Category Archives: Food security

Gene machinery helps plants handle CO2 rise

 

The mouse-ear cress (Arabidopsis thaliana) provides vital scientific clues Image: Alberto Salguero Quiles via Wikimedia Commons
Mouse-ear cress (Arabidopsis thaliana) provides valuable scientific clues
Image: Alberto Salguero Quiles via Wikimedia Commons

By Tim Radford

The discovery of how plants respond to increasing levels of carbon dioxide in the atmosphere could provide agricultural scientists with new tools to engineer crops that can deal with droughts and high temperatures.

LONDON, 10 July, 2014 − Biologists in the US have identified the genetic machinery that tells a plant how to respond to more carbon dioxide caused by the burning of fossil fuels.

Four genes from three different gene families together control the density of stomata, or breathing pores, on the foliage of the healthy plant. As carbon dioxide levels in the atmosphere rise, plants respond and make fewer stomata.

That means they can detect a gradual change in the levels of a vital gas – a change from 280 parts per million 200 years ago to 400 parts per million now – and change their plumbing arrangements.

In theory, more carbon dioxide in the atmosphere should be better for plant fertility, and the reduction in stomata means that they should use water more economically. Water is a big expense for the growing plant.

Lose water

“For each carbon dioxide molecule that is incorporated into plants through photosynthesis, plants lose about 200 molecules of water through their stomata,” says Julian Schroeder, professor of biological sciences at the University of California San Diego, who led the team that reports in Nature  journal.

“Because elevated CO2 reduces the stomatal density in leaves, this is at first sight beneficial for plants, as they would lose less water. However, the reduction in the number of stomatal pores decreases the ability of plants to cool their leaves during a heat wave via water evaporation. Less evaporation adds to heat stress in plants, which ultimately affects crop yield.”

Quite how crops will respond to a greenhouse gas world has been exercising field biologists, agronomists and government planners for decades.

Plants respond to warmth and to plentiful carbon dioxide. But, as researchers found in April this year, that may not make crops more nourishing. It would be possible to have vigorous growth but lower protein yields in, for example, fields of wheat.

There is a second unresolved question: a warmer world will mean more evaporation, more rainfall in some regions, and greater aridity in others − not helpful to productive farming.

A third challenge is that extremes of heat in the growing season can have a catastrophic effect on the harvest later in the year.

But the San Diego research may, in the end, help tomorrow’s farmers. The study shows that when their test species Arabidopsis thaliana – a little mustard plant also known as mouse-ear cress − senses a rise in atmospheric levels of CO2, it increases the levels of a peptide hormone that alters the genetic machinery in the skin of growing leaves, and blocks the formation of stomata.

The challenge was to identify all the proteins involved, and the genes that are at work.

Plant health

“This change causes leaf temperature to rise because of a decrease in the plant’s evapotranspirative cooling ability, while simultaneously increasing the transpiration efficiency of plants,” the report says. “These phenomena, combined with the increasing scarcity of fresh water for agriculture, are predicted to dramatically impact on plant health.”

The more researchers know about the physiological response of a growing thing, the more confidently they can predict how it will react to changing conditions, the better they will be able to advise farmers on the plants to sow, and the more likely it is that they will be able to breed new strains that can adapt to new conditions.

“At a time when the pressing issues of climate change and inherent agronomic consequences which are mediated by the continuing atmospheric rise of CO2 are palpable, these advances could become of interest to crop biologists and climate change modellers,” said molecular biologist Cawas Engineer, lead author of the paper. – Climate News Network 

South Asia slow to act on water threats

The Ganges river delta in Bangladesh and India Image NASA World Wind via Wikimedia Commons
Satellite image of the vast Ganges river delta in Bangladesh and India
Image: NASA World Wind via Wikimedia Commons

By Nivedita Khandekar

A study of the five countries sharing and relying on the Indian sub-continent’s great rivers shows that Bangladesh is the only one that is taking climate change seriously.

