturbed tropical forest, grassland and wetland.

Around a quarter of all wild terrestrial vertebrate species are traded globally. International, legal wildlife trade has increased fivefold in revenue in the last 14 years. It is now worth an estimated $107bn.

The illegal traffic in wildlife could be worth anywhere between $7bn and $23bn annually. The US imports around 10 to 20 million wild animals a year. In China in 2016, what is now called wildlife farming employed 14 million people and generated $77bn in revenue.

Negligible cost

Researchers have already argued that intrusion into what should be protected ecosystems that are home to the shrinking pool of wild birds, mammals, reptiles and amphibians − a million species could be nearing global extinction − not only threatens the wellbeing of the planet; it also generates an increasing health hazard.

The latest study lists a range of policy options to reduce the risk of assault by new plagues. These rest upon greater awareness of, and respect for, the natural capital of the wilderness. Conservation of this kind costs money, but at least 100 times less than the toll of successive pandemics likely without a change in human attitudes.

“We have increasing ability to prevent pandemics, but the way we are tackling them right now largely ignores that ability,” Dr Daszak said. “Our approach has effectively stagnated − we still rely on attempts to contain and control diseases after they emerge, through vaccines and therapeutics.

“We can escape the era of pandemics, but this requires a greater focus on prevention in addition to reaction.” − Climate News Network

There will be more avoidable pandemics, more devastating and lethal, as humans intrude further upon the planet’s forests.

LONDON, 11 November, 2020 − Once again, naturalists have warned that the invasion of wilderness can seriously damage human health: avoidable pandemics − Covid-19 is an instance of a disease transferred from wild mammals to humans − threaten to arrive more often, spread more rapidly, do more damage to the global economy, and kill more people.

That’s because the odds on even more fearful infections remain very high: the world’s wild mammals could between them be hosts to 1.7 million viruses that have yet to be identified and named. If only a third of them them could infect humans, that’s 540,000 new diseases waiting to happen.

The number could be higher: perhaps 850,000 potential infections lie so far undisturbed, waiting to happen.

A new report by a team of 22 global experts warns that Covid-19 is at least the sixth global health pandemic since the Great Influenza Epidemic of 1918: all had their origins in microbes carried by animals, and all were awakened and spread by human interaction with the wilderness.

By July 2020, the coronavirus linked to a market in wild animals in Wuhan in China had spread around the planet at a cost of between US$8 trillion and $16tn. The world has already seen the Ebola virus devastating West African communities, the HIV/Aids epidemic, Zika, and many others claiming lives in the last century.

Wilderness no more

The arrival of new zoonotic diseases − infections caught from other creatures − has been counted at roughly two a year since 1918. The number could increase to as many as five a year. And most of them will be linked to increasing human impact upon what had once been largely undisturbed wilderness.

“There is no great mystery about the cause of the Covid-19 pandemic − or of any modern pandemic”, said Peter Daszak, president of EcoHealth Alliance and chair of a workshop of the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES for short) that assembled the research.

“The same human activities that drive climate change and biodiversity loss also drive pandemic risk through their impacts on our environment. Changes in the way we use land; the expansion and intensification of agriculture; and unsustainable trade, production and consumption disrupt nature and increase contact between wildlife, livestock, pathogens and people. This is the path to pandemics.”

All living things are host to viruses and other microbes: in most cases host and parasite adapt to live peaceably with each other. The danger comes when a microbe transfers to a new host that is entirely unprepared for the invader.

“We still rely on attempts to contain and control diseases after they emerge. We can escape the era of pandemics, but this requires a greater focus on prevention”

What became known as the human immuno-deficiency virus HIV-1 is believed to have emerged first in West or Central Africa from the remains of chimpanzees hunted and sold for bushmeat. It spread around the planet within a decade, to claim millions of lives as the disease AIDS. Ebola infects both primates and humans: in an outbreak among humans, it has been known to kill 90% of all infected people.

Researchers have consistently linked epidemic and pandemic outbreaks to climate change, to the destruction and degradation of the wilderness, and to the traffic in wild creatures as objects of value or commerce.

And all are consequences ultimately of exponential growth in human numbers in the last century, a growth that puts ever greater pressure on what had once been largely undisturbed tropical forest, grassland and wetland.

