Changing weather patterns hit Pakistan’s crops

Changing weather patterns hit Pakistan's crops

Torrential rain and hailstorms have raised fears that Pakistan’s winter crops yield could be seriously depleted – and global warming is the likely culprit.

Islamabad, 23 March, 2015 − Anxious farmers in Pakistan waited for weeks for the rains to arrive – but when the skies finally opened, the downpour was so intense it destroyed crops and put the harvest in jeopardy.

“We weather scientists are really in shock, and so are farmers, who have suffered economic losses due to crop damage,” says Muzammil Hussain, a weather forecasting scientist at the Pakistan Meteorological Department (PMD).

“The wind from the southeast has carried moisture from the Arabian Sea. Normally, the northeast wind brings rain during winter, and the southeast wind brings monsoon rains in summer. But the pattern has changed this year because of what is believed to be global warming.”

Unusually heavy

Farmers across much of Pakistan plant winter crops of wheat, oilseed and potato late in the year and wait for rains to water the land. This year, the rains arrived more than three weeks late and were unusually heavy, accompanied by violent hailstorms. Along with the rains, temperatures also dropped.

Ibrahim Mughal, chairman of the Pakistan Agri Forum, says excessive moisture due to heavy bouts of late rain is likely to lead to outbreaks of fungus on crops, and production could be halved.

“If the rains come a month ahead of the harvesting time [April to mid-May], it is always disastrous,” he says. “It can hit production for a crop such as wheat by between 20% and 30%, and if the rain is accompanied by hailstorms and winds then the losses can escalate to more than 50%.”

Arif Mahmood, a former director general at PMD, says the onset of winter across much of Pakistan is being delayed by two to three days every year, and there is an urgent need for farmers to adapt to such changes.

“If the rains come a month ahead of the harvesting time, it is always disastrous”

“Over recent years, winter has been delayed by 25 to 30 days, and also the intensity of the cold has increased, which has affected almost every field of life − from agriculture to urban life.”

This year has also been marked by abrupt changes in temperature. Ghulam Rasul, a senior scientist at PMD, says big swings in temperature are likely to add to the problems being faced by millions of farmers in Pakistan.

“The average temperature during the first two weeks [of March] was between 11 and 13 degrees Celsius, but now it’s on a continuous upward trend and has reached 26˚C over the space of two days,” he reports.

“The winter rains in the north and central area of Pakistan, and the sudden rise and fall in temperature, are related to climate change.”

Serious damage

Similar storms and late winter rains have also caused serious damage across large areas of northern India.

The states of Uttar Pradesh and Maharashtra – the two most populous states in the country – have been particularly badly hit.

In Maharashtra, snow and landslides have blocked roads and cut off towns and villages.

In Uttar Pradesh, there are fears that more than 50% of the wheat crop has been lost in the eastern part of the state. – Climate News Network

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Forecast of less stormy weather is not good news

Forecast of less stormy weather is not good news

Scientists say intense droughts and heatwaves are the likely climate-related outcome of less frequent summer storms in recent decades.

LONDON, 14 March, 2015 − Storms on fine summer days might be unwelcome to many, but at least the rain and winds does act like a big brush on the weather system − bringing fresh air and relief from oppressive heat.

And scientists now warn that a decrease in the frequency of such storms across much of the US, Europe and Russia in recent decades − with climate change the probable cause – could mean that summer heat waves and droughts are likely to become ever more persistent and intense.

Scientists from the Potsdam Institute for Climate Impact Research (PIK) in Germany report in Science journal that storm activity data they collected from weather stations and satellites shows a clear reduction in the frequency and intensity of summer storms in the mid-latitudes of the northern hemisphere over recent decades.

Heat extremes

This makes heat extremes – such as the period of intense heat that hit Russia in 2010, causing widespread crop failure and multiple wildfires – ever more likely.

“While you might expect reduced storm activity to be something good, it turns out that this reduction leads to a greater persistence of weather systems in the northern hemisphere mid-latitudes,” says Dim Coumou, an Earth systems analyst at PIK and lead author of the study.

“In summer, storms transport moist and cool air from the oceans to the continents, bringing relief after periods of oppressive heat. Slack periods, in contrast, make warm weather conditions endure, resulting in the build-up of heat and drought.”