NEW DELHI, 7 July, 2014: Even before this year’s delayed and inadequate monsoon recently brought some relief to the Indian sub-continent, researchers discovered widespread concern by local experts that their governments are mismanaging the water supplies on which a billion people depend for survival, and giving insufficient attention to climate change.

A new report, Attitudes to Water in South Asia, explores domestic water management and transboundary water issues in five countries – Afghanistan, Bangladesh, India, Nepal and Pakistan. It focuses on two river systems, the Ganges-Brahmaputra-Meghna and the Indus-Kabul basins, which are vital to the lives of a vast population.

Chatham House – the home of the Royal Institute of International Affairs − worked on the report with India’s Observer Research Foundation, and similar partner organisations in the other four countries. Their findings are based on evidence from almost 500 interviews conducted in the five countries in 2013 with a range of water experts, government officials, policy-makers and decision-makers from NGOs and the private sector.

Observing that water is “highly politicised in the region, with strong links to food security and the livelihoods of the large proportion of the population dependent on agriculture”, the report underscores the relation between the domestic mismanagement of water in each country and the failure to address transboundary water relations.

Few agreements

“In spite of the shared river system and the interdependencies, South Asian governments have signed few bilateral water agreements and no regional ones,” the report says. “Those transboundary water treaties that do exist face criticism on a number of grounds: for time periods too short to too long; and for their lack of provision for environmental factors or new challenges, such as climate change.”.

Yet the ability of countries in South Asia to deal with the possible effects of climate change will be in part determined by their ability to manage water, and also how they deal with weather events such as floods and droughts.

“The majority . . .  expressed concern that their governments
were giving the issue of climate change insufficient attention”

While many respondents across the region felt that other immediate concerns were more pressing, the majority of those interviewed expressed concern that their governments were giving the issue of climate change insufficient attention,” said Gareth Price, a senior research fellow at Chatham House and lead author of the report.

For instance, in Afghanistan, even where respondents had some knowledge of the body responsible for setting government-wide policy on climate change, they were equally certain that the amount of practical action on ground was virtually zero.

In Bangladesh, where most respondents were acutely aware of climate change and its possible effects, many said their government was doing better. There was a general consensus that ministers had made climate change a priority by setting aside funds for adaptation and mitigation.

However, Afghani and Bangladeshi respondents noted the lack of availability of important policy documents − currently available only in English − in local languages..

And Indian respondents felt that climate change was not a major priority for the government, although it was widely recognised that it could wreak havoc on the country.

“Inadequate water storage leaving farmers vulnerable to the vagaries of weather suggest an urgent need for appropriate investment in such facilities in order to not just increase agriculture production, but also to ensure farmers have an option to adjust to changing climate,” the report says.

Food security

Climate change could also have a big impact on the transboundary water relations, the report warns. Some respondents from India and Bangladesh feared that a variation in the timing and intensity of monsoons could affect agricultural production and weaken food security, “driving tension between the two countries over access to water in a dry period”.

Interviewees from Nepal perceived climate change as a “future threat”, in comparison with immediate challenges and the need to increase access to water and electricity. Most respondents felt that Nepal’s approach was “inadequate” and pointed out the gap between national plans and local implementation.

Pakistani respondents believed their country’s approach to climate change lacked “urgency”. They particularly pointed out that a Ministry of Climate Change had recently been reduced to a mere division of another ministry, and had had its funding slashed by 62%.

Brink of cataclysm

The report quoted a climate change expert working with the Pakistan government, who said his country stood on the brink of an environmental cataclysm, with the seasonal monsoon shifting away from traditional catchment areas towards Afghanistan. “This trend, reinforced by climate change, [has]increased the likelihood of extraordinary rainfall patterns, cloudbursts, and flash floods,” he said.