Around a quarter of all wild terrestrial vertebrate species are traded globally. International, legal wildlife trade has increased fivefold in revenue in the last 14 years. It is now worth an estimated $107bn.

The illegal traffic in wildlife could be worth anywhere between $7bn and $23bn annually. The US imports around 10 to 20 million wild animals a year. In China in 2016, what is now called wildlife farming employed 14 million people and generated $77bn in revenue.

Negligible cost

Researchers have already argued that intrusion into what should be protected ecosystems that are home to the shrinking pool of wild birds, mammals, reptiles and amphibians − a million species could be nearing global extinction − not only threatens the wellbeing of the planet; it also generates an increasing health hazard.

The latest study lists a range of policy options to reduce the risk of assault by new plagues. These rest upon greater awareness of, and respect for, the natural capital of the wilderness. Conservation of this kind costs money, but at least 100 times less than the toll of successive pandemics likely without a change in human attitudes.

“We have increasing ability to prevent pandemics, but the way we are tackling them right now largely ignores that ability,” Dr Daszak said. “Our approach has effectively stagnated − we still rely on attempts to contain and control diseases after they emerge, through vaccines and therapeutics.

“We can escape the era of pandemics, but this requires a greater focus on prevention in addition to reaction.” − Climate News Network

Carbon speeds crop growth but often for little gain

More carbon dioxide speeds up crop growth with some key food harvests, but extra heat can hit the yield.

LONDON, 10 November, 2020 − Thirty years of experiments in testing crop growth, and notably the effects of increased atmospheric carbon dioxide (CO2) on some human staples like rice, wheat and soya, have found that − given perfect growing conditions − they would increase yields by 18%.

But sadly, in “real world” conditions, any gains from carbon fertilisation are lost − because of the stress caused to crops by the 2°C temperature rise that the gas causes in the atmosphere. Even worse, the fact that crops grow faster does not mean that their nutritional value is greater – many showed lower mineral nutrients and protein content.

The work, 30 years of “free air carbon dioxide enrichment” (FACE), carried out by 14 long-term research facilities in five continents, is a blow to the hope that in a world with more atmospheric CO2 more people could be fed with less land under cultivation. Earlier results had held out the hope that this “fertiliser effect” would feed more people.

While commercial growers of plants like tomatoes, peppers and cucumbers have used increased CO2 to boost production in controlled conditions in greenhouses, it does not work so well in open fields where temperature and moisture content are affected by climate change.

“When you have other stresses, you don’t always get a benefit of elevated CO2. The last 15 years have taught us to account more for the complex interactions from other factors”

Some crops do get a boost from more carbon in the atmosphere because it makes photosynthesis more efficient, but this is only if nutrients and water are available at optimum levels. This group includes soybean, cassava and rice, all vital in feeding some of the hungriest people in the world.

The author of the study, Stephen Long from the University of Illinois,  said that while it seemed reasonable to assume “a bounty as CO2 rises” this was not the case, because “CO2 is the primary cause of change in the global climate system. The anticipated 2°C rise in temperature, caused primarily by this increase in CO2, could halve yields of some of our major crops, wiping out any gain from CO2.”

His co-author Lisa Ainsworth, a research plant physiologist with the US Department of Agriculture, said: “It’s quite shocking to go back and look at just how much CO2 concentrations have increased over the lifetime of these experiments.

“We are reaching the concentrations of some of the first CO2 treatments 30 years back. The idea that we can check the results of some of the first FACE experiments in the current atmosphere is disconcerting.

Need for nitrogen

“Lots of people have presumed that rising CO2 is largely a good thing for crops, assuming more CO2 will make the world’s forests greener and increase crop yields,” Ainsworth said.

“The more recent studies challenge that assumption a bit. We’re finding that when you have other stresses, you don’t always get a benefit of elevated CO2. The last 15 years have taught us to account more for the complex interactions from other factors like drought, temperature, nutrients and pests.”

The poor quality of some of the grain, with less mineral and protein content, is also a blow to add to the crop growth doubts. The potential increased yield is also much smaller under conditions where there is low nitrogen fertiliser, typical of the world’s poorest countries.

