Light from plant growth shows carbon budget

Invisible flickering detected by satellite could throw new light from plant growth on the mysteries of the planet’s carbon budget.

LONDON, 18 June, 2018 – For the first time, light from plant growth may let humans see – almost at a glance – how greedily the planet’s vegetation sucks carbon dioxide from the atmosphere.

US-based researchers have confirmed that they can detect the same glow – invisible to the human eye – from trees, grasslands, crops, mangroves, marches and desert plants as the green things put chlorophyll to work and photosynthesise leaves, flowers, fruits and roots from atmospheric carbon.

The pay-off is simple: an easier and potentially more accurate way of calculating the global carbon budget and assessing the climate cost of human exploitation of fossil fuels.

But the same information will help biologists and geoscientists advance what is sometimes called earth system science: how carbon-based lifeforms make their living from sunlight, water and carbon dioxide in a continuous trafficking that has fuelled 3bn years of evolution.

And at the heart of the study is a new realisation that images from an orbiting satellite deliver better information in a reliable fashion.

“This is a big step towards being able to solely rely on satellite measurements”

Researchers have exploited data from orbiting earth observation satellites to measure the diminishing thickness of the polar ice caps and their dwindling extent, as human-induced global warming warms the oceans and raises the sea levels.

They have helped measure the response of different kinds of forest to global warming, and changes to ocean chemistry as ever greater levels of greenhouse gas enter the atmosphere, as humans burn ever more fossil fuels.

But one satellite, launched specifically to answer questions about the traffic between living things and the carbon dioxide in the atmosphere, has delivered information with even greater precision that anyone expected.

Researchers from the University of New Hampshire report in the journal Global Change Biology that years of observation of solar-induced fluorescence – a glow from plants that no human could expect to see, but an instrument can detect – have confirmed that there is a direct relationship between gross primary productivity and the amount of fluorescence registered by the eye in the sky.

No exceptions

It means that what is true for the canopy of tropical forests in the Congo would also be true for a landscape of maize in the American mid-West, or the grasses and wildflowers of the savannah, the dusty maquis of the Mediterranean, or the swamps of the Louisiana bayous.

Up till now, researchers have tried to make accurate and reliable estimates on the ground, playing with air temperature, sunlight, rainfall and other factors to arrive at their conclusions about what they like to call carbon “sinks.” The message from OCO-2, the NASA orbiting carbon observatory, is that the gleam from the foliage below provides an answer more swiftly, and perhaps more surely.

“The importance of these results is that rather than look at several different types of data and computer-based models from information collected on the ground to monitor plant photosynthesis across the globe, using the satellite observations will provide a near real-time option that is simple, reliable and fast,” said Jingfeng Xiao, of the University of New Hampshire, the chief investigator.

“This is a big step towards being able to solely rely on satellite measurements.” – Climate News Network

Homeless Bangladeshis flee before rising waters

Rising sea levels and recurrent floods mean more homeless Bangladeshis, with unpredictably changing rainfall patterns compounding their plight.

LONDON, 13 June, 2018 – As another monsoon season begins, huge numbers of homeless Bangladeshis are once again bracing themselves against the onslaught of floods and the sight of large chunks of land being devoured by rising water levels.

Bangladesh, on the Bay of Bengal, is low-lying and crisscrossed by a web of rivers: two thirds of the country’s land area is less than five metres above sea level. With 166 million people, it’s one of the poorest and most densely populated countries on Earth – and one of the most threatened by climate change.

A recently released report by the Environmental Justice Foundation (EJF) says rises in sea levels caused by climate change could result in Bangladesh losing more than 10% of its land area by mid-century, resulting in the displacement of 15 million people.

The country is already experiencing some of the fastest-recorded sea level rises in the world, says the EJF, a UK-based organisation that lobbies for environmental security to be viewed as a basic human right.

Unpredictable rains

Increasingly erratic rainfall patterns – linked to changes in climate – are adding to the nation’s problems. Sudden, violent downpours have resulted in rivers breaking their banks and land being washed away.

Rising sea levels mean land and drinking water is contaminated by salt. Farmers are forced to abandon their land and move – many to Dhaka, the capital, one of the world’s so-called megacities, with a population of more than 15 million.

“Bangladesh has a long history of floods, but what used to be a one-in-20-year event is now happening one year in five”, says Saleemul Huq, director of the International Centre for Climate Change and Development in Dhaka. “It is what we would expect with climate change models.”