The researchers’ recommendations Include: improving domestic water management, and rainwater harvesting; enhancing data collection, data sharing and discussions between the five countries, particularly in relation to floods and droughts, and the management of watersheds and river basins; easing water demand through less water-intensive crops and irrigation methods.

They also stress that existing treaties should be revisited, ensuring that they address technological advances, environmental factors and climate change. – Climate News Network

  • Nivedita Khandekar is a journalist based in New Delhi, focusing on environmental and developmental issues. She has worked at the Press Trust of India, India’s premier news agency, and the Hindustan Times, one of the leading national daily newspapers in India. Her journalistic achievements include a national award for environmental reporting, an award for reporting on health issues, and a Rural Reporting Fellowship.

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

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

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

Potatoes pioneer crops swap trail

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Potatoes native to the high Andes come in many shapes, sizes and colours Image: Edgar Amador Espinosa Montesinos via Wikimedia Commons

Potatoes native to the high Andes come in many shapes, sizes and colours
Image: Edgar Amador Espinosa Montesinos via Wikimedia Commons

By Alex Kirby

Small-scale farmers from as far apart as Peru, China and Bhutan have agreed to share indigenous crop varieties in a pioneering initiative to help adaptation to climate change.

LONDON, 21 May − A warming climate may confront any of us with unfamiliar problems. The upside, though, is that people half a world away from each other may already have some answers.

Small-scale farmers on two continents – from Yunnan in China and from Bhutan and Peru − are now working together to help their communities to adapt to the impacts of a hotter world.

They have agreed to share indigenous crop varieties, and the knowledge needed to grow them in different climates and landscapes, in a scheme that aims to maintain resilient food systems relying on a number of crops, not simply monocultures.

The aim is also to provide the farmers with secure access to seeds each season, and to protect “food sovereignty”, so that they retain control of their harvests without agribusiness intervening.

Food security

The agreement was reached in late April at a meeting in the Potato Park, near the high-altitude Peruvian city of Cusco. The Park conserves 1,460 different potato varieties to protect food security in the face of climate change.

For the moment, the agreement involves only potatoes, although other species may be included later. The tubers themselves will not be swapped, but only in vitro material   –  with scientists from Peru‘s International Potato Center (CIP) in Lima alert to preventing any unwitting transfer of parasites or diseases.

“This partnership represents a unique alliance forged by indigenous peoples to overcome the threats to agriculture and food security in a changing climate,” said Alejandro Argumedo, the director of not-for-profit Asociación ANDES, one of the scheme’s organisers.

He told the Climate News Network that there was no comparable scheme “with this particular focus on climate change adaptation and biocultural heritage innovation as key to resilience”.

“Although our communities are half a world apart,
they share similar concerns.”

Yiching Song, from the Center for Chinese Agricultural Policy of the Chinese Academy of Sciences, said: “Although our communities are half a world apart, they share similar concerns. Communities are stronger working together than apart.”

The head of CIP’s Gene Bank, David Ellis, said: “Achieving sustainable food security in a world with a growing population, changing diets and a changing climate is a major challenge. Alliances among farming communities and scientists, such as this one, are a critical element in the response to these challenges.”

Planting line

Farming communities in all three countries are already being affected by climate change, the scheme’s organisers say. They are experiencing higher temperatures, leading to more pests and reduced water availability. For example, in the Potato Park, high in the Peruvian Andes, glaciers are melting, and the top of the planting line has been reached, so farmers are having to find new areas to plant the potatoes.

Krystyna Swiderska, an agro-ecologist at the London-based International Institute for Environment and Development, which helped to fund the farmers’ meeting, told the Network that the agreement was concentrating on species that would grow well in mountain conditions.

She said: “The focus will be on crops that perform well in harsh environments prone to droughts, frost, flooding, pests and so on, and on increasing diversity. The greater the diversity of crops th at communities have, the greater the chances of growing food in the face of increasingly extreme weather.”

