Category Archives: Rainfall

Emissions are fuelling Australian droughts

Water depth marker in Lake Albert, South Australia Image: Bidgee via Wikimedia Commons
Water depth marker in the dried out bed of Lake Albert, South Australia
Image: Bidgee via Wikimedia Commons

By Tim Radford

The Australian prime minister may be scathing about climate science, but new research shows that burning fossil fuels is a significant factor in the long-term rainfall decline that is leaving southern regions of the country parched and sweltering.

LONDON, 17 July, 2014 − American scientists have just confirmed that parts of Australia are being slowly parched because of greenhouse gas emissions – which means that the long-term decline in rainfall over south and south-west Australia is a consequence of fossil fuel burning and depletion of the ozone layer by human activity.

Such a finding is significant for two reasons. One remains contentious: it is one thing to make generalised predictions about the consequences overall of greenhouse gas levels, but it is quite another to pin a measured regional climatic shift directly on human causes, rather than some possible as-yet-unidentified natural cycle of climatic change.

The other is contentiously political. Australia’s prime minister, Tony Abbott, has in the past dismissed climate science as “crap”, and more recently has cut back on Australian research spending.

Australia has already experienced a pattern of heat waves and drought – punctuated by catastrophic flooding – and even now, in the Australian winter, New South Wales is being hit by bush fires.

Tom Delworth, a research scientist at the US National Oceanic and Atmospheric Administration, reports in Nature Geoscience that he and a colleague conducted a series of long-term climate simulations to study changes in rainfall across the globe.

Pattern of change

One striking pattern of change emerged in Australia, where winter and autumn rainfall patterns are increasingly a cause of distress for farmers and growers in two states.

The simulation showed that the decline in rainfall was primarily a response to man-made increases in greenhouse gases, as well as to a thinning of the stratospheric ozone layer in response to emissions of destructive gases by human sources.

The computer simulations tested a series of possible causes for this decline, such as volcanic eruptions and changes in solar radiation. But the only cause that made sense of the observed data was the greenhouse explanation.

South Australia has never been conspicuously lush and wet, but decline in precipitation set in around 1970, and this decline has increased in the last four decades. The simulations predict that the decline will go on, and that average rainfall will drop by 40% over south-west Australia later this century.

Dr Delworth described his model as “a major step forward in our effort to improve the prediction of regional climate change”.

In May, scientists proposed that greenhouse gas emissions were responsible for a change in Southern Ocean wind patterns, which in turn resets the thermostat for the world’s largest island.

Australian scientists report in Geophysical Research Letters that they, too, have been using climate models to examine Antarctic wind patterns and their possible consequence for the rest of the planet.

Temperature rise

“When we included projected Antarctic wind shifts in a detailed global ocean model, we found water up to 4°C warmer than current temperatures rose up to meet the base of the Antarctic ice shelves,” said Paul Spence, a researcher at Australian Research Council’s Centre of Excellence for Climate System Science. This temperature rise is twice previous estimates.

“This relatively warm water provides a huge reservoir of melt potential right near the grounding lines of ice shelves around Antarctica,” Dr Spence said. “It could lead to a massive increase in the rate of ice sheet melt, with direct consequences for global sea level rise.”

Since the West Antarctic ice sheet holds enough water to raise sea levels by 3.3 metres, the consequences would indeed be considerable.

“When we first saw the results it was quite a shock,” Dr Spence said. “It was one of the few cases where I hoped the science was wrong.” – Climate News Network

Climate puts US at risk of multi-billion bill

Overheating: US crops such as cotton face a %20 drop in yield Image: Wars via Wikinmedia Commons
Overheated economy: US crops such as cotton face a 20% drop in yield
Image: Wars via Wikimedia Commons

By Alex Kirby

A study of the possible cost of climate change to the US economy warns government and business that billions of dollars could be at risk through damage to property, reduced harvests and workers incapacitated by extreme heat.

LONDON, 29 June, 2014 − The sheer economic cost of climate change to Americans could be far greater than many realise, an influential study says.

The study was commissioned by the Risky Business Project, a research organisation chaired by a bi-partisan panel and supported by several former US Treasury Secretaries.

It expects climate change to have varied impacts across different regions and industries. Rising sea levels, it says, could destroy many billion dollars’ worth of coastal properties by 2050, and warming temperatures, especially in the south, south-west and mid-west, could cut the productivity of people working outdoors by 3%.

Without a change in crops, harvests in these regions could fall by 14%. But further north, in states such as North Dakota and Montana, winter temperatures will probably rise, reducing frost and cold-related deaths and lengthening the growing season for some crops.