Farmers further inland are also forced to move to the capital in search of work due to surging rivers eating away their lands. The city’s slums are expanding, and Dhaka’s population is increasing by more than 4% each year.

Farming abandoned

“We had a small farm – we used to produce peanuts and gourd, corn and sugar all year round”, says one farmer quoted in the EJF report. “Now I collect scraps of work as a labourer.”

EJF says climate change should not be seen only as an environmental issue; climate change is also contributing to a rapidly developing humanitarian crisis, not just in Bangladesh but in many other regions around the world.

“It is countries like Bangladesh, and people like those we met, whose contributions to climate change have been among the smallest, that are now facing the worst impacts”, says Steve Trent, EJF’s executive director.

“We must act now to prevent this becoming a full-scale humanitarian crisis.”

“Bangladesh has a long history of floods, but what used to be a one-in-20-year event is now happening one year in five”

In recent months more than 600,000 people – Rohingya refugees from violence in neighbouring Myanmar – have set up shelters in southern Bangladesh. There are fears that this community could also be under threat during the monsoon period.

The EJF report highlights how women in Bangladesh are especially vulnerable to climate-related disasters. In 1991 a cyclone which swept across the Bay of Bengal caused the deaths of 140,000 people and forced 10 million to leave their homes.

EJF says 90% of the dead were women; their lower status means they are often not taught survival skills. Women also tend to stay with children and other family members when disaster strikes.

Those women who do migrate find it more difficult to adapt to life in a Dhaka slum or elsewhere. Some become victims of trafficking, ending up in brothels in India.

Foreign migration grows

EJF says that while most climate migration is internal, there are indications that growing numbers of Bangladeshis are seeking to move outside the country. It says that in early 2017 there was a particularly big surge in the number of Bangladeshi migrants arriving in Italy after completing the perilous journey by land and sea from their homeland.

EJF is calling for the creation of an international legally binding agreement for the protection of climate refugees. The EU should take the lead in this process, it says.

“There should be clarifications on the obligations of states to persons displaced by climate change, with new legal definitions”, says EJF.

“Definitions of climate-induced migration are urgently needed to ensure a rights-based approach and give clarity to the legal status of ‘climate refugees’; these must be developed without delay.” – Climate News Network

Humans put conservation reserves at risk

In theory conservation reserves are set aside to preserve wild creatures. But then the humans move in. Land almost twice the area of India is threatened.

LONDON, 8 June, 2018 – Many of the world’s conservation reserves, intended to safeguard species at risk of survival, are increasingly unable to provide effective refuge.

At least one third of all the forests, grasslands, wetlands and mangroves notionally protected by laws to safeguard the wild things that evolved with them are under intense human pressure, according to the first detailed study for 25 years.

Major road systems criss-cross African wildlife reserves, cities have grown up in national park areas, and farmland and buildings blight landscapes supposedly reserved for endemic species at hazard from extinction. Altogether 6 million square kilometres (2.3m square miles) of protected land, researchers say, are “under intense human pressure.”

Since the global Convention on Biological Diversity (CBD) was agreed in 1992, the area of the world declared as protected has doubled in size, and more than 202,000 patches of conservation area and national park cover 14.7% of the Earth’s land surface.

“A well-run protected area network is essential in saving species. If we allow our protected area network to be degraded there is no doubt biodiversity losses will be exacerbated”

Some of these areas are strictly for conservation of biodiversity; some permit limited human exploitation but are still intended mainly to provide habitat for the wild creatures.

Australian and Canadian scientists report in the journal Science that they examined what they call “human footprint” maps of the globe to make their assessment. The human footprint metric incorporates built environments, intensive agriculture, pasture lands, human population density, night-time lights, roads, railways and navigable waterways.

The scientists found that only 42% of these lands were free of measurable human pressure. But 32.8%, an area of more than 6m sq km – almost twice the size of India – counted as under intense pressure.

What worried the scientists most was what happened to some landscapes that were intact and in a natural state when declared as protected: since 1993, around 280,000 square kilometres of such wilderness had shifted from low disturbance to intense human pressure: this is an area almost as large as Italy.

Complete human dependence

Almost three fourths of the world’s nations – that is, 137 countries – have 50% of their protected land under intense human pressure. “If one assumes that protected land under intense human pressure does not contribute towards conservation targets,” the scientists write, “we show that 74 of 111 nations that have reached a level of 17% protected coverage would drop out of that list.”