Swiderska said Peru, Bhutan and China shared similar basic cultural values and traditional farming systems. The three countries also had been involved because they are participating in the Mountain Communities Initiative (MCI) meeting in Bhutan on climate change impacts, in the last week of May.

She believes that the Cusco agreement could work elsewhere. “The transfer of knowledge will be replicated at the MCI, which will involve 14 communities from 10 countries,” she said. “The transfer of seeds has not happened yet, but could potentially be replicated in other communities participating in the MCI and beyond.” − Climate News Network

Climate worries insurers and military

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US Navy personnel help with the clean-up in Staten Island, New York, after Superstorm Sandy hit in 2012 Image: US Navy via Wikimedia Commons

The US Navy helps with the clean-up in New York state after Superstorm Sandy in 2012
Image: US Navy via Wikimedia Commons

By Alex Kirby

Powerful voices in finance and the armed forces raise concerns about the risks of increasingly extreme weather events causing billions of dollars of damage and potentially igniting humanitarian disasters and regional conflicts

LONDON, 15 May − The risks associated with climate change have got some very important people worried − the people who pick up the bills, and those who clear up the mess or try to prevent it happening.

The world’s biggest and oldest insurance market, Lloyd’s of London, has published a report that urges insurers to include climate risks in their models. It says: “Scientific research points conclusively to the existence of climate change driven by human activity.

“Nevertheless, significant uncertainty remains on the nature and extent of the changes to our climate and the specific impacts this will generate. Many of the effects will become apparent over the coming decades and anticipating them will require forward projections, not solely historical data.”

Quoting the Munich Re insurance group , the World Bank says damage and weather-related losses around the world have increased from an annual average of $50bn in the 1980s to nearly $200bn over the last decade.

Causing havoc

The Lloyd’s report was published the day after the US National Climate Assessment (NCA) warned Americans that climate change is already causing havoc across the country. John Holdren, the White House science adviser, said the NCA was the “loudest and clearest alarm bell to date signalling the need to take urgent action to combat the threats to Americans from climate change”.

The most expensive year on record for natural disasters was 2011, when insured losses cost the industry more than $126bn. In 2012, Superstorm Sandy caused $35bn of insured losses, making it the most expensive hurricane in US history after Hurricane Katrina in 2005.

The Lloyd’s report says a 20cm rise in sea level at the southern tip of Manhattan Island increased Sandy’s surge losses by 30% (up to $8bn) in New York alone.

John Nelson, chairman of Lloyd’s, told the Guardian newspaper in London: “The destruction Sandy brought to the eastern US seaboard was responsible for claims of up to $300m in lost fine art, a consequence of the many expensive US beachfront homes damaged.”

Typhoon Haiyan, which devastated much of the Philippines and other parts of south-east Asia in November 2013, was one of the strongest tropical cyclones on record.

Trevor Maynard, head of exposure management and reinsurance at Lloyd’s, said: “Climate change is very much here to stay. Hurricanes are getting stronger worldwide, and especially over the north Atlantic. . .  At the moment we are heading for a rise of four degrees by the end of the century.”

Mission reality

IT’S NOT ONLY the insurers who believe that climate change is a real and growing risk. Increasingly, the prospect is preoccupying military planners.

Mark Wright, a Pentagon spokesman, said: “This is a mission reality, not a political debate. The scientific forecast is for more Arctic ice melt, more sea-level rise, more intense storms, more flooding from storm surge, and more drought.”

A former US Navy officer, retired Vice-Admiral Lee Gunn, is reported by NBC News as saying that the 2011 Arab Spring uprising could in part be traced to a winter drought in China, plus record heat waves and flooding in several other countries, including Russia.

Gunn concluded: “There was a drought and a wheat shortage that resulted in an increase in wheat prices and, therefore, an increase in bread prices − a staple in North Africa.”

NBC says US security experts are also concerned by possible threats to the rice harvest in south-east Asia, and specifically in Vietnam. They say the melting of the Himalayan glaciers would add to sea-level rise, ruining rice production and ravaging Bangladesh. If it did, they believe, that could create a flow of refugees into India, and also threaten fresh water resources in India and Pakistan.

