Risk of new Katrinas rises as climate warms

Risk of new Katrinas rises as climate warms

Climate change may drastically increase the risk of simultaneous cyclones and storm surges striking populous coastlines around the world.

LONDON, 1 September, 2015 – Perfect storms are by definition improbable. But climate scientists now think that the devastating combination of extreme tropical cyclone and unprecedented storm surge is going to get a whole lot less improbable by the end of the century.

The chances that the city of Tampa, in Florida, will be hit by a devastating hurricane and an 11-metre wall of ocean water by 2100 could have increased by up to fourteen-fold, they report in Nature Climate Change.

All climate modelling involves a calculation of probabilities. Ning Lin, a civil engineer at Princeton University in New Jersey in the US, and Kerry Emanuel, a climate scientist at Massachusetts Institute of Technology in Cambridge, Massachusetts, started exploring the idea of events that are highly improbable, but worth trying to predict anyway because their consequences could be so calamitous.

If storms that could not be expected are “black swan” events, then they have identified a second category: “grey swan” events that are worse than any in recorded history, but are nevertheless foreseeable, using knowledge of atmospheric physics, topography and the climate record.

So – on the tenth anniversary of Hurricane Katrina’s assault on New Orleans, the most costly disaster in American history – they decided to see how bad things could really get.

Advance warnings

The horror of Katrina was that although it was a storm surge without precedent, engineers and meteorologists had repeatedly warned that New Orleans could be vulnerable. And when it arrived, New Orleans, the state of Louisiana and the Washington Administration were all taken by surprise.

For their study, the two scientists selected three vulnerable bits of coastline and set about modelling the worst that could happen, and the probabilities that it might happen. They chose Dubai in the Persian Gulf – an area never before hit by a tropical cyclone – Cairns on the coast of Australia, and Tampa in Florida.

They found that a “grey swan” cyclone right now could cause a storm surge of six metres in Tampa, Cairns 5.7 metres and Dubai four metres. The chances of such a thing happening in any one year, however, were as low as one in 10,000. That is, not very likely.

And then they factored in continuing climate change, driven by global warming as a consequence of prodigal fossil fuel combustion by humankind, and started to consider the long-term consequences.

By the end of the century, the hazard to Dubai had increased to seven metres, and to Tampa to 11 metres. And the probabilities had increased too: the likelihood of a devastating storm and an overwhelming wall of water in the Persian Gulf had become “non-negligible”: the extreme in Tampa’s case was one in 700.

“The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon”

But such research is based only on known hazards now and projections for the future. In fact, hurricane conditions in one region can be matched by awful hazards in places far away according to a team from the University of California, Irvine, and the US space agency Nasa.

They report in Geophysical Research Letters that they have identified a link between catastrophic wildfires in the Amazon and hurricanes such as Katrina that devastate the northern hemisphere coasts.

Yang Chen, an earth system scientist from UC Irvine, and colleagues looked at years of sea surface temperature and other climate data to find the connection. In years of high numbers of hurricanes and high fire risk, warm waters in the North Atlantic help hurricanes develop and gather strength and speed on their way to North American shores.

These same warm waters drag rainfall away from the southern Amazon, leaving the rainforests increasingly vulnerable to fire. Since the Amazon forests are a vital repository of stored carbon, any fires there can only fuel global warming still further, increasing sea surface temperatures and stepping up yet more the probability of tropical cyclones, typhoons or hurricanes.

“Hurricane Katrina is, indeed, part of this story”, said UCI earth system scientist James Randerson, senior author of the paper. “The ocean conditions that led to a severe hurricane season in 2005 also reduced atmospheric moisture flow to South America, contributing to a once-in-a-century dry spell in the Amazon. The timing of these events is perfectly consistent with our research findings.” – Climate News Network

Share This:

Northern forests face onslaught from heat and drought

Northern forests face onslaught from heat and drought

Many northern hemisphere forests face destruction as climate change brings both fiercer droughts and higher temperatures. 

LONDON, 31 August, 2015 – In the long term, many of the great oak forests of Europe or the giant redwoods and pines of America may not survive. US researchers foresee potential widespread loss of the great temperate forests of both continents.

Under the combined assault of increasing global temperatures and unprecedented drought, some forests could inexorably slide into savannah or scrubland.