Almost all human resources – including food and drink, fabrics and medicines – are derived from the planet’s biodiversity: even the coal, natural gas and petrol that drives the human economy was once wild forest and reed bed. Researchers have repeatedly stressed the importance of biodiversity to all human economic activity – they call it natural capital – and warned that continued loss of wild native plants and animals could have catastrophic consequences. The authors of the Science study warn that if human pressure increases, the goals of the CBD will be severely undermined.

“A well-run protected area network is essential in saving species,” said Kendall Jones of the University of Queensland. “If we allow our protected area network to be degraded there is no doubt biodiversity losses will be exacerbated.”

And his co-author James Watson of the World Conservation Society said: “Most importantly, we’ve got to recognise that these jewels in the crown need support – there are some protected areas that are safeguarding nature and that still haven’t got any evidence of human encroachment in them. We must ensure these values are maintained.” – Climate News Network

China’s trade plan may cause lasting harm

China’s trade plan could cause  environmental catastrophe, scientists warn, because of its voracious appetite for natural resources and its climate impact.

LONDON, 1 June, 2018 – Possibly the most ambitious and far-reaching development scheme ever launched, China’s trade plan, the Belt and Road Initiative (BRI), may pose an unacceptable risk to the environment, scientists say.

Launched in 2013, the BRI plans a huge expansion of trade routes linking Asia, Africa and Europe, involving China itself and 64 other countries, and affecting about two thirds of the world’s people and one third of its economy. There will be new ports on the Pacific and Indian Ocean coasts, new roads, and a rail network linking China to north-west Europe.

But an international group of scientists, writing in the journal Nature Sustainability, expresses serious doubts about the possibility of completing the scheme without causing permanent environmental damage.

Economy vs. environment

The scientists write: “Economic development aspirations under the BRI may clash with environmental sustainability goals, given the expansion and upgrading of transportation infrastructure in environmentally sensitive areas, and the large amounts of raw material needed to support that expansion…

“If not properly addressed, the negative environmental impacts of the BRI are likely to disproportionately affect the world’s poor, hence putting at risk the wellbeing of the very people it aims to help.”

Some of the scientists’ comments are positive. They say, for instance, that the BRI includes “examples of well-planned road developments” with negligible impacts on wildlife and protected areas.

They cite the proposed Serengeti Highway in Tanzania, which would go round the national park, not through it. An alternative route for Nigeria’s planned Cross River Superhighway will cause far less environmental harm than the original scheme, and the Bangladesh Railway is improving the protection of elephants by building five overpasses across the tracks for them at well-used crossing points.

“In biodiversity and environmental terms, it’s the worst thing we’ve seen anywhere  –  and in the past forty years, I and my colleagues have seen some pretty horrific stuff”

To improve the BRI’s research and monitoring, Beijing has announced its intention to build a Digital Silk Road with the Chinese Academy of Sciences, a potential boost to environmental research elsewhere in Asia.

But despite these expected benefits from the BRI, doubts remain. The scientists say a recent report by the World Wildlife Fund found “a clear risk of severe negative environmental impacts from infrastructure developments”.

These include the scheme’s gargantuan appetite for natural resources, including sand and limestone for making the immense quantities of concrete and cement that it will demand. Global sand extraction, the scientists say, has already passed its natural renewal rate, causing severe damage to deltas and coastal ecosystems.

And with China already responsible for one-third of global greenhouse gas emissions, the vast pipeline network planned under the BRI, and the infrastructure construction involved, will mean further and faster exploitation of fossil fuel reserves.

Riskiest scheme ever

One of the authors of the commentary in Nature Sustainability is Bill Laurance, of James Cook University, Australia. In an interview with Nexus Media he had more to say about his concerns – and he didn’t pull his punches.

Professor Laurance thinks the BRI “environmentally, the riskiest venture ever undertaken”, which “simply blows out of the water anything else that’s been attempted in human history…In biodiversity and environmental terms, it’s the worst thing we’ve seen anywhere  –  and in the past forty years, I and my colleagues have seen some pretty horrific stuff in the Amazon, Africa, Southeast Asia and the South Pacific.”

On climate change, he holds out little hope that the Initiative can offer anything much: “If you also consider everything China is doing or promoting overseas in terms of extractive industries and large-scale infrastructure, they utterly overwhelm any other nation as climate changers.

“In real terms – digging through a great deal of greenwashing – I don’t see anything in the BRI that squares with China’s stated climate goals.” – Climate News Network

Earth bears a massive human load

Gross up the mass of all life on Earth, with its disproportionate human load , and the answer is staggeringly heavy. But the uncertainties are huge.