The PIK study looks at a particular set of turbulences − called synoptic eddy − in weather systems over the summer months, and calculates the total energy of their wind speeds.

“Climate change disturbs airstreams that are
important for shaping our weather”

It shows that the level of this energy, which measures the interplay between the intensity and frequency of high and low pressure systems in the atmosphere, has dropped by approximately 10% over the past 35 years.

Previous studies have focused mostly on winter storms, which tend to do more damage than those in summer. The PIK study found that average storm activity in the winter months in many regions is largely unchanged.

The Arctic region probably holds the key to the drop in summer storm activity, say the scientists.

Temperatures around the globe are rising due to greenhouse gas emissions caused by the burning of fossil fuels, but the rate of warming is faster in the Arctic.

As the sea ice cover in the Arctic shrinks, the surface reflects less sunlight and absorbs more heat. The warmer waters then warm the air, setting in motion a process through which the relative difference in temperature is reduced between the cold polar region and the rest of the northern hemisphere.

Air circulation

Temperature differences drive air circulation. As the difference in temperatures between the two regions decreases, so does the rate of summer storm activity.

The study also found that this reduction in the temperature differential weakens the polar jet stream, which − often travelling at speeds of more than 200 miles per hour high up in the troposphere − acts as a boundary between the cold polar air and warmer air further south.

“From whichever angle we look at the heat extremes, the evidence we find points in the same direction,” Dim Coumou says.

“The heat extremes do not just increase because we’re warming the planet, but because climate change disturbs airstreams that are important for shaping our weather.

“The reduced day-to-day variability that we observed makes weather more persistent, resulting in heat extremes on monthly timescales. So the risk of high-impact heat waves is likely to increase.” – Climate News Network

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Warming raises drought’s threat to California

Warming raises drought's threat to California

US researchers say climate change, not random chance, is likely to be causing California’s long drought, one of the worst on record.

LONDON, 3 March, 2015 –  Climate change could be driving the sustained Californian drought. Arid spells have been more frequent in the last two decades than in the preceding century. And warmer global temperatures linked to man-made climate change could be at the heart of it.

Right now, California is in the sustained grip of one of its worst-ever droughts. Noah Diffenbaugh of Stanford University in California and colleagues looked at the patterns of precipitation, temperature and drought in the historical record and report in the Proceedings of the National Academy of Sciences that the latest conditions were not just a random outcome.

In a sunlit landscape with a long record of intermittent drought, researchers make such predictions only cautiously. But the Stanford team worked through 120 years of rainfall, snowfall and temperature data to identify connections.

They found that, puzzlingly, the two sets of measurements were not directly connected: for the first 60 or 70 years of the historical record, it could be wet and warm, or cool and dry. But drought was more likely in those years that by chance were both dry and warm.

Doubled risk

“Of course low precipitation is a prerequisite for drought but less rain and snowfall alone don’t ensure a drought will happen. It really matters if the lack of precipitation happens during a warm or a cool year,” said Dr Diffenbaugh.

“We’ve seen the effects of record heat on snow and soil moisture this year in California and we know from this new research that climate change is increasing the probability of those warm and dry conditions occurring together.”

On the flip-a-coin analogy, the weather could be either wet or dry, and cold or hot. So only one time in four, the weather was both hot and dry. For most of the past two decades, years in California have been either warm, or hot.

“Now the temperature coin is coming up tails most years. So even though the precipitation coin is coming up tails only half the time, it means that over the past two decades we have gotten two tails-warm and dry in half the years, compared with only a quarter of years in the preceding century.”

Most populous

Accordingly, drought frequency has doubled. Model simulations suggest that the risk of any year being both warm and dry will continue. More frequent warm years will also increase the probability of multi-year drought.

The present drought is now in its fourth year, and is one of the longest consecutive periods during which conditions are severely dry and severely warm.

And soon California – home to one in eight Americans, and the country’s most populous state – could enter a climate regime in which the risk that every year will be warmer than the 20th century norm will be almost 100%.

The findings, said Dr Diffenbaugh, provide “very strong evidence that global warming is already making it much more likely that California experiences conditions that are similar to what we have already experienced during the current severe drought.” – Climate News Network

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Climate change is likely factor in Syria’s conflict

Climate change is likely factor in Syria’s conflict

Researchers say climate change probably caused the savage drought that affected Syria nearly a decade ago − and helped to spark the country’s current civil war. 