Constance Millar is an ecologist with the US Department of Agriculture’s Forest Service Pacific Southwest Station. She and a colleague, Nathan Stephenson of the US Geological Survey, report in the journal Science that the boreal forests of the fast-warming sub-Arctic zones are not the only imperilled woodlands.

They see climate change – driven by rising concentrations of atmospheric carbon dioxide, in turn fuelled by ever-greater fossil fuel combustion – as an emerging “mega-disturbance”: the bringer of not just longer and hotter droughts but of a new class of affliction, the unprecedented “global-change-type drought”.

This cumbersome terminology masks a spell of longer, more severe and hotter droughts that will set the circumstances for new insect pests, fresh plant diseases, invasive competitor species and more extensive and more severe wildfires.

Change imminent

Old forests matter: Dr Stephenson led a huge research team that in 2014 established – against intuition – that the oldest forest giants absorbed more carbon dioxide than young, fast-growing members of the same species.

But unless the professional and government foresters understand what is coming, stands of woodland that have for thousands of years survived periodic assault and then recovered could within decades convert to grassland, or low-growing shrub.

The scientists say that climate change and rising average global temperatures mean not just drought, but drought matched with increasing spells of prolonged heat, far more severe than anything experienced in the 20th century.

Air temperatures will mean that foliage in the canopy becomes too hot, drawing moisture from the leaf tissue at ever-faster rates. In the last century, heat would melt mountain snow in summer to supply more water to the forests in the dry seasons: in this century, most of the winter precipitation will be rain that will run off immediately. Forests will have fewer or no reserves.

Since forests are – in general – agencies that absorb atmospheric carbon, and help cool the planet, any loss can only accelerate global warming and create even more difficult conditions for the surviving woodlands.

“The emergence of mega-disturbances, forest diebacks beyond the range of what we’ve normally seen over the last century, could be a game-changer”

“Some temperate forests already appear to be showing chronic effects of warming temperatures, such as slow increases in tree deaths”, said Dr Stephenson. “But the emergence of mega-disturbances, forest diebacks beyond the range of what we’ve normally seen over the last century, could be a game-changer for how we plan for the future.”

Nor is there any guarantee that the end of a drought will permit young trees to recolonise the burnt, parched and blighted landscape: fast-growing grass and shrub species will get there first and block any regrowth.

Since forests support not just ecosystems and species that are beautiful for their own sakes and valuable both as resources and as tourist attractions, but also deliver “services” in the form of water management and global air-conditioning, human settlements will soon feel their loss.

Such research evokes the big picture. It embodies not just prediction but warning: if governments, state authorities and communities know what could happen, they can take steps to identify and manage the most vulnerable forests in ways that might increase resilience.

But the message is that unprecedented threat will require unprecedented action. “While we have been trying to manage for resilience to 20th century conditions, we realise now that we must prepare for transformations and attempt to ease these conversions,” said Dr Millar. – Climate News Network

Share This:

Drought becoming the ‘new normal’ for Californians

Drought becoming the ‘new normal’ for Californians

Human impacts on global warming and water resources are threatening to turn the landscape of the US west into a dustbowl.

LONDON, 28 August, 2015 – One way or another, humans are to blame for the catastrophic drought in California that scientists say may be emerging as a “new normal”.

Either humans have mismanaged the state’s water, or human-triggered global warming has begun to help turn America’s landscape of wine and roses into a dustbowl, according to two new studies.

And the arguments have relevance extending far beyond the US west, as the European Drought Observatory has warned that much of mainland Europe is now caught up in the continent’s worst drought since 2003.

The consequences of any drought could also be more enduring than expected.  A research team in the US reports in the journal Ecological Applications that trees that survived severe drought in the US southeast 10 years ago are now dying – because of the long-ended drought.

Complex connections

Such statements are simple, but the connections with climate change are complex. That is because drought is a natural cyclic turn of events, even in well-watered countries. It is one of those extremes that, summed up, make the average climate.

Global warming or not, droughts would happen. California in particular has a history of periodic drought that dates back far beyond European settlement and the state’s growth to become the most populous in the US.

But the drought that began in 2012 – and which has cost the agricultural industry more than $2 billion, lost 17,000 jobs, and so far killed 12 million trees – is the worst in at least a century.