LONDON, 31 May, 2018 – The human load on the Earth, an audit of all life on the planet shows, is out of kilter with our numbers: we constitute a hugely heavier presence than all wild mammals together.

Israeli and US researchers found the whole package of living tissue – bone, blood, shell, chitin, collagen, timber, cellulose, muscle, blubber, teeth, hair, hoof, horn and all the myriad cells that make up self-replicating, greedy, carbon-based organisms – if tossed on the scales, would (if reduced to carbon) weigh an estimated 550 billion metric tons.

Most of it would be foliage, wood, root and fruit: the green plants that have colonised the terrestrial globe account for about 450 billion tons, or gigatons, of carbon. Another 70 gigatons would be composed of bacteria, and most of that would be invisible: at work beneath the surface of the land and sea.

And although the oceans cover 70% of the globe, the share of marine life is much smaller: the blue water is home to a mere six billion tons of living things. The fungi that colonise the forests and grasslands alone account for twice that mass.

Top mammal

Mammalian life in sharp contrast to all this sheer weight of living things is almost inconsequential: even so, one mammal dominates.

The mass of all the humans on the planet – just humans, not their livestock – is more or less 10 times the mass of all other living wild mammals.

Research like this is fundamental. It is vital. And it is provisional.

It is fundamental because, ultimately, it can help answer questions about how life survives: how the energy of the sun is turned into, and then sustains, life everywhere. That is because, ultimately, all the carbon in living things is derived from atmospheric carbon dioxide, in a process powered by photosynthesis.

“Humans and livestock outweigh all other vertebrates combined, with the exception of fish”

It is vital because to make long-term reliable calculations about the carbon budget, and therefore calculations about the future rate of global warming and climate change as factories and exhaust pipes pump ever more greenhouse gases into the atmosphere, climate scientists need to understand the big picture: how life sequesters and recycles carbon on a massive scale.

And it is provisional because some of the calculations are almost certainly wrong: estimates of global plant life can be checked by satellite data and national forestry accounting, but some questions have barely been addressed. The authors concede – “our work highlights gaps in the current understanding of the biosphere”, in their words – that their estimates for the mass of bacteria could be wrong by a factor of 10, and viruses by a factor of 20.

But the researchers report in the Proceedings of the National Academy of Sciences that they see a full census of life on Earth as key to understanding how the biosphere works, and a step towards that would be a better understanding of how biomass – the sheer weight and substance of life – is concentrated, and shared.

Insects abound

And the sums are bewildering. Insects make up the richest group of creatures, with so far one million described species. But their fraction of biomass, say the authors, is negligible. Some single species contribute much more than entire families or even classes.

The Antarctic krill Euphausia superba adds up to about the same mass as humans, or cows. The measure of a huge variety of termites far surpasses the entire biomass of birds. The nematode worms contain more individuals than any other species, but their collected mass is only about 1% of the grand total for all life.

There are entire environments, the authors say, “for which our knowledge is very limited.”

The research also assesses the impact of Homo sapiens – one mammalian species among many – on all other life on Earth. The biomass of domesticated poultry is three times that of all other birds. “In fact”, the authors say, “humans and livestock outweigh all other vertebrates combined, with the exception of fish.” – Climate News Network

Lakes emit more methane as they evaporate

Even the world’s freshwater could affect climate change calculations, as lakes emit more methane from the mud, and vapour from the surface.

LONDON, 24 May, 2018 – The amounts of a powerful greenhouse gas leaking into the atmosphere are set to rise as lakes emit more methane in reaction to climate change.

The vegetation decomposing in the lakes will change – and the northern lakes of Canada could send 73% more methane – a potent greenhouse gas – into the atmosphere to accelerate global warming at an ever greater rate

And a further cause for concern as the world warms is the most abundant greenhouse gas of them all. As the world warms, its 250,000 lakes will evaporate faster. By the century’s end, they will be sending 16% more water into the atmosphere as vapour – to fall again as rain.

Both studies represent climate research at its most detailed: each is an attempt to understand the intricacies of environmental change on a small scale and then predict global impact. And both deliver the unexpected.

“We believe we have discovered a new mechanism that has the potential to cause increasingly more greenhouse gases to be produced by freshwater lakes”

US and Chinese researchers who built computer models of the responses of freshwater reservoirs to changing climate report in Nature Geoscience on what may befall the vapour.

