Wildfire threat spreads across warming world

Wildfire threat spreads across warming world

As climate change warms the world vegetation dries, rainfall patterns waver and the threat of wildfire spreads.

LONDON, 1 August, 2015 – Wildfire – nature’s way of turning fallen vegetation into the next season’s nutrients – is a growing hazard. In the last 35 years, the wildfire season has grown longer by a fifth, and wildfire is now a threat to one fourth of all the plant-covered land on the planet.

US researchers report in Nature Communications that since 1970 the number of days without rain has increased by well over one day every decade.

William Jolly of the US Forest Service in Missoula, Montana and colleagues say they examined the fire season worldwide for the study period, taking into consideration all the factors that are used to calculate fire hazard: wind, humidity and temperature, as well as rainfall levels.

They found that the combined changes in the surface weather have meant that the fire season has increased so far by 18.7%

Worldwide, wildfires sear, scorch or incinerate about 350 million hectares of ground cover every year. Changes in the rainfall patterns were a factor, with the number of rain-free days increasing by 1.31 days per decade. The season of smoke and cinders and smouldering stumps had been extended almost everywhere.

Lower humidity

The average temperature on land that could support vegetation – for obvious reasons, the researchers did not include Antarctica or Greenland or the most arid desert zones – had increased by 0.185°C per decade and relative humidity, a measure of moisture in the air, had dropped 0.217% per decade.

Throughout Africa, the season of weather that carried a risk of fire was extended, and in Europe there were longer summers of greater risk in Spain, Portugal, France, Italy, Greece and Latvia.

In 2010 Russia had its worst fire season in recorded history, and in eastern Canada in the same year drier seasons and greater temperatures led to huge fires. Between 1979 and 2013, the Mediterranean forest fire season grew 29 days longer.

The largest increase was in South America, where the season was extended by 33 days in 35 years. Peat fires in Indonesia in 1997-98, following a drought induced by that cyclic weather phenomenon El Niño, released carbon dioxide emissions that added up to somewhere between 13% and 40% of global fossil fuel emissions – but from just 1.4% of the planet’s total vegetated land area.

Fires play a role in natural ecosystems, and some landscapes – the maquis (thick evergreen scrub) of southern Europe, the mulga forests of Australia and the chaparral of western North America – are adapted to periodic but not frequent visitations of fire.

But, say the researchers, there has been a recent surge of “extremely destructive fires with corresponding social disruption and substantial economic costs.” The annual bill for fire suppression cost the US $1.7bn over the last decade, and US$1bn in Canada. In just one year, 2005, fire losses in Australia added up to US$9.4bn, or just about 1.3% of the nation’s gross domestic product.

Endangered conifers

Researchers have identified wildfire as an increasing hazard everywhere. But in the US there has been repeated concern about risks in California and other parts of the American west.

But the research team also noted that the danger of fire had spread to the temperate conifer forests of the northern Rockies, while South America’s tropical and subtropical forests and savannahs had all seen “tremendous” fire season changes. And in 2005, a rare drought in the Amazon basin meant that even the rainforests were damaged.

“We have shown that combined surface weather changes over the last three and a half decades have promoted global wildfire weather season lengthening,” the authors conclude.

“If these trends continue, increased wildfire potential may have pronounced global socio-economic, ecological and climate system impacts.” – 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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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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Climate change offers rare respite for African farmers

Climate change offers rare respite for African farmers

A surprise effect of greenhouse gases is that changes in air temperature and wind patterns are increasing rainfall and crop yields in the drought-prone Sahel region.

LONDON, 18 June, 2015 − A wide belt of tropical Africa is enjoying higher rainfall than for decades past, boosting harvests and keeping the threat of drought at bay. And the main factor, according to new research, is climate change.

Drought killed at least 100,000 people in the Sahel region south of the Sahara desert over a period of about 15 years from the late 1960s, but scientists in the UK report that summer rainfall was 0.3 mm (0.01 inches) a day higher from 1996-2011 than from 1964 to 1993.

“Amounts of rainfall have recovered substantially, and it was a surprise that the increase in greenhouse gases appears to have been the dominant factor,” Professor Rowan Sutton, director of climate research at the University of Reading’s National Centre for Atmospheric Science, UK, told Reuters news agency.