LONDON, 2 March, 2015 – In a dire chain of cause and effect, the drought that devastated parts of Syria from 2006 to 2010 was probably the result of climate change driven by human activities, a new study says.

And the study’s authors think that the drought may also have contributed to the outbreak of Syria’s uprising in 2011.

The drought, which was the worst ever recorded in the region, ravaged agriculture in the breadbasket region of northern Syria, driving dispossessed farmers to the cities where poverty, government mismanagement and other factors created the unrest that exploded four years ago. The conflict has left at least 200,000 people dead, and has displaced millions of others.

The study, by scientists from Lamont-Doherty Earth Observatory at Columbia University, US, is published in the Proceedings of the National Academy of Sciences.

The authors are quite clear that the climatic changes were human-driven (anthropogenic) and cannot be attributed simply to natural variability, but are careful to stress that their findings are tentative.

“We’re not saying the drought caused the war,” says Richard Seager, one of the co-authors. “We’re saying that, added to all the other stressors, it helped kick things over the threshold into open conflict.

“And a drought of that severity was made much more likely by the ongoing human-driven drying of that region.”

Link with violence

Their study, although it contains new material, is not the first to suggest a possible link between extreme weather and the likelihood of violence.

Some researchers have investigated whether there may be a link between El Niño and La Niña − the periodic Pacific weather disruptions − and outbreaks of unrest.

Syria was not the only country affected by the drought. It struck the Fertile Crescent, linking Turkey, Syria and Iraq, where agriculture and animal herding are believed to have started around 12,000 years ago.

Suggestions of a global connection between climate change and political instability is being taken seriously by two influential groups − insurers and military planners.

The Levant has always seen natural weather swings. Other research has suggested that the Akkadian empire, spanning much of the Fertile Crescent about 4,000 years ago, probably collapsed during a long drought.

Drought can lead to devastating consequences when coupled with pre-existing acute vulnerability

But the authors of the Lamont-Doherty study, using existing studies and their own research, showed that the area has warmed by between 1°C and 1.2°C since 1900, and has undergone a 10% reduction in wet-season precipitation.

They say this trend is a neat match for models of human-influenced global warming, and so cannot be attributed to natural variability.

Global warming has had two effects, they say. First, it appears to have indirectly weakened wind patterns that bring rain-laden air from the Mediterranean, reducing precipitation during the usual November-April wet season. And higher temperatures have increased the evaporation of moisture from soils during the hot summers.

The authors say an episode of this severity and length would have been unlikely without the long-term changes.

Other researchers have observed the long-term drying trend across the Mediterranean region, and have attributed at least part of it to anthropogenic warming.

The researchers say Syria was especially vulnerable because of other factors − including a huge increase in population from four million in the 1950s to 22 million in recent years.

Water-intensive crops

The government has also encouraged water-intensive export crops such as cotton, while illegal drilling of irrigation wells depleted groundwater, says co-author Shahrzad Mohtadi, an international affairs consultant at the US Department of State.

The drought’s effects were immediate and overwhelming. Agricultural production − typically, a quarter of Syria‘s gross domestic product − fell by a third. In the northeast, livestock was practically wiped out, cereal prices doubled, and nutrition-related diseases among children increased steeply.

As many as 1.5 million people fled from the countryside to cities already strained by waves of refugees from the war in neighbouring Iraq.

“Rapid demographic change encourages instability,” the authors say. “Whether it was a primary or substantial factor is impossible to know, but drought can lead to devastating consequences when coupled with pre-existing acute vulnerability.”

Solomon Hsiang, professor of public policy at the University of California, Berkeley, says the study is “the first scientific paper to make the case that human-caused climate change is already altering the risk of large-scale social unrest and violence”. – Climate News Network

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Big cities head for water crisis as populations explode

Big cities head for water crisis as populations explode

With more than half the world’s population now in cities, scientists warn that inadequate surface water supplies will leave many at increasing risk of drought.

LONDON, 21 February, 2015 − More than 40% of the world’s great cities supplied by surface water could become vulnerable to shortages and drought by 2040, according to new research. And more than three out of 10 were already vulnerable in 2010.

Meanwhile, the vital array of satellites designed to monitor rainfall and to warn of potential flooding is reported to be coming to the end of its shelf life.