They found that, as global temperatures rose, lakes in the high latitudes – and that represents about 80% of the world’s lakes – would freeze later each winter and thaw earlier each spring.

That would mean more open water, which absorbs radiation more efficiently than ice. At the same time warmer temperatures would deliver more energy to support evaporation: the two processes could account for half of all future changes in evaporation. So much energy is trafficked in the process of lake evaporation that researchers have even suggested it as a potential source of renewable electricity.

“Typically we focus on the ‘top-down’ ways that the upper part of the atmosphere triggers feedbacks that enhance warming,” said Xuhui Lee, a meteorologist at the Yale School of Forestry & Environmental Studies.

Understanding hydrology

“But if we want to make accurate predictions of the hydrological changes we’ll need to understand what’s happening at the bottom of the atmosphere, including what’s happening at the surface of lakes – because those changes are driving the hydrological response to climate change.”

But evaporation is not the only factor that will change. British, Canadian and German scientists report in the journal Nature Communications that they asked a simple question: how will warmer temperatures change the release of greenhouse gases from lakes?

They took samples from the decaying vegetation – deciduous leaves, pine needles and reeds and rushes – in lake beds and incubated them for 150 days to see what gases emerged.

Those lakes rich in cattails – sometimes called bulrushes – produced 400 times more methane than lakes layered with conifer needles, and 2,800 times the methane from deciduous leaves submerged in temperate forest lakes.

Rapid spread

Methane is reckoned to be at least 30 times more powerful than CO2 at warming the Earth, with some estimates putting its potency over the short term much higher still, and climate scientists need to calculate the volumes likely to be added to the atmosphere as climates change.

The researchers found that the boreal shield of Canada – with more lakes and forests than anywhere else in the world – would change with rising global temperatures, and the numbers of lakes colonised by the cattail Typha latifolia could double in the next 50 years, to produce 73% more methane.

“We believe we have discovered a new mechanism that has the potential to cause increasingly more greenhouse gases to be produced by freshwater lakes,” said Andrew Tanentzap, of the University of Cambridge.

“The warming climates that promote the growth of aquatic plants have the potential to trigger a damaging feedback loop in natural ecosystems.” – Climate News Network

Insects face calamitous habitat loss

Unless nations act fast, habitat loss could rob half of all insects of over half their habitat. Other creatures, too, could suffer in a 3°C warmer world.

LONDON, 21 May, 2018 – Habitat loss may soon mean half the world’s insects, and many plants and animals as well, could find themselves without their familiar home ranges.

Right now, climate scientists warn, global planetary temperatures are on course to rise 3.2°C above the average for most of human history. They have already risen by about 1°C in the last 100 years.

And if they do, then 49% of insects, 44% of plants and 26% of vertebrates could lose more than half of their ranges.

If the 195 nations that agreed in Paris in 2015 to take steps to restrict global warming to a target of 1.5°C keep their pledges, only 6% of insects, 8% of plants and 4% of vertebrates will experience severe reductions in their ranges. Even half a degree makes a huge difference.

”We could literally move the world back 20 to 30 million years in the space of a century. It is like moving ecosystems backwards in time at the speed of light”

“Insects are particularly sensitive to climate change. At 2°C warming, 18% of the 31,000 insects we studied are projected to lose more than half their range. This is reduced to 6% at 1.5°C. But even at 1.5°C, some species lose larger proportions of their range,” said Rachel Warren of the University of East Anglia, who led the study.

“The current global warming trajectory, if countries meet their international pledges to reduce CO2, is around 3°C. In this case, almost 50% of insects would lose half their range.”

These figures are projections based on a sample of animal and plant studies: the sample is however one of the largest undertaken.

Professor Warren and colleagues from Australia report in the journal Science that they studied data involving 34,000 insects and other invertebrates, 8,000 birds, 1,800 reptiles, 1,000 amphibians and 71,000 plants, and took into account the capacity of each species to move to new habitat as the world warms.

Pattern of alarm

Such studies build on evidence assembled piecemeal, sometimes over many decades, about the impact of humanity on its fellow citizens of the planet. This evidence confirms a consistent pattern of alarm.

Researchers have established repeatedly that ecosystems already under pressure from human invasion are made more vulnerable by global warming and climate change. More precisely, German scientists have established that the sheer numbers of insects that used to make a living around European farmlands have fallen dramatically, and even those insects that seem to survive almost everywhere could be under threat.