However, the researchers are not all gloomy. Genetic variations in crops show that some strains can still benefit despite increased temperatures. If new crop cultivars are developed, then the future could be brighter, but work needs to start now, the scientists say. − Climate News Network

More carbon dioxide speeds up crop growth with some key food harvests, but extra heat can hit the yield.

LONDON, 10 November, 2020 − Thirty years of experiments in testing crop growth, and notably the effects of increased atmospheric carbon dioxide (CO2) on some human staples like rice, wheat and soya, have found that − given perfect growing conditions − they would increase yields by 18%.

But sadly, in “real world” conditions, any gains from carbon fertilisation are lost − because of the stress caused to crops by the 2°C temperature rise that the gas causes in the atmosphere. Even worse, the fact that crops grow faster does not mean that their nutritional value is greater – many showed lower mineral nutrients and protein content.

The work, 30 years of “free air carbon dioxide enrichment” (FACE), carried out by 14 long-term research facilities in five continents, is a blow to the hope that in a world with more atmospheric CO2 more people could be fed with less land under cultivation. Earlier results had held out the hope that this “fertiliser effect” would feed more people.

While commercial growers of plants like tomatoes, peppers and cucumbers have used increased CO2 to boost production in controlled conditions in greenhouses, it does not work so well in open fields where temperature and moisture content are affected by climate change.

“When you have other stresses, you don’t always get a benefit of elevated CO2. The last 15 years have taught us to account more for the complex interactions from other factors”

Some crops do get a boost from more carbon in the atmosphere because it makes photosynthesis more efficient, but this is only if nutrients and water are available at optimum levels. This group includes soybean, cassava and rice, all vital in feeding some of the hungriest people in the world.

The author of the study, Stephen Long from the University of Illinois,  said that while it seemed reasonable to assume “a bounty as CO2 rises” this was not the case, because “CO2 is the primary cause of change in the global climate system. The anticipated 2°C rise in temperature, caused primarily by this increase in CO2, could halve yields of some of our major crops, wiping out any gain from CO2.”

His co-author Lisa Ainsworth, a research plant physiologist with the US Department of Agriculture, said: “It’s quite shocking to go back and look at just how much CO2 concentrations have increased over the lifetime of these experiments.

“We are reaching the concentrations of some of the first CO2 treatments 30 years back. The idea that we can check the results of some of the first FACE experiments in the current atmosphere is disconcerting.

Need for nitrogen

“Lots of people have presumed that rising CO2 is largely a good thing for crops, assuming more CO2 will make the world’s forests greener and increase crop yields,” Ainsworth said.

“The more recent studies challenge that assumption a bit. We’re finding that when you have other stresses, you don’t always get a benefit of elevated CO2. The last 15 years have taught us to account more for the complex interactions from other factors like drought, temperature, nutrients and pests.”

The poor quality of some of the grain, with less mineral and protein content, is also a blow to add to the crop growth doubts. The potential increased yield is also much smaller under conditions where there is low nitrogen fertiliser, typical of the world’s poorest countries.

However, the researchers are not all gloomy. Genetic variations in crops show that some strains can still benefit despite increased temperatures. If new crop cultivars are developed, then the future could be brighter, but work needs to start now, the scientists say. − Climate News Network

Natural hotspots lose ground to farms and cities

Nature concentrates its riches in selected spots. Save those natural hotspots, and you could save biodiversity. Really?

LONDON, 6 November, 2020 − Nations that signed up to preserve biodiversity − the richness of living things in the world’s forests, grasslands and wetlands − are not doing so very well: in one generation they have altered, degraded or cleared at least 1.48 million square kilometres of natural hotspots unusually rich in wildlife.

This is an area in total larger than South Africa, or Peru. It is almost as large as Mongolia. And importantly, this lost landscape adds up to 6% of the scattered ecosystems that make up the world’s biodiversity hotspots.

The biodiversity hotspot was defined, in 2000, as an area of land home to at least 0.5% of the world’s endemic species of plant. That means that a tract of marsh, savannah, upland or forest that may have already lost 70% of its cover is host to at least 1500 species native to that landscape and nowhere else.

Researchers at the time calculated that 44% of all vascular plants and 35% of all amphibians, reptiles, birds and mammals could be concentrated in just 25 such hotspots on the world’s continents and islands.

