Tag Archives: Population

Eat a plant and spare a tree

A less meat-intensive diet is essential for the sake of wildlife and forests and to slow climate change, says a report by UK-based researchers. LONDON, 31 August 2014 – Say goodbye to the steaks. Forget the foie gras. Put that pork chop away (assuming you can afford any of them). UK-based scientists say eating less meat is a vital part of tackling climate change. A study published in Nature Climate Change says that on present trends food production on its own will reach – and perhaps exceed – the global targets for total greenhouse gas emissions in 2050. Healthier diets – defined as meaning lower meat and dairy consumption – and reduced food waste are among the solutions needed to ensure food security and avoid dangerous climate change, the study says. More people, with more of us wanting meat-heavy Western diets, mean increasing farm yields will not meet the demands of an expected 9.6 billion humans. So we shall have to cultivate more land. This, the authors say, will mean more deforestation, more carbon emissions and further biodiversity loss, while extra livestock will raise methane levels.

Inefficient converters

Without radical changes, they expect cropland to expand by 42% by 2050 and fertiliser use by 45% (over 2009 levels). A further tenth of the world’s pristine tropical forests would disappear by mid-century. All this would cause GHG emissions from food production to increase by almost 80% by 2050 – roughly equal to the target GHG emissions by then for the entire global economy. They think halving food waste and managing demand for particularly environmentally-damaging food products – mainly from animals –  “might mitigate some” GHG emissions. “It is imperative to find ways to achieve global food security without expanding crop or pastureland,” said the lead researcher, Bojana Bajzelj, from the University of Cambridge’s department of engineering, who wrote the study with colleagues from Cambridge’s departments of geography and plant sciences and the University of Aberdeen’s Institute of Biological and Environmental Sciences. “The average efficiency of livestock converting plant feed to meat is less than 3%, and as we eat more meat, more arable cultivation is turned over to producing feedstock for animals… Agricultural practices are not necessarily at fault here – but our choice of food is.”

Squandered resources

This measure of efficiency is based on the units used in the study, which are grams of carbon in the biomass material, plant or meat. The team created a model that compares different scenarios for 2050, including some based on maintaining current trends. Another examines the closing of “yield gaps”. These gaps, between crop yields from best practice farming and actual average yields, exist everywhere but are widest in developing countries – particularly in sub-Saharan Africa. The researchers advocate closing the gaps through sustainable intensification of farming. But even then projected food demand will still demand additional land and more water and fertilisers – so the impact on emissions and biodiversity remains. Food waste occurs at all stages in the food chain, caused in developing countries by poor storage and transport and in the north by wasteful consumption. This squanders resources, especially energy, the authors say.

“As well as encouraging sustainable agriculture, we need to re-think what we eat”

Yield gap closure alone still shows a GHG increase of just over 40% by 2050. Closing yield gaps and halving food waste shows emissions increasing by 2%. But with healthy diets added too, the model suggests that agricultural GHG levels could fall by 48% from their 2009 level. The team says replacing diets containing too much food, especially emission-intensive meat and dairy products, with an average balanced diet avoiding excessive consumption of sugars, fats, and meat products, significantly reduces pressures on the environment even further. It says this “average” balanced diet is “a relatively achievable goal for most. For example, the figures included two 85g portions of red meat and five eggs per week, as well as a portion of poultry a day.” Co-author Professor Pete Smith from the University of Aberdeen said: “Unless we make some serious changes in food consumption trends, we would have to completely decarbonise the energy and industry sectors to stay within emissions budgets that avoid dangerous climate change. “That is practically impossible – so, as well as encouraging sustainable agriculture, we need to re-think what we eat.” – Climate News Network

