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

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Extreme weather puts Africa’s food security at risk

Extreme weather puts Africa's food security at risk

A British government scientific panel says increasingly frequent heat waves, droughts and other extreme weather threaten more – and more severe – global food crises.

LONDON, 15 August, 2015 – Developing countries in sub-Saharan Africa which depend heavily on food imports will be worst hit by the increasingly extreme global weather, a report says, with the Middle East and North Africa also threatened, in this case by social unrest.

In contrast, the authors say the impact on the world’s biggest economies is likely to be muted. But they think a serious crisis could occur as soon as 2016, with repercussions in many countries.

They write: We present evidence that the global food system is vulnerable to production shocks caused by extreme weather, and that this risk is growing…preliminary analysis of limited existing data suggests that the risk of a 1-in-100 year production shock is likely to increase to 1-in-30 or more by 2040.”

The report was jointly commissioned by the UKs Foreign and Commonwealth Office and its Government Science and Innovation Network, with a foreword by the countrys former chief government scientist, Sir David King.

He writes: We know that the climate is changing and weather records are being broken all the time…The food system we increasingly rely on is a global enterprise. Up to now its been pretty robust and extreme weather has had limited impact on a global scale. But…the risks are serious and should be a cause for concern…

Likely scenarios

We should be looking carefully at even very low probability situations, and the likelihood of the scenarios suggested in this report are far too significant to ignore.”

The report says the UN’s Food and Agriculture Organisation estimates that by 2050 global food demand will be 60% above todays, with per capita demand also growing, and more meat-eating.

In 2007/8 a small weather-related production shock, coupled with historically low stock levels, led to rapid food price inflation in the main internationally traded grains, as measured by the FAO Food Price Index.

Prices rose by over 100%. A similar price spike occurred in 2010/11, partly driven by the weather in eastern Europe and Russia.

In 2012, the worst drought to hit the American Midwest for half a century triggered comparable spikes in international maize and soya prices. There is good evidence, the report says, that extreme weather events, from intense storms to droughts and heat waves, are increasing significantly.

Food production of the globally most important commodity crops (maize, soya, wheat and rice) comes from a small number of major producing countries.

Multiple failure

Simultaneous extreme weather events in two or more of these regions – creating a multiple bread basket failure – would represent a serious production shock. There is an urgent need to understand the driving dynamics of linked problems such as the El Niño effect – which may be becoming more extreme – the report says.

By examining production shocks in the recent past, the authors devised what they call a plausible worst case scenario” – a simultaneous drought affecting maize and soya production, and another which damages wheat and rice harvests.

More topically, they also describe what they say is a plausible worst case scenario for 2016. This involves a complex sequence, starting with a disappointing 2015 Indian monsoon, the loss of much of 2016s Black Sea winter wheat crop, and then Russian and Ukrainian export bans.

International wheat prices rise fast, prompting similar measures in south and central Asia and Argentina, and repercussions as far afield as China, Iran, Saudi Arabia and Morocco.

In late spring a persistent drought starts in North America, affecting soya and maize forecasts and prices. Then a heatwave and drought hit the European wheat crop, leading to further rises across all cereals.

Panicked markets

In early summer a second failure of the Indian monsoon unleashes panic in the rice market, where Asian households have been steadily hoarding. Myanmar, Sri Lanka, Egypt and Nepal impose export restrictions.

Major importers such as Nigeria, Malaysia and the Philippines place orders far above normal levels in a bid to calm domestic markets. The scenario ends with still more countries
– Vietnam, Cambodia and Indonesia – imposing export bans.

One of the reports recommendations is that agriculture should adapt to a changing climate.

That, it says, means productivity must be increased by reversing declines in yield growth and closing the gap between actual and attainable yields in the developing world, while also reducing agricultures environmental impact, including the depletion of fresh water and the increase in greenhouse gas emissions.

However, it says, given the increasing risk of extreme weather, this cannot come at the expense of production resilience. – Climate News Network

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Added gene can make rice more climate-friendly

Added gene can make rice more climate-friendly

Scientists discover a way to boost production of the grain that billions rely on for food – and reduce its damaging emissions of methane.

LONDON, 14 August, 2015 – An international team of scientists has found a way to make rice more productive, more nutritious and less of a greenhouse gas producer – simply by adding just one gene from the cereal, barley.