Kate Gordon, executive director of the Risky Business Project, said : “We still live in a single integrated national economy, so just because it’s not hot where you are doesn’t mean you won’t feel the heat of climate change.”

Michael Bloomberg, a former mayor of New York, said: “Damages from storms, flooding, and heat waves are already costing local economies billions of dollars. We saw that firsthand in New York City with Hurricane Sandy.

Costs of inaction

“With the oceans rising and the climate changing, the Risky Business report details the costs of inaction in ways that are easy to understand in dollars and cents − and impossible to ignore.”

Hank Paulson, a former Treasury Secretary and co-chair of the Risky Business Project, said the report shows us that “our economy is vulnerable to an overwhelming number of risks from climate change.

“But if we act immediately, we can still avoid most of the worst impacts of climate change and significantly reduce the odds of catastrophic outcomes. But the investments we’re making today will determine our economic future.”

In a section on short-term climate threats, the authors say: “The American economy is already beginning to feel the effects of climate change. These impacts will likely grow materially over the next 5 to 25 years…”

“Just because it’s not hot where you are doesn’t mean
you won’t feel the heat of climate change”

They say there is a 1-in-20 chance of yield losses of more than 20% in corn, wheat, soya and cotton crops over that timespan.

On energy, they say changes in temperature driven by greenhouse gases will probably mean a need to build roughly 200 average coal-fired or natural gas-fired power plants between 2020 and 2045, costing up to $12 billion per year.

Climate impacts, the report says, are unusual because future risks are directly tied to present decisions. By failing to lower greenhouse gas emissions today, decision-makers put in place processes that increase overall risks tomorrow.

By 2050, on present trends, $66bn-$106bn worth of existing coastal property will probably be below sea level nationwide, with $238-$507bn worth by 2100.

By mid-century, the average American will probably see 27 to 50 days over 95°F (35°C) each year − two to more than three times the average annual number of such days seen over the last 30 years. By the end of the century, this number will probably average 45 to 96 days over 95°F each year.

But the study says that the south-west, south-east, and upper mid-west will probably see several months of 95°F days annually.

Human threshold

In the longer term, extreme heat during parts of the year could pass the threshold at which the human body can no longer maintain a normal core temperature without air conditioning. At these times, anyone who has to work outdoors, or without access to air conditioning, will face severe health risks and possible death.

The authors say they hope it will become standard practice for the American business and investment community to factor climate change into its decision-making process. They say: “We are already seeing this response from the agricultural and national security sectors; we are starting to see it from the bond markets and utilities as well.

“But business still tends to respond only to the extent that these risks intersect with core short-term financial and planning decisions.”

And the authors warn the government: “We also know that the private sector does not operate in a vacuum, and that the economy runs most smoothly when government sets a consistent policy and a regulatory framework within which business has the freedom to operate.

“Right now, cities and businesses are scrambling to adapt to a changing climate without sufficient federal government support…” − Climate News Network

Flow chart unclear for glacial rivers

 

Confluence of the Indus and Zanskar rivers that rise in Tibet SImage Sundeep Bhardway via Wikimedia Commons
Confluence of the glacial Indus and Zanskar rivers flowing from Tibet
Image: Sundeep Bhardwaj via Wikimedia Commons

By Kieran Cooke

Glaciers in the high Himalayas and on the Tibetan Plateau are a vital source of water for millions of people in Asia, but scientists question what will happen to supplies if the rate of melting continues to rise due to climate-related factors

 

LONDON, 19 June – A new study examining river basins in the Asia region suggests that amounts of water supplied to the area by glaciers and rainfall in the Himalayas will increase in the coming decades.

At first reading, that looks like good news, as an estimated 1.3 billion people in Pakistan, India, Bangladesh, Nepal, China and elsewhere are dependent for their water supplies on rivers fed by glaciers and snowmelt.

But the less welcome news is that scientists are unsure what will happen after 2050 if the rate at which glaciers melt continues to increase as a result of climate change.

Scientists say rising temperatures and more intense rainfall patterns in the higher Himalayas are causing the retreat of the majority of glaciers in the region.

Heat build-up

They say glacier melt is also being caused by black carbon – particulate matter that, in South Asia, comes mainly from cooking fires, the burning of waste, plus coal burning and diesel exhausts. The black carbon, or soot, falls on the glaciers, reducing reflectivity and increasing heat build-up.

This latest study of glacier melt and water flows, appearing in the journal Nature Climate Change, was carried out by scientists at Future Water, a Netherlands-based research group, Utrecht University, and the Nepal-based International Centre for Integrated Mountain Development.

It assesses the contribution of glacier and snowmelt to the region’s river basins, incorporating some of the world’s mightiest rivers – the Indus, the Ganges, the Brahmaputra, the Mekong and the Salween.