The hotspot count has since been increased to 34. But the message has remained. Focus on preserving and protecting these areas and you have a “silver bullet” strategy for conserving wildlife worldwide.

First such inventory

But, say scientists in the journal Frontiers in Ecology and the Environment, between 1992 and 2015 much of this precious wilderness has been consumed by agriculture, or paved by sprawling cities.

Their analysis of high resolution land-cover maps made by the European Space Agency is the first to try to look at the global inventory of hotspots, over a time frame of almost a quarter century.

“We see that not even focusing protection on a small range of areas worked well,” said Francesco Cherubini of the Norwegian University of Science and Technology, who with colleagues carried out the research. “There was major deforestation even in areas that were supposed to be protected.”

Two fifths of the lost landscapes were in forests, and agriculture accounted for most of this loss, particularly in the tropical forests of Indonesia, the Indo-Burma region and Mesoamerica. Five per cent of the lost hotspots were in areas formally declared as under state protection.

“The soils in these areas are very fertile, and agricultural yields can be very high. So it’s very productive land from an agricultural point of view, and attractive to farmers and local authorities that have to think about rising local incomes by feeding a growing population,” Professor Cherubini said.

“Not even focusing protection on a small range of areas worked well … There was major deforestation even in areas that were supposed to be protected.”

But most of the lost land went not to feeding people: it went instead to producing palm oil or soybeans for cattle feed. And local people may not have benefited: the change was driven by commercial agribusiness.

“You have these big companies that are making these investments, with high risks of land overexploitation and environmental degradation. The local population might get some benefits from revenues, but not much.”

The tension between hungry humans and vulnerable wilderness continues. Once again, such research supports a call for the people of the planet to consider a switch to plant-based diets, a switch that could contain climate change and preserve the natural capital on which all life depends. But many of those rich habitats are in some of the poorest countries.

“We need to be able somehow to link protection to poverty alleviation, because most of the biodiversity hotspots are in underdeveloped countries and it’s difficult to go there and say to a farmer, ‘Well, you need to keep this forest − don’t have a rice paddy or a field to feed your family’”, Professor Cherubini said.

“We need to also make it possible for the local communities to benefit from protection measures. They need income, too.” − Climate News Network

Nature concentrates its riches in selected spots. Save those natural hotspots, and you could save biodiversity. Really?

LONDON, 6 November, 2020 − Nations that signed up to preserve biodiversity − the richness of living things in the world’s forests, grasslands and wetlands − are not doing so very well: in one generation they have altered, degraded or cleared at least 1.48 million square kilometres of natural hotspots unusually rich in wildlife.

This is an area in total larger than South Africa, or Peru. It is almost as large as Mongolia. And importantly, this lost landscape adds up to 6% of the scattered ecosystems that make up the world’s biodiversity hotspots.

The biodiversity hotspot was defined, in 2000, as an area of land home to at least 0.5% of the world’s endemic species of plant. That means that a tract of marsh, savannah, upland or forest that may have already lost 70% of its cover is host to at least 1500 species native to that landscape and nowhere else.

Researchers at the time calculated that 44% of all vascular plants and 35% of all amphibians, reptiles, birds and mammals could be concentrated in just 25 such hotspots on the world’s continents and islands.

The hotspot count has since been increased to 34. But the message has remained. Focus on preserving and protecting these areas and you have a “silver bullet” strategy for conserving wildlife worldwide.

First such inventory

But, say scientists in the journal Frontiers in Ecology and the Environment, between 1992 and 2015 much of this precious wilderness has been consumed by agriculture, or paved by sprawling cities.

Their analysis of high resolution land-cover maps made by the European Space Agency is the first to try to look at the global inventory of hotspots, over a time frame of almost a quarter century.

“We see that not even focusing protection on a small range of areas worked well,” said Francesco Cherubini of the Norwegian University of Science and Technology, who with colleagues carried out the research. “There was major deforestation even in areas that were supposed to be protected.”

Two fifths of the lost landscapes were in forests, and agriculture accounted for most of this loss, particularly in the tropical forests of Indonesia, the Indo-Burma region and Mesoamerica. Five per cent of the lost hotspots were in areas formally declared as under state protection.