The scientists report in Nature Climate Change that greenhouse gas (GHG) emissions accounted for three-quarters of the recovery in rainfall, rather than other possible factors such as changes in sea temperature or air pollution from acid rain. Air warmed by GHGs can hold more moisture − which releases more rain − and can also affect wind patterns.

Welcome sign

Not surprisingly, the report comes with qualifications, and no one is hailing it as anything more than a welcome sign that one part of Africa is gaining more than it is losing from global warming − for the moment, at least.

Prof Sutton, co-author of the study, stressed that the change in Sahelian rainfall was only local, and that warming is still affecting many parts of Africa through desertification, floods and rising sea levels.

“It would be naïve to conclude that this is a good thing for Africa,” he said. “And, in future, there are other effects. The rise in temperatures can be detrimental to crops.”

But whatever climate change may bring, the people of the Sahel are working for a better future.

The World Resources Institute (WRI), based in Washington DC, has researched the role that the region’s farmers are playing, and has produced a report containing practical guidance and examples of how to scale up “regreening”.

This is a restoration technique that hundreds of thousands of farmers in three Sahelian countries − Burkina Faso, Ethiopia and Niger − and in Malawi are already using to make their land more productive.

“It would be naïve to conclude that this is a good thing for Africa. In future . . . the rise in temperatures can be detrimental to crops”

Regreening uses a range of agroforestry and sustainable land management practices, and the WRI report focuses on one in particular that it says is “particularly promising”: farmer-managed natural regeneration (FMNR).

In FMNR systems, farmers protect and manage the growth of trees and shrubs that regenerate naturally in their fields from root stock or from seeds dispersed through animal manure. It can be an easy, low-cost way for farmers to increase the number of trees in the fields – and it is producing results in the Sahel.

In Burkina Faso, farmers are using water-harvesting techniques such as building stone lines and improved planting pits, known locally as zai. These help trap rainfall on crop fields, increasing average cereal yields from 400kg to around 900kg (880-1,984 lbs) per hectare.

Important food crops

One farmer in Burkina Faso said he had not needed to plant a single tree since 1979, because they grew naturally. Others said that FMNR had improved their yield from important food crops, such as millet.

In neighbouring Niger, the increased density of trees on cropland has reduced the time women spend collecting firewood from 2.5 hours each day to an average of half an hour.

Robert Winterbottom, a senior fellow with WRI’s forests programme, made a radical suggestion in a recent blog. He said that regreening the Sahel could enable people to stay at home, instead of joining the current tide of migration by refugees risking their lives to cross the Sahara and the Mediterranean to escape to Europe.

“Farmers have already demonstrated their ability to innovate and adopt practices that restore degraded land and provide a means to secure their futures,” he said.

“Perhaps citizens throughout Africa can prosper in their home countries, eliminating the need to take to the sea to pursue a better quality of life.” − Climate News Network

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Australia faces stormy future as temperatures soar

Australia faces stormy future as temperatures soar

Destructive storms and sudden floods are set to intensify across Australia as global warming plays havoc with rainfall patterns.

LONDON, 13 June, 2015 − New research into storm patterns warns that flash floods are likely to sweep across the Australian landscape with increasing intensity, particularly in urban or residential areas.

Peak rainfall is predicted to soar with rising surface temperatures as the world’s largest island – and also its smallest continent − experiences ever greater extremes of heat.

Civil engineers from the Water Research Centre at the University of New South Wales (UNSW) report in Nature Geoscience that they looked at 40,000 storms across the whole of the continent over the last 30 years and identified a pattern that warmer temperatures are linked to disruptive rainfall events.

“Our results were consistent across all the climate zones in Australia, regardless of season or storm type, without exception,” says Professor Ashish Sharma, one of the study’s authors.

Unexpected finding

“This was an unexpected finding, and it supports our hypothesis that increasing temperatures are changing rainfall patterns. It means that most people in Australia can expect to see intensification in the magnitude of flash flooding in smaller catchments, particularly in urban or residential areas.”

The researchers worked from data from the 500 largest storms as measured by total rainfall at 79 locations. They looked not so much at the total volume of rainfall during a storm as at the pattern of intensity of rainfall at 12-minute intervals during each storm’s duration.