The single gene SUSIBA 2 – the acronym stands for sugar signalling in barley – makes all the difference. And the importance of the breakthrough is that rice feeds half the world – but, as it grows, is one of the great sources of the greenhouse gas, methane.

The world’s rice paddy fields release up to 100 million tonnes each year of methane − possibly 17% of the global total.

And although methane emissions are small compared with carbon dioxide, each molecule of methane is far more potent a global warmer. The gas is 34 times more potent than CO2 over a century, but 84 times more so over a much shorter timespan – just 20 years.

Ideal conditions

The conditions ideal for rice – warm and waterlogged, and mud, rich with nutrients − are also ideal for the generation of methane.

The scientists from China, Sweden and the US report in Nature journal that they calculated that if they could do something to encourage the conversion of sugars to starches in the rice plant, there would be more productivity in the stalk and ears, and less around the roots, where the methane-generating bacteria flourish.

In their words, this would “generate a high starch, low methane emission variety”.

They used transcription factor technology – a form of genetic modification that could soon also deliver better drought tolerance in some important crop plants – and began tests at the Fujian Academy of Agricultural Sciences in Fuzhou, China, in 2012 and 2013. Transcription factors bind to genes and turn them on or off.

“As the world’s population grows, so will rice production. And as the Earth warms, so will rice paddies, resulting in even more methane emissions”

Earlier experiments in Sweden had helped the team understand how to manage the transcription factors so they could just about dictate which parts of the plant absorbed more of the carbon taken from the atmosphere by photosynthesis.

The result was a rice variety that yielded more starch, so that it delivered more energy per spoonful for a hungry household, or that could be converted to more biofuel during times of surplus.

Japanese scientists, too, have been looking for ways to get all the value they can out of one of the world’s most vital crops. But the other important outcome, the researchers say, was a near-elimination of methane production from around the roots.

The next step is to look at what happens in the paddy fields, and try to understand what is going on and what the change could mean for methane-generating bacteria.

Test variety

The scientists also dried the whole plant once it had ripened to examine what had occurred, and to compare it with control varieties in the same fields. They found that grains of the test variety contained almost 87% starch, compared with 77% in the control sample.

The research still has a long way to go, but given that global population could sometime this century hit or even surpass 10 billion, and given that the land available for farming cannot expand, there is pressure to increase yields per field.

Ominously, research so far suggests that global warming – and the accompanying greater extremes of heat in the growing season – could reduce yields. So plant scientists must make the most of any advances in the understanding of the biology of growth.

“The need to increase starch content and to lower methane emissions from rice production is widely recognised, but the ability to do both simultaneously has eluded researchers,” says Christer Jansson, a co-author of the report, and director of plant sciences at the US Pacific Northwest National Laboratory.

“As the world’s population grows, so will rice production. And as the Earth warms, so will rice paddies, resulting in even more methane emissions. It’s an issue that must be addressed.” – Climate News Network

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Climate threat as grave a risk as nuclear war

Climate threat as grave a risk as nuclear war

An international scientific report commissioned by the UK government says the risks of climate change are comparable to those posed by nuclear conflict.

LONDON, 18 July, 2015 – The UK government says that climate change poses risks that demand to be treated as seriously as the threat  of nuclear war.

Scientists from the UK, US, India and China say in a report commissioned by the UK that deciding what to do about climate change depends on the value we put on human life, both now and in years to come.

One of the lead authors of the report is Sir David King, formerly the UK government’s chief scientist, who last month co-authored a report on the scale of investment that should be made to move from fossil fuels to renewable energy by 2025. 

In a foreword to the latest report, Baroness Anelay, a minister at the British foreign office, writes that assessing the risks surrounding nuclear disarmament and non-proliferation means understanding inter-dependent elements − including what science says is possible, what other countries may intend, and systemic factors such as regional power dynamics.

“The risk of climate change demands a similarly holistic assessment,” she says.

Value human life

She concludes: “How much do we care about the effects of climate change? How important is it that we act to avoid them? What probability of their occurrence can we tolerate?…The answers to these questions depend in part on how we value human life – both now, and in the future.”