The scientists say that highly-sophisticated modelling techniques were used to study the river basins in unprecedented detail.

They report: “Despite large differences in runoff composition and regimes between basins and between tributaries within basins, we project an increase in runoff at least until 2050, caused primarily by an increase in precipitation in the upper Ganges, Brahmaputra, Salween and Mekong basins and from accelerated melt in the upper Indus Basin.

“These findings have immediate consequences for climate change policies where a transition towards coping with intra-annual shifts in water availability is desirable.”

Uncertain supplies

But while the study says that, up to mid-century, little change is likely in the amount of glacier melt water flowing into river basins, it is unclear what will happen thereafter to the water supplies for  what is a significant portion of the world’s population.

“Our study does not include projections after 2050,” Arthur Lutz, lead author of the study, told Climate News Network. “However, at some point in time, the contribution of glacier melt to the total flow will decrease, because of the decreasing glacier extent. When this happens, it will differ for different river basins and sub-basins.”

The study says the long-term outlook is particularly uncertain for the upper Indus basin. While glacier melt contributes only 11.5% of the total runoff in the upper basin of the Ganges river, it contributes more than 40% of total water runoff in the upper Indus basin.

The Indus river, which flows for nearly 2,000 miles from high up in the Hindu Kush-Karakoram Himalaya mountain range down to the Arabian Sea, is vital to life in Pakistan, providing water for 90% of the country’s agricultural crops. Hydro plants along the Indus also supply about half the country’s electricity. – Climate News Network

Rainforest tribes seek World Cup spotlight

 

Kayapò tribal leaders from the Amazon rainforest put their case to the media Image: Sue Cunningham/SCP
Kayapò tribal leaders from the Amazon rainforest put their case to the media
Image: Sue Cunningham/SCP

By Kieran Cooke

Tribal leaders from the Amazon rainforest are using the glare of publicity on the football World Cup in Brazil to highlight an impassioned plea for recognition of their lands and an end to dam building and deforestation

LONDON, 17 June − Chief Raoni Metuktire, head of the Kayapò indigenous group from the Xingu region, deep in the Amazon rainforest, sits in a packed lecture hall in London. With his jutting lip plate and large feather headdress, the elderly, gently-spoken tribal leader is an imposing presence.

“When I’m gone I want my children and grandchildren to live in the forest as I have done,” he says. “I ask for your help. In the past, we didn’t knock down the trees, destroy the land and build dams, but now all that is happening.

“The climate in the forest is changing: it is a lot hotter than it used to be, and the pattern of the winds is altering.”

Lungs of the world

The Amazon rainforest – often referred to as the lungs of the world – has a major influence on the world’s climate. Its trees and vegetation act as a vital carbon sink, soaking up carbon dioxide from the atmosphere.

Megaron Txucarramãe, a long-time campaigner for land rights for indigenous tribes in the Amazon region, sits alongside Chief Raoni, his uncle.

“The logging in our region is increasing,” he says. “Our lands and those of other indigenous tribes should be properly demarcated, but the Brazilian government is seeking to alter the constitution and undermine our land rights, giving more power to loggers, dam builders and mining companies.

“While the government worries about building stadiums
for the World Cup, our land is being threatened.”

“We went to Brasilia [Brazil’s capital] to protest, but we were received with rubber bullets, tear gas and pepper spray. While the government worries about building stadiums for the World Cup, our land is being threatened. I would like to ask the world to pay attention to our problems and help us.”

In a tour of European capitals that coincided with the opening of the World Cup, the two tribal leaders met Prince Albert of Monaco and, in London, Prince Charles. They also took their message to the Norwegian royal family.

The Kayapò are by far the largest ethnic group in the Xingu region. After years of campaigning and sometimes violent struggle, the group succeeded in having 19,000 square miles of land demarcated as an indigenous reserve in 1992.

The tribal leaders say the government of President Dilma Rousseff – which faces an election in October – is now threatening the land rights of indigenous groups and the health of the whole Amazon by allowing mining and other projects to go ahead.

In recent years, Brazil has embarked on a wide-ranging dam building programme in the Amazon. The Xingu river, a major tributary of the Amazon river, runs through the Kayapò’s lands. Despite various court judgements and continuing protests by the Kayapò and other groups, construction of the Belo Monte dam − which will be one of the world’s biggest when it is completed − began on the Xingu in 2011.

After years of decline in deforestation rates in the Amazon rainforest, they then increased dramatically by 28% over the 2012 to 2013 period, with many blaming controversial reforms to Brazil’s forest laws pushed through by a powerful and extremely wealthy land lobby.