“The soils in these areas are very fertile, and agricultural yields can be very high. So it’s very productive land from an agricultural point of view, and attractive to farmers and local authorities that have to think about rising local incomes by feeding a growing population,” Professor Cherubini said.

“Not even focusing protection on a small range of areas worked well … There was major deforestation even in areas that were supposed to be protected.”

But most of the lost land went not to feeding people: it went instead to producing palm oil or soybeans for cattle feed. And local people may not have benefited: the change was driven by commercial agribusiness.

“You have these big companies that are making these investments, with high risks of land overexploitation and environmental degradation. The local population might get some benefits from revenues, but not much.”

The tension between hungry humans and vulnerable wilderness continues. Once again, such research supports a call for the people of the planet to consider a switch to plant-based diets, a switch that could contain climate change and preserve the natural capital on which all life depends. But many of those rich habitats are in some of the poorest countries.

“We need to be able somehow to link protection to poverty alleviation, because most of the biodiversity hotspots are in underdeveloped countries and it’s difficult to go there and say to a farmer, ‘Well, you need to keep this forest − don’t have a rice paddy or a field to feed your family’”, Professor Cherubini said.

“We need to also make it possible for the local communities to benefit from protection measures. They need income, too.” − Climate News Network

Rewilded farmland can save money − and the Earth

To save civilisation, try rewilded farmland. But that salvation depends on which land goes back to forest and savannah.

LONDON, 2 November, 2020 − An international consortium of scientists has worked out − once again − how to conserve life on the planet and absorb dramatic quantities of the atmospheric carbon that is driving potentially calamitous climate change: go for rewilded farmland, fields of crops and livestock returned to prairie and forest. And they have identified the most cost-effective way to do it.

Global salvation requires the world’s nations to do simply what they have already undertaken to do: restore 15% of cultivated land to natural forest, grassland, shrubland, wetland and desert ecosystem.

If such restoration happened in the highest priority zones, then almost two-thirds of the wild things now threatened with imminent extinction could survive.

And the restored wilderness that would protect them would also start absorbing atmospheric carbon at an accelerating rate: it could sequester an estimated 229 billion tonnes of the greenhouse gas carbon dioxide (CO2). This is almost a third of all the CO2 spilled into the atmosphere by coal, oil and gas combustion in the last 200 years.

All that would be possible if the world’s nations delivered on vows made 10 years ago in Japan, to restore 15% of ecosystems worldwide. If the 196 nations that signed up went further, and restored a carefully chosen 30%, they could save more than 70% of the million or so species sliding towards extinction, and absorb 465 billion tonnes of CO2: almost half of all the extra atmospheric carbon loaded into the atmosphere by human societies since the Industrial Revolution.

Two provisos

“Pushing forward on plans to return significant sweeps of nature to a natural state is critical to preventing ongoing biodiversity and climate crises from spinning out of control,” said Bernado Strassburg, of the Pontifical Catholic University in Brazil, who led the study.

“We show that if we’re smarter about where we restore nature, we can tick the climate, biodiversity and budget boxes on the world’s urgent to-do list.”

There is a catch. To be most effective, and for the lowest costs, nations would have to work together.

Right now, scientists report in the journal Nature, each nation has undertaken to restore 15% of its wilderness. But to save the greatest number of species, and absorb the highest levels of carbon, with the lowest cost to farmland and food security, humankind would have to assess the world as a whole, and restore those ecosystems that would serve the goals most effectively.

There is a second catch: barely a month ago, a UN report confirmed that although 196 nations agreed on 20 targets to protect biodiversity − to be achieved by 2020 − a decade ago, there has been “partial progress” in just six of them. The million species then threatened with extinction are still threatened.

Potential ignored

“Many good things are happening around the world and these should be celebrated and encouraged,” said Elizabeth Maruma Mrema, executive secretary of the Convention on Biological Diversity.

“Nevertheless the rate of biodiversity loss is unprecedented in human history, and pressures are intensifying. Earth’s living systems as a whole are being compromised.”

And that threat starts with the green things on which all life depends: in September, the Royal Botanic Gardens at Kew in London published a new study on ways to identify and care for the plants and fungi that underwrite survival for what could be seven million or more species alive on the planet, and more than seven billion humans.