The report is not the first to put climate chaos and nuclear devastation in the same category of risk, but its sponsorship by one of the world’s nuclear powers is eloquent.

It says the most important political decision is how much effort to exert on countering climate change, taking into account what we are doing to the climate, how it may respond, what that could do to us, and what we might then do to each other.

The authors’ best guess, based on current policies and trends, is that greenhouse gas emissions will keep going up for another few decades, and then either level off or slowly decline.

“Uncertainty is not our friend. There is much more scope to be unlucky than there is to be lucky”

This, they say, is for two reasons: governments are not making maximum use of the technologies already available; and technology is not yet progressing fast enough to give governments the policy options they will need. In the worst case, emissions could keep on rising throughout the century.

They warn that how the climate may change, and what that could do to us, are both highly uncertain. “The important thing to understand is that uncertainty is not our friend,” the report says. “There is much more scope to be unlucky than there is to be lucky.”

High emissions pathway

The report foresees wide ranges of possible global temperature and sea level increase. On a high emissions pathway, it says, where the most likely temperature rise is estimated at 5°C by 2100, anything from 3°C to 7°C may be possible.

On this pathway, the chances of staying below 3°C will become “vanishingly small”, but the chances of exceeding 7°C will increase and could become more likely than not within the next century.

The authors see very little chance that global sea level rise will slow down, and every chance that it will accelerate. The only question is by how much.

“While an increase of somewhere between 40cm and 1m looks likely this century, the delayed response of huge ice-sheets to warming means we may already be committed to more than 10m over the longer term. We just do not know whether that will take centuries or millennia.”

A temperature increase of 4°C or more could pose very large risks to global food security, and to people.

Humans have limited tolerance for combinations of high temperature and humidity. Their upper limits of tolerance are rarely if ever exceeded by climatic conditions alone, but with temperature increase somewhere between 5°C and 7°C, it starts to become likely that hot places will experience conditions that are fatal even for people lying down in the shade.

Population growth alone is also likely to double the number of people living below a threshold of extreme water shortage by mid-century.

Sea level thresholds

Coastal cities, according to the report, probably have thresholds in terms of the rate and extent of sea level rise that they can deal with, but we have very little idea where those thresholds are.

The authors say that even the 0.8°C of climate change experienced so far is now causing us significant problems, and that “it seems likely that high degrees of climate change would pose enormous risks to national and international security” − for example, through extreme water stress and competition for productive land.

In a highly topical passage, they say migration from some regions may become more a necessity than a choice, and could happen on a historically unprecedented scale.

“The capacity of the international community for humanitarian assistance, already at full stretch, could easily be overwhelmed,” the report warns.

The risks of state failure could rise significantly, affecting many countries simultaneously, and even threatening those currently considered developed and stable.

But the report is not relentlessly downbeat. “An honest assessment of risk is no reason for fatalism,” it says. “Just as small changes in climate can have very large effects, the same can be true for changes in government policy, technological capability, and financial regulation… the goal of preserving a safe climate for the future need not be beyond our reach.” – Climate News Network

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Warming planet heightens plight of the bumblebee

Warming planet heightens plight of the bumblebee

Scientists warn that human intervention may be needed to protect bees as climate change overheats their southern habitat range.

LONDON, 10 July, 2015 − The humble bumblebee is feeling the squeeze from climate change. Research shows that its southern range is being reduced as the planet warms − and yet it seems to show no sign of migrating northwards to safety.

This unwillingness to head for cooler climes could prove disastrous, and has prompted some scientists to suggest that humans may need to intervene by creating refuges for the bees away from the heat.

Jeremy Kerr, a biologist at the University of Ottawa, Canada, and colleagues report in the journal Science that they generated a database of 423,000 local observations of 36 European and 31 North American species of the genus Bombus and mapped the patterns of change.

They found that in recent, increasingly warmer decades, bumblebees tended to disappear from the southernmost and hottest parts of their range, but did not shift north. In some cases, the insects’ range had shrunk by as much as 300 kilometres.

Dramatic losses

“Global warming has trapped bumblebee species in a kind of climate vice,” Professor Kerr says. “The result is dramatic losses of bumblebee species from the hottest areas across two continents.

“For species that evolved under cool conditions, like bumblebees, global warming might be the kind of threat that causes many of them to disappear for good.

