Tag Archives: Weather

Arctic warming blamed for dangerous heat waves

Feeling the heat: a wildfire rages in New Mexico during the 2012 heat wave in the US Image: Kari Greer/USFS Gila National Forest via Wikimedia Commons
Feeling the heat: a wildfire rages in New Mexico during the 2012 heat wave
Image: Kari Greer/USFS Gila National Forest via Wikimedia Commons

By Paul Brown

Giant waves in the jet stream that often governs our weather are changing as the Arctic warms more rapidly − leading to long periods of soaring temperatures that pose major threats to economies and human health.

LONDON, 16 August, 2014 − Few people have heard of Rossby waves and even less understand them, but if you are sweltering in an uncomfortably long heat wave, then they could be to blame.

New discoveries about what is going on in the atmosphere are helping to explain why heat waves are lasting longer and causing serious damage to humans and the natural world. These events have doubled in frequency this century, and the cause is believed to be the warming of the Arctic.

The weather at the Earth’s surface is often governed by high winds in the atmosphere, known as jet streams. In 1939, Carl-Gustaf Arvid Rossby, a Swedish-born America meteorologist, discovered waves in the northern jet stream that were associated with the high and low pressure systems at ground level that form daily weather patterns.

Jet streams travel at up to 200 kilometres an hour, frequently wandering north and south − with cold Arctic air to the north, and warmer air to the south.

Rapid variations

When the jet stream develops Rossby waves and they swing north, they suck warm air from the tropics to Europe, Russia or the US. And when they swing south, they do the same thing with cold air from the Arctic. The waves constantly change shape, and so cause rapid variations in the weather.

But new research, published in the Proceedings of the National Academy of Sciences of the USA, has discovered a tendency for these waves in the jet stream to get much bigger and to get stuck – particularly in July and August. This causes heat waves that last not just for a few days but for weeks.

This is a serious health and economic threat. A recent example is the record heat wave in the US that hit corn farmers and worsened wildfires in 2012.

Close study of records shows that, from 1980 to 2003, there were two such heat wave events every four years on average. From 2004-07, there were three events, and between 2008-11 there were five.

Ice shrinking

Theory and the new data both suggest a link to processes in the Arctic. Since 2000, the Arctic has been warming about twice as fast as the rest of the globe. One reason for this is that ice is rapidly shrinking in the White Sea − a southern inlet of the Barents Sea on the north-west coast of Russia – and so less sunlight gets reflected back into space, while the open ocean is dark and hence warms more.

“This melting of ice and snow is actually due to our lifestyle of churning out unprecedented amounts of greenhouse gases from fossil fuels,” says Hans Joachim Schellnhuber, co-author of the study and founding director of the Potsdam Institute for Climate Impact Research.

As the Arctic warms more rapidly, the temperature difference to other regions decreases. Yet temperature differences are a major driver of the atmospheric circulation patterns that in turn rule our weather.

“The planetary waves topic illustrates how delicately interlinked components in the Earth system are,” Schellnhuber concludes: “And it shows how disproportionately the system might react to our perturbations.” – Climate News Network

US climate change debate heats up

Skiing areas such as Colorado are being hit by warmer winters Image: DebateLord at Wikimedia Commons
Skiing tourism areas such as Colorado are being hit by warmer winters
Image: DebateLord at Wikimedia Commons

By Kieran Cooke

Groups for and against US government plans for new regulations aimed at cutting greenhouse gas emissions have been slugging it out at a series of heated debates across America.

LONDON, 11 August, 2014 − Achieving progress in cutting back on greenhouse gas emissions and preventing serious global warming is never easy. But just how difficult a task that is became clear at a series of recent meetings across the US held to discuss the Obama administration’s latest plans for tackling climate change.

Those plans, announced in early June by the government’s Environmental Protection Agency, call for substantial nationwide cuts in greenhouse gas emissions.