“It’s very likely these same trends will be observed around the world”

They projected their findings into a hotter world and calculated that a 5°C rise in temperatures could be accompanied by up to 20% more flood peaks in urban catchment areas. Some cities could experience much worse: for Perth, the rise is projected at 10%, for Sydney 12%, and for Darwin a whopping 45%.

Australia is a landscape of extremes of heat and drought and occasional devastating flood. It is also a land of paradox.

Its own scientists have calculated that the island’s most recent and devastating heatwaves are a clear consequence of greenhouse gas emissions from fossil fuels, yet the government that finances such research has questioned the validity of its climate science and encouraged the increase of emissions.

Lost productivity

The 2013 extremes of heat cost the nation an estimated US$6bn in lost productivity, and there is evidence that such events could become five times more likely as global average temperatures rise.

The intensification of dangerous flash floods − which, by definition, are sudden and potentially lethal − is a consequence that nobody expected. And if the team’s finding is replicated by further studies, then the impact is not likely to be limited to Australia.

“These more intense patterns are leading to more destructive storms, which can significantly influence the severity of flood flows,” says the reports lead author, Conrad Wasko, from the UNSW School of Civil and Environmental Engineering.

“The climate zones we studied in Australia are representative of most global climates, so it’s very likely these same trends will be observed around the world.” – Climate News Network

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Rainforests are left on edge of destruction

Rainforests are left on edge of destruction

Eminent conservationist says climate change’s major threat to the world’s tropical rainforests comes not from heat, but from drought and uncertain rainfall.

LONDON, 23 May, 2015 – Rising temperatures will not themselves spell disaster for the world’s rainforests. It is the droughts and unpredictable rainfall patterns, which climate change is already worsening, that will settle the forests’ fate before the century ends, according to a new book.

Claude Martin, who has worked in tropical rainforest conservation since the 1970s, is author of On the Edge, commissioned by the Club of Rome, which published the seminal Limits to Growth report in 1972. Since then, nearly 50% of the world’s forest cover has disappeared.

Martin, a former director-general of WWF International, recognises that there are many drivers of forest damage and destruction − including the pressures of the global economy for animal feed and food for humans, and the worldwide demand for biofuels.

Essential ecosystem

Acknowledging the progress made in science and conservation, he reminds his readers that the forests are not just huge repositories of biodiversity, but an essential ecosystem providing everyone on the planet with fresh water, clean air and climate regulation.

Evaluating the impact of climate change on rainforests means focusing on the length of dry seasons and water stress, rather than temperature, Martin writes.

The likeliest cause of forest collapse and severe risks of reaching a tipping point is not temperature rise, but the change from the dependable rainfall patterns of the past, and the probability of increasing droughts and forest fires.

He sees a likelihood of drought and fires increasing − not least in the Amazon − because of the way in which climate change is fuelling El Niño and La Niña, the twin periodic temperature disruptions that occur every few years in the eastern Pacific Ocean.

Known together as the El Niño-Southern Oscillation (ENSO), their impacts spread for thousands of miles.

“Lethargy of governments and the impotence of the intergovernmental system make it very unlikely that average global warming will be kept below 2°C

Martin is one of those scientists who are convinced that climate change will intensify ENSOs. As global warming effects become stronger, ENSO events become more frequent, rainfall drops further because of forest loss and fragmentation, and droughts are likely to become more common and more severe. And so the vicious circle becomes a constant downward spiral.

“When the 20th century’s strongest ENSO occurred in 1997/98,” Martin writes, “it was considered to be an unusual phenomenon. . . . [It] caused severe drought in Amazonia, Southeast Asia and Mexico, and had massive effects on the net primary productivity of forests, thus their capacity of carbon storage as well as forest fires.”

After another severe drought in 2001, following another ENSO event, about a third of the Amazon forests stored significantly less carbon and became vulnerable to fire. Two more droughts followed soon after, in 2005 and 2010. The first was estimated to be a once-in-a-century occurrence.

Fastest warming

Martin’s concerns are not confined to Amazonia. He cites modelling by the Intergovernmental Panel on Climate Change, which shows that Africa is expected to warm by 3-4°C by the end of the century − the fastest warming since the end of the last ice age around 11,500 years ago. This would expose the great Congo Basin forest to the risk of severe damage.