“Unlike so many other species, bumblebees generally haven’t expanded into more northern areas. We may need to help these species establish new colonies to the north, and at continental scales.”

The finding is a clear indication that some naturally mobile species may not be able to adapt to climate change.

In recent decades, biologists have used animal and even plant migration to monitor climate change. Alpine species in Switzerland have been observed moving uphill, and in the UK, the butterfly range has tended to shift northwards.

In the latest study, the scientists looked at a range of factors that might limit bumblebee migration − things such as changes in land use, and pesticide prevalence, create problems for all wild species. But these factors seemed to play no significant part in limiting the creature’s range.

“Bumblebees are at risk, and the services
they provide are increasingly threatened
by human-caused climate change”

There is evidence that, where they can do, some species are moving uphill by as much as 300 metres, while still staying in the same latitude. But researchers do know that bumblebees don’t thrive in the extremes of heat that have been an increasing feature of recent decades.

“We don’t know for sure what is causing a stagnation at the northern end of things,” says Paul Galpern, a landscape ecologist at the University of Calgary, and a co-author of the report.

“Bees should be able to start new colonies in places they did not historically occupy. But we don’t know why this is happening so slowly that it looks like the ranges are not moving at all

“This all points to the fact that bumblebees are at risk, and the services that they provide are increasingly threatened by human-caused climate change.”

Important role

Such creatures play an important role in temperate zone ecosystems. “Bumblebees pollinate many plants that provide food for humans and wildlife,” says Leif Richardson, a biologist at the University of Vermont, and also a co-author of the report.

“If we don’t stop the decline in the abundance of bumblebees, we may well face higher food prices, diminished varieties, and other troubles.”

Professor Kerr reinforces the message. “Pollinators are vital for food security and our economy, and widespread losses of pollinators due to climate change will diminish both,” he says.

“We need to figure out how we can improve the outlook for pollinators at continental scales, but the most important thing we can do is begin to take serious action to reduce the rate of climate change.” – Climate News Network

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Climate change may knock seafood off the menu

Climate change may knock seafood off the menu

Researchers warn of a serious threat to fish, mussels and other marine species as carbon dioxide acidifies the world’s waters and increases temperatures.

LONDON, 7 July, 2015 – Pink salmon – the smallest and most abundant of the Pacific salmon species, and a supper table mainstay in many parts of the world – may be swimming towards trouble.

And they are not the only dish likely to disappear from the menu. Mussels, oysters, clam and scallop could all become scarcer and more expensive as the seas become more acid. And as the world’s waters warm, fish will start to migrate away from their normal grounds at an ever-increasing rate.

New research shows that as the world’s waters acidify because of carbon dioxide levels in the atmosphere, the pink salmon (Oncorhynchus gorbuscha) could become smaller and less likely to survive.

Potentially problematic

Previous studies have repeatedly and consistently explored potentially problematic consequences of change in the pH value of the world’s oceans. The higher the carbon dioxide concentrations in the air as a consequence of the burning of fossil fuels, the greater the change in oceanic acidity levels.

But researchers at the University of British Columbia, Vancouver, and colleagues looked at the special problems of freshwater fish.

Only about 0.8% of the world’s water is fresh – that is, found in lakes and rivers – but freshwater species represent 40% of all fishes. Salmon spawn and the young are reared in fresh water, before taking to the seas to mature, then returning to repeat the cycle.

The Vancouver scientists report in Nature Climate Change that they tested very young embryos in water at acidity levels expected at the end of this century, and observed them for 10 weeks.

They found that these laboratory-reared salmon were smaller, and their ability to smell was reduced, which could mean problems in returning to their spawning grounds or for scenting danger and responding to it.

“It is not too late for society to benefit greatly from immediate reductions in CO2 emissions”

At the age of seaward migration, they were less able to use oxygen in their muscles, which promised problems finding food, evading predators or making long journeys.

“The increase in carbon dioxide in water is actually quite small from a chemistry perspective, so we didn’t expect to see so many effects,” said Michelle Ou, lead author of the study. “The growth, physiology and behaviour of these developing pink salmon are very much influenced by these small changes.”

Salmon aren’t the only freshwater fish at risk from climate change. Research published in the journal Environmental Toxicology and Chemistry reveals that a rise in water temperatures of 5°C could make common pesticides and industrial contaminants ever more toxic.