Power companies − in particular, those operating coal-fired plants − will have to make big adjustments, reducing overall CO2 emissions by 25% on 2005 levels by 2025 and by 30% by 2030.

The EPA-sponsored public meetings, held in four US cities, were packed.

Long overdue

In Denver, in the state of Colorado, representatives of the skiing industry − a vital part of the state’s economy − said the new regulations were long overdue.

Skiing organisations said changes in climate were already happening and the industry was being badly hit, with drier and warmer winters resulting in less and less snow.

But coal mining is also central to Colorado’s economy. One resident of a coal mining community told the meeting: “The environmental extremist war on coal is really a war on prosperity. Coal means families can buy homes and put food on the table.”

The multi-billion dollar US coal industry is training its big guns on the EPA proposals.

Fred Palmer, a representative for Peabody Energy Corporation, the biggest coal producer in the US, told a meeting at the EPA’s HQ in Washington that the government should provide more funds for new technologies such as carbon capture and storage.

“Climate change is an issue we need to deal with in the right way,” Palmer said, “The only way to approach it is with technology, not with command-and-control from Washington.”

Other coal lobbyists have been wading into the fray. The American Coalition for Clean Coal Electricity said the EPA’s emissions cutting programme “threatens to dismantle our nation’s economy, fundamentally alter the American way of life, and severely hamper US energy independence and leadership”.

Groups of campaigners in favour of the EPA proposals demonstrated at the meetings, with the area round the EPA’s Washington office turned into the site of a large green carnival.

Adamantly opposed

Although the Obama administration has a considerable battle on its hands – with many politicians, corporate groups and powerful business organisations adamantly opposed to the new proposals – there are signs that the White House is determined to implement the measures.

Coinciding with the public meetings around the country, the government’s Council of Economic Advisers issued a report saying cutting emissions makes sense economically, as well as environmentally.

For each decade that action on emissions is delayed, costs of meeting reduction targets rise by more than 40%, the report says.

The public mood about the seriousness of climate change and the need to take action seems to back Washington’s stance.

A recent poll carried out by the ABC news network in the US and the Washington Post found that seven out of 10 people think global warming is a serious problem that needs to be tackled – and more than 60% of those questioned wanted action on emissions, even if it means higher energy bills. – Climate News Network

Climate change damages Europe’s forests

Forest fire damage such as this in Portugal is expected to increase Image: Osvaldo Gago via Wikimedia Commons
Forest fire damage such as this in Portugal is expected to increase
Image: Osvaldo Gago via Wikimedia Commons

By Alex Kirby

New research shows that forest ecosystems are particularly vulnerable to rapid changes in the climate – and have been suffering intensified disturbance in Europe for decades.

LONDON, 5 August, 2014 − Climate change is here, it’s happening now, and for the last few decades it has been demonstrably bad news for many of Europe’s forests.

An international team of researchers say in a report from the European Forest Institute that climate change is altering the environment, and it is long-lived ecosystems like forests that are particularly vulnerable to the comparatively rapid changes occurring in the climate system.

The report, published in the journal Nature Climate Change, shows that damage from wind, bark beetles, and wildfires has increased significantly in Europe’s forests in recent years. Windthrow −  the wind’s effect in damaging or uprooting trees − is an increasing problem.

“Disturbances such as windthrow and forest fires are part of the natural dynamics of forest ecosystems, and are not a catastrophe for the ecosystem,”, says the study’s principal researcher, Rupert Seidl, senior scientist at the University of Natural Resources and Life Sciences, Vienna.

Increasing challenges

“However, these disturbances have intensified considerably in recent decades, which increasingly challenges the sustainable management of forest ecosystems.”

The authors show that damage caused by forest disturbance has increased continuously over the last 40 years in Europe, reaching 56 million cubic metres of timber annually in the years from 2002 to 2010.

Analysis of scenarios for the decades ahead suggest this trend will continue, with the study estimating that forest disturbance will increase damage by another million cubic metres of timber every year over the next 20 years.