Weather patterns

In recent months, large parts of Brazil have been suffering a drought that is one of the worst on record. Environmentalists say deforestation in the Amazon has disturbed weather patterns and has resulted in less rainfall in many areas.

Patrick Cunningham, who has travelled extensively through the Xingu region, photographing and documenting the lives of the indigenous tribes, is a spokesman for Tribes Alive, a group that highlights indigenous peoples’ issues.

He said: “Chief Metuktire and Megaron are not only asking for an end to the destruction of their lands, they are also campaigning to stop what is a suicidal rush to develop their region.

“Such actions will not only be a setback for them but also for the whole of Brazil as rain patterns alter farther south, in what is the most agriculturally productive region of the country.” – Climate News Network

Europe faces cereals crop crash

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Cereal numbers: yields could be slashed from barley fields such as this one in Suffolk, UK Image: Eileen Henderson via Wikimedia Commons

Cereal failures: yields could be slashed from barley fields such as this one in Suffolk, England
Image: Eileen Henderson via Wikimedia Commons

By Tim Radford

Two new studies raise concerns that Europe’s wheat and barley yields could be heading for a serious fall as a result of temperature rise and an increase in extreme weather

LONDON, 2 June − Harvests of wheat and barley across Europe could be 20% lower by 2040 as average temperatures rise by 2°C. And by 2060, European farmers could be facing very serious losses.

As the likelihood of weather extremes increases with temperature, the consequences of lower yields will be felt around the world. Europe produces, for example, 29% of the world’s wheat.

Two consecutive studies in Nature Climate Change examine the challenges faced by the farmers − the first of the reports being by a team led by Miroslav Trnka, of the Czech Global Change Research Centre in Brno.

They considered the impact of changing conditions in 14 very different wheat growing zones − from the Alpine north to the southern Mediterranean, from the great plains of Northern Europe to the baking uplands of the Iberian peninsula, and from the Baltic seascapes of Denmark to the fertile flood plains of the Danube.

It is a given that farmers are at the mercy of the weather, and that crops are vulnerable to unseasonal conditions. But a rise in average temperatures of 2°C is likely to increase the frequency of unfavourable conditions.

Incidence of drought

The researchers, therefore, factored in such data as the numbers of days with very high temperatures, the incidence of drought, late spring frosts, severe winter frosts with too little snow, spells with too much rain, spells when the weather is too cool at the wrong time.

Altogether, they totted up 11 sets of adverse conditions that could blight winter wheat in all 14 sample environments. They then used climate models to simulate the probability of things going wrong once, and also more than once, in any single growing season. And they found that, by 2060, the occurrence of adverse weather conditions would increase for all environments.

“This is likely to result in more frequent crop failure across Europe,” they conclude. “The study provides essential information for developing adaptation strategies.”

Adaptation strategies − according to Frances Moore and David Lobell, of Stanford University, California, in the second of the Nature Climate Change studies − are exactly what European cereal farmers should be thinking about.

They analysed the yield and profit records from thousands of European farms between 1989 and 2009. They then matched the data with climate records to test performance under a suite of different weather histories, and ran simulations using 13 different climate models.

“Modest amounts of climate change
can have a big impact on yields. . .”

“The results clearly showed that modest amounts of climate change can have a big impact on yields of several crops in Europe,” Moore said.

“This is a little surprising because the region is fairly cool, so you might think it would benefit from moderate amounts of warming. Our next step was to measure the potential of European farmers to adapt to these impacts.”

Increasing levels of carbon dioxide in the atmosphere should, in theory, be good for crops – fertility should increase – but a procession of recent scientific studies has painted a different picture.

Plant protein levels

With extra heat comes a greater likelihood of drought to slash maize yields.  And even when the extra carbon dioxide increases growth, it may reduce the levels of all-important plant protein in the yield.

In addition, extremes of heat at the wrong time in the growing season could devastate crops, while the change in average temperatures will open the way for invasions of new kinds of pest.

The Stanford researchers argue that what matters most is how quickly farmers in Europe can adapt, and how crop yields will respond.

“By adaptation, we mean a range of options based on existing technologies, such as switching varieties of a crop, installing irrigation, or growing a different crop,” Lobell said.

“These things have been talked about for a long time, but the novelty of this study was using past data to quantify the actual potential of adaptation to reduce climate change impacts.” – Climate News Network

India’s lethal heat wave strikes again

 

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Hot spot: policeman Kumar Srinivasan directs traffic in the swetering Chennai heat Image: Pramila Krishnan

Hot spot: policeman Kumar Srinivasan directs traffic in the sweltering Chennai heat
Image: Pramila Krishnan

 

By Pramila Krishnan

Large numbers of people die in India each year because of heat waves − and as climate change takes hold and the country swelters again, doctors are warning the public to take extra precautions

Chennai, 28 May − Kumar Srinivasan, a 34-year-old policeman, is struggling to cope with the heat as he controls traffic at a busy city-centre road junction in Chennai, South India. “I feel like a roasted chicken,” he says. “But it’s actually worse, since I am alive while the chicken would have gone to rest in heaven.”