Ronald Patra, an environmental scientist at the Department of Planning and Environment in New South Wales, Australia, and colleagues tested rainbow trout, silver perch, rainbowfish and western carp gudgeon at temperatures higher than optimum for the species and in the presence of endosulfan, chlorpyrifos and phenol − all of which wash into waterways from the land.

Results varied according to pollutant, species and temperature, but, overall, all three chemicals became increasingly toxic as water temperatures rose.

Future toxicity

On the coast of Mangalore in southwest India, where mussel farming has become a growing industry, researchers decided to test future toxicity conditions for the green mussel.

The Society of Experimental Biology meeting in Prague learned that the bivalves were raised in high temperature and low salt conditions and exposed to toxic algae and bacteria of the kind that might be expected in a changing climate, which in turn affected the timing of the monsoon in ways that could lower seawater salinity.

“This is likely to increase the chance of outbreaks of toxic plankton blooms and make farming bivalves such as mussels increasingly challenging,” the meeting was told.

But changes to water chemistry – once again, the shift in pH values as yet more carbonic acid builds up in the seas – create problems enough for the commercial shellfisheries.

Wiley Evans, research associate at the Ocean Acidification Research Centre of the University of Alaska Fairbanks, and colleagues report in the Public Library of Science journal PLOS One that shellfish farmers off the Alaska coast might, at extra expense, have to start modifying the sea water in their hatcheries because, the researchers reported, they expect “significant effects” from acidification by 2040.

The scientists monitored for 10 months the effects of water chemistry changes on oyster, clam, scallop and other shellfish larvae.

Alaska – with a limited growing season, melting glaciers that affect salinity, and with colder waters that more readily dissolve carbon dioxide – is a special case.

But in general, as researchers have repeatedly found, increasingly corrosive waters would make it more difficult for shellfish to exploit the calcium carbonate minerals needed to make shells.

Shellfish spend their maturity in one spot, whereas fish can and do shift their grounds when the conditions become uncomfortable − with consequences for established commercial catches such as sardines and sea bass.

Likely to migrate

But a 5°C average warming in global atmospheric temperatures – and climate scientists have repeatedly warned that this is possible before 2100 – means that fish are likely to migrate away from their existing habitats considerably faster than they are doing now.

Jean-Pierre Gattuso, of the Oceanological Observatory in Villefranche, France, and colleagues looked at the evidence on a global scale and report in Science journal that, without attempts to mitigate global warming, the oceans and the creatures in them will be seriously affected by temperature changes and acidification.

This is very bad news for the millions of people in the communities that depend on the seas for a living.

“On a positive note, we still have options to substantially reduce these impacts now, but the longer we wait the fewer and fewer options we have,” warns co-author William Cheung, of the fisheries centre at Canada’s University of British Columbia.

Commenting on the research, Jason Hall-Spencer, a professor of marine biology at Plymouth University in the UK, said: “This review screams at me that the evidence is in, and it is not too late for society to benefit greatly from immediate reductions in CO2 emissions.” – Climate News Network

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Stress on water resources threatens lives and livelihoods

Stress on water resources threatens lives and livelihoods

Satellite data raises red-flag warning about the draining of underground aquifers to meet the demands of expanding populations.

LONDON, 29 June, 2015 – The planet’s great subterranean stores of water are running out – and nobody can be sure how much remains to supply billions of people in the future.

Satellite instruments used to measure the flow from 37 underground aquifers between 2003 and 2013 have revealed that at least one-third of them were seriously stressed – with little or almost no natural replenishment.

The research was conducted by scientists from California and the US space agency NASA, who report in the journal Water Resources Research that they used data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites to calculate what is happening to aquifers.

The two satellites measure variations in the gravitational pull of the planet’s surface, and have already revealed changes in the mass of ice sheets on the planetary surface. But buried water, too, has mass, and changes in the mass of bedrock in known aquifer regions would therefore offer a guide to depletion.

Driest regions

Not surprisingly, the researchers found that those regions that are already driest were drawing most heavily on the groundwater below the surface.

The Arabian aquifer system, − the principal water source for 60 million people − is the worst stressed, followed by the Indus Basin of north-west India and Pakistan, and then the Murzuk-Djado basin in northern Africa.