The study says this increase is roughly equivalent to 7,000 football fields’ worth of timber. The authors say climate change is the main driver behind the increase. Forest disturbance did not increase much beyond present levels in their simulations while climate conditions remained stable.

They estimate that forest fires will cause increased damage on the Iberian peninsula, with damage by bark beetles increasing most markedly in the Alps. Wind damage, they say, is likely to increase most in central and western Europe.

Feedback effect

What the climate does to the forests is not a one-way street, the study says. There is a strong feedback effect from forest disturbances on the climate system.

Europe’s forests are at present helping to mitigate climate change by absorbing large quantities of carbon dioxide. But the carbon lost from the increasing numbers of trees that are damaged or die could reduce this effect and reverse the positive impact of forest management measures aimed at reducing climate change.

So the increase in forest disturbance caused by the climate could simply make climate change worse. Management steps such as increasing biodiversity and thinning the forests to give them better protection can help to reduce these carbon losses and support the forests’ role in mitigating climate change.

But the authors say Europe’s forest managers will need to adapt to changing disturbances in order to keep the forests capable of functioning  to society’s benefit. − Climate News Network

New seeds of hope for Nepal’s farmers

Growing concern: in Nepal, 50% of arable land is planted with rice Image: Sigismund von Dobschütz via Wikimedia Commons
Growing concern: in Nepal, 50% of arable land is planted with rice
Image: Sigismund von Dobschütz via Wikimedia Commons

By Om Astha Rai

Climate-resilient varieties of rice could help to protect crop yields from the ravages of droughts and floods caused by the increasingly erratic weather patterns in South Asia.

KATHMANDU, 30 July, 2014 − Farmers badly affected by changing weather patterns in South Asia now have the opportunity to improve food security by planting new varieties of rice capable of withstanding the impact of both severe droughts and floods.

This is particularly good news for countries such as Nepal, where around 65% of its more than 26 million people are involved in agriculture. Rice is the country’s most important crop, planted on more than 50% of its arable land.

And it comes at a time when new research using satellite imaging has highlighted the growing need to change agricultural practices in South Asia as higher average temperatures cause the reduction of crop yields on the Indo-Gangetic plain.

Scientists say the new seeds, developed by the International Rice Research Institute in the Philippines and approved by the Nepal Agricultural Research Council (NARC), are vital in order to deal with changing weather patterns − in particular, the increasingly erratic behaviour of the all-important South Asia monsoon.

“These new varieties can really change the future of the country’s farmers,” says Dr Dil Bahadur Gurung, NARC’s executive director. “The new rice can, in most cases, beat the effects of droughts and floods.

Reduce impact

“All these varieties have been tested in Nepal’s soil and climate over and over again. If all the country’s farmers replace their traditional varieties with these new ones, the impact of climate change on our agriculture could be reduced considerably.”

Local scientists say the timing of the South Asia monsoon − the only source of irrigation for the majority of Nepali farmers − is changing.

“Each year, we see the monsoon arriving later,” says Mani Ratna Shakya, a leading meteorologist in Nepal. “The duration of the monsoon is also getting shorter as each year passes.”

According to Nepal’s Meteorological Forecasting Division, the monsoon − which usually arrives in Nepal during the first week in June − came 10 days late this year.

Droughts are becoming more frequent. This year, the monsoon is generally judged to be very weak, leaving a vast area of arable land parched, particularly in western parts of Nepal. And often, when the rains eventually do arrive, they are torrential, causing flash floods.

So far, NARC has approved six drought-tolerant varieties of rice, under the name Sukkha − meaning dry.

“Ordinary rice varieties dry out and die in droughts,” says Hari Krishna Uprety, a paddy expert at NARC. “The new seeds survive droughts even in the early stage of growth. And uncertainty about the onset of monsoon has made these varieties even more important.”

Hari Krishna Uprety, NARC paddy expert, with new rice seed varieties Image: Om Astha Rai
Hari Krishna Uprety, NARC paddy expert,
with the new rice seed varieties
Image: Om Astha Rai

The new varieties still need water, of course, but they become more drought tolerant by being able to store energy during the early stages of their growth.