A less meat-intensive diet is essential for the sake of wildlife and forests and to slow climate change, says a report by UK-based researchers. LONDON, 31 August 2014 – Say goodbye to the steaks. Forget the foie gras. Put that pork chop away (assuming you can afford any of them). UK-based scientists say eating less meat is a vital part of tackling climate change. A study published in Nature Climate Change says that on present trends food production on its own will reach – and perhaps exceed – the global targets for total greenhouse gas emissions in 2050. Healthier diets – defined as meaning lower meat and dairy consumption – and reduced food waste are among the solutions needed to ensure food security and avoid dangerous climate change, the study says. More people, with more of us wanting meat-heavy Western diets, mean increasing farm yields will not meet the demands of an expected 9.6 billion humans. So we shall have to cultivate more land. This, the authors say, will mean more deforestation, more carbon emissions and further biodiversity loss, while extra livestock will raise methane levels.

Inefficient converters

Without radical changes, they expect cropland to expand by 42% by 2050 and fertiliser use by 45% (over 2009 levels). A further tenth of the world’s pristine tropical forests would disappear by mid-century. All this would cause GHG emissions from food production to increase by almost 80% by 2050 – roughly equal to the target GHG emissions by then for the entire global economy. They think halving food waste and managing demand for particularly environmentally-damaging food products – mainly from animals –  “might mitigate some” GHG emissions. “It is imperative to find ways to achieve global food security without expanding crop or pastureland,” said the lead researcher, Bojana Bajzelj, from the University of Cambridge’s department of engineering, who wrote the study with colleagues from Cambridge’s departments of geography and plant sciences and the University of Aberdeen’s Institute of Biological and Environmental Sciences. “The average efficiency of livestock converting plant feed to meat is less than 3%, and as we eat more meat, more arable cultivation is turned over to producing feedstock for animals… Agricultural practices are not necessarily at fault here – but our choice of food is.”

Squandered resources

This measure of efficiency is based on the units used in the study, which are grams of carbon in the biomass material, plant or meat. The team created a model that compares different scenarios for 2050, including some based on maintaining current trends. Another examines the closing of “yield gaps”. These gaps, between crop yields from best practice farming and actual average yields, exist everywhere but are widest in developing countries – particularly in sub-Saharan Africa. The researchers advocate closing the gaps through sustainable intensification of farming. But even then projected food demand will still demand additional land and more water and fertilisers – so the impact on emissions and biodiversity remains. Food waste occurs at all stages in the food chain, caused in developing countries by poor storage and transport and in the north by wasteful consumption. This squanders resources, especially energy, the authors say.

“As well as encouraging sustainable agriculture, we need to re-think what we eat”

Yield gap closure alone still shows a GHG increase of just over 40% by 2050. Closing yield gaps and halving food waste shows emissions increasing by 2%. But with healthy diets added too, the model suggests that agricultural GHG levels could fall by 48% from their 2009 level. The team says replacing diets containing too much food, especially emission-intensive meat and dairy products, with an average balanced diet avoiding excessive consumption of sugars, fats, and meat products, significantly reduces pressures on the environment even further. It says this “average” balanced diet is “a relatively achievable goal for most. For example, the figures included two 85g portions of red meat and five eggs per week, as well as a portion of poultry a day.” Co-author Professor Pete Smith from the University of Aberdeen said: “Unless we make some serious changes in food consumption trends, we would have to completely decarbonise the energy and industry sectors to stay within emissions budgets that avoid dangerous climate change. “That is practically impossible – so, as well as encouraging sustainable agriculture, we need to re-think what we eat.” – Climate News Network

Where on Earth will the waste go?