The scientists warn that climate change – a consequence of increasing atmospheric carbon dioxide emissions from the human combustion of fossil fuels – and population growth will make things worse.

“What happens when a highly-stressed aquifer is located in a region with socioeconomic or political tensions that can’t supplement declining water supplies fast enough?” asks Alexandra Richey, who conducted the research as a University of California Irvine doctoral student. “We’re trying to raise red flags now to pinpoint where active management today could protect future lives and livelihoods.”

“We can no longer tolerate this level of uncertainty, especially since groundwater
is disappearing so rapidly”

Her colleague, hydrologist James Famiglietti, identified his own home state of California as a cause for concern because it is in the grip of an extended drought that threatens agriculture.

“As we’re seeing in California right now, we rely much more heavily on groundwater during drought,” he says. “When examining the sustainability of a region’s water resources, we absolutely must account for that dependence.”

Groundwater accumulates slowly in the underlying bedrock over millennia. There is no problem if it is withdrawn slowly, but human population has exploded threefold in one human lifetime, and water use has risen even faster.

Supply problem

Research like this is a demonstration of ways to address a supply problem − but there is more work to be done.

In a second study in Water Resources Research, the same team examined the challenge of trying to calculate the rates at which aquifers are being emptied, and the uncertainties as to how much might remain in them.

In the Northwest Sahara, for instance, estimates of the projected “time to depletion” varied from 10 years to 21,000 years. “In a water-scarce society,” Richey says, “we can no longer tolerate this level of uncertainty, especially since groundwater is disappearing so rapidly.”

Professor Famiglietti concludes: “I believe we need to explore the world’s aquifers as if they had the same value as oil reserves. We need to drill for water in the same way that we drill for other resources.” – Climate News Network

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Scientists detect mysterious warming in US coastal waters

Scientists detect mysterious warming in US coastal waters

Unprecedented ocean temperature rises off the Atlantic and Pacific coasts of the US may be linked to sea level rise or the recent pattern of “weird” weather.

LONDON, 28 June, 2015 − Oceanographers are puzzled by an accelerated burst of warming sea that threatens the fisheries of the American Atlantic coast.

Meanwhile, off the US West coast, scientists report that they have been baffled by a mysterious “blob” of water up to 4°C warmer than the surrounding Pacific, linked to weird weather across the entire country.

Jacob Forsyth and research colleagues from the Woods Hole Oceanographic Institution (WHOI) in Massachusetts report in the Journal of Geophysical Research: Oceans that the ocean off the US north-east continental shelf has been warming at unprecedented levels for 13 years.

Their findings came after analysis of data from sensors − called bathythermographs − dropped 14 times a year from the container ship Oleander, which for 37 years has travelled between New Jersey and Bermuda. Each detector takes the temperature of the water column as it sinks up to 700 metres.

Startling discovery

What they were startled to discover was an unexplained, and unprecedented, rise in the water temperatures that may be linked with an equally mysterious sea level anomaly: sea levels are going up, but they are going up faster off the north-east coast of the US than almost anywhere else.

“The warming rate since 2002 is 15 times faster than from the previous 100 years,” says Glen Gawarkiewicz, a WHOI senior scientist and one of the authors of the report.

“There’s just been this incredible acceleration to the warming, and we don’t know if it’s decadal variability or if this trend will continue.”

“It’s producing conditions that we think are going to be more common with global warming”

To make sure of their perspective, the authors compared their analysis with surface data from the Nantucket lightship and other such installations along the coast, from 1880 to 2004. The new study shows that the warming is not just confined to surface waters.

Although there must be some link with the steady rise in atmospheric temperatures because of global warming as a result of human-made carbon dioxide emissions, the oceanographers suspect there may also be another explanation, so far undiscovered.

Off the Pacific coast, meteorologists have been scratching their heads over the appearance in 2014 of a “remarkably” warm patch −  1,500 kilometres across in every direction and 100 metres deep − that could be linked to “weird” weather across the continental US that has seen heat and drought in the west and blizzards and chills in the East.

High pressure ridge

Nicholas Bond,  a research meteorologist at the University of Washington in Seattle, and colleagues report in Geophysical Research Letters that what they have called “the blob” was linked to a persistent high pressure ridge, linked in turn to a calmer ocean during the last two northern hemisphere winters.