The new study found that a small number of species will extend their range in a warming world. Most will not. Many will have fewer places to go.

“This is really important because insects are vital to ecosystems and for humans,” said Professor Warren. “They pollinate crops and flowers, they provide food for higher-level organisms, they break down detritus, they maintain a balance in ecosystems by eating the leaves of plants, and they help recycle nutrients in the soil.”

Options narrowing

And, writing separately in the same journal, Guy Midgley of Stellenbosch University in South Africa warned that the options for humanity are becoming severely restricted.

Humans depend on plants, insects and other animals to deliver water quality, soil conservation, flood prevention, crop pollination and natural pest control. All this is now threatened, not just by the clearing of forests and the growth of the cities, but by the profligate use of fossil fuels which release greenhouse gases such as carbon dioxide into the atmosphere, to drive global warming.

Researchers know, through a detailed study of the geological past, what higher concentrations of carbon dioxide can do to global climate. “There is way too much debate about the issue of climate change and whether or not it is real. What we really need to be doing is debating how we solve this problem,” said Professor Midgley.

“Those very high CO2 concentrations could well change the ecosystems of the world irrevocably. If we increase CO2 to over a thousand parts per million, over the next fifty to sixty years, which we are quite capable of doing if we fail to reduce our dependence on fossil fuels, we could literally move the world back 20 to 30 million years in the space of a century. It is like moving ecosystems backwards in time at the speed of light.” – Climate News Network

Birds go hungry as warmth means earlier springs

Climate change means warmer and earlier springs. And that may be of no help to those bird species that get the timing wrong.

LONDON, 16 May, 2018 – Insectivorous birds could find that earlier springs leave them late at the supper table. Global warming and the advance of spring could mean that the caterpillars have already peaked by the time the blue tits and flycatchers have hatched their hungry broods.

Scientists from six British universities report in the journal Nature Ecology and Evolution that the hatching of forest birds could become increasingly out of step with the maximum supply of the grubs that feed their hungry young.

And, they believe, this may be a change with no winners. A study of blue tits, great tits and pied flycatchers found that geography made no significant difference: the prediction that birds in the warmer south of England may suffer most from this avian mistiming could not be confirmed.

“Forests have a short peak in caterpillar abundance, and some forest birds time their breeding so this coincides with the time when their chicks are hungriest,” said Malcolm Burgess, of the University of Exeter in the UK, and the Royal Society for the Protection of Birds.

“Our work suggests that as springs warm in the future, less food is likely to be available for the chicks of insectivorous woodland birds”

“With spring coming earlier due to climate change, leaves and caterpillars emerge earlier and birds need to breed earlier to avoid being mismatched. We found that the earlier the spring, the less able birds are to do this.”

Amateur and professional ornithologists have been observing bird populations for more than a century and have huge bodies of data to work with.

In any changing situation, some species respond to evolution’s challenges, and some – at least for a while – falter.

Researchers have recorded examples of what they call “phenotypic plasticity” in the great tit Parus major. Five years ago they confirmed that the little birds were laying eggs two weeks earlier than 50 years ago. Swiss scientists have evidence that alpine species are moving uphill as temperatures edge ever higher.
But as human populations have swollen, and natural habitat has been lost, bird counts have been falling. Climate change amplifies the hazard.

Arriving too late

And one seeming victim is the pied flycatcher, which migrates to the UK for the breeding season and isn’t in British forests in time to respond to ever-earlier springs.

To establish their findings, researchers collected evidence of oak leafing dates, the droppings from caterpillars that exploit oak trees, and records of egg laying within the three species.

“Our work suggests that as springs warm in the future, less food is likely to be available for the chicks of insectivorous woodland birds, unless evolution changes the timing of their breeding,” said Karl Evans, of the University of Sheffield, one of the authors. – Climate News Network

Hopes rise for some coral survival

US scientists have good news about prospects for coral survival on one of the world’s great reefs, threatened by climate change.

LONDON, 25 April, 2018 – Researchers have raised hopes that limited coral survival may be possible, allowing one of the world’s best-known reefs to survive a little longer.

Although corals are highly sensitive to ocean warming, and notoriously bleach when temperatures exceed a certain limit, a new study has shown that at least one coral can evolve tolerance to excessive temperatures.

The implication is that even though other teams have repeatedly warned that the world’s reefs are in peril as the world warms because of ever-greater ratios of greenhouse gases in the atmosphere, as a consequence of human combustion of fossil fuels at a profligate rate, the world’s great reefs may survive for perhaps another century, rather than perish within the next 50 years.