Dennis McGinn, the US Navy assistant secretary for energy, installations and environment, told NBC that there were also worries in military circles about unstable governments and fragile societies.

“The last thing in the world these nations need are the severe and more frequent effects of bad weather, including crop failures,” McGinn said. “Therein is a recipe for the kind of instability that will inevitably involve the United States in humanitarian assistance, disaster relief or, indeed, in a regional conflict.”

A further report, by 16 retired generals and admirals, says climate change is a direct threat to national security and the US economy. The authors, members of the Military Advisory Board of the not-for-profit CNA Corporation, blame rising temperatures for, in part, worsening international tension. 

Their study says that the impacts of climate change are already intensifying instability in vulnerable regions, especially the resource-rich and rapidly changing Arctic. It says the projected impacts within the US will threaten its homeland security and major sectors of its economy. − Climate News Network

Heat extremes threaten crop yields

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An undersized cob from a failed maize crop in Ghana's Upper West Region, which has suffered failed rains and rising temperatures Image: By CIAT (NP Ghana23_lo  Uploaded by mrjohncummings), via Wikimedia Commons

An undersized cob from a failed maize crop in Ghana which has suffered failed rains and rising temperatures
Image: By CIAT (NP Ghana23_lo Uploaded by mrjohncummings), via Wikimedia Commons

By Tim Radford

Yields of several major crops are likely to be seriously affected by rising temperatures, scientists say, with spells of extreme heat posing the greatest risk.

LONDON, 21 March – Rampant climate change driven by ever-rising levels of carbon dioxide in the atmosphere poses a serious threat to world food supply, according to a new study in Environmental Research Letters.

The hazard comes not from high average temperatures, but the likelihood of heat extremes at times when crops are most sensitive to stress. And the message is: those communities that rely on maize as a staple are more at risk than most.

Delphine Derying of the Tyndall Centre for Climate Change Research at the University of East Anglia in the UK and colleagues looked at one of the big puzzles of the coming decades: what will global warming do for crop yields?

It is not a simple question: climate change must mean more evaporation, more precipitation, longer growing seasons, more warmth, and higher levels of the carbon dioxide that plants exploit by photosynthesis (the process they use to convert light into chemical energy), so the consequence ought to be greater yields. But as every farmer knows, what matters most is the timing of all that warmth, rain, and those dry spells in which the harvest can ripen.

Danger in extremes

There is a second consideration. Climate is the sum of all events. Rather than a steady overall rise in daily temperatures, an increasing number of ever-larger regions are predicted to experience ever more intense extremes of heat, and sometimes cold. Plants can be very sensitive to extremes of heat at flowering time: if the thermometer goes up, the pollen becomes increasingly sterile and less seed is likely to be set. So an extended heat wave in the wrong season could be calamitous.

The Tyndall team included the assumption that nothing would be done about climate change – that is, that governments, industry and people would continue with a business-as-usual scenario. They then chose three well-studied and vital crops – spring wheat, maize and soybean – and tested predictions under 72 different climate change scenarios for the rest of this century.

They allowed for the already-established benign effects of carbon dioxide-driven warming, one of which is that plants can make more tissue and at the same time use water more efficiently, and therefore respond more effectively to drought conditions. They also looked for the outcomes in places where yields could be most vulnerable: for example, the North American corn belt.

Emissions cuts essential

What they found was that – if carbon dioxide fertilisation effects are not taken into account – then maize, wheat and soya yields are all likely to fall, in all five top-producing countries for each of these crops.

When they factored in the benefits of more CO2 in the atmosphere, the picture changed. There would be positive impacts on soya and wheat, but not on maize.

There is another proviso: so far, the benefits of extra CO2 have been confirmed in experimental plant laboratories. The experience in the fields 60 years in the future may be rather different. And in any case, these positive impacts could be severely offset by extremes of heat at the moment when the crops were most vulnerable, so overall, harvests remain at risk.