India is sizzling under hot winds as many parts of the country suffer temperatures hovering above 40˚C. And officials in the National Weather Forecasting Center of the India Metrological Department have warned that “heat waves to severe heat wave conditions would prevail in isolated parts of the country in the last week of May”.

As the latest Intergovernmental Panel on Climate Change (IPCC) reports confirm that India will continue to get hotter because of climate change, doctors are concerned that the public needs to be warned of the danger they are in.

Excess heat is already claiming many lives. Research published earlier this year in the journal Plos One showed that in May 2010, when the Indian city of Ahmedabad in the state of Gujarat experienced a heat wave with record-breaking maximum temperatures of 46.8˚C, an estimated 1,344 deaths occurred − 43% higher than expected.

Road fatalities

Another chilling statistic in 2012, recently published by the National Crime Records Bureau, is that 5.4% of the total 22,960 road fatalities in India were attributable to heat strokes. That is more than 1,000 people.

The Indian government has done its bit to make the summer slightly more bearable for policemen such as Srinivasan, providing them with packets of aerated fruit juices and buttermilk (yoghurt diluted in water), as well as sunglasses.

“I am just waiting for the summer to be over, or for some of the summer showers that sometimes happen during June,” Srinivasan says before stepping out of the shade of his little booth to start directing traffic manually again in the scorching heat because a power failure has cut out the traffic lights.

Indian politicians, trying to woo voters, put up water pandals (small stalls made of dried palm/coconut leaves) to supply water, and even buttermilk at times, to the public during the recent election period.

In fact, the Indian elections are deliberately timetabled to avoid the worst part of summer, and the entire election process this time was completed by the second week of May, when the sun was beginning to get harsh..

Doctors at the government’s Rajiv Gandhi General Hospital in Chennai have asked the public to take preventive measures to avoid heat strokes – including wearing light-coloured, loose-fitting cotton clothes, staying hydrated, and avoiding strenuous exercise during the day.

“The maximum temperature will reach 40˚C  in many places
in Tamil Nadu . . .  It’s going to be sweltering hot.”

And the Regional Meterological Centre (RMC) in Chennai has been publishing weather projections for the state of Tamil Nadu on its website, keeping people informed with with regular updates of  projections of average temperatures for one week for every district in the state. S.R. Ramanan, director of the RMC, told Climate News Network: “The maximum temperature will reach 40˚C  in many places in Tamil Nadu in the coming days.  It’s going to be sweltering hot.”

While rich and middle-class Indians go for upgraded refrigerators, air conditioners and coolers, the poor households have to settle for earthen pots to keep drinking water cool.

The plight of people is the same, or even worse, in most parts of tropical India during the hostile summers, particularly since fast-moving urbanisation is taking its toll on trees, which are being chopped down to make way for new high-rise buildings, roads and shopping malls

Loss of shade

The loss of the natural shade of avenue trees means that it’s not just humans who are suffering. The bovine population roams around the streets looking for any tiny puddle of urban gutter water to quench their thirst, and the government’s forest department has had to build concrete tanks and fill them with water to try to prevent animals from suffering dehydration.

Many milkmen live in urban areas and do not take enough care of their cows to protect them from the summer heat, and the Tamil Nadu Veterinary and Animal Sciences University has also found that many aged animals suffer kidney failures in the summer season because of dehydration.

Meanwhile, as more people die every year in India due to heat strokes, social activists are calling for the government to take up initiatives to protect people and spread awareness about preventive measures.

“Curbing privatisation of water and ensuring supply of good quality drinking water for the residents is a major step to avoid dehydration and heat strokes,” said Chennai social activist A.Devaneyan. “The government health department should conduct awareness campaigns to inform people about taking additional care of elders and children during the summer.”

Devaneyan pointed out that the rising number of players in the bottled drinking water industry has also led to rising prices. He said: “A one-litre bottle now costs 20 rupees. How many can afford that?”

Not surprisingly, the popularity of the Tamil Nadu state chief minister, Ms Jayalalithaa Jayaram, also rose after she recently ordered her government to supply water at 10 rupees per bottle − half the price of the “private” water. – Climate News Network.

  • Pramila Krishnan is based in Chennai as Principal Correspondent of the Deccan Chronicle, an English-language newspaper in India.