“Soaring temperatures will increase demand
for energy just when water for power generation
and cooling is in short supply”

Amir AghaKouchak, a hydrologist at the University of California Irvine, and colleagues say in Nature journal that they want authorities to recognise that human factors are making cyclic water scarcity worse.

They say: “Severe and long-lasting droughts have occurred in reconstructions of the region’s past climate, so it is not clear whether California’s current drought is a temporary weather condition or is the emergence of a ‘new normal’.

“Observations and climate projections indicate that California’s climate is warming, with more winter rainfall instead of snow, earlier snow melt, and decreases in spring and summer stream flows. Future droughts will be compounded by more-intense heatwaves and more wildfires.

“Soaring temperatures will increase demand for energy just when water for power generation and cooling is in short supply. Such changes will increase the tension between human priorities and nature’s share.”

Rising levels

The researchers leave open the question of the role of global warming, fuelled by rising levels of atmospheric carbon dioxide because of increasing fossil fuel combustion. But US scientists report in Geophysical Research Letters that they think global warming could have contributed up to 27% of the present drought.

Their study, based on analysis of month-by-month meteorological data for more than a century, identifies a trend towards drought that is in step with warming since 1901. And they argue that even through the present drought is natural, it has been modestly intensified by climate change.

More ominously, global warming has amplified the probability of severe drought. The new study suggests that, by the 2060s, California may be in more or less permanent drought. Rainfall might increase, but not enough to make up for greater evaporation because of rising temperatures.

“A lot of people think that the amount of rain that falls out the sky is the only thing that matters,” says the report’s lead author, A. Park Williams, a bioclimatologist at Columbia University’s Lamont-Doherty Earth Observatory. “But warming changes the baseline amount of water that’s available to us, because it sends water back into the sky.” – Climate News Network

Share This:

Emissions are putting species in lethal danger

Emissions are putting species in lethal danger

Scientists warn that lizards, coral reefs and forests are all seriously under threat unless agreement is reached to reduce drastically fossil fuel emissions.

LONDON, 27 August, 2015 – Global warming is going to be very bad for the boreal forests of Siberia and Canada, calamitous for the coral reefs of the tropics and the cold deep waters – and lethal for the lizards of North America.

New research warns that the double assault of warmer and increasingly acidic oceans will affect coral reefs everywhere, growing conditions will move north faster than trees can migrate, and increasing extremes of heat will roast vulnerable reptile embryos to death.

As humankind pours more and more carbon dioxide into the planetary atmosphere as a consequence of fossil fuel combustion, these are among the impacts scientists say we should prepare for by 2100 and perhaps even earlier.

About one-third of the planet’s woodlands are strewn across Europe, Scandinavia, Russia, Alaska and Canada. These forests are a “sink” for atmospheric carbon, and at the same time they provide shelter for rich ecosystems and a source of income for tens of millions of people around the world.

Climate zone shifting

But the climate is changing. The region of the northern forests is warming at 0.5°C per decade, and by 2100 it could be on average between 6°C and 11°C higher that it is now. The climate zone is shifting at least 10 times faster than trees can migrate, according to a new study in Science journal.

The likelihood is that the species to the south will be at greater risk of wildfire, drought, infection and insect assault, but the species at the northern fringe will not be able to colonise new ground to keep up. The loss of forest could accelerate global warming even further, although researchers cannot yet be sure.

“These forests evolved under cold conditions, and we do not know enough about the impacts of warming on their resilience and buffering capacity,” says one of the report’s co-authors, Anatoly Shvidenko, a senior researcher in the forestry programme at the International Institute for Applied Systems Analysis in Austria.

The consequences for the coral reefs of the world have been well reported, but geochemists at a global conference in Prague thought it worthwhile spelling out the dangers yet again.

“I find it very unlikely that coral reefs as I knew them in the mid-1960s will still be found
anywhere on this planet by mid-century”

Peter Sale, a marine biologist at the University of Windsor, Canada, used the hazard to the coral ecosystems to underscore the urgency of an international agreement at the UN’s forthcoming Paris conference on climate change to take steps to control emissions and limit average temperature increase to 2°C this century. But that may not be enough.

“Even if Paris is wildly successful, and a treaty is struck, ocean warming and ocean acidification are going to continue beyond the end of this century,” Sale says.