“It means these corals will still go extinct if we do nothing,” said Misha Matz, of the University of Texas at Austin, who led the study. “But it also means we have a chance to save them. It buys us time to actually do something about global warming, which is the main problem.”

The argument is based on Darwinian logic: coral colonies produce colossal numbers of larvae each year, set adrift on ocean currents to colonise new reefs. As conditions change, those corals that by an accident of genetic inheritance have the traits needed to cope with environmental challenge will get a foothold, and flourish. Those that don’t will fade out. Natural selection will respond.

”While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers”

And this is hopeful news, if only because the world’s reefs are under threat as never before. Bleaching – the response to heat in which coral rejects the algae with which it normally lives in symbiosis – has always happened: research earlier this year suggests it could become five times more frequent, and reefs such as Australia’s Great Barrier would have no time to recover.

Some reefs have already been pronounced too damaged ever to be restored. This is bad news not just for the coral animals: the tropical reefs are just about the richest habitats on the planet, and of profound economic importance to humans too.

A partnership of US and Australian scientists reports in the Public Library of Science journal PLOS Genetics that computer simulation models and genetic evidence of variation from one species of staghorn coral, called Acropora millepora, together show that the coral could in theory adapt over a stretch of 20 to 50 generations.

“This genetic variation is like fuel for natural selection,” Dr Matz said. “If there is enough of it, evolution can be remarkably fast, because all it needs to do is reshuffle the existing variants between the populations.

“It doesn’t have to wait for a new mutation to appear; it’s already there. The problem is, when the genetic variation is exhausted, it is over and the future is unclear.”

Tentative conclusions

There are problems with such studies. This one is based on genetic evidence from one species of coral. But the 2,300 km Great Barrier Reef of Australia is home to at least 411 species of hard coral. It is based on a mathematical model, not on observed change in the reefs.

And global warming is not the only challenge to coral reefs, which are also threatened by human exploitation, pollution and increasing acidification  of the surrounding seas, again as a consequence of ever higher levels of carbon dioxide in the atmosphere.

“Corals live in a symbiotic relationship with zooxanthellae, which are plant-like cells hosted in surface tissues that provide up to 90% of the energy to the colony,” said Stephen Simpson, a marine biologist at the University of Exeter in the UK, commenting on the study.

“Whether there is also sufficient genotypic variation in the zooxanthellae to tolerate further warming remains to be seen. While the fact that one species may do well is good news, there are many other reef organisms that may fare far worse, so it is easy to envisage a future with a few winners but many losers, threatening the functional integrity of reef ecosystems.” – Climate News Network

High Arctic species respond to climate warming

The northern ocean is abuzz with life, but the composition of those high Arctic species is changing as the world gets warmer.

LONDON, 23 April, 2018 – Global warming is beginning to change the high Arctic species which make up the region’s most numerous occupants. Scientists who have been collecting spiders, mites, ticks, bugs, bees, wasps, ants, moths and springtails in the northeast of Greenland report that the arthropod population is starting to respond to the changing seasons.

Arthropods make up the largest variety of animals on the planet: this is a phylum of jointy-legged things with exoskeletons that includes spiders as well as flies, bees and butterflies as well as mites. In the tundra, the mass of arthropods is greater than that of birds or mammals.

Danish and US scientists report in the Royal Society journal Open Science that between 1996 and 2014, researchers collected 593,788 specimens of different arthropod groups around the Zackenberg research station and noted the way the species composition of a population changed with time and with the pattern of summer rainfall.

In this region, the winter temperatures fall to minus 30°C and average annual temperature is minus 9°C. The ground is more or less permanently frozen. But in the brief Arctic summer, temperatures can soar to between 3°C and 7°C and the Arctic fens, heaths and arid zones effervesce with life.

”We often don’t pay much attention to these small animals, but there could be real consequences to their changing abundances”

Compared with the past, the population is changing. There are more herbivores and creatures that parasitise other animals, but the detritivores – the creatures that consume carrion, excrement and decomposing plants – seem to be on the way down, with, the scientists say, potential implications for key ecosystem processes such as decomposition, nutrient cycling and primary productivity.

Change varied according to habitat: the changes in the composition of the community of arthropods were up to five times more extreme in the drier ecosystems. The implication of such research is that study of shorter-lived, tinier creatures may provide more information about adaptation and loss in the rapidly warming Arctic than, for instance, study of seals and polar bears.