FOR IMMEDIATE RELEASE As the world’s population continues to grow, so too the collective rubbish dump of human waste increases – and according to a recent report, it might not be until sometime next century that it begins to recede. LONDON, 2 November – Human waste production has multiplied tenfold in the last century. Rubbish – plastic bags, pizza boxes, empty beer cans, tinfoil, bubble wrap, old mattresses, rusty machinery, broken bottles, spent batteries, stale sandwiches, wilting salads and abandoned newsprint – is being generated faster than any other environmental pollutants, including greenhouse gases. And the problem will go on getting bigger until some time in the next century. Daniel Hoornweg of the University of Ontario and Chris Kennedy of the University of Toronto in Canada and Perinaz Bhada-Tata of Dubai in the United Arab Emirates argue in Nature that the combination of urban growth and material affluence is creating a throwaway problem that won’t go away. The average person in the US throws away his (or her) own body weight in rubbish every month. The detritus linked to modern living has not only grown tenfold in a century; by 2025 it will double again. Solid waste disposal has become one of any modern city’s biggest costs. Landfill sites near Shanghai, in Rio de Janeiro, and in Mexico City typically receive 10,000 tonnes of waste a day.  The world now has more than 2,000 waste incinerators, some able to burn 5,000 tonnes a day, creating attendant problems of ash and air-polluting fumes. Landfill waste is of course also a notorious source of methane – a potent greenhouse gas – but the authors are primarily concerned with the simple problems posed by the increasing volume of affluent society’s rejected stuff. It’s a city thing, they say. Country dwellers don’t buy so much packaged food, don’t have factories and don’t throw so much food away. City dwellers on average generate twice as much waste; the more affluent urbanites throw away four times as much. The three researchers – an expert in energy systems, a civil engineer and an urban waste consultant – say that in 1900 there were 220 million people in the cities. That was 13% of the planet’s population, and these townsfolk produced 300,000 tonnes of discarded stuff every day. By 2000, there were 2.9 billion people in cities – 49% of the world’s population – creating more than three million tonnes of solid waste per day. By 2025, it will be twice that = enough to fill a line of rubbish trucks 5,000 kilometres long every day.

International idiosyncrasies

Some countries are more profligate than others. Japan’s citizens produce about one third less, per person, than US citizens, even though the gross domestic product per capita is about the same. China’s solid waste generation is expected to go from 520,550 tonnes per day to 1.4 million by 2025. “As a country becomes richer, the composition of its waste changes,” the authors say. “With more money comes more packaging, imports, electronic waste and broken toys and appliances. The wealth of a country can readily be measured, for example, by how many mobile phones it discards.” Hoornweg and Bhada-Tata are the authors of a 2012 World Bank report in which they projected a world dustbin collection of 6 million tonnes a day by 2025. They calculate that under a business-as-usual scenario waste will grow with population and affluence as the century wears on, with increasing growth in South Asia and sub-Saharan Africa, and by 2100 it will exceed 11 million tonnes a day and peak sometime in the next century. But this scenario is not inevitable. “With lower populations, denser, more resource-efficient cities and less consumption (along with higher affluence) the peak could come forward to 2075 and reduce in intensity by more than 25%,” they say. This would save around 2.6 million tonnes per day. – Climate News Network

FOR IMMEDIATE RELEASE As the world’s population continues to grow, so too the collective rubbish dump of human waste increases – and according to a recent report, it might not be until sometime next century that it begins to recede. LONDON, 2 November – Human waste production has multiplied tenfold in the last century. Rubbish – plastic bags, pizza boxes, empty beer cans, tinfoil, bubble wrap, old mattresses, rusty machinery, broken bottles, spent batteries, stale sandwiches, wilting salads and abandoned newsprint – is being generated faster than any other environmental pollutants, including greenhouse gases. And the problem will go on getting bigger until some time in the next century. Daniel Hoornweg of the University of Ontario and Chris Kennedy of the University of Toronto in Canada and Perinaz Bhada-Tata of Dubai in the United Arab Emirates argue in Nature that the combination of urban growth and material affluence is creating a throwaway problem that won’t go away. The average person in the US throws away his (or her) own body weight in rubbish every month. The detritus linked to modern living has not only grown tenfold in a century; by 2025 it will double again. Solid waste disposal has become one of any modern city’s biggest costs. Landfill sites near Shanghai, in Rio de Janeiro, and in Mexico City typically receive 10,000 tonnes of waste a day.  The world now has more than 2,000 waste incinerators, some able to burn 5,000 tonnes a day, creating attendant problems of ash and air-polluting fumes. Landfill waste is of course also a notorious source of methane – a potent greenhouse gas – but the authors are primarily concerned with the simple problems posed by the increasing volume of affluent society’s rejected stuff. It’s a city thing, they say. Country dwellers don’t buy so much packaged food, don’t have factories and don’t throw so much food away. City dwellers on average generate twice as much waste; the more affluent urbanites throw away four times as much. The three researchers – an expert in energy systems, a civil engineer and an urban waste consultant – say that in 1900 there were 220 million people in the cities. That was 13% of the planet’s population, and these townsfolk produced 300,000 tonnes of discarded stuff every day. By 2000, there were 2.9 billion people in cities – 49% of the world’s population – creating more than three million tonnes of solid waste per day. By 2025, it will be twice that = enough to fill a line of rubbish trucks 5,000 kilometres long every day.