The study, involving 210 scientists in 42 countries, said Alexandre Antonelli, director of science at the Royal Botanic Gardens, paints a picture “of a world that has turned its back on the incredible potential of plant and fungal kingdoms to address some of the biggest challenges we face.

“We have particularly earmarked the gaps in our knowledge, the changes we are seeing, the species being named new to science and the shocking pace of biodiversity loss.”

“The rate of biodiversity loss is unprecedented in human history, and pressures are intensifying. Earth’s living systems as a whole are being compromised”

The most recent finding builds on the drive not just to fulfil the obligations undertaken 10 years ago, but to identify the very best ways to fulfil them, so as to benefit the greatest number of people.

It delivers the evidence that restoration in the most carefully chosen regions would have the most profound impact: put simply, restoration could be 13 times more cost-effective if it happened in what the Nature researchers have identified as the highest priority locations.

They used sophisticated mathematical tools and detailed geographic data to take a closer look at the 28.7 million square kilometres of natural wilderness that have been converted to farmland: 54% of these were originally forest, 25% grasslands, 14% shrublands, 4% arid lands and 2% wetland.

They then tested these areas against three considerations: their value as habitat, their capacity for carbon storage and their cost-effectiveness. And they came up with recommendations that would deliver 91% of the potential benefit for plants and animals of the wilderness and 82% of the climate mitigation benefit, and reduce costs by 27%.

And then they considered the nation-by-nation approach: were each country to restore 15% of its own forests, the biodiversity boon fell by 28%, the climate benefits by 29%, while the costs would rise by 52%.

Vital partnership

They then considered the impact on the world’s food supplies, to find that 15.78 million sq kms, or 55% of wilderness converted to farmland, could be restored without squeezing food supplies, always providing nations encouraged what they call the “sustainable intensification” of farming, along with a reduction in food waste and a move away from meat and dairy products.

The findings simply extend a procession of such outcomes by other teams. It has been a given for decades that, if forest and other ecosystems become farmland, greenhouse gas levels rise. If wilderness is restored, then the carbon dioxide levels in the atmosphere will fall.

Researchers have repeatedly argued that simply planting more trees could have a dramatic impact on global heating; that a switch towards a plant-based diet could help stem biodiversity loss and reduce emissions; and that without concerted global action, precious ecosystems could collapse altogether.

They have over and over again confirmed that conservation delivers real rewards. And they have pointed out that although nations have promised to act, such promises have not always been kept. The latest study highlights the need for action to be concerted, and global.

“These results highlight the critical importance of international co-operation in meeting these goals,” Dr Strassburg said. “Different countries have different, complementary roles to play in meeting overarching global targets on biodiversity and climate.” − Climate News Network

To save civilisation, try rewilded farmland. But that salvation depends on which land goes back to forest and savannah.

LONDON, 2 November, 2020 − An international consortium of scientists has worked out − once again − how to conserve life on the planet and absorb dramatic quantities of the atmospheric carbon that is driving potentially calamitous climate change: go for rewilded farmland, fields of crops and livestock returned to prairie and forest. And they have identified the most cost-effective way to do it.

Global salvation requires the world’s nations to do simply what they have already undertaken to do: restore 15% of cultivated land to natural forest, grassland, shrubland, wetland and desert ecosystem.

If such restoration happened in the highest priority zones, then almost two-thirds of the wild things now threatened with imminent extinction could survive.

And the restored wilderness that would protect them would also start absorbing atmospheric carbon at an accelerating rate: it could sequester an estimated 229 billion tonnes of the greenhouse gas carbon dioxide (CO2). This is almost a third of all the CO2 spilled into the atmosphere by coal, oil and gas combustion in the last 200 years.

All that would be possible if the world’s nations delivered on vows made 10 years ago in Japan, to restore 15% of ecosystems worldwide. If the 196 nations that signed up went further, and restored a carefully chosen 30%, they could save more than 70% of the million or so species sliding towards extinction, and absorb 465 billion tonnes of CO2: almost half of all the extra atmospheric carbon loaded into the atmosphere by human societies since the Industrial Revolution.