And the insects do respond, even to subtle change: researchers four years ago noted that around 80 species of moth inside Finland’s Arctic seemed to be coping with warmer summers.

“Twenty years may not be long enough to detect changes in abundances of longer-lived species, like some mammals, but because of their short life spans, it’s a pretty long time for arthropods. Still, the fact that we can detect changes over 20 years in some of these animal groups at such a coarse taxonomic resolution is remarkable,” said Amanda Koltz, of Washington University in St Louis, who led the study.

“We often don’t pay much attention to these small animals, but there could be real consequences to their changing abundances.” – Climate News Network

Company averts climate chocolate threat

Fears that the supply of cocoa beans would dry up have led a confectionery giant to help farmers avert a climate chocolate threat.

LONDON, 20 April, 2018 – If you have a sweet tooth, a liking not only for sugar-rich sweets but especially for chocolate, you’ve cause for celebration: the prospect of a climate chocolate threat is a little less likely.

Keeping the world supplied with chocolate is becoming more difficult as deforestation and climate change make it harder for farmers in the tropics to grow the trees that produce the cocoa beans.

Paying producers more for beans under the banner of Fairtrade certainly improved the lot of poor farmers, most of them small-scale cultivators, but that did not solve the long-term problem of providing enough cocoa to supply the huge world market.

The cocoa tree’s natural habitat is the lower storey of the evergreen rainforest, but cocoa farmers do not always grow their trees in the best conditions.
The trees only thrive 10 degrees either side of the Equator, where they need sufficient warmth, rainfall, soil fertility and drainage if they are to flourish.

Clearing rainforest to make space for cocoa tree plantations is some farmers’ preferred practice, but it is not a sustainable way to maintain production.

“We pioneered Cocoa Life to address cocoa farm productivity alongside community development. We strive to not only empower cocoa farmers but also to help their communities thrive”

But, fearing that the supply of cocoa beans was in jeopardy and the price of their raw material would affect production, one of the world’s largest manufacturers is now to invest US$400m by 2022 to help 200,000 cocoa farmers secure a long-term future.

The scheme, called Cocoa Life, is helping farmers in six key cocoa-growing countries: Ghana, Côte d’Ivoire, Indonesia, India, the Dominican Republic and Brazil.

The company responsible, Mondelēz International, which owns brands like Cadbury, Suchard and Milka, believes many cocoa-growing regions could be wiped out unless action is taken.

Cathy Pieters, director of the Cocoa Life programme at Mondelēz, told the Climate News Network: “The challenges in cocoa are becoming more diverse and complex. In fact, some reports show current cocoa-producing regions may no longer be suitable for cocoa production in the next 30 years if we don’t take action.

Expecting change

“Our approach to climate change is deliberate because we expect a change to happen – a transformation. As one of the largest chocolate makers in the world, we are mobilising farmers and their communities to prioritise forest protection.”

Key to the programme is educating farmers, helping women by providing finance and stopping child labour, and also improving the environment. The company is helping farmers prevent further destruction of rainforest and planting trees around cocoa farms to protect them and recreate the habitat in which trees are most productive.

In this way farmers are producing far more cocoa beans from the same area of land. This year the programme has planted more than a million trees to restore the forest canopy.

Cocoa Life was launched in 2012 and to the end of last year had trained more than 68,000 members of the cocoa-farming community in best practice to ensure a sustainable industry. Cocoa saplings and shade trees needed to replicate rainforest conditions had been distributed to 9,600 farmers.

Industry example

The company says that by the end of 2017 it had increased the amount of its cocoa from sustainable sources by 14 percentage points to 35% and reached 120,000 farmers, 31% more than in 2016.

The potential crisis in the cocoa-growing industry and the threat of climate change have led other manufacturers to embark on similar schemes, and 11 companies have now joined together in a World Cocoa Foundation alliance to protect rainforest from further destruction by cocoa farmers looking for new land.

Although Mondelēz is protecting its own interests by ensuring its cocoa supply chain, Cathy Pieters is clear that the programme is much more than that alone: “We pioneered Cocoa Life to address cocoa farm productivity alongside community development. We strive to not only empower cocoa farmers but also to help their communities thrive.

“We help them find real solutions like diversifying their income beyond the farm, which in turn develops their capacity to stand strongly on their own feet. I believe when we involve farmers as part of the solution, we see lasting, positive change happen.” – Climate News Network