For the first time in history, more than half the world’s population is now concentrated in cities, and this proportion is predicted to increase to two-thirds. Cities grow up near plentiful water supplies − and as a population explodes, so does demand. But the flow remains much the same.

Some cities are already under drought stress. Chennai in southern India had to be supplied with tankers in 2004 and 2005, and São Paulo in Brazil is now at crisis point.

Supply analysis

Environmental scientist Julie Padowski and Steven Gorelick, director of the Global Freshwater Initiative at Stanford University in California, report in Environmental Research Letters that they analysed supplies to 70 cities in 39 countries, all of them with more than 750,000 inhabitants, and all of them reliant on surface water.

They defined vulnerability as the failure of an urban supply basin to meet demands from human, environmental and agricultural users, and they set the supply target as 4,600 litres per person per day – which factors in “virtual water”, defined as the total volume of water needed to produce and process a commodity or service.

They proposed three different kinds of measure of supply. If a city failed to meet one or two of these metrics, it was considered threatened. If it failed to meet all three, it was rated as vulnerable.

Importantly, the scientists did not factor in climate change, which is likely to make conditions worse. Instead, they simply considered current demand and supply, and then projected demand in 2040.

Of their 70 cities, they found that 25 (36%) could already be considered vulnerable by 2010. By 2040, this number had grown to 31 (44%).

The six cities that will begin to face water shortages are Dublin in Ireland, Charlotte in the US, Ouagadougou in Burkina Faso, and Guangzhou, Wuhan and Nanjing in China.

Most of the cities that are already vulnerable rely on reservoirs, and the study implies that urban planners will need to think about more reservoirs, deeper wells or desalination plants, or will have to contemplate the diversion of rivers from somewhere else.

Rainfall data

Meanwhile, they cannot rely on rainfall data because – as geological engineer Patrick Reed, professor of civil and environmental engineering at Cornell University, and colleagues report in Environmental Research Letters − the network of dedicated satellites “fails to meet operational data needs for flood management”.

Four of the 10 satellites have exceeded their design life − some by more than a decade. There are already weak spots in the network, especially in developing countries, which means that floods could take people by surprise.

Space-based instruments offer a way of monitoring rainfall and ground moisture upstream, in a way that gives authorities time to predict the moment when the rivers will start to rise and flood the cities. When four fail to deliver, the potential for catastrophe will be even worse.

So the scientists call for better international co-ordination of satellite replacement.

“It is important for us to start thinking as a globe about a serious discussion on flood adaptation and aiding affected populations to reduce their risks,” Professor Reed says. “We want to give people time to evacuate, to make better choices, and to understand their conditions.” – Climate News Network

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Climate impacts on European farmers’ yields per field

Climate impacts on European farmers’ yields per field

Scientists says changes in temperature and snow or rainfall are key factors in the stagnation of wheat and barley yields across Europe since the early 1990s.

LONDON, 19 February, 2015 – Farmers in Europe have already begun to feel the pinch of climate change as yields of wheat since 1989 have fallen by 2.5% and barley by 3.8% on average across the whole continent.

And two Californian scientists now believe that changes in temperature and snow or rainfall during the last quarter of a century are at least partly to blame.

The pinch may be gentle, but environmental scientists Frances Moore and David Lobell, of Stanford University, believe it is real.

They report in the Proceedings of the National Academy of Sciences that although changes in farming and environmental policies explain much of the stagnation of yields in Europe in the last 25 years, at least 10% of this change could be attributed to climate trends.

Sugarbeet and maize harvests have gone up slightly − and that, too, could be pinned on global warming.

Overall trends

It is no small challenge to find an overall trend to crop yields across a continent that stretches from Scotland to the Black Sea, from northern Norway to Sicily, and over a timescale that embraces floods, droughts, forest fires and heat waves that may or may not have been made worse or more frequent by global warming, but which would have occurred anyway.

The other complication is that, in the same 25 years, the patterns of agricultural subsidy and market demand have also changed.

But the Stanford scientists started with conditions on the farms in the 1980s, when Europe’s farmers were, on average, getting 0.12 more tonnes of wheat and barley per hectare than the year before. Yields per field were rising steadily.