Two rice varieties capable of surviving flood conditions for up to two weeks have also been approved by NARC.

Erratic climate

Although the experts are backing the introduction of the new seeds in order to combat an increasingly erratic climate, persuading farmers to change their cultivation methods is a difficult task.

Farmers are often reluctant to replace traditional rice varieties, which in Nepal tend to be specific to each part of the country, depending on soil conditions, elevation, and other factors.

The new seeds are no more expensive than the traditional ones, and farmers even get a 30% discount on seeds approved by NARC, but a factor that could hamper uptake is that distribution is through the National Seed Company, which is not yet reaching out to farmers in every village.

But scientists warn that the new varieties must be planted – not only to combat changes in climate, but also to feed growing populations. – Climate News Network

• Om Astha Rai is a reporter with Nepalese national newspaper, Republica Daily.

Atlases reveal climate and weather impacts

NASA says Arctic sea ice thickness in some areas has halved since 1980 Image: Hannes Grobe 20:05 via Wikimedia Commons

NASA says Arctic sea ice thickness in some areas has halved since 1980
Image: Hannes Grobe 20:05 via Wikimedia Commons

By Alex Kirby

Two new atlases provide clear visual evidence of the effect climate change and extreme weather can have on people and property.

LONDON, 12 July 2014 – For people who find it hard to believe the Earth really is warming, new visual evidence will soon be available – two atlases, one showing graphically the retreat of Arctic ice, the other the human and economic price exacted by extreme weather.

The 10th edition of the National Geographic Atlas of the World is to be published on 30 September. The publication’s geographer, Juan José Valdés, says the reduction in multi-year ice – ice that has survived for two summers – is so noticeable compared with previous editions that it is the biggest visible change since the breakup of the USSR.

“You hear reports all the time in the media about this,” he said. “Until you have a hard-copy map in your hand, the message doesn’t really hit home.” He believes atlases “open people’s eyes to what’s happening in the world.”

The Arctic sea ice has been retreating in the last 30 years or so by 12% each decade, NASA says. (On land the change is even more marked. Spring and autumn on the Greenland icecap have warmed by more than 3°C, although summer temperatures have not changed)

According to NASA’s Operation IceBridge the sea ice is now as much as 50% thinner than in previous decades, falling from an average thickness of 3.8 metres (12.5 feet) in 1980 to 1.9 m (6.2 ft) in recent years. May 2014 represented the third lowest extent of sea ice for that month in the satellite record, the US National Snow and Ice Data Center (NSIDC) says.

Self-supporting

The ice loss is accelerated by what scientists call a positive feedback: the warming in effect fuels itself. Thin ice reflects light less effectively than thick ice, allowing more sunlight to be absorbed by the ocean, which further weakens the ice and warms the ocean even more.

The melting ice also triggers another feedback. Thinner ice is flatter and scientists say this allows melt ponds to accumulate on the surface, reducing the ice’s reflectiveness and absorbing more heat.

In National Geographic’s atlas the multi-year ice, which is older, is shown as a large white mass, with the maximum extent of sea ice – the pack ice that melts and refreezes each season – shown by a simple line. This edition shows the area of multi-year ice is strikingly smaller than previously.

Some scientists say the atlas should show the total ice area at the end of the Arctic summer, including the remaining ice newly formed in the previous winter. This total minimum cover is measured in September, while total maximum cover is measured in March, at the end of winter.

Omitting the minimum cover means ice one year old or less is not being shown, the critics say. But the mapmakers say they do not show the minimum extent because there is only so much information they can include without confusing users.

There is also criticism of the atlas’s reliance on a single year (the new edition uses 2012 data, an extremely low year for ice cover). The critics say this probably over-emphasises long-term trends. But if 2013, a year with more ice, is shown, the mapmakers counter, it could under-emphasise the trend towards rising temperatures.