Two provisos

“Pushing forward on plans to return significant sweeps of nature to a natural state is critical to preventing ongoing biodiversity and climate crises from spinning out of control,” said Bernado Strassburg, of the Pontifical Catholic University in Brazil, who led the study.

“We show that if we’re smarter about where we restore nature, we can tick the climate, biodiversity and budget boxes on the world’s urgent to-do list.”

There is a catch. To be most effective, and for the lowest costs, nations would have to work together.

Right now, scientists report in the journal Nature, each nation has undertaken to restore 15% of its wilderness. But to save the greatest number of species, and absorb the highest levels of carbon, with the lowest cost to farmland and food security, humankind would have to assess the world as a whole, and restore those ecosystems that would serve the goals most effectively.

There is a second catch: barely a month ago, a UN report confirmed that although 196 nations agreed on 20 targets to protect biodiversity − to be achieved by 2020 − a decade ago, there has been “partial progress” in just six of them. The million species then threatened with extinction are still threatened.

Potential ignored

“Many good things are happening around the world and these should be celebrated and encouraged,” said Elizabeth Maruma Mrema, executive secretary of the Convention on Biological Diversity.

“Nevertheless the rate of biodiversity loss is unprecedented in human history, and pressures are intensifying. Earth’s living systems as a whole are being compromised.”

And that threat starts with the green things on which all life depends: in September, the Royal Botanic Gardens at Kew in London published a new study on ways to identify and care for the plants and fungi that underwrite survival for what could be seven million or more species alive on the planet, and more than seven billion humans.

The study, involving 210 scientists in 42 countries, said Alexandre Antonelli, director of science at the Royal Botanic Gardens, paints a picture “of a world that has turned its back on the incredible potential of plant and fungal kingdoms to address some of the biggest challenges we face.

“We have particularly earmarked the gaps in our knowledge, the changes we are seeing, the species being named new to science and the shocking pace of biodiversity loss.”

“The rate of biodiversity loss is unprecedented in human history, and pressures are intensifying. Earth’s living systems as a whole are being compromised”

The most recent finding builds on the drive not just to fulfil the obligations undertaken 10 years ago, but to identify the very best ways to fulfil them, so as to benefit the greatest number of people.

It delivers the evidence that restoration in the most carefully chosen regions would have the most profound impact: put simply, restoration could be 13 times more cost-effective if it happened in what the Nature researchers have identified as the highest priority locations.

They used sophisticated mathematical tools and detailed geographic data to take a closer look at the 28.7 million square kilometres of natural wilderness that have been converted to farmland: 54% of these were originally forest, 25% grasslands, 14% shrublands, 4% arid lands and 2% wetland.

They then tested these areas against three considerations: their value as habitat, their capacity for carbon storage and their cost-effectiveness. And they came up with recommendations that would deliver 91% of the potential benefit for plants and animals of the wilderness and 82% of the climate mitigation benefit, and reduce costs by 27%.

And then they considered the nation-by-nation approach: were each country to restore 15% of its own forests, the biodiversity boon fell by 28%, the climate benefits by 29%, while the costs would rise by 52%.

Vital partnership

They then considered the impact on the world’s food supplies, to find that 15.78 million sq kms, or 55% of wilderness converted to farmland, could be restored without squeezing food supplies, always providing nations encouraged what they call the “sustainable intensification” of farming, along with a reduction in food waste and a move away from meat and dairy products.

The findings simply extend a procession of such outcomes by other teams. It has been a given for decades that, if forest and other ecosystems become farmland, greenhouse gas levels rise. If wilderness is restored, then the carbon dioxide levels in the atmosphere will fall.

Researchers have repeatedly argued that simply planting more trees could have a dramatic impact on global heating; that a switch towards a plant-based diet could help stem biodiversity loss and reduce emissions; and that without concerted global action, precious ecosystems could collapse altogether.

They have over and over again confirmed that conservation delivers real rewards. And they have pointed out that although nations have promised to act, such promises have not always been kept. The latest study highlights the need for action to be concerted, and global.

“These results highlight the critical importance of international co-operation in meeting these goals,” Dr Strassburg said. “Different countries have different, complementary roles to play in meeting overarching global targets on biodiversity and climate.” − Climate News Network