International idiosyncrasies

Some countries are more profligate than others. Japan’s citizens produce about one third less, per person, than US citizens, even though the gross domestic product per capita is about the same. China’s solid waste generation is expected to go from 520,550 tonnes per day to 1.4 million by 2025. “As a country becomes richer, the composition of its waste changes,” the authors say. “With more money comes more packaging, imports, electronic waste and broken toys and appliances. The wealth of a country can readily be measured, for example, by how many mobile phones it discards.” Hoornweg and Bhada-Tata are the authors of a 2012 World Bank report in which they projected a world dustbin collection of 6 million tonnes a day by 2025. They calculate that under a business-as-usual scenario waste will grow with population and affluence as the century wears on, with increasing growth in South Asia and sub-Saharan Africa, and by 2100 it will exceed 11 million tonnes a day and peak sometime in the next century. But this scenario is not inevitable. “With lower populations, denser, more resource-efficient cities and less consumption (along with higher affluence) the peak could come forward to 2075 and reduce in intensity by more than 25%,” they say. This would save around 2.6 million tonnes per day. – Climate News Network

Are we doomed? It all depends

EMBARGOED until 0001 GMT on Thursday 10 January There are immense threats to human survival, two population biologists say. But the end of our civilisation is not inevitable if we act now. LONDON, 10 January – Humanity faces a possible collapse of global civilisation, according to two Californian scientists. Paul Ehrlich and Anne Ehrlich, of Stanford University, US, argue in the Proceedings of the Royal Society B, published by the UK’s national academy of science, that civilisation is faced with a menacing array of environmental problems. “The most serious of these problems show signs of rapidly escalating severity, especially climate disruption,” they write. They list other ingredients in the recipe for worldwide disaster: these include the accelerating extinction of vital animal and plant populations; land degradation; the pole-to-pole spread of toxic compounds; ocean acidification and the appearance of dead zones; increases in human vulnerability to infectious disease; the depletion of scarce resources, including groundwater; and resource wars. “These are not separate problems; rather they interact in two gigantic complex adaptive systems; the biosphere system and the human socio-economic system. The negative manifestations of these interactions are often referred to as ‘the human predicament’ and determining how to prevent it from generating a global collapse is perhaps the foremost challenge confronting humanity.” Paul Ehrlich is a population biologist and ecologist of academic distinction who startled the world in 1967 with a book called The Population Bomb: critics have dubbed him an “irrepressible doomster”, and even admirers concede that he doesn’t often present a cheerful view of the human condition. Anne, who is married to Paul and is co-author of several books with him, is associate director of the Center for Conservation Biology at Stanford University.