Steep underestimate

The second publication, the Atlas of Mortality and Economic Losses from Weather, Climate and Water Extremes 1970-2012, is the work of the World Meteorological Organization (WMO) and the Centre for Research on the Epidemiology of Disasters (CRED) of the Catholic University of Louvain (UCL) in Belgium.

Disasters caused by such extremes, it says, are increasing globally, killing people and slowing economic and social development by years or decades. The period covered, the authors say, saw 8,835 disasters, 1.94 million deaths and US$2.4 trillion of economic losses resulting from droughts, extreme temperatures, floods, tropical cyclones and related health epidemics.

Preparations start in Geneva, Switzerland, on 14 July for the third World Conference on Disaster Risk Reduction, to be held in Japan in March 2015 by the United Nations.

Jochen Luther of WMO told the Climate News Network: “It’s not necessarily the number of extreme events that is increasing, but the increasing exposure and vulnerability that turns them into disasters, as well as better reporting of them than in the past.”

The UN’s Global Assessment Report on Disaster Risk Reduction 2013 said direct and indirect losses from natural hazards of all kinds had been underestimated by at least half because of problems with data collection. – 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

Monsoon brings late relief to scorched India

 

Sweltering heat has hit Kolkata street hawkers by keeping many customers away Image: Biswarup Ganguly via Wikimedia Commons
Fierce heat has hit Kolkata street hawkers by keeping many customers away
Image: Biswarup Ganguly via Wikimedia Commons

By Shiba Nanda Basu

Meteorological researchers in India suspect that climate change is a contributory factor to the changing weather patterns that have caused  the late arrival of the monsoon after a summer of swelteringly dry heat that has broken temperature records

Kolkata, 24 June, 2014 − At last, the rains have come. The summer monsoon arrived in West Bengal last week – almost two weeks later than usual − and brought relief to Kolkata and other cities and states across India that have been enduring an unusually hot summer.

A temperature of 41.5˚C was recorded in Kolkata in late May – the highest in 10 years – while temperatures in New Delhi  earlier this month exceeded 43˚C for seven consecutive days, and at one stage reached 48˚C. Other cities and states have had record temperatures, and many lives have been lost due to the heat.

Livelihoods have also suffered. Kolkata is famous for its bustling streets and pavements crowded with hawkers, but throughout recent months there has been a deserted look to the city.

“We have had to close our stalls earlier than usual and there’s been hardly any customers,” says Asraf Ali, a street hawker. “People from neighbouring districts, who are our main customers, have not been coming into the city due to the terrible heat.”

Absence of humidity

One thing that’s been worrying residents of Kolkata is an unusual period of what is called “dry heat” – an absence of humidity. Locals say this has made daytime conditions even more scorching.

Aminul Hasaan, a worker in one of Kolkata’s notoriously polluting leather tanning factories, says: “I was working so hard, and usually I sweat so much. But in the weeks before the monsoon I felt my forehead was always dry. It made me feel sick.”

Anshujyoti Das, who works for Express Weather, a private weather research organisation that aims to provide location-specific weather forecasts, says the dry heat indicates certain changes in weather patterns.

He says: “We cannot claim that this is the direct result of climate change, but we can’t brush the issue under the carpet. We must conduct studies to ascertain the reasons behind such unusual weather patterns.”

One possible cause for the dry conditions is thought to be the absence of the north-westerly storms that usually lash Kolkata and surrounding areas in the run-up to the monsoon.

On average, five to seven such storms hit in April and May, but this year only one was recorded. There was also an absence of moisture-laden winds blowing from the south.

Due to the conditions, the local government authorities extended summer vacations at 57,000 primary schools and more than 18,000 secondary schools. And the city police in Kolkata decided that traffic constables aged 55 and above should be relieved of their duties because of the extreme heat.

Dilip Adak, a senior officer at Kolkata’s traffic department, said: “We try to help [traffic policemen] by providing oral rehydration kits and umbrellas, but often that is not enough.”