“Agriculture is one of the economic sectors most exposed to climate change impacts”

“If they had continued growing at that rate after 1995, wheat and barley yields would be 30% and 37% higher today, respectively,” they write.

Climate trends could perhaps account for around 10% of the stagnation revealed in the statistics. The remaining change could be put down to economic and political shifts and other factors.

One of these would be that crops had been improving to a point called the biophysical limits: just how much weight of grain could one stalk hold anyway? So some change would be expected, and climate must be a component of that.

To arrive at their conclusion, the two scientists looked at the predictions made for climate change – southern Europe was always expected to become drier, but farmers in moist northern climates could benefit from temperature increases – and the available data, and then applied sophisticated mathematical probability techniques to isolate the possible impact of climate change so far.

Social costs

They have looked at the economic and social challenges of global warming before. Last year, they warned that Europe’s farmers were going to have to adapt to climate change in the 21st century, and Moore and a colleague claimed last month that economists had badly underestimated the economic and social costs of each tonne of carbon added to the levels of CO2 in the atmosphere.

The new research is, they argue, important because “agriculture is one of the economic sectors most exposed to climate change impacts, but few studies have statistically connected long-term changes in temperature and rainfall with yields.

“Doing so in Europe is particularly important because yields of wheat and barley have plateaued since the early 1990s ,and climate change has been suggested as a cause of this stagnation.” – Climate News Network

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Stalagmite links rain reduction to industrial revolution

Stalagmite links rain reduction to industrial revolution

Research shows the explosion of fossil fuel use to power the 19th-century industrial boom began the pattern of lower rainfall affecting the northern tropics. 

LONDON, 17 February, 2015 − Scientists have identified a human-induced cause of climate change. But this time it’s not carbon dioxide that’s the problem − it’s the factory and power station chimney pollutants that began to darken the skies during the industrial revolution.

Analysis of stalagmite samples taken from a cave in Belize, Central America, has revealed that aerosol emissions have led to a reduction of rainfall in the northern tropics during the 20th century.

In effect, the report in Nature Geoscience by lead author Harriet Ridley, of the Department of Earth Sciences at the University of Durham, UK, and international research colleagues invokes the first atmospheric crisis.

Acid rain

Before global warming because of greenhouse gases, and before ozone destruction caused by uncontrolled releases of chlorofluorocarbons, governments and environmentalists alike were concerned about a phenomenon known as acid rain.

So much sulphur and other industrial pollutants entered the atmosphere that raindrops became deliveries of very dilute sulphuric and nitric acid.

The damage to limestone buildings was visible everywhere, and there were concerns – much more difficult to establish – that acid rain was harming the northern European forests.

But even if the massive sulphate discharges of an industrialising world did not seriously damage vegetation, they certainly took a toll on urban human life in terms of respiratory diseases.

Clean-air legislation has reduced the hazard in Europe and North America, but it seems that sulphate aerosols have left their mark.

Researchers in a cave in Belize. Credit: Dr James Baldini/Durham University

Researchers in a cave in Belize.
Image: Dr James Baldini/Durham University

The Durham scientists reconstructed tropic rainfall patterns for the last 450 years from the analysis of stalagmite samples taken from a cave in Belize.

The pattern of precipitation revealed a substantial drying trend from 1850 onwards, and this coincided with a steady rise in sulphate aerosol pollution following the explosion of fossil fuel use that powered the Industrial Revolution.

They also identified nine short-lived drying spells in the northern tropics that followed a series of violent volcanic eruptions in the northern hemisphere. Volcanoes are a natural source of atmospheric sulphur.

Atmospheric pollution

The research confirms earlier suggestions that human atmospheric pollution sufficient to mask the sunlight and cool the upper atmosphere had begun to affect the summer monsoons of Asia, and at the same time stepped up river flow in northern Europe.

The change in radiation strength shifted the tropical rainfall belt, known as the intertropical convergence zone, towards the warmer southern hemisphere, which meant lower levels of precipitation in the northern tropics.

“The research presents strong evidence that industrial sulphate emissions have shifted this important rainfall belt, particularly over the last 100 years,” Dr Ridley says.

“Although warming due to man-made carbon dioxide emissions has been of global importance, the shifting of rain belts due to aerosol emissions is locally critical, as many regions of the world depend on this seasonal rainfall for agriculture.” – Climate News Network

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California is left high and dry by cannabis growers

California is left high and dry by cannabis growers

As California endures its worst drought since records began, illegal marijuana plantations are being blamed for further depleting precious water resources.