Droughts may slash US maize gains

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Ripening stalks of maize in the American  Corn Belt state of Indiana Image: Huw Williamsd via ikimedia Commonsstate of

Ears and fears: maize ripens in the American Corn Belt state of Indiana
Image: Huw Williams via Wikimedia Commons

By Tim Radford

High yields in the Corn Belt states of America’s Midwest could drop by up to 30%, scientists say, as crops become increasingly sensitive to droughts and hot, dry air as the world warms through climate change

LONDON, 14 May − Maize yields are on the increase in the US − but so is the crop’s sensitivity to drought. Scientists calculate that, as things stand, crops could lose 15% of their yield within 50 years. And if the trend towards drought-sensitivity continues, then as much as 30% of the yield could be lost as the world warms and droughts become more frequent or more severe.

David Lobell, associate professor of Environmental Earth System Science at Stanford University, California,  and colleagues report in the journal Science that the scientific drive to gain more and more productivity from the same area of soil has been accompanied by an unexpected sensitivity to drought conditions.

The US produces 40% of the world’s corn – the crop Zea mays, or maize – mostly in the Corn Belt states of Illinois, Iowa and Indiana in the MIdwest, and more than four-fifths of US agricultural land depends on rainfall, rather than irrigation. Drought conditions have been severe in the American West and are predicted to become more challenging as temperatures rise through the 21st century.

“The Corn Belt is phenomenally productive , but in the past two decades we have seen very small yield gains under the hottest conditions,” Dr Lobell said in the Stanford University report. “This suggests farmers may be pushing the limits of what’s possible under these conditions.

Trade water

“The data clearly indicates that drought stress for corn and soy comes partly from low rain, but even more so from hot and dry air. Plants have to trade water to get carbon from the air to grow, and the terms of the trade become much less favourable when it’s hot.”

He and his colleagues looked at field data from more than a million US Department of Agriculture crop insurance records between 1995 and 2012. They show that, during that period, plant breeders introduced new traits − including better soil pest resistance − and planted the crop more closely to enhance yield per hectare. But the scientists concluded that any increasing incidence of drought would begin to limit the gains from plant breeding.

And drought remains a hazard. More than 40% of the western US has been in severe drought this spring. The same thing happened in 2013, and in 2012 even the normally rainy east of the US suffered water shortages.

But new research based on dendrochronology  – analysis of tree rings and the message they carry about climatic change over the centuries – offers perspective. It suggests that drought is a periodic phenomenon, right across the US.

Last straw

The years just before the American Revolution were marked by sustained drought, and the last straw in 1774 − according to diaries kept by Thomas Jefferson, one of the Founding Fathers of the new republic − was “a frost which destroyed almost every thing”.

Neil Pederson, assistant research professor at Columbia University’s Lamont-Doherty Earth Observatory, and colleagues report in Ecological Monographs journal that such dramatic climate events have a way of altering the character of the countryside, by weakening trees, and making them more likely to succumb to insect attack and disease.

“With this perspective, the changes predicted by models under future climate change seem more real,” Pederson warns.

Tree ring studies in the American Rocky Mountains also reveal a pattern of terrible stress on forests in the past. Researchers in Utah have identified a drought that began in 1703 and lasted for 16 years, intense drought in 1580, and the most severe of all in 1492 − the year that Columbus discovered the New World.

“We’re conservatively estimating the severity of these droughts that hit before the modern record, and we still see some that are kind of scary if they were to happen again,” said Matthew Bekker, a geographer at Brigham Young University, Utah. “We really would have to change the way we do things here.” Climate News Network

Bricks on wheels face road closure

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A brick on wheels? The traditional British lorry may before lone give way to a new and perhaps safer design Image: By Adrian S Pye via Wikimedia Commons

A brick on wheels? The traditional British lorry may before long give way to a new and perhaps safer design
Image: By Adrian S Pye via Wikimedia Commons

By Kieran Cooke

The European Parliament has voted in favour of changing the design of goods lorries throughout the EU – from their present brick shape to a more streamlined-looking vehicle. The idea is not only to increase fuel efficiency and cut back on CO2 emissions, but also to reduce accidents.

LONDON, 23 March – It’s one of those small steps that could help in the battle against greenhouse gas emissions and climate change.

Lorry design in the European Union at present is governed by legislation dating back to the mid-1990s, stipulating total maximum lengths for cabs and trailers.

This has resulted in the general adoption by road hauliers of a brick-shaped design for cabs on lorries: by making the cab more upright and shorter, transport companies have more space for goods.

But according to Transport & Environment (T&E), a Brussels-based group which campaigns for more sustainable and environmentally friendly transport policies within the EU, lorries have lagged seriously behind other vehicles in terms of environmental performance over the past 20 years.