“This is now serious. I find it very unlikely that coral reefs as I knew them in the mid-1960s will still be found anywhere on this planet by mid-century. Instead, we will have algal-dominated, rubble-strewn, slowly eroding limestone benches.

“I see little hope for reefs unless we embark on a more aggressive emissions reduction plan.”

Lizards lay their eggs in the ground in spring and summer and leave them to gestate for up to two months. They are cold-blooded creatures that respond to the heat to become more active, and seek shade when it becomes too hot. − but infant lizards have no such freedom.

A team of scientists from Arizona State University (ASU) report in the Proceedings of the Royal Society B that, in experiments, they found that while adult animals might benefit from a warmer world, their embryos could be seriously at risk.

Pessimistic forecasts

They found that the lizard embryos die when subjected to temperatures greater than 43°C (110°F). Right now, only about 3% of the US gets to this temperature in the shade. By 2100, under the more pessimistic climate forecasts, this could have grown to 48%.

This could be bleak news for whole ecosystems, because lizards consume insects, and are in turn prey for snakes and birds and mammals.

“Lizards put all of their eggs in one basket, so a single heat wave can kill an entire group of eggs,” says Ofir Levy, postdoctoral fellow at the ASU School of Life Sciences, who led the study.

“If mothers don’t dig deeper nests to lay their eggs, we expect this species to decline throughout the United States.” – Climate News Network

Share This:

Solar power takes giant strides as prices fall

Solar power takes giant strides as prices fall

Massive solar power stations are being built in the world’s “sun belts” − with the US and India competing to have the largest in the world.

LONDON, 26 August, 2015 – The US Navy is investing in what will be the largest solar farm in the world in order to provide power for 14 of its bases.

The climate of Arizona, where the two earlier phases of the Mesquite solar farm are already up and running, provides 300 days of sunshine a year. And the Navy’s deal to extend the farm is the largest purchase of renewable energy ever made by a US federal government agency.

The solar farm project is one of a growing number being installed across what is known as the American Sun Belt − the southern states of America, which have expanding populations, plenty of sunshine, but also large areas of arid and unproductive land.

The price of solar panels has now fallen so far worldwide that, in sunny climes, they can compete on cost with any other form of energy generation. This new generation of huge solar farms produces as much power as a large coal-fired plant.

China and India are also building similarly massive installations, taking advantage of their own sun belts and desert regions. It is doubtful that Mesquite 3, huge as it is, will manage to remain the world’s largest for long.

Barren land

In the same week that the US Navy disclosed its plans, the central Indian state of Madya Pradesh announced it was to construct a 750 MW plant (one megawatt is roughly enough to supply 1,000 typical British homes) on barren, government-owned land in the country’s Rewa district.

It is claimed that it would be the world’s largest solar plant, and the state’s energy minister, Rajendra Shukla, says the plan is to have the plant up and running by March 2017.

A number of other giant projects are also in the pipeline in India, as part of government plans for a dramatic expansion of the industry, although they have yet to be constructed.

The Navy boasts that Mesquite 3 will require
no water, so saving “this precious resource
for other needs”

Mesquite 3, which will be sited 60 miles west of Phoenix, Arizona, will provide the Navy with 210 MW of direct power. This means the installation of more than 650,000 extra solar panels, which will move to track the sun as it crosses the sky, to get the maximum value from the intense desert sunshine. The Navy says it will save $90 million in power costs over the 25-year lifetime of the contract.

Some solar power plants in India have caused controversy because they need teams of people to wash off the layer of dust and particles from air pollution to keep the panels efficient. This uses a lot of scarce water.

Illustration: US Navy/Austin Rooney

Illustration: US Navy/Austin Rooney

However, in the cleaner desert air of Arizona, this is not a problem. The Navy boasts that Mesquite 3 will require no water, so saving “this precious resource for other needs”.

The building of the plant will require 300 construction workers, but it will create only 12 long-term jobs. The plant also avoids controversy because it is sited on “previously disturbed land”, and so is not damaging a pristine environment. It is also near existing power plants and transmission lines, so will not need additional infrastructure.

Reduced emissions

The Navy estimates that the station will reduce greenhouse gas emissions by 190,000 tonnes annually − the equivalent of taking 33,000 cars off the road.