Driving up prices

About half of India’s 1.25 billon people are involved in agriculture and are dependent on the summer monsoon rains. The late arrival of the monsoon can have a serious impact, driving up prices of many agricultural goods.

The latest report from the Indian Meteorological Department shows that the monsoon has not only arrived late but is less intense than normal, with many areas receiving well below average rainfall.

Climate change and the influence of an El Niño – a periodic warming of waters in the western Pacific that affects prevailing trade winds, with serious consequences on both sides of the Pacific and Indian Oceans – are seen as important influences on the behaviour of the monsoon– Climate News Network

• Shiba Nanda Basu is a reporter with The Statesman newspaper, Kolkata, India.

• Additional reporting by Kieran Cooke.

US corn’s gravy train faces derailment

 

A field of Maize in the Corn Belt state of South Dakota on the American Great Plains Image: Lars Plougmann via Wikimedia Commons
A ripening field of maize in the American Corn Belt state of South Dakota
Image: Lars Plougmann via Wikimedia Commons

By Kieran Cooke

The US produces enough corn in one year to fill a freight train stretching round the world, according to a recent study. But climate change and unsustainable use of water resources and fertilizers threaten this vast industry.

LONDON, 22 June, 2014 – One-third of cropland in the US is devoted to corn. It produces nearly 40% of the world’s corn, and a record harvest last year was valued at nearly $70 billion.

But now there are warnings that this mighty agricultural edifice – which supports not only farmers, but a legion of food and animal feed, transport and other companies, big and small − could be seriously damaged by a changing climate.

To make matters worse, increasingly scarce water supplies could also have an adverse effect, and so too could the intensification of growing techniques − in particular, the overuse of  fertilizers and pesticides.

A study by Ceres, a US not-for-profit group that lobbies for more environmental sustainability in the business sector, looks at the risks facing one of the country’s main industries.

Negative impact

States in the American Midwest and the Great Plains region – known as the Corn Belt − account for the bulk of corn production. But the study warns: “Record-breaking weather events – including prolonged drought, intense precipitation and high temperatures – are increasingly common in the Corn Belt and are negatively impacting corn yields and corporate profits.”

Floods in 2010/11 caused millions of dollars worth of crop losses in many areas. Lands were also degraded, and erosion increased. The following year there was drought, when the rains didn’t arrive and temperatures soared.

“The 2012/13 drought exemplified the vulnerability of the US corn supply chain to extreme weather,” the study says.

The bulk of US corn output goes either to animal feed or to the production of ethanol fuels, with only 10% going to food processing.

According to the report: “The 2012/13 drought had unusually severe financial impacts for many companies in the US corn value chain, hitting the meat and grain trading sectors particularly hard.

“Impacts ranged from interruptions to corn supply − which affected meat processing and ethanol refining activities − to operational challenges linked to insufficient water for manufacturing facilities, to low Mississippi river water levels that restrict transport of agricultural goods.”

While the percentage of corn production shipped abroad is relatively small, the US is still the world’s biggest corn exporter. Shortages or rising prices can have an adverse impact on the developing world, with the potential for outbreaks of serious social unrest.

The study points out that extreme weather events in recent years have resulted in large-scale price volatility. This in turn has led to what it calls riskier growing practices, with farmers and the big agricultural conglomerates seeking to cash in on rises in the market by using ever more fertilizer and pesticides on their lands.

The US government’s recent National Climate Assessment said the negative effects of climate change, such as higher temperatures and drought, would outweigh any positive impacts in the Midwest and Great Plains.

The Ceres study says corn is particularly sensitive to higher temperatures, and much of the corn is grown in regions where water supplies are already limited. In future, corn growing might have to move to cooler and more water-abundant areas further north.

Northward shift

“Higher temperatures and increased water stress mean that increased irrigation for corn will be required. Given limited water supply in parts of the Great Plains region, a northward shift in corn acreage is predicted, increasing the risk of stranded agricultural assets, such as processing, storage and transportation infrastructure.”