“Whilst only three per cent of vehicles (in the EU), lorries account for a quarter of Europe’s road transport emissions. That share is expected to grow as traffic increases further”, it says.

Improving protection

T&E says the brick-shaped design is not only inefficient in terms of fuel consumption – it is also dangerous: “Lorries also have a dreadful safety record: every year 15% of all fatal collisions – around 4,200 deaths – involve lorries.”

About 75% of freight in Europe is delivered by lorry. Studies indicate road freight transport is one of the fastest-growing sources of CO2 emissions in the EU, with emissions from the sector likely to increase by more than 20% over the next 15 years. The EU imports 500 million barrels of oil each year, wortharound €60bn, to power its freight fleet.

European Parliament members say relatively simple changes in design can bring about advances in fuel efficiency and cut back on CO2 emissions. Under the Parliament’s proposals, the brick-shaped cab design would be replaced by a more streamlined, aerodynamic nose. The rear of the vehicle would also have aerodynamic flaps and shaping.

T&E says giving lorries a rounder front and putting in place other improvements could improve fuel economy by between seven and ten per cent. It says a more curved cab front would also give drivers greater visibility, eliminate blind spots and so avoid accidents.

Powerful backing

“Today is a good day for pedestrians, cyclists, drivers, hauliers and the environment”, said William Todts of T&E following the EU Parliament vote. “This vote brings the end of the brick-shaped cab closer. It’s a key decision that will reduce road deaths and kickstart progress on lorry CO2 emissions after 20 years of stagnation.”

After a spate of fatal accidents involving lorries and cyclists, London’s mayor, Boris Johnson, has joined the call for changes in lorry design.

The era of more fuel-efficient, safer lorries in Europe is likely to be delayed for some time. Hauliers and truck manufacturers object to the costs of design changes.  To compensate for the haulage space lost due to any new shapes for lorries, the trucking industry is likely to press for bigger, longer vehicles.

The Parliament’s vote still needs to be confirmed by the full parliamentary body. It then goes forward to be considered by all member states. The brick on wheels could be charging down Europe’s roads for some time yet. – Climate News Network

Farming on sand

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It was once a rice paddy but now it's only sand Image: Kieran Cooke

It was once a rice paddy but now it’s only sand
Image: Kieran Cooke

By Kieran Cooke

The Brahmaputra river is one of the world’s mightiest rivers, with millions dependent on its waters. The river also brings misery, with flooding and erosion major problems: climate change is likely to bring more hardship. Kieran Cooke, one of the editors of the Climate News Network, has been in Assam in northeast India, meeting villagers living on the Brahmaputra’s banks.

Laupani village, Assam, 10 March – The holes are dug laboriously in the dusty, sandy soil. Krishna Maya Sharma stops her work to wipe the sweat from her lined face.

“In the old days we would plant paddy here and have enough to sell at market” says Krishna, a 42 year old mother of six children.

“Now the soil is so bad, sweet potato is the only thing that will grow. The rest of our land is ruined.”

Laupani is a village in the north of the tea state of Assam, spread along the banks of the Brahmaputra river. In the distance, the pink evening light shines on the snow capped ridges of the eastern Himalayas.

The Brahmaputra, its waters rising more than 5,000 metres up on the Tibetan Plateau and flowing for about 3,000 kilometres through China, India and Bangladesh before joining up with the Ganges and out into the Bay of Bengal, is one of the world’s major rivers, 10 kilometres wide in places.

Widespread flooding

According to a recent report by India’s Third Pole organisation, the Brahmaputra carries a volume of water exceeded only by the Amazon and Congo rivers – and greater than the combined flow of Europe’s 20 largest rivers.

The river is a lifeline to millions, delivering vital nutrients to the soils of the plains but its fast flowing waters also cause widespread misery to people like Krishna.

Floods are frequent. There is widespread erosion and massive amounts of sand washed out of the river’s banks are deposited on surrounding fields, making once verdant areas into what looks like an enormous beach. The floods also bring invasive plant species that colonise agricultural lands.

More than 40% of Assam’s geographical area is designated as being flood prone: more than 1.5 million people were displaced by floods in 2012, lives were lost and whole villages were washed away.

Sand accumulations

“The waters were so deep and stayed so long that the grass was destroyed and our cattle died because they had no fodder” says Krishna.

“The sand means our land is no good anymore – my husband has given up being a farmer and is working in construction. Many young men go away to try and find jobs, there is nothing for them here.”

Locals – the majority of whom are poor, subsistence farmers – say river flows are becoming more unpredictable, with erosion and what’s called sandcasting becoming worse.