“All nations need to stop waiting for others to act”

The growth in human numbers remains a prime concern for the Ehrlichs. They warn that the projected additional 2.5 billion people on Earth by 2050 “would make the human assault on civilisation’s life-support systems disproportionately worse.” Future global collapse could be triggered by anything from a small nuclear war to a more gradual breakdown because of famines, epidemics and resource shortages. No civilisation could avoid collapse if it failed to feed its population. Despite food production “miracles” in the last century, the Ehrlichs argue, two billion people today were hungry or poorly nourished. Food was wasted, and demand for meat was increasing, forcing up the price of food grains. “Perhaps even more critical, climate disruption may pose insurmountable physical barriers to increasing crop yields. Indeed, if humanity is very unlucky with the climate, there may be reductions in yields of major crops, though near term this may be unlikely to affect harvests globally,” they write. (See our earlier story on warming and food production here.) Other threats to production could come from sea level rise and increasingly severe droughts, storms, heat waves and floods. “Unless greenhouse gas emissions are dramatically reduced, dangerous anthropogenic climate change could ravage agriculture.” The authors believe that humans can develop enough “foresight intelligence” to respond to the challenge, but they argue that we cannot afford to delay action to address climate change. “All nations need to stop waiting for others to act and be willing to do everything they can to mitigate emissions and hasten energy transition, regardless of what others are doing.” (See earlier story on emissions targets here.) – Climate News Network

EMBARGOED until 0001 GMT on Thursday 10 January There are immense threats to human survival, two population biologists say. But the end of our civilisation is not inevitable if we act now. LONDON, 10 January – Humanity faces a possible collapse of global civilisation, according to two Californian scientists. Paul Ehrlich and Anne Ehrlich, of Stanford University, US, argue in the Proceedings of the Royal Society B, published by the UK’s national academy of science, that civilisation is faced with a menacing array of environmental problems. “The most serious of these problems show signs of rapidly escalating severity, especially climate disruption,” they write. They list other ingredients in the recipe for worldwide disaster: these include the accelerating extinction of vital animal and plant populations; land degradation; the pole-to-pole spread of toxic compounds; ocean acidification and the appearance of dead zones; increases in human vulnerability to infectious disease; the depletion of scarce resources, including groundwater; and resource wars. “These are not separate problems; rather they interact in two gigantic complex adaptive systems; the biosphere system and the human socio-economic system. The negative manifestations of these interactions are often referred to as ‘the human predicament’ and determining how to prevent it from generating a global collapse is perhaps the foremost challenge confronting humanity.” Paul Ehrlich is a population biologist and ecologist of academic distinction who startled the world in 1967 with a book called The Population Bomb: critics have dubbed him an “irrepressible doomster”, and even admirers concede that he doesn’t often present a cheerful view of the human condition. Anne, who is married to Paul and is co-author of several books with him, is associate director of the Center for Conservation Biology at Stanford University.

“All nations need to stop waiting for others to act”

The growth in human numbers remains a prime concern for the Ehrlichs. They warn that the projected additional 2.5 billion people on Earth by 2050 “would make the human assault on civilisation’s life-support systems disproportionately worse.” Future global collapse could be triggered by anything from a small nuclear war to a more gradual breakdown because of famines, epidemics and resource shortages. No civilisation could avoid collapse if it failed to feed its population. Despite food production “miracles” in the last century, the Ehrlichs argue, two billion people today were hungry or poorly nourished. Food was wasted, and demand for meat was increasing, forcing up the price of food grains. “Perhaps even more critical, climate disruption may pose insurmountable physical barriers to increasing crop yields. Indeed, if humanity is very unlucky with the climate, there may be reductions in yields of major crops, though near term this may be unlikely to affect harvests globally,” they write. (See our earlier story on warming and food production here.) Other threats to production could come from sea level rise and increasingly severe droughts, storms, heat waves and floods. “Unless greenhouse gas emissions are dramatically reduced, dangerous anthropogenic climate change could ravage agriculture.” The authors believe that humans can develop enough “foresight intelligence” to respond to the challenge, but they argue that we cannot afford to delay action to address climate change. “All nations need to stop waiting for others to act and be willing to do everything they can to mitigate emissions and hasten energy transition, regardless of what others are doing.” (See earlier story on emissions targets here.) – Climate News Network