MENDOCINO, 4 February, 2015 − Take a flight over the densely forested area in California’s northern coastal region and it’s not hard to spot the marijuana plantations, their bright green plants standing out in clearings in the surrounding vegetation.

But now the big-money cannabis industry is being blamed for adding to water shortage problems caused by a three-year drought that has seriously affected California’s huge agricultural sector.

Although cultivating and using marijuana is illegal under US Federal law, California state law allows marijuana growing – as long as it is for medicinal purposes.

Rules flouted

However, the rules governing who can and cannot grow pot are complex – and openly flouted by thousands of growers, both big and small-time operators.

A report by the California Department of Fish and Wildlife (CDFW) estimates that, in this northern region of the state,  marijuana growing doubled between 2009 and 2012.

Marijuana plants are extremely thirsty, consuming between five and 10 gallons of water per day, depending on the phase of their growing cycle. Officials at the CDFW say that marijuana growers are sucking up precious water resources, exacerbating water shortages and threatening fish in the area’s lakes and streams.

Marijuana growing is particularly prevalent in an area of northern California known as The Emerald Triangle, encompassing Mendocino, Humbolt and Trinity counties. Some estimates say the crop accounts for up to 40% of the region’s economy.

Officials of the CDFW say that the small, well-established marijuana plantations – run by what are described as old time hippies − are not to blame for pumping up excess water.

Illegal marijuana plantations in forest clearings. Image: US Drug Enforcement Agency

Illegal marijuana plantations in forest clearings.
Image: US Drug Enforcement Administration

It is the incomers from outside the area − part of a “green rush” into highly-profitable marijuana growing – that are mainly to blame. These growers are out to make quick profits, and care little about the environment.

Growers of various crops in California are bound by rules stipulating that no more than 10% of the flow of water courses should be diverted for crops, and that such diversions should stop altogether in late summer, when water levels are at their lowest.

The CDFW says the incomers take vast amounts of water in order to harvest their crops as fast as possible. They also use excessive quantities of fertilizer, which leach into water courses, endangering fish stocks and polluting land.

Armed gangs

Fines of up to $8,000 per day are now being imposed for water theft, although monitoring illegal activities is difficult − and, at times, dangerous. Heavily-armed gangs are often involved in the marijuana growing business, and the CDFW has warned that, as the drought continues, conflicts over water resources are likely to increase.

The Emerald Growers Association, a group that represents some of northern California’s marijuana growers, says more regulation is needed to separate the legitimate pot growers from illegal ones.

The drought in California has been going on since 2011 and is described as the worst in the state since records began in the 1850s.

Arguments continue as to whether man-made climate change or natural phenomena are causing the drought.

Although significant amounts of rain last December helped alleviate dry conditions in some parts of the state, experts say more rain is urgently needed to feed watercourses and restock severely depleted aquifers. – Climate News Network

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Chimps’ survival hopes jeopardised by climate change

Chimps’ survival hopes jeopardised by climate change

One of our closest animal relatives is at risk of being wiped out as changing rainfall patterns threaten to destroy its Central African habitat.

LONDON, 30 January, 2015 − Climate change is a challenge for chimpanzees, too. New research warns that a primate subspecies – one of humanity’s closest animal relatives – could become endangered within five years

The threatened subspecies of the common chimpanzee is Pan troglodytes ellioti, and there are only 6,000 remaining individuals, surviving in two populations in Cameroon.

Field biologist Paul Sesink Clee, of Drexel University, US, and colleagues report in BMC Evolutionary Biology that they combined climate, environmental and population data to model how the chimpanzees’ preferred habitats would change with climate under a “business as usual” scenario in which the world went on burning fossil fuels.

Habitat change

Underlying such research is the larger question of how variation in habitat drives evolutionary change: why are there four subspecies of chimpanzee, and how much does geography and habitat have to do with it?

So the scientists made a chimpanzee population map, and imposed it on a map of habitats.

They found two distinct populations of the chimpanzee − one in the mountainous rainforests of western Cameroon, and one in a distinctive region of grassland, forest and woodland in central Cameroon.