In part the flooding caused by the Brahmaputra’s waters is a natural phenomenon which has been going on for centuries. As the river’s waters cascade down from the Tibetan Plateau and Himalayas, millions of tons of sediment is washed onto the alluvial plains of Assam and others states in India’s northeast.

Earthquake danger

There are other forces at work: the region is a highly seismic zone. In 1950 the Brahmaputra river basin suffered one of the most violent earthquakes ever recorded. The geology of the area was changed and the river level was raised dramatically, by between eight and 10 metres in places.

Climate change is another factor, with a combination of rising temperatures and accumulations of what’s known as black carbon or soot in the high Himalayas and on the Tibetan Plateau causing glaciers which feed into upper reaches of the Brahmaputra to melt.

Increasingly unpredictable rainfall patterns, with periods of intense downpours, are also contributing to more volatile river flows.

Professor Jogendra Nath Sarma is a locally based geologist who has been studying the Brahmaputra for years.

“Over time different rivers in the Brahmaputra basin have merged, braiding over a very wide area. Thousands of square kilometres of land has been eaten away. Rampant deforestation is another big contributor to land erosion. “

In the past, says Professor Sarma, people would migrate to higher ground during the flood season but now, due to population growth and large scale immigration, there is nowhere for them to go.

Doubtful future

The future does not look good. According to models produced by scientists at the Indian Institute of Technology in Guwahati, Assam’s capital, climate change will result in the Brahmaputra valley region experiencing more flood events.

The Institute says that not only will river peak flows increase: so will the incidence of pre-monsoon flooding, endangering key phases of the agricultural cycle.

Talk of climate change is not of great interest to Krishna, digging holes for her sweet potato plants. She has more immediate things to worry about.

“Life is getting harder. Every time the floods come, I wonder what will happen. But where else can we go?” – Climate News Network


 

 

 

 

Evidence ‘suggests climate change is worsening UK winter’

FOR IMMEDIATE RELEASE

Flooding on the Somerset Levels in the West of England: Parts have been under water for weeks Image: Nigel Mykura via Wikimedia Commons

Flooding on the Somerset Levels in the West of England: Parts have been under water for weeks
Image: Nigel Mykura via Wikimedia Commons

By Alex Kirby

Scientists at the UK Met Office say all the evidence supports the theory that the exceptionally wet and stormy winter affecting much of Britain is caused at least in part by climate change.

LONDON, 9 February – The British Government’s main climate science adviser, the UK Met Office, says the present exceptionally wet and stormy winter “could be a manifestation of climate change.”

Its chief scientist, Dame Julia Slingo, says the variable UK climate means there is “no definitive answer” to what is producing this winter weather, with the “most exceptional period of rainfall in 248 years”. But “all the evidence suggests there is a link to climate change”.

She said there was no evidence to counter what the basic science says will happen as the world warms – that heavy, fierce downpours of rain will occur more often.

“Nobody has come forward to counter the basic premise that if you have a warmer world you are going to get more intense heavy rain rates”

Dame Julia told BBC Radio: “We know that warmer air holds more water…As scientists we always go back to the evidence base. I always challenge the climate sceptics to provide me with the same level of scientific integrity of the evidence base. I can’t see it.

“Nobody has come forward to counter the basic premise that if you have a warmer world you are going to get more intense heavy rain rates…as we’re beginning to detect now over the UK.”

The Met Office, with the UK’s Centre for Ecology & Hydrology (CEH), has published a report, The recent storms and floods in the UK, which strikes a cautious note.

It concludes: “It is not possible, yet, to give a definitive answer on whether climate change has been a contributor or not” to the frequent and torrential rain, storms and floods affecting much of the UK since early December.

But deep in the detail of the report’s findings are clear statements by its authors showing they are convinced that climate change may be partly responsible, despite the well-known fickle nature of the British weather.

The report says, for example, that although the number of strong winter storms over the mid-latitude North Atlantic – the path of the current storms – has not increased since 1871, the storms’ average intensity has grown significantly. The continual run of deep depressions through December, January and into February is also unusual.

“What in the 1960s and 1970s might have been a 1 in 125 day event is now more likely to be a 1 in 85 day event”

There are questions as well about whether the jet stream “is making greater excursions north and south, and whether these waves in the jet stream are becoming more locked in one position.

“This is a critical question because it raises the possibility that disruption of our usual weather patterns may be how climate change may manifest itself.”

The report says there is now some emerging evidence that, over the United Kingdom, daily heavy rain events may be more frequent: “What in the 1960s and 1970s might have been a 1 in 125 day event is now more likely to be a 1 in 85 day event.”

It says there is an increasing body of evidence that shows that extreme daily rainfall rates are becoming more intense, and that the rate of increase is consistent with what is expected from fundamental physics. – Climate News Network