Costs, to the agricultural industry and to the US government are mounting. In 2012-13, the government’s Federal Crop Insurance Programme paid out a record $10.8 billion to farmers, mostly for reasons related to the drought.

Ceres says farmers and the large conglomerates that control increasing amounts of agricultural land must learn to farm more sustainably. In many cases, this means a less intensive crop regime.

There should be more measured use of fertilizers and pesticides. More efficient irrigations methods and charging systems that encourage less water use should also be implemented.

More mixed cropping should be introduced in order to preserve soil fertility, the report recommends. And companies should examine their supply chains, and pressure the farming sector to put in place better land practices.

Perhaps most controversially, Ceres has a simple message that is likely to cause a storm of anger across the Corn Belt: buy less corn. – Climate News Network

Longer flight paths can cut climate impact

Aircraft contrails in the sky above Reading, just west of London Image: University of Reading
Aircraft condensation trails line the sky above Reading, just west of London
Image: University of Reading

By Alex Kirby 

British scientists have developed a simple framework that shows how aircraft can become more environmentally friendly by choosing flight paths that reduce the formation of their distinctive vapour trails − even if it means flying further

LONDON, 21 June, 2014 − Air travel is a rapidly-growing source of carbon dioxide and is helping to heat the Earth. It accounted for 6% of the UK’s total greenhouse gas emissions in 2011.

But researchers from the University of Reading, UK, say the CO2 that aircraft emit may be less damaging to the climate than the vapour trails they often leave behind them.

Writing in the journal Environmental Research Letters, the scientists demonstrate that aircraft contribute less to global warming when they avoid the places where the thin-shaped clouds of vapour − called condensation trails, or contrails − are produced, even if that means flying further and emitting more CO2.

Wispy clouds

Contrails form only in parts of the sky with very cold and moist air, often in the ascending air around high pressure weather systems. They sometimes stay in the air for many hours, eventually spreading out to resemble natural, wispy clouds.

Previous research by scientists at Reading has shown that, on average, 7% of the total distance flown by aircraft is in cold, moist air where long-lasting contrails can form − 2.4 billion km out of a global total of 33 billion km flown in 2005.

The new findings from Reading follow research published recently in the journal Nature Climate Change showing that the amount of global warming caused by contrails could be as large as, or even larger than, the contribution from aviation’s CO2 emissions.

The work was carried out by three scientists in Reading’s Department of Meteorology − Dr Emma Irvine, Professor Keith Shine, and Professor Sir Brian Hoskins, who is also chair of the Grantham Institute at Imperial College London.

“It may be possible to mitigate [contrails’] effect
by routing aircraft to avoid them”

Dr Irvine said: “If we can predict the regions where contrails will form, it may be possible to mitigate their effect by routing aircraft to avoid them. Our work shows that, for a rounded assessment of the environmental impact of aviation, more needs to be considered than just the carbon emissions of aircraft.”

Just like natural clouds, contrails reflect some of the sun’s incoming energy, and so produce a cooling effect. But they also trap some of the infra-red energy that radiates from the Earth into space, and so have a warming effect − again, like other clouds. The researchers say detailed calculations show that, generally, the warming influence is greater than the cooling.

But the picture is more complex than that. For a start, the team estimates that smaller aircraft can fly much further to avoid forming contrails than larger ones.

With a small aircraft that is predicted to form a contrail 20 miles long, an alternative route would have a smaller climate impact if it adds less than 200 miles to its journey . For larger aircraft, the alternative route could still be preferable, but only if it added less than 60 miles to the journey.

But there is a further twist. The team had to allow for the varying length of time the different impacts would persist. As Dr Irvine explained: “Comparing the relative climate impacts of CO2 and contrails is not trivial. One complicating factor is their vastly differing lifetimes. Contrails may last for several hours, while CO2 can last for decades.”