Ray Mabus, the Secretary of State for the Navy, who opened the project, has been pushing hard for renewables to be used for military power generation.

In 2009, the US Department of Defense was instructed by Congress to get 25% of its energy from renewable resources by 2025, but Mabus accelerated that goal and directed that one gigawatt (1,000 MW) should be procured by the end of 2015.

The new contract adds to a 17 MW installation at Camp Lejeune, North Carolina, and another of 42 MW at Kings Bay, Georgia. The Navy says that, in total, its renewable energy procurement will be 1.2 GW by the end of 2015, which is well ahead of target.

It will use the power for Navy and Marine Corps shore installations in California and surrounding states.

Opening the project at one of the installations, the Naval Air Station North Island, in California, Mabus said the project was “a triumph of problem solving” and would help increase the Department of the Navy’s energy security by diversifying the supply. – Climate News Network

Share This:

Hi-tech analysis pinpoints Antarctic ice sheet dangers

Hi-tech analysis pinpoints Antarctic ice sheet dangers

Precision mapping of West Antarctica’s melting glaciers could help climate scientists to predict potentially calamitous effects on sea levels.

LONDON, 25 August, 2015 – Scientists have used high-resolution computing techniques to calculate the future of the West Antarctic ice sheet over the next two or three centuries.

The West Antarctic peninsula right now is about the fastest-warming place on Earth. And, in the worst case scenario, glaciers will retreat by hundreds of kilometres, and seas will rise everywhere.

An estimated 80,000 cubic kilometres of ice could flow into the sea by 2100, and by 2200 this could rise to 200,000 cubic kilometres. By the end of this century, sea levels could have risen by 20cms, and 50cms by 2200.

This is an extreme case, but the forecasts for West Antarctica’s glaciers have been consistently alarming. In the last two years, scientists have confirmed that the rates of melt and retreat have accelerated, and that, under the combined effects of warmer air and sea, this melting may be irreversible.

Vulnerable mass

Stephen Cornford, a researcher at the School of Geographical Sciences at the University of Bristol in the UK, and colleagues report in the European Geosciences Union journal The Cryosphere that their chief concern was to help climate science by fixing with greater precision the things that might happen to the most vulnerable mass of ice on the frozen continent.

The new study tests a range of climate predictions in greater detail than before, over a greater area, and a longer period of time. But the uncertainties remain. Will human-induced greenhouse gas levels continue to rise? How will the oceans respond? What will be the consequences for snowfall south of the Antarctic Circle?

“Other regions of West Antarctica could thin to a similar extent if the ocean warms sufficiently”

So the study looks at all the possibilities in more detail, and the pay-off could be more confident predictions of climate change as the circumstances begin to change.

Dr Cornford says: “We expect future change in the West Antarctic ice sheet to be dominated by thinning in the Amundsen Sea Embayment, just as it is today, until at least the 22nd century. But other regions of West Antarctica could thin to a similar extent if the ocean warms sufficiently.”

A computer-generated map of the projected glacial retreat in the Amundsen Sea Embayment by 2154. Image: S.Cornford et al/The Cryosphere

A computer-generated map of the projected glacial retreat in the Amundsen Sea Embayment by 2154.
Image: S.Cornford et al/The Cryosphere

Serious consequences

The worst-case predictions are disconcerting, and could have serious consequences for the hundreds of millions of people who live in cities and on productive land at or near sea level – for instance on the Nile Delta or in Bangladesh – or even below sea level, protected by sea walls, such as in the Netherlands.

But they remain just that: worst case predictions. The scientists were not concerned with establishing probabilities for any scenario, just with employing complex mathematical techniques to extend climate models.

The chief aim of the study has been to find ways of making sense of all possibilities − from no change to calamitous change − in the factors that govern glacier loss.

Co-author Dan Martin, a computational scientist at the Lawrence Berkeley National Laboratory in California, says: “Much like a higher-resolution digital camera transforms a blur into a flock of birds, higher resolution in a computer model often helps to capture details of the physics involved, which may be crucial to the broad picture.” – Climate News Network

Share This:

Prehistoric dogs learned new tricks as climate changed

Prehistoric dogs learned new tricks as climate changed

Scientists have found evidence that profound changes in climate caused ancient predators to evolve into the ancestors of today’s dogs.