Globally, Martin is not hopeful. “The current rate of greenhouse gas emissions, the lethargy of governments and the impotence of the intergovernmental system make it very unlikely that average global warming will be kept below 2°C,” he says.

Under a mid-range emissions scenario, atmospheric CO2 concentrations are likely to rise by the end of the century to levels not seen in the last 50 million years. But he thinks the forest crisis will be developing uncontrollably some decades before then.

He predicts: “The decisive period for the long-term future of the rainforests . . . will be the second half of the century, when global warming is likely to exceed 2°C above the pre-industrial global average.

“It will be too late then to avoid a dangerous tipping point of self-reinforcing climate change.” – Climate News Network

  • On the Edge − The State and Fate of the World’s Tropical Rainforests. A Report to the Club of Rome, by Claude Martin (Greystone Books, £20/US$32.95).

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Heat and drought pose threat to US power supplies

Heat and drought pose threat to US power supplies

Global warming will leave people in the western states of the US exposed to increasingly extreme temperatures that could seriously affect electricity generation.

LONDON, 22 May, 2015 – Climate change could mean that things get really tough for people in the US west in the second half of this century, according to new research.

Higher temperatures and increased intensity of droughts could compromise the electricity grid, while the number of people exposed to extremes of heat is likely to multiply at least fourfold, and perhaps more.

Sustainability scientists Matthew Bartos and Mikhail Chester, of Arizona State University, report in Nature Climate Change that changes in precipitation, air and water temperature, air density and humidity could combine to create problems for electricity generating plant in the western US.

They estimate that around 46% of the generating capacity in 14 US states could experience reductions of up to 3% in the next few decades.

Stream flow

That is because there may not be enough stream flow for hydroelectric stations, and coal and nuclear power plant may not be able to get enough water through the cooling systems to keep generating at peak capacity, especially in the summer months.

Gas turbines, wind turbines and solar cells also could be affected by changes in air temperature.

“Drought and heat-related capacity reductions are especially problematic, because they are likely to occur during periods of high demand,” the researchers warn.

“From 2001 to 2008, a series of droughts caused electricity shortages in the American  southeast, the Pacific  northwest, and continental Europe. As concentrations of atmospheric carbon increase, drought events are anticipated to increase in frequency, duration and intensity.”

“Power providers are not taking into account climate change impacts”

Research such as this is intended to help energy utilities plan for problems ahead. Scientists identify a worst-case scenario, outline the probable  difficulties, and prompt the engineers and managers to take steps to avoid future embarrassments.

As global temperatures rise on average in the coming decades – as carbon dioxide levels in the atmosphere increase with the continued use of fossil fuels – so regions such as the American southwest will experience greater extremes of heat and longer periods of drought.

This will mean that available water will have to be pumped further, and there will be greater demand for cooling and air-conditioning systems.

California and the US  southwest have already been in the grip of extended drought.

“Power providers are not taking into account climate change impacts,” Bartos says. “They are likely overestimating their ability to meet future electricity needs.”

Reduced capacity

The scientists calculated that – if a drought lasted for a decade – capacity in vulnerable power generating stations could be reduced by as much as 8.8%.

Meanwhile, Bryan Jones, a demographer at the City University of New York, and colleagues report in the same issue of Nature Climate Change that the number of people who will want to switch on the air conditioning in the second half of the century will increase dramatically.

“We find that US population exposure to extreme heat increases fourfold to sixfold over observed levels in the late 20th century, and that changes in population are as important as changes in climate in driving this outcome,” they report.

And they add a warning: “Extreme heat is responsible for more deaths in the United States than any other weather-related event, and its frequency and intensity is expected to increase over this century.” – Climate News Network

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Weather events taken to extremes by climate change

Weather events taken to extremes by climate change

Scientists warn that global warming could greatly increase the likelihood of droughts, floods and heatwaves reaching record levels of frequency and intensity.

LONDON, 15 May, 2015 − As temperatures soar to record heights, blame it on global warming − but only about three-quarters of the time. And when the rain comes down by the bucketful, you can attribute one downpour in five to climate change.