The best answer, the scientists argue, is to attempt to limit climate change. “Climate mitigation policy would help reduce risks of serious negative impacts on maize worldwide and reduce risks of extreme heat stress that threaten global crop production,” says Deryng. – Climate News Network

AAAS: Climate risks irreversible change

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By Alex Kirby

In a highly unusual intervention in the debate over climate policy, US scientists say the evidence that the world is warming is as conclusive as that which links smoking and lung cancer.

LONDON, 18 March – The American Association for the Advancement of Science (AAAS) says there is a “small but real” chance that a warming climate will cause sudden and possibly unalterable changes to the planet.

This echoes the words used in its 2007 report by the Intergovernmental Panel on Climate Change (IPCC), which said climate change might bring “abrupt and irreversible” impacts.

A child with kwasiorkor, caused by evere protein deficiency: Child malnutrition may rise by about a fifth Image: Dr Lyle Conrad via Wikimedia Commons

A child with kwashiorkor, caused by evere protein deficiency: Child malnutrition may rise by about a fifth
Image: Dr Lyle Conrad, Centers for Disease Control and Prevention, via Wikimedia Commons

In a report, What We Know, the AAAS makes an infrequent foray into the climate debate. The report’s significance lies not in what it says, which covers familiar ground, but in who is saying it: the world’s largest general scientific body, and one of its most knowledgeable.

The AAAS says: “The evidence is overwhelming: levels of greenhouse gases in the atmosphere are rising. Temperatures are going up. Springs are arriving earlier. Ice sheets are melting. Sea level is rising. The patterns of rainfall and drought are changing. Heat waves are getting worse, as is extreme precipitation. The oceans are acidifying.

“The science linking human activities to climate change is analogous to the science linking smoking to lung and cardiovascular diseases. Physicians, cardiovascular scientists, public health experts and others all agree smoking causes cancer.

Few dissenters

“And this consensus among the health community has convinced most Americans that the health risks from smoking are real. A similar consensus now exists among climate scientists, a consensus that maintains climate change is happening, and human activity is the cause.”

The report’s headline messages are unambiguous. It says climate change is occurring here and now: “Based on well-established evidence, about 97% of climate scientists have concluded that human-caused climate change is happening.

“This agreement is documented not just by a single study, but by a converging stream of evidence over the past two decades from surveys of scientists, content analyses of peer-reviewed studies, and public statements issued by virtually every membership organization of experts in this field.

“We are at risk of pushing our climate system toward abrupt, unpredictable, and potentially irreversible changes with highly damaging impacts…Disturbingly, scientists do not know how much warming is required to trigger such changes to the climate system.

Expensive to delay

“The sooner we act, the lower the risk and cost. And there is much we can do…as emissions continue and warming increases, the risk increases”.

The AAAS says there is scarcely any precedent for the speed at which this is happening: “The rate of climate change now may be as fast as any extended warming period over the past 65 million years, and it is projected to accelerate in the coming decades.”

Historically rare extreme weather like once-in-a-century floods, droughts and heat waves could become almost annual occurrences, it says, and there could be large-scale collapses of the Antarctic and Greenland ice sheets, and of part of the Gulf Stream, loss of the Amazon rain forest, die-off of coral reefs, and mass extinctions.

The authors acknowledge that what the AAAS is doing is unusual: “As scientists, it is not our role to tell people what they should do or must believe about the rising threat of climate change.

“But we consider it to be our responsibility as professionals to ensure, to the best of our ability, that people understand what we know: human-caused climate change is happening…”

More child malnutrition

At the end of March the IPCC, the UN’s voice on climate science, is due to release a summary of the report of its Working Group II, on impacts, adaptation and vulnerability to climate change.