The blob plays a sure role in the West Coast weather. Air sweeping across it picks up heat, and this results in warmer temperatures and lower snowpack in coastal mountains − which certainly stoke up the conditions for drought.

A second study in Geophysical Research Letters links the warm Pacific puzzle to the big freeze in the eastern states in 2013 and 2014.

Once again, there doesn’t seem to be a direct connection with climate change, but it raises the spectre of changes to come.

“This is a taste of what the ocean will be like in future decades,” Dr Bond says. “It wasn’t caused by global warming, but it’s producing conditions that we think are going to be more common with global warming.” − Climate News Network

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Combating climate dangers is seen as medical emergency

Combating climate dangers is seen as medical emergency

International experts say the last 50 years of health advances worldwide will be jeopardised unless urgent steps are taken to confront climate change.

LONDON, 23 June, 2015 – The threat that climate change poses to human health is so great that it could undermine the last half-century of gains in development and global health, says an international commission of medical experts.

One author, fiercely critical of international efforts to confront the problem, says it is a medical emergency that demands an emergency response.

More hopefully, though, the group’s report says that international efforts to tackle climate change – “the defining challenge of our generation” – represent one of the greatest opportunities to improve health worldwide this century.

The report, published in The Lancet medical journal, is the work of the 2015 Lancet Commission on Health and Climate Change.

Unparalleled chance

It says many responses to climate change have direct and indirect health benefits – from reducing air pollution to improving diet – and so efforts to reduce the threat offer an unparalleled chance for far-reaching gains in health.

But the commission is under no illusions about what is at stake. The authors say the potentially catastrophic risk to human health posed by climate change has been underestimated

They add – in a familiar refrain – that while the technologies and finance required to address the problem do exist, the global political will to implement them is lacking.

Professor Hugh Montgomery, one of the commission’s co-chairs and director of the University College London (UCL) Institute for Human Health and Performance, UK, says: “Climate change is a medical emergency. It thus demands an emergency response, using the technologies available right now.

“Under such circumstances, no doctor would consider a series of annual case discussions and aspirations adequate, yet this is exactly how the global response to climate change is proceeding.”

“Now is the time for us to lead the way in responding to another great threat to the human and environmental health of our generation

Lancet Commission on Health and Climate Change

Image: The Lancet Commission on Health and Climate Change

Professor Anthony Costello, another of the commission’s co-chairs and director of the UCL Institute for Global Health, says: “Climate change has the potential to reverse the health gains from economic development that have been made in recent decades – not just through the direct effects on health from a changing and more unstable climate, but through indirect means such as increased migration and reduced social stability.”

The report says the direct health impacts of climate change come from the increasing frequency and intensity of extreme weather events, especially heatwaves, floods, droughts and storms. Indirect impacts result from changes in infectious disease patterns, air pollution, food insecurity and malnutrition, involuntary migration, displacement and conflicts.

It says there are many ways in which action on climate change brings immediate health gains. For example, burning fewer fossil fuels reduces respiratory diseases, and what doctors call “active transport” (walking and cycling) cuts pollution and traffic accidents, and reduces rates of obesity, diabetes, coronary heart disease and stroke. There are also health benefits from changes to diet, such as eating less red meat.

Entrenched interests

The commission is an extensive collaboration between experts from Europe and China. Its other co-chair, Professor Peng Gong, from Tsinghua University, Beijing, says: “The health community has responded to many grave threats to health in the past.

“It took on entrenched interests such as the tobacco industry, and led the fight against HIV/AIDS. Now is the time for us to lead the way in responding to another great threat to the human and environmental health of our generation.”

The report provides a set of recommendations for policy-makers, and the authors propose the formation of a new global independent body on climate change and health − to be called Countdown to 2030: Climate Change and Health Action − to monitor and report every two years on the health impacts of climate change. – Climate News Network

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Rise in CO2 could restrict growing days for crops

Rise in CO2 could restrict growing days for crops

While plants in temperate zones may benefit from higher temperatures, global warming’s impact in the tropics threatens catastrophe for food security.