Yet another team of research scientists has looked at the probabilities, and has linked extremes of weather with global warming.

Extremes have always happened and are, by definition, rare events. So, for the last 30 years, climate scientists have carefully explained that no particular climate event could be identified as the consequence of a rise in global average temperatures driven by the release of carbon dioxide and other greenhouse gases from the burning of fossil fuels.

But some events that were once improbable have now become statistically more probable because of global warming, according to Erich Fischer and Reno Knutti, climate scientists at ETH Zurich − the Swiss Federal Institute of Technology.

They report in Nature Climate Change that they looked at simulations of probabilities and climate records for the period 1901 to 2005, and projections for the period 2006 to 2100.

Rise in temperatures

Then they settled down to calculate the likelihood that a proportion of past heatwaves or floods could be linked to a measured average rise in planetary temperatures so far of 0.85°C.

They worked out how these proportions would change if the average planetary temperatures reach 2°C above the “normal” of the pre-industrial world, and they found that human-induced global warming could already be responsible for 18% of extremes of rain or snow, and 75% of heatwaves worldwide.

If the temperatures go up to the 2°C that nations have agreed should be the limit, then the probability of precipitation extremes that could be blamed on global warming rises to 40%. They are less precise about heatwaves, but any rise could be sharp.

“If temperatures rise globally by 2°C, we would expect twice as many extreme heat events worldwide than we would with a 1.5% increase,” Dr Fischer says.

“These global warming targets, which are discussed in climate negotiations and which differ little at first glance, therefore have a great influence on the frequency of extremes.”

The researchers are talking about probabilities: it will still be difficult ever to say that one event was a random happening, and another a result of climate change. In such research, there are definition problems. What counts as extreme heat in northern England would not be extreme in India or Saudi Arabia.

But such distinctions could become increasingly academic for people who live in the path of unusual heat and extended drought, or flash floods and catastrophic hailstorms.

A scientist recently told the European Geosciences Union that some regions of the planet will see unprecedented drought, driven once again by climate change, before 2050.

Ignored warnings

Yusuke Satoh, of the International Institute for Applied Systems Analysis, warned that under the notorious business-as-usual scenario −where nations ignore such warnings and just go on burning fossil fuels − 13 of 26 global regions would see “unprecedented hydrological drought levels” by 2050. Some would see this parching much earlier − the Mediterranean by 2027, and the western US as early as 2017.

Such studies are calculated to help provoke governments, states and water authorities into preparing for climate change, but it just may be that the western US is already feeling the heat. California, in particular, has been in the grip of unprecedented drought, and researchers have already linked this to climate change.

Reservoirs and irrigation systems are built on historical data. “But in the next few decades, these historical data may no longer give us accurate information about current conditions,” Dr Satoh says. “The earlier we take this seriously, the better we will be able to adapt.” – Climate News Network

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Climate poses new threat to survival of Arabian oryx

Climate poses new threat to survival of Arabian oryx

Global warming is the suspected cause of the series of dry years in Arabia that have brought starvation to a desert species saved from extinction.

LONDON, 7 April, 2015 − One of conservation’s triumphs – the reintroduction of the oryx to the deserts of Arabia – could be at risk because of climate change, according to a new book.

The animal already beautifully adapted by thousands of years of evolution to an arid environment met a problem on its return: even deserts have droughts.

The Arabian oryx had been hunted almost to extinction before a handful were captured in 1962 and flown to Phoenix, Arizona, as the nucleus of a captive breeding programme.

By 1972, the last wild oryx had been captured or killed in Oman, but the bloodline survived in captivity.

The first reintroductions to the wild began in 1982, and numbers began to increase. There were incursions by poachers, but there were more releases.

However, there have been so many dry years over the last two decades − according to Malcolm Smith, once chief scientist for the Countryside Commission in Wales, in his new book, Back from the Brink − that many of the newly-wild oryx have not been able to find sufficient grazing.

Closely monitored

The animal is one of the most closely monitored in the world. Of all recorded deaths, 19% have occurred in fights between males, 13% have been due to poaching, and 65% have been due to starvation.

The succession of particularly dry years in the region might be due to global warming as a consequence of human combustion of fossil fuels.