LONDON, 24 August, 2015 – Man-made climate change is expected to have a “significant effect” on the wildlife of the planet. And, if fossil evidence is anything to go by, it could seriously alter the course of evolution.

The hunting habits of the wolf – ancestor of man’s best friend, the dog – evolved over millions of years to cope with profound climate change, according to new research.

Borja Figueirido, of the Department of Ecology and Geology at the University of Malaga in Spain, and colleagues report in Nature Communications that they examined the elbows and teeth of 32 native North American species of the dog family from between 39 million and 2 million years ago.

Ambush and pursuit

What they found was clear evidence that, in response to changing climate and foliage cover, dogs evolved from ambush predators that survived by surprising their prey, to pursuit predators that wore them down.

The story begins with a warm, wooded North America in which a canine creature with flexible forelimbs, and not much bigger than a mongoose, used stealth to surprise and pounce cat-like on its dinner. Ultimately, it gave way to animals like wolves, which could chase a deer all day.

“It’s reinforcing the idea that predators
may be as directly sensitive to climate
and habitat as herbivores”

In the course of those 37 million years, the climate cooled, the forests gave way to savannah and prairie, and the dog family began to evolve new strategies − including the short pursuit-and-pounce technique of the coyote or the fox, and the long-distance stamina hunting of the wolf.

“It’s reinforcing the idea that predators may be as directly sensitive to climate and habitat as herbivores,” says Christine Janis, professor of ecology and evolutionary biology at Brown University in the US, and a co-author of the report. “Although this seems logical, it hadn’t been demonstrated before.”

The scientists backed up their conclusions by studying the teeth and forelimb structures of a wide range of hunting animals, including cheetah, hyena and wild dog in Africa, the tiger and snow leopard in Asia, and the jaguar, puma and wolverine in the Americas.

Conservation worries

Their formal conclusion is that when things changed for the herbivores that shaped the landscape, the predators also responded.

Such research confirms the worries of wildlife conservationists that man-made climate change in response to rising levels of carbon dioxide in the atmosphere − as a consequence of the burning of fossil fuels − could seriously alter the evolutionary conditions and the ecosystems from which civilised humankind and its domestic animals emerged.

The scientists say their studies demonstrate that “long periods of profound climatic change are critical for the emergence of ecological innovations, and could alter the direction of lineage evolution”. – Climate News Network

Share This:

Too warm, too few fish: Health warning for world’s oceans

Too warm, too few fish: Health warning for world’s oceans

Rampant overfishing combined with the impact of climate change is seriously endangering the wellbeing of the oceans, environmental analysts say.

LONDON, 23 August, 2015 – The world’s oceans – covering nearly two-thirds of the Earth’s surface, and on which much of human life depends – are under severe pressure, a report says.

Over-fishing has dramatically reduced fish stocks. The thousands of tonnes of rubbish dumped in the oceans wreak havoc on marine life, while climate change is warming and acidifying them, putting them under further stress.

These are the sobering conclusions of a wide-ranging study of the Earth’s ecosystems by the Worldwatch Institute, a US-based organisation widely rated as one of the world’s foremost environmental think-tanks.

“Our sense of the ocean’s power and omnipotence – combined with scientific ignorance – contributed to an assumption that nothing we did could ever possibly impact it”, says Katie Auth, a researcher at Worldwatch and one of the authors of the report.

“Over the years, scientists and environmental leaders have worked tirelessly to demonstrate and communicate the fallacy of such arrogance.”

Decadal doubling

More than 50% of commercial fish stocks are now fully exploited with another 20% classified as over-exploited, the report says, while the number of dead zones – areas of the ocean depleted of oxygen and incapable of supporting marine life – has doubled in each decade since the 1960s.

The oceans play a key role in absorbing vast amounts of greenhouse gases and slowing the warming of the atmosphere.

The report says: “…Evidence suggests that as the ocean becomes saturated with CO2, its rate of uptake will slow, a process that has already begun.”

Sea surface temperatures are rising, putting marine systems under pressure and causing fish and sea bird populations to migrate to colder areas.

Worldwatch says there must be big cutbacks in fossil fuel emissions: “If emissions continue at current levels, ocean acidity in surface waters could increase by almost 150% by 2100, creating a marine environment unlike anything that has existed in the past 20 million years.”