LONDON, 20 June, 2015 − The positive consequences of climate change may not be so positive. Although plants in the colder regions are expected to thrive as average global temperatures rise, even this benefit could be limited.

Some tropical regions could lose up to 200 growing days a year, and more than two billion rural people could see their hopes wither on the vine or in the field. Even in  temperate zones, there will be limits to extra growth.

Plants quicken, blossom and ripen as a response to moisture, warmth and the length of daylight. Global warming will clearly change the temperatures and influence the patterns of precipitation, but it won’t make any difference to the available hours of sunlight at any point on the globe.

Scientists at the University of Hawaii at Mānoa report in the Public Library of Science journal PLOS Biology that they looked at the big picture of complex change. Higher concentrations of atmospheric carbon dioxide – the greenhouse gas from car exhausts, forest fires and factory chimneys – are expected overall to aid crop and forest growth.

Extended season

Average global warming of less than 1°C in the last 30 years has extended the northern hemisphere growing season by up to 11 days, but plants are still limited by radiation.

“Those that think climate change will benefit plants need to see the light, literally and figuratively,” says Camilo Mora, lead author of the report and assistant professor in the Department of Geography at the University of Hawaii.

“A narrow focus on the factors that influence plant growth has led to major underestimations of the potential impacts of climate change on plants, not only at higher latitudes but more severely in the tropics, exposing the world to dire consequences.”

Professor Mora has made a career of thinking about global consequences. He and colleagues recently tried to calculate the possible dates at which local climates could shift inexorably in different parts of the world, and tried also to build a picture of how ocean warming and acidification would affect incomes everywhere.

“Many plants will not be able to take advantage of those warmer temperatures because there will not be enough sunlight to sustain their growth”

His team is not the first to try to calculate the potential impact of catastrophic global warming on global food supply. Cereals are vulnerable to extremes of heat, and climate change may already be affecting yields in Europe.

But the Hawaiian scientists tried a simple theoretical approach, by first identifying the ranges of temperature, soil moisture and light that drive 95% of the world’s plant growth today.

They then tried to calculate the number of days in a year in which these growth conditions could be expected at various latitudes in the future, as carbon dioxide levels – and average temperatures – climb.

They found that, nearer the poles, the number of days above freezing would increase by 7%.

“But many plants will not be able to take advantage of those warmer temperatures because there will not be enough sunlight to sustain their growth,” says Iain Caldwell, of the Hawaii Institute of Marine Biology.

The same warming at the lowest latitudes could be devastating: in some tropical regions, conditions could become too hot and dry for any growth.

Overall, the planet could see an 11% reduction in the number of days suited to growth, and some places in the tropics could lose 200 growing days a year.

Although some regions in China, Russia and Canada will see an improvement, around 2.1 billion people who rely on forests and agriculture for food and revenue could lose 30% of the days they now bank on for plant growth.

But rising levels of carbon dioxide could also affect the quality of plant growth, according to a new study in Global Change Biology.

Zhaozhong Feng, of the Department of Biological and Environmental Sciences at the University of Gothenburg, Sweden, and colleagues looked at the results of eight experiments in four continents on crops, grasslands and forests, and found that as carbon dioxide levels go up, the nitrogen content of the crop is lowered. In the case of wheat and rice, this would also mean lower protein levels.

Negative effect

“Furthermore, we can see that this negative effect exists regardless of whether or not the plants’ growth increases, and even if fertiliser is added,” says Johan Uddling, a plant physiologist at Gothenburg, and a co-author of the report. “This is unexpected and new.”

In the same week, a team of scientists at the University of Alaska Fairbanks produced evidence that climate change has already begun to alter the forests of the far north.

They report in the journal Forest Ecology and Management that in the interior of Alaska, already at the optimum temperature range for white spruce, tree growth slowed as summer temperatures rose.

In Western Alaska, once at the low end of the ideal temperature range for the same species, trees are now growing more rapidly.

“For the first time across a major forest region, we have real data showing that biome shift has started”, said Glenn Juday, professor of forest ecology at the university’s School of Natural Resources.

“This is not a scenario model, or a might, or a maybe. The boreal forest in Interior Alaska is very near dying from unsuitably warm temperatures. The area in Western Alaska where the forest transitions to tundra is now the productive heart of the boreal forest.” − Climate News Network

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