Since climate simulations seem to predict that, in general, moist regions will get more rain and dry regions will experience ever drier regimes as greenhouse gas levels build up in the atmosphere, things don’t look good for the oryx − although captive populations for the time being remain secure.

Other recently-rescued species may face even leaner times − once again, because of climate change.

Spanish and Portuguese authorities have established safe territories for the Iberian lynx and, by 2013, more than 300 lived wild in Spain, while 150 lynx paced the enclosures in the breeding centres awaiting reintroduction.

But the wild rabbit makes up 90% of the lynx’s diet, and rabbit numbers are limited by hunting and by outbreaks of myxomatosis and rabbit haemorrhagic disease.

There have been fears too, that southern Spain and Portugal may become too hot and dry to sustain the prey, let alone the predator.

Such threats to biodiversity, and to individual animals, are not new. Climate change has in various ways reportedly threatened Arctic marine mammalscreatures of the Borneo forests,  and chimpanzees in isolated woodland in West Africa.

Whole ecosystems that evolved in geographical climate zones may be doomed to sudden and rapid change.

But Malcolm Smith’s book concerns itself only with the choicest last-minute success stories of conservation bodies: with those creatures that were all but gone when the conservationists stepped in.

They were hunted, their habitats had been destroyed, and their ecosystems were always precarious. But climate change was, at the time of rescue, the least of their problems.

Large Blue butterfly (Maculinea arion). Image: PJC&Co via Wikimedia Commons

Large Blue butterfly (Maculinea arion).
Image: PJC&Co via Wikimedia Commons

One instance he explores shows just how intricate the living arrangements of charismatic species can be, and illustrates the finely-balanced play of climate and ecological stability in preserving a species.

The Large Blue butterfly (Maculinea arion) exists in respectable numbers worldwide, but became all but extinct in the UK − with changes in farming practices and land use the suspected causes.

Peculiar lifestyle

Until 1972, nobody quite understood the peculiar lifestyle of the Large Blue. It lays its eggs on the flower bud of the wild herb, thyme. A larva hatches and, after an initial vegetarian diet, falls off the plant. Thereafter, its life depends on just one species of red ant, Myrmica sabuleti.

The Large Blue grub secretes a fluid that somehow suggests that of a red ant queen grub, so the ants take it home and nurse it. The Large Blue caterpillar turns carnivore and, for 10 months, feeds on red ant larvae.

In pupate form, it makes queen ant noises and the ants continue to protect it. It hatches, gets out to the open − still protected by the ants − and flies off. It then has about a week in which to find a thyme flower bud, mate, and lay its eggs.

But the complexities multiply. The thyme flower bud that bears the eggs must be within metres of the right kind of red ant nest, or the larva perishes.

Dependent on temperature

The grass above the ant nest must be closely grazed because the ants’ survival is dependent on temperature, and if the grass grows even a centimetre ground is shaded, the nest temperature drops by 2°C to 3°C, and the ant colony is at risk − along with any parasitic caterpillars in the nest.

So the thyme has to flower at the right time, very near a red ant nest, the herbage has to be closely cropped, and the temperatures have to stay near the optimum.

If anything goes wrong, there are no surviving Large Blue larvae to pupate. If things go well, and too many Large Blue grubs are taken into a colony, the ant larvae are all consumed, and both ants and butterflies perish.

And then there’s the climate question − one that affects almost all insects.

“Overall, butterfly populations have moved northward by about 75km in the last 20 years as overall temperatures have risen,” Smith writes. “They are likely to move yet further.” – Climate News Network

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“Water Man of India” makes rivers flow again

“Water Man of India” makes rivers flow again

Revival of traditional rainwater harvesting has transformed the driest state in India, and could be used to combat the effects of climate change across the world.

Chennai, 6 April, 2015 − School textbooks in India have been telling children for generations that Rajasthan is an inhospitable state in the northwest of the country, constrained by the hot, hostile sands of the Thar Desert.

But the driest state in India has a softer, humane face as well – that of Rajendra Singh, known as the “Water Man of India”, whose untiring efforts in water conservation in arid Rajasthan have led to him being awarded the Stockholm Water Prize, commonly referred to as the Nobel Prize for Water.