Feasible and safe

Nor are the relative climate impacts the only factors for aviators to think about. Air traffic controllers would need to be sure re-routing aircraft flight by flight is both feasible and safe, and weather forecasters would want to know whether they can reliably predict when and where contrails are likely to form.

As well as CO2, aircraft engines emit a number of other gases and particles that can also alter climate – such as oxides of nitrogen and sulphur gases − and their effects might also depend on the route taken.

The researchers have devised a framework to calculate how much further an aircraft could travel in a single flight before the extra CO2 that is emitted causes more warming than the contrail would have caused. It takes into account the characteristics of the aircraft and the prevailing weather conditions, since the altitude at which contrails are formed depends greatly on weather patterns.

They are confident their work has practical implications. “The mitigation targets currently adopted by governments all around the world do not yet address the important non-CO2 climate impacts of aviation, such as contrails,” Dr Irvine said.

“We believe it is important for scientists to assess the overall impact of aviation and the robustness of any proposed mitigation measures in order to inform policy decisions.” − Climate News Network

May days’ heat sets up record El Niño

 

Flooding in California during the “El Niño of the century” in 1998 Image: Dave Gatley/FEMA via Wikimedia Commons
Flooding in California during the “El Niño of the century” in 1998
Image: Dave Gatley/FEMA via Wikimedia Commons

By Tim Radford

Scientists believe that soaring global temperatures during an unusually hot month of May may have created the ideal conditions to provide a warm welcome for an El Niño weather phenomenon that will break records

LONDON, 20 June, 2014 − Last month was the third warmest May since NASA satellites began taking the temperature of the planet 35 years ago, and was also the warmest May that did not fall within an El Niño Pacific warming event – which could mean a record-breaking appearance this year by the fearsome “Child”.

Scientists in the US says the global average was 0.33°C warmer than the seasonal norms for the month. The warmest May ever was in 1998 during the “El Niño of the century”, when global average temperatures rose by 0.56°C, and the second warmest at 0.45°C was in 2010, another El Niño year.

So if indications are correct that an El Niño event is taking shape in the Pacific right now off the equatorial coast of South America, then it could become a record-setter − even if it isn’t a very spectacular event − just because it will get a warmer start, according to John Christy, professor of atmospheric science at the University of Alabama in Huntsville, US.

Temperature patterns

An El Niño (Spanish for The Child, because it was first observed by Peruvian fishermen around Christmas) is a shift in the temperature patterns of the Pacific, as a blister of equatorial ocean heat moves eastwards. It is a natural cyclic event that tends to reverse the prevailing Pacific weather patterns, often damagingly, and is not connected with climate change  although its effects could be made worse by climate change.

“The long-term baseline temperature is about three tenths of a degree warmer than it was when the big El Niño of 1997-1998 began, and that event set the one month record,” Christy said. “With the baseline so much warmer, this upcoming El Niño won’t have very far to go to break that 0.66°C record. That isn’t to say it will, but even an average-sized warming event will have a chance to get close to that level.”

Meanwhile, according to new research in Nature Climate Change, people in the northern hemisphere can also expect warmer temperatures in autumn and winter – in spite of last winter’s spectacular ice storms in the US north-east that shut down cities from the Atlantic to the Midwest, and where − to the joy of headline writers − the town of Hell in Michigan froze over.

Extremes of cold

The report’s author, James Screen, Natural Environment Research Council research fellow at the University of Exeter, UK, says that even though there will be extremes of cold, these will be less frequent and less severe. The Arctic is warming, and a study of autumn and winter temperature variations shows that variability in the temperate zone overall has in fact decreased.

“Autumn and winter days are becoming warmer on average, and less variable from day to day,” Dr Screen said. “Both factors reduce the chance of extremely cold days.

“Cold days tend to occur when the wind is blowing from the north, bringing Arctic air south into the mid-latitudes. Because the Arctic air is warming so rapidly, these cold days are now less cold than they were in the past.” – Climate News Network