Then they simulated how these habitats would change under global warming scenarios by 2020, 2050 and 2080.

“Preliminary projections suggest that rainfall patterns will change dramatically in this region of Africa”

Their findings were that the mountain rainforest habitat would survive, but the lowland dwellers would decline quickly under all scenarios by 2020, and could disappear almost entirely under the worst case scenario by 2080.

Since half of the entire population of Nigeria-Cameroon chimpanzees survive in this habitat, the suggestion is that the chimpanzees are particularly vulnerable to climate change.

Severely affected

The researchers did not take into account the opportunities for the chimpanzees to migrate, or to adapt to new circumstances. They point out that Central Africa in particular, and the continent in general, is likely to be severely affected by climate change.

“Preliminary projections suggest that rainfall patterns will change dramatically in this region of Africa, which will result in significant alterations of forest and savanna habitats,” the report says.

“Models of global climate change also have been used to show that 30% of plant and animal species are at risk of extinction if the rise in mean global temperature exceeds 1.5°C − an increase that is nearly certain to occur under future climate scenarios.” – Climate News Network

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California rains bring little relief from harsh drought

California rains bring little relief from harsh drought

Unless substantial rain falls soon, California’s worst drought on record threatens dire consequences for the state’s massive agricultural industry.

DAVIS, CALIFORNIA, 29 January, 2015 − Doing the right thing in the environs of the University of California, Davis – one of the foremost agricultural institutions in the US – means driving a carbon efficient car. And having a lawn that’s burned dry.

California’s worst drought on record is forcing people to cut back radically on water use – and that means letting lawns die. There was considerable rainfall last month, but it was not nearly enough to replenish the badly-depleted water resources.

“If we don’t have rain in significant amounts by early March, we’ll be in dire straits,” says Professor Daniel Sumner, director of the Agricultural Issues Center at Davis.

Water restrictions

Higher than average temperatures – particularly during the winter months – have combined with a lack of rainfall to produce severe drought conditions across much of the state. Water restrictions have been brought in following the imposition of a drought emergency in January last year.

“Historically, California’s water has been stored in the snow pack in the mountains, but warmer winter temperatures have meant the pack has been melting.” Sumner says.

“The agricultural sector has made considerable advances in limiting water use, and new, more drought resistant, crops and plant varieties have been introduced, but aquifers have been pumped and they are not being replenished.

“In the past, massive projects were undertaken to distribute water round the state, but now there’s not the money available to do any more big-time plumbing work. Also, the regulations on diverting water for agriculture use are very tight – rivers can’t be pumped if it means endangering fish stocks or other wildlife.”

“California is still growing – and exporting – rice, which is a real water drinker. How crazy is that?”

Whether or not climate change is causing the drought is a matter of considerable debate. A recent report sponsored by the US government’s National Oceanic and Atmospheric Administration (NOAA) says natural oceanic and atmospheric patterns are the primary drivers behind the drought.

A high pressure ridge that has hovered over the Pacific off California’s coast for the past three years has resulted in higher temperatures and little rainfall falling across the state, the report says.

However, a separate report by climate scientists at Stanford University says the existence of the high pressure ridge, which is preventing rains falling over California, is made much more likely by ever greater accumulations of climate-changing greenhouse gas emissions in the atmosphere.

Whatever the cause of the drought, the lack of rain is doing considerable environmental and economic damage. The Public Policy Institute of California, a not-for-profit thinktank, estimates that $2.2 billion in agricultural revenues and more than 17,000 jobs have been lost as a result of the drought.

Severely depleted

Thousands of acres of woodland have been lost due to wildfires, while fisheries experts are concerned that severely depleted streams and rivers could lead to the disappearance of fish species in the area, such as coho salmon and steelhead trout.

The drought is not limited to California. Adjacent states are also affected, and over the US border to the south, in Mexico’s Chihuahua state, crops have been devastated and 400,000 cattle have died.

Frank Green, a vineyard owner in the hills of Mendocino County, northern California, says: “The vines are pretty robust and, despite the drought, our wines have been some of the best ever over the past two years.

“But there’s no doubt we need a lot more rain, and plenty more could be done on saving and harvesting water. Farmers have cut back on growing water-hungry crops like cotton, but California is still growing – and exporting – rice, which is a real water drinker. How crazy is that?” – Climate News Network

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