The London daily The Independent, which says it has seen a draft of the report’s final version, says it will spell out a prospect of “enormous strain, forcing mass migration, especially in Asia, and increasing the risk of violent conflict.”

The newspaper says the report predicts that climate change “will reduce median crop yields by 2% per decade for the rest of the century”, against a backdrop of rising demand set to increase by 14% per decade until 2050. “This will in turn push up malnutrition in children by about a fifth”, it adds.

Other predictions in the draft, The Independent says, include possible global aggregate economic losses of between 0.2 and 2.0%; more competition for fresh water; and by 2100 hundreds of millions of people affected by coastal flooding and displaced by land loss, mainly in Asia. – Climate News Network

Climate science ‘is beyond argument’

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Not as sunny as it seems: The ocean is under attack on many fronts, with climate change foremost among them Image: kein via Wikimedia Commons

Not as sunny as it seems: The ocean is under attack on many fronts, with climate change foremost among them
Image: kein via Wikimedia Commons

By Alex Kirby

The Global Ocean Commission says climate change is one of the key threats to the health of the world’s marine life, which it says faces multiple pressures in a warming world.

HONG KONG, 17 March - South Africa’s former Finance Minister, Trevor Manuel, has derided those who deny the scientific argument that climate change is an urgent problem caused largely by human activity.

He told journalists here: “The science is now incontrovertible. There are a few people in the world who deny it, but they are mainly in lunatic asylums.”

Mr Manuel is one of three co-chairs of the Global Ocean Commission, a panel of global leaders who have just ended a meeting here to finalise the proposals they will present to the United Nations in June.

The meeting agreed that another key threat to the world’s oceans is overfishing and the subsidies which help to make it possible. It says this, and the other factors causing ocean degradation, threaten the food security of as many as 500 million people.

It is deeply worried about pollution. With plastic remains now so pervasive that they are found even in deep seafloor sediments, Mr Manuel said, it sometimes seemed that “you might as well not bother to buy seafood at all – just buy the plastic bag it comes in and eat that.”

Shells corroded

The Commission says climate change threatens the oceans in three main ways: by raising the temperature of the water; by reducing its oxygen content; and by increasing its acidity. Antarctic pteropods, small sea snails also known as sea butterflies, are already being found with severely corroded shells because of acidification, and larger creatures, including bigger shellfish and corals, are likely to be seriously affected.

Another of the co-chairs, José María Figueres, the former president of Costa Rica, told the Climate News Network the Commission was concerned at the prospect of exploitation of the high seas in the Arctic as the region’s sea ice continues to melt.

He said: “Beyond Arctic countries’ EEZs (exclusive economic zones stretching 200 nautical miles from the coast), the melting will leave us with a doughnut-shaped hole in the Arctic high seas, which are not under international control.

“Some nations are now looking to explore there for fish, minerals, valuable biodiversity and other resources. I believe we should not go down that route.

We should listen to the science and follow the precautionary principle, keeping this pristine area off-limits for exploitation until we understand the consequences.

Coalition builders

“We’re already pushing the high seas to the limit. We don’t need to push them over the edge by a lack of proper precaution in the Arctic.”

He said: “The jury is still out on whether we have 20 or 30 years ahead as a window of opportunity to act. But why wait? Listen to the science, which is overwhelming, and to the economics, which are sound.”

Describing the Commission as “not just a bunch of treehuggers, but a group that’s grounded itself in good sound economics”, Mr Figueres said the recommendations it planned to present to the UN on 24 June would represent about 20% of its work. The other 80% would involve building coalitions around each recommendation: there are expected to be no more than 10 in total.

The Commission’s third co-chair is the UK’s former Foreign Secretary, David Miliband. He told the Network: “Answers that sit on a shelf are a waste of time, and people who are positively inclined to protect the oceans are held back by institutional inertia.

“But the interplay between climate change and ocean damage is rising, and it very much needs to. The science of most of the last half-century shows us how we’ve been playing tricks with nature.” – Climate News Network