It is time for homo sapiens sapiens to live up to its somewhat presumptuous Latin name, and grow up”

The Worldwatch report, State of the World 2015, examines a range of sustainability issues. It says the goal of continued economic growth – an economic doctrine which has prevailed only since the 1950s – is a threat to the sustainability of multiple ecosystems.

The world’s resources – whether its fossil fuels or water resources – cannot go on being plundered. Changes in climate – in particular the prevalence of drought in some of the world’s main food-producing regions – is threatening the planet’s ability to feed itself.

The report concludes: “There is no question that scholars and scientists who study the human economy, the earth and the interactions between them are drawing profoundly troubling conclusions…

It is time for homo sapiens sapiens to live up to its somewhat presumptuous Latin name, and grow up.” – Climate News Network

Share This:

Central Asia’s glaciers may lose half their ice by mid-century

Central Asia’s glaciers may lose half their ice by mid-century

The speed at which the warming climate is melting glaciers in Central Asia may ruin the water supply of millions of people within 50 years.

LONDON, 22 August, 2015 – Glaciers in the largest mountain range in Central Asia, the Tien Shan, have lost over a quarter of their mass in the last 50 years, and nearly a fifth of their area.

An international team of researchers estimates that since the 1960s the glaciers have shrunk by almost 3,000 square kilometres, losing an average of 60 sq km of ice annually.

The Tien Shan reach almost 7,500 metres (24,500 feet) in height, and are a vital reservoir for the countries through which they pass – China, Kazakhstan, Kyrgyzstan and Uzbekistan.

The team, from the GFZ German Research Centre for Geosciences and France’s National Centre for Scientific Research (CNRS), report in the current online issue of Nature Geoscience that about half of the mountains’ glacier volume could be depleted by the 2050s.

The researchers say the Tien Shan (which in Chinese means “the celestial mountains”) have lost 27% of their mass and 18% of their area since 1960.

Glaciers worldwide are melting at unprecedented rates, which is serious because they are often irreplaceable sources of drinking water, hydropower and irrigation. The Tien Shan are no different.

Long-term storage

The mountains form a vital part of Central Asia’s water cycle. Snow and glacier melt from the Tien Shan is essential for the water supply of the four countries they traverse.

“Despite this importance, only a little was known about how glaciers in this region changed over the last century,” says the principal investigator, Daniel Farinotti. Most of the direct monitoring programmes, which were closed with the end of the Soviet Union, have been resumed only recently.

Farinotti, from GFZ, and his colleagues have completed a reconstruction of the glaciers’ evolution in the Tien Shan. “We combined various methods based on satellite gravimetry, laser altimetry and glaciological modelling”, he says.

This let them plot the evolution of every single glacier. They came up with some surprising findings: currently, the range is losing ice at a pace that equals roughly double the annual water consumption of the whole of Germany.

Glaciers can store water as ice for decades, transferring winter snow and rainfall to the summer months by releasing it as meltwater. This is particularly important in seasonally arid regions which have months with virtually no precipitation. Their local water supply depends on meltwater availability, as Central Asia knows from experience.

Increased temperature contributes to both increased melt and reduced glacier nourishment”

Many people in Central Asia depend on water seasonally impounded by the glaciers of the Tien Shan, not only for water itself but for hydro-electricity and for food.

The pace of glacier retreat in the Tien Shan accelerated noticeably in the decade from the 1970s. Daniel Farinotti says: “The long-term signal is clearly related to the overall rise in temperature”. The study shows that the rise in temperature, and summer temperature in particular, is a primary influence on the region’s glaciers.

“Since the winter months in Central Asia are very dry and the mountains are that high, glaciers receive most of their snowfall during the summer”, Farinotti explains. “This means that an increased temperature contributes to both increased melt and reduced glacier nourishment – and obviously, both contribute to glacier wastage.”

Using the latest climate projections, which expect an additional 2°C of warming in summer temperatures between 2021 and 2050, the authors suggest what the mountains’ future evolution may look like. Half of the total glacier ice volume of the Tien Shan today could be lost by the 2050s, they believe. – Climate News Network

Share This:

China’s carbon count is not as high as feared

China’s carbon count is not as high as feared

The use of poor-quality coal in Chinese power plants means that the carbon dioxide emissions of the world’s biggest polluter are 10% less than previously thought.