Singh did not attempt to design a new technology to address Rajasthan’s water problems. He began simply by de-silting several traditional surface level rainwater storage facilities – called “johads” in the local Hindi language − that fell out of use during British colonial rule. And, in doing so, he has quenched the thirst of villages that were dying.

Thousands of villages followed his example, and so much water was captured and soaked into aquifers that dry rivers have begun to flow again.

Water wars

Singh believes that water conservation is vital to combat the effects of climate change and to avoid “water wars” in the future.

And such is his reputation on water issues that he received a call from Prince Charles, heir to the UK throne, seeking advice on how to handle the devastating summer floods in England in 2007.

In an interview with Climate News Network, Singh recalled how he began making water flow again in perennially dry Rajasthan by inculcating do-it-yourself initiatives in the villagers.

He explained: “I imbibed Gandhian ideals during my school days that emphasised working for empowerment of villages.

“As an Ayurvedic (traditional medicine system in India) doctor, I went to the Alwar district of Rajasthan early in 1982 to start a clinic and spread awareness among youth about health and hygiene.

“I was perturbed because the majority of young men had already left the village, and the rest were about to leave for green pastures in the cities as they were unable to battle the water scarcity. Besides, they also wanted to earn good money.

“Women, old people and children were left behind in the village. I reworked my doctor plans to address the water scarcity, as that would actually save people from several diseases.

A village johad in arid Rajasthan. Image: LRBurdak via Wikimedia Commons

A village johad in arid Rajasthan. Image: LRBurdak via Wikimedia Commons

“Along with the support of the villagers, I de-silted a couple of johads in Alwar. When rains filled them, people in neighbouring villages trusted my initiative and over 8,000 johads are renovated now.

“Hordes of youth have returned to their villages as water filled tanks and the standard of living in hamlets rose in a big way.”

He said that five rivers in this region had revived and started to flow again.

Johads are simple tanks built across a slope, with a high embankment on three sides and the fourth side left open for rainwater to enter. They hold water during rains and recharge the aquifer below to ensure continuous water supply to the neighbourhood in the dry season.

“Community-based water management yields
long-lasting results and is the only solution for water shortages”

But Singh explained: “After the advent of bore wells and pipelines connecting every hamlet in India, we forgot the traditional water conservation facility used by our ancestors.”

Having won the Stockholm prize, what does the future hold for the Water Man?

“My immediate plans are to take up a global-level campaign on water conservation and peace,” he said. “As predicted by several experts, the next world war will be for water. Unless every one of us starts at least now to save water and protect the water bodies, we face severe conflicts − apart from suffering climate change impacts. I will be leading the global water walk in the UK in August 2015.

“During his two visits (2004 and 2006), Prince Charles told me that he was impressed by the johad model of conservation. He then called me in 2007 to be part of his team of water engineers to work out all possibilities to address the crisis during the floods in England. They listened to my suggestions on creating the johad model on hilltops and downhill to arrest water in the hills and prevent floods in the future.”

In India, however, he is not confident that the government has the right ideas. “Our government is pushing a different idea of inter-linking of rivers, which will only politicise the water crisis. I was part of the national-level body to clean up the holy Ganga River from 2010 to 2012, but I quit as there was lack of accountability and it ended up as a toothless organisation.

“Inter-linking of rivers is not a solution for flood and drought. As far as India is concerned, it will result only in inter-linking of corruption and politics.

Hearts and brains

“What we need is inter-linking of the hearts and brains of people to take up water conservation in their homes and community. If exploitation of river water and polluting the river are stopped, every river will flow. Water engineering should be focused on conservation of each drop, and not on changing the course of rivers, which are designed by Mother Nature.”

Singh is also against the idea of privatising water supplies, and does not believe it would result in people using water more judiciously.

“Water is not a commodity,” he said. “In my own example, johads are de-silted by the people and used by people. Community-based water management yields long-lasting results and is the only solution for water shortages.

“When people realise their need and de-silt lakes and ponds as a group, they can use the water without having to pay for it. Right to water is every man’s right, and monetising water will increase conflicts in the society.

“Helping a community to have access to clean and safe water means helping the community to have a dignified life.” – Climate News Network

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