LONDON, 21 August, 2015 – Calculations on how much carbon dioxide China produces have been wrong for more than 10 years because the official bodies that calculate it have assumed the country’s power stations burn high-quality coal.

In fact, the world’s biggest polluter uses coal with a lower carbon content than power stations in Europe and the US, and so produces less carbon dioxide per tonne − around 14% less according to experts from 18 research institutions.

Getting the total quantities of CO2 emitted by each country correct is crucial if the world is going to reach agreement on tackling dangerous climate change at the UN conference in Paris in December. One of the stumbling blocks to agreements in the past has been politicians’ need to have a fair system of sharing the burden of cuts.

Calculating how much pollution each country produces has been largely based on the quantities of fossil fuels burned in electricity and heat production and in motor vehicles.

This has not taken into account the fact that the amount of carbon in coal and oil varies according to its quality, and so an average figure has been used, which turns out to be unfair in the case of China.

Appalling air quality

One of the ironies of the finding is that while the carbon content of the coal may be less, its impurities means it emits more of other kinds of pollution. This is what has made air quality in Chinese cities so appalling, and has started a big debate in China about whether the country should seek to burn better-quality coal to avoid killing its citizens with bad air.

The revised estimates of China’s carbon emissions, published in the journal Nature, were produced by an international team, led by researchers from Harvard University, the University of East Anglia (UEA), in England, the Chinese Academy of Sciences and Tsinghua University, in collaboration with 15 other international research institutions.

The team re-evaluated emissions from the burning of fossil fuels and cement production from 1950 to 2013. They used independently-assessed activity data on the amounts of fuels burned, and new measurements of emissions factors – the amount of carbon oxidised per unit of fuel consumed – for Chinese coal.

Because the amount of coal burned in China is so vast, the size of the error is also huge. It means there are 2.9 fewer gigatonnes of carbon in the atmosphere. That is more than the total amount of carbon stored by China’s forests over roughly the same period.

“Evaluating progress towards countries’ commitments to reduce CO2 emissions depends upon improving the accuracy of annual emissions estimates”

It is particularly important because nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China.

The lead UK researcher, Prof. Dabo Guan, of UEA’s School of International Development, said the key contributor to the new estimates was fuel quality, which for the first time was taken into consideration in establishing emission inventories – something the Intergovernmental Panel on Climate Change (IPCC) and most international data sources had not done.

“China is the largest coal consumer in the world, but it burns much lower quality coal, such as brown coal, which has a lower heat value and carbon content compared to the coal burned in the US and Europe,” Prof. Guan says.

“China is one of the first countries to conduct a comprehensive survey for its coal qualities, and a global effort is required to help other major coal users, such as India and Indonesia, understand their physical coal consumptions as well as the quality of their coal types.

“Our results suggest that Chinese CO2 emissions have been substantially over-estimated in recent years. Evaluating progress towards countries’ commitments to reduce CO2 emissions depends upon improving the accuracy of annual emissions estimates and reducing related uncertainties. These findings represent progress towards improving estimates of annual global carbon emissions.”

Total consumption

The discrepancy would have been even greater if China more accurately counted its coal consumption. According to researchers, total energy consumption was 10% higher between 2000 and 2012 than reported in China’s national statistics. However, even taking that into account, emissions were still less than previously believed because emissions per tonne were on average 40% lower than the levels assumed by the IPCC.

This alters substantially the estimates of the Carbon Dioxide Information Analysis Centre (CDIAC) in the US and the Emissions Database for Global Atmospheric Research (EDGAR) in the EU, which are the official data sources for the IPCC Fifth Assessment Report (AR5) – providing scientific evidence for the climate change policy negotiations in Paris later this year.

The figure is also about 10% less than the estimate given for China in the most recent publication of the Global Carbon Project, which annually updates global carbon emissions and their implications for future trends.

Prof. Corinne Le Quéré, director of the Tyndall Centre for Climate Change Research at UEA, co-leads the publication of annual updates of emissions for the Global Carbon Project.

She says: “The strong message here is that as we refine our estimates of carbon emissions we get closer to an accurate picture of what is going on, and we can improve our climate projections and better inform policy on climate change.” – Climate News Network

Share This: