Climate renews famine risk to Africa’s Sahel

Climate renews famine risk to Africa’s Sahel

With population increasing and food demand far outstripping supply, the Sahel is vulnerable to a new humanitarian crisis − and researchers warn that rising temperatures will only make matters worse.

LONDON, 20 October, 2014 − The Sahel, the arid belt of land that stretches from the Atlantic to the Red Sea and separates the Sahara desert from the African savanna, is no stranger to drought and famine.

Now scientists in Sweden say the Sahel faces another humanitarian crisis even than in the recent past − with the changing climate partly responsible.

Writing in the journal Environmental Research Letters, the researchers from Lund University say people in the Sahel need more food, animal feed and fuel every year. But demand, which has more than doubled over a recent 10-year period, is growing much faster than supply.

Fewer resources

Data from 22 countries shows the result: fewer resources per capita and a continued risk of famine in areas with low primary production – that is, the availability of carbon in the form of plant material for consumption as food, fuel and feed.

Human numbers are part of the reason. Between 2000 and 2010, the population of the Sahel grew from 367 million to 471 million people − an annual rise of 2.2% over the decade.

But crop production remained essentially unchanged, so the margin between supply and demand for primary production is shrinking every year, while the Sahel’s population is forecast to total nearly a billion people by 2050.

Children's graves at a refugee camp in Kenya during the famine in 2011 Image: Andy Hll/Oxfam via Wikimedia Commons
Children’s graves at a Kenyan refugee camp during the 2011 famine
Image: Andy Hall/Oxfam via Wikimedia Commons

Some studies suggest that modern plant strains can withstand the effects of drought better than traditional cultivars, although this was not a focus of the Lund team.

They were mainly concerned with the staple crops grown regionally − such as sorghum and millet, which are used as food for people, with the residues used as fodder for livestock − and with the dry woodlands that provide fuel.

They used remote analysis and satellite images to calculate annual crop production in the 22 countries they studied, and compared the figures with data on population growth and consumption of food, animal feed and fuel. This relationship helps to measure a region’s vulnerability.

The study shows that 19% of the Sahel’s total primary production in 2000 was consumed. Ten years later, consumption had increased to 41%.

Reduced harvest

It says several forecasts suggest that harvests will be reduced as a result of the higher air temperatures the region is now experiencing, even though climate change is predicted to result in the Sahel receiving more rain in future.

So, the researchers say, climate change can only increase the vulnerability of the Sahel.

Asked by the Climate News Network whether higher air temperatures alone were likely to cancel the gains from increased rainfall, one of the study’s authors, Hakim Abdi, a doctoral student in physical geography and ecosystem science at Lund, said: “The short answer is yes. Studies indicate that higher temperatures offset both increased rainfall and CO2 fertilisation.

“Additionally, a recent study found that increase in future rainfall in the Sahel, a region where the soil generally receives little nutrient input and is over-exploited, causes nutrient leaching, and hence induces nitrogen stress.

“When we were in our study site in North Kordofan in Sudan, the most common complaint we received from the villages we visited was the lack of water.

“I think that if a drought occurs with an impact that matches or exceeds the ones in 1972/73 or 1982/83, we will see serious consequences − worse impacts than past ones.” − Climate News Network

Croplands changed by climate’s ups and downs

Croplands changed by climate's ups and downs

New research shows that the complex balance of gains and losses caused by climate change could mean more land being available for agriculture − but fewer harvests.

LONDON, 25 September, 2014 − With climate change, you win some, you lose some. New research shows that suitable new cropland could become available in the high latitudes as the world warms − but tropical regions may become less productive.

Florian Zabel and two fellow-geographers from Ludwig Maximilians University in Munich, Germany, report in the journal Public Library of Science One that they made judgments about the climate, soil and topography to suit the 16 most important food and energy crops. They then compared data for the period 1981-2010 with simulations of a warming world for the period 2071-2100.

The results looked good: in northern Canada, China and Russia, they found that a notional additional land area of 5.6 million sq km became available for crops.

Significant losses

Less happily, in the Mediterranean and sub-Saharan Africa there were significant losses of agricultural productivity – if no additional irrigation was factored in. Also, the chances of multiple harvests in tropical Brazil, Asia and Central Africa would be reduced.

Altogether, the land suitable for agriculture by 2100 would total 54 million sq km. But of this, 91% is already under cultivation.

“Much of the additional area is, however, at best only moderately suited to agricultural use, so the proportion of highly fertile land suited to agricultural use will decrease,” Dr Zabel says.

“In the context of current projections, which predict that the demand for food will double by the year 2050 as the result of population increase, our results are quite alarming.”

The Munich calculations were essentially mathematical projections based on climate models that are, in turn, based on broad conclusions of change. But what if those broad conclusions are too sweeping?

Climate researcher Peter Greve, of the Swiss Federal Institute of Technology (ETH) in Zurich, and colleagues report in Nature Geoscience that the rule of thumb for climate change – that wet regions will tend to get wetter, and already dry regions will in general become more arid – may not always hold.

So they looked at the calculations again, and began to search for trends towards increasing humidity or aridity.

In effect, they were trying to see if they could predict what should have happened in the past, so they chose two periods − 1948 to 1968, and 1984 to 2004 − and examined the patterns of change.

Clear trends

They could find no obvious trend towards either a wetter or a drier climate over about three-quarters of the land area under consideration. There were clear trends for the remaining quarter, but, once again, the answers were not simple. In about half of this land area, the dry-gets-drier, wet-gets-wetter rule seemed to hold. In the other half, the trends seemed to be contradictory.

In the past, parts of the Amazon, Central America, tropical Africa and Asia should have got wetter, but instead became less moist. Patagonia, central Australia and the US Midwest were all dry areas that became wetter.

The wet-gets-wetter rule held good for the eastern US, northern Australia and northern Eurasia, and the already dry Sahel, Arabian Peninsula and parts of central Asia and Australia became more parched.

The lesson is not that climate projections are wrong, but that climate systems are very complex. “Our results emphasise how we should not overly rely on simplifying principles to assess past developments in dryness and humidity,” Greve says. – Climate News Network

UN population growth data is bad news for climate

UN population growth data is bad news for climate

Sophisticated new analysis indicates an 80% probability that the planet’s population will continue to rise this century, with serious implications for food security, political stability − and climate change.

LONDON, 19 September, 2014 − The demographers may have got it wrong. New projections say the population of the planet will not stabilise at 9 billion sometime this century. In fact, there is an 80% likelihood that, by 2100, it will reach at least 9.6 bn − and maybe rise as high as 12.3 bn.

The latest data, published in the US journal Science, has profound and alarming implications for political stability, food security and, of course, climate change, since greater numbers of people mean greater demands on agricultural land, water and fuel.

At the heart of the findings − led by Patrick Gerland, of the United Nations Population Division in New York, and backed by sociologists, statisticians and population scientists from Seattle, Singapore and Santiago in Chile − is both new data and a more sophisticated approach to the mathematical probabilities for fertility and life expectancy, and for international migration.

Larger families

The new evidence is that, contrary to previous expectations, women in Africa are still having larger families − in part, because contraceptives are not available and because mortality linked to HIV infection has been reduced.

So, by the end of the century, Africa – once relatively sparsely populated, but now home to around one billion people – will have to feed between 3.5 bn and 5.1 bn.

The new information is available because the UN Population Division re-examines its calculations every two years − and the new techniques include the adoption of a methodology known to mathematicians as “Bayesian probabilistic”.

In the new scenarios, Africa remains at the heart of the population explosion, and African women on average have 4.6 children. There are 4.4 bn people in Asia now, but this is expected to peak at 5bn in 2050 and then decline. North America, Europe, Latin America are expected to stay below 1bn each.

“Earlier projections were strictly based on scenarios, so there was no uncertainty,” said Dr Gerland. “This work offers a more statistically-driven assessment that allows us to quantify the predictions and offer a confidence interval that could be useful in planning.”

The study makes no mention of climate change, and the demographers are more concerned with the numbers of young workers who will have to support increasingly elderly populations. But population, economic growth and global warming are inexorably linked.

Most climate change predictions, when they incorporate population growth at all, have been based on the long-standing assumption that the planet’s burden of humans will peak around 2050, and then begin a slow decline.

Because of this, some researchers have been able to put forward arguments for optimism and propose that climate change can be contained and food security assured with careful management and new thinking.

But recent research suggests that while climate change will open more land in higher latitudes for potential crop growth, the gains will not be great, because the conditions for multiple harvests in the tropics will be reduced.

There are other factors. For example, land once available for crops is disappearing under tarmac and cement as the world’s cities grow, and even with a projected population peak of 9bn, an estimated additional 1.5 million square kilometers of tilth and pasture would be lost to the cities by 2030.

Losses of farmland

In addition, the encroachment of the world’s deserts and the erosion of once fertile farmland continues to exact its toll. Statisticians say that between 19 hectares and 23 hectares of land is abandoned every minute. With the latest, and more alarming, population projections, these losses of farmland can only increase.

But these are all projections, rather than predictions. Armed with such information, governments could take steps to ensure a more secure future.

The authors of the Science paper argue that fertility decline could be helped by better access to contraception, and by the education of women.

They add, grimly, that things could also get worse: “It should also be noted that the projections do not take into account potential negative feedback from the environmental consequences of rapid population growth.

“The addition of several billion people in Africa could lead to severe resource shortages, which in turn could affect population size through unexpected mortality, migration, or fertility effects.” – Climate News Network

Dietary effect on GHG emissions is hard to swallow

Dietary effect on GHG emissions is hard to swallow

Controversial new research findings say that US government guidelines on a better diet might be good for Americans’ health, but would be far from healthy for the climate.

LONDON, 13 September, 2014  − The news is enough to make climate campaigners choke on their high-fibre breakfast cereal: if Americans adopted the dietary guidelines suggested by their own Department of Agriculture, greenhouse gas emissions (GHGs) would actually go up by 12%.

And even if Americans did what dietary campaigners urge and restricted themselves to a healthier 2000 calories a day, GHGs would not fall significantly.

Martin Heller and Gregory Keoleian, scientists at the University of Michigan’s Centre for Sustainable Systems, publish these findings in the Journal of Industrial Ecology.

And their conclusion  is liable to prove controversial, if only because other agriculturalists and economists have already argued that changes in human diet and more intelligent ways of promoting agriculture could simultaneously deliver better nutrition, greater food security, and less damage to global climate.

Contentious conclusions

Cynics will remind each other that all scientific conclusions about diet, health, environment and nutrition tend to become contentious shortly after publication.

Others are likely to agree with Paul Palmer, of the University of Edinburgh, and Matthew Smith, of the University of Cambridge, who argue in Nature journal that it makes no sense to speculate on climate change without considering how people will respond to that change. “Omitting human behaviour is like designing a bridge without accounting for traffic,” they say.

Social commentators will also point out that in a society in which one-third of all Americans are classed as clinically obese and another third are overweight − and in which, paradoxically, 49 million are also “food insecure” or just plain hungry − there might be something irrelevant about the US government’s dietary guidelines.

But the study by Heller and Keoleian, at bottom, simply addresses the problems associated with bureaucratic advice on subjects as personal as breakfast, lunch and dinner.

Direct emissions from agriculture make up between 10% and 12% of overall greenhouse gas emissions. If you throw in factors such as fertilizer and chemical production, fuel use and agricultural land-use change, the proportion rises – along with the uncertainty – to between 17% and 32%.

Researchers may enhance yields and farmers may use resources more efficiently, but populations will increase − and so will demand for meat and dairy products.

So the two scientists looked at greenhouse gas emissions associated with 100 foods. They considered the losses and waste in the food business: around a third of all food globally is lost or thrown away, and emissions from wasted food in the US add up to the equivalent of an extra 33 million cars on American roads.

Costs and losses

They added into the mix the potential effects of social change − looking at studies from Germany and Switzerland, at EU targets, and at calculations of the demand for water and fertilizer in Asia and Africa − to get a surer picture of the costs and losses and emissions associated with agriculture.

They then examined the particular case of the US, where, they say, “repeated assessments find that Americans do not meet the federal dietary recommendations”.

Those guidelines recommend that Americans eat more fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood, and also consume less salt, saturated fat, trans fats, cholesterol, added sugar and refined grains.

Their calculation is that even if US citizens consumed less beef and thus reduced greenhouse gas emissions – beef makes up 4% by weight of available food, but 36% of emissions − the increased use of dairy products would have the opposite effect.

If Americans followed the recommendations and continued to consume the same number of calories on average, greenhouse gas emissions would rise by 12%. If the nation reduced its intake to 2000 calories a day on average, the reduction would be only 1%.

“These findings emphasise the need to consider environmental costs in formulating recommended food patterns,” Heller and Keoleian conclude. – Climate News Network

Waste could fertilise food cost cuts

Waste could fertilise food cost cuts

Scientists are developing a way to squeeze the last vestiges of value from renewable energy processes by combining their waste products to produce eco-friendly fertilisers that could help slow food price rises.

LONDON, 30 August 2014 − Researchers in the UK think they may have found a way to produce fertilisers that should cut farmers’ costs and at the same time boost some types of renewable energy.

Their scheme, which involves using waste material from anaerobic digesters and ash from burnt biomass, would also cut fossil fuel use and save natural resources.

The team, based at the Environment Centre at the University of Lancaster, says their fertiliser would help to slow the rise in food prices. And they believe it would work worldwide.

The three-year project has received more than £850,000 (US$1.4 m) in funding from the UK’s Natural Environment Research Council. Research, due to start this year, will take place in labs at the university and in field trials.

The project, which includes several partners working with the university, aims to produce a sustainable, environmentally-friendlier source of soil conditioner and crop fertiliser.

Potential

It builds on research originally conducted by one of the partners, Stopford Energy and Environment Ltd consultancy, which investigated using a mixture of digestates − the waste left over after material has been through an anaerobic digester − and ash, from burnt biomass, as an alternative to existing fertilisers.

Most fertilisers now in use, such as phosphorous-based and nitrate-based products, are made using energy-intensive methods that involve the consumption of oil and gas.

Phosphate-based fertiliser relies as well on the mining of phosphate, a finite and unsustainable resource, and on a production process using various toxic chemicals.

There are already projects in several countries − including the UK − that use waste from digesters to make fertiliser.

But Professor Kirk Semple, of the Lancaster Environment Centre, who leads the project, said: “It is the mixing of anaerobic digestate with biomass ash that is important. . . This would reduce pressure on natural resources and develop a new market for problematic by-products of the bio-energy industry.

“Although the project is based here in the UK, we believe there is exciting potential to produce a sustainable alternative to existing fertiliser use across the globe.”

Nutrients

A successful digestate-ash fertiliser would reduce costs and provide additional income to biomass and anaerobic digestion operators. The Lancaster team says this could make these forms of renewable energy − which could meet more than 15% of UK energy demand by 2020 − more appealing to investors, as at the moment ash has to be expensively dumped in landfills.

They say it could help to improve food security and reduce costs to farmers as production of the new fertiliser would not be linked to the global price of oil and gas.

Previous studies by Stopford show that biomass ash and digestate can be useful nutrient sources for crops in conditions which lack them.

Professor Semple told the Climate News Network that he and his colleagues were working to ensure that the new fertiliser was entirely safe. He said: “Part of the grant will be used to chemically analyse the materials, individually and together, for metals and potentially other chemicals.”

He says commercial-scale production of a successful digestate-ash fertiliser “is some way off”. But he adds: “This project offers the first detailed interrogation of this type of soil amendment. If successful, we would then look to develop this for the commercial sector.” − Climate News Network

Food security faces growing pest advance

Food security faces growing pest advance

A world with more people will see more competition for food. Many of our competitors may not be human, because natural pests are spreading far and wide.

LONDON, 29 August 2014 - Coming soon to a farm near you: just about every possible type of pest that could take advantage of the ripening harvest in the nearby fields.

By 2050, according to new research in the journal Global Ecology and Biogeography, those opportunistic viruses, bacteria, fungi, blights, mildews, rusts, beetles, nematodes, flies, mites, spiders and caterpillars that farmers call pests will have saturated the world.

Wherever they can make a living, they will. None of this bodes well for food security in a world of nine billion people and increasingly rapid climate change.

Dan Bebber of the University of Exeter, UK,  and colleagues decided to look at the state of pest populations worldwide. They combed the literature to check the present status of 1,901 pests and pathogens and examined historical records of another 424 species. This research included the records made since 1822 by the agricultural development organization CABI.

Crop pests often emerge in one location, evolve and spread. That notorious potato pest the Colorado beetle, for instance, was first identified in the Rocky Mountains of the US in 1824.

Rising trend

The scientists reasoned that climate change and international traffic made transmission of pests across oceans and other natural barriers increasingly probable, and tried to arrive at a rate of spread.

They found that more than one in 10 of all pest types can already be found in half of the countries that grow the host plants on which these pests depend. Most countries reported around one fifth of the pests that could theoretically make their home there.

Australia, China, France, India, Italy, the UK and the USA already had more than half of all the pests that could flourish in those countries. The pests that attack those tropical staples yams and cassava can be found in one third of the countries that grow those crops.

This trend towards saturation has increased steadily since the 1950s. So if the trend continues at the rate it has done during the late 20th century, then by 2050 farmers in western Europe and the US, and Japan, India and China will face saturation point.

They will be confronted with potential attack from just about all the pests that, depending on the local climate and conditions, their maize, rice, bananas, potatoes, soybeans and other crops could support.

Early warning

“If crop pests continue to spread at current rates, many of the world’s biggest crop-producing nations will be inundated by the middle of the century, posing a grave threat to global food security,” Dr Bebber said.

Three kinds of tropical root knot nematode produce larvae that infect the roots of thousands of different plant species. A fungus called Blumeria graminis causes powdery mildew on wheat and other grains; and a virus called Citrus tristeza, first identified by growers in Spain and Portugal in the 1930s, had by 2000 reached 105 out of the 145 countries that grow oranges, lemons, limes and grapefruit.

Predictions such as these are intended to be self-defeating: they present a warning of what might happen if no steps are taken.

“By unlocking the potential to understand the distribution of crop pests and diseases, we’re moving one step closer to protecting our ability to feed a growing global population,” said Timothy Holmes, of CABI’s Plantwise knowledge bank, one of the authors. “The hope is to turn data into positive action.” - Climate News Network

Climate change heralds end of civilisations

Climate change heralds end of civilisations

New research supports the growing body of evidence that many past civilisations have collapsed because of climate change. So is history repeating itself?

LONDON, 13 August, 2014 –  Scientists looking at what is known as the “Fertile Crescent” of ancient Mesopotamia have found new evidence that drought caused by climate change brings an end to civilisations.

It is the latest study that confirms the threat posed to present civilisations in Africa, Asia and parts of the United States by changes in rainfall pattern that could lead to the abandonment of once-fertile areas − and the cities that once were fed by them.

The focus of research by a team from Tübingen University, Germany, is the area currently part of Iraq and the Persian Gulf where the development of ancient agriculture led to the rise of large cities.

Evidence from grain samples up to 12,000 years old shows that while the weather was good, the soil fertile and the irrigation system well managed, civilisation grew and prospered. When the climate changed and rainfall became intermittent, agriculture collapsed and the cities were abandoned.

Analysed grains

Dr Simone Riehl, of the Institute for Archaeological Sciences and the Senckenberg Center for Human Evolution and Palaeoenvironment at Tübingen University, analysed grains of barley up to 12,000 years old from 33 locations across the Fertile Crescent to find out if they had had enough water while growing and ripening.

The 1,037 ancient samples were between 12,000 and 2,500 years old. They were compared with modern samples from 13 locations in the former Fertile Crescent.

Dr. Riehl and her team measured the grains’ content of two stable carbon isotopes.

When barley grass gets insufficient water while growing, the proportion of heavier carbon isotopes deposited in its cells will be higher than normal. The two isotopes 12C and 13C remain stable for thousands of years and can be measured precisely – giving Riehl and her colleagues reliable information on the availability of water while the plants were growing.

They found that many settlements were affected by drought linked to major climate fluctuations. “Geographic factors and technologies introduced by humans played a big role and influenced societies’ options for development, as well as their particular ways of dealing with drought,” Riehl says.

Her findings indicate that harvests in coastal regions of the northern Levant, at the eastern end of the Mediterranean Sea, were little affected by drought. But further inland, drought led to the need for irrigation or, in extreme cases, abandonment of the settlement.

The findings give archaeologists clues as to how early agricultural societies dealt with climate fluctuations and differing local environments. “They can also help evaluate current conditions in regions with a high risk of crop failures,” Riehl adds.

The study is part of a project, backed by the German Research Foundation, looking into the conditions under which Ancient Near Eastern societies rose and fell.

Scientists carrying out similar research in the Indus Valley, in present Pakistan and north-west India, home to the Harappan Civilisation, also believe that drought was the cause of the civilisation’s demise.

It was characterised by large, well-planned cities with advanced municipal sanitation systems and a script that has never been deciphered. But the Harappans seemed to slowly lose their urban cohesion, and their cities were gradually abandoned.

Cities abandoned

According to an article in Nature in March, a 200-year drought, caused by the failure of the monsoon, led to the abandonment of the cities and the end of the civilisation.

Across the Atlantic, another puzzle was the loss of the Mayan cities and culture in Central America. This was a people that had the time, money and manpower to build massive temples and cities for a population estimated at 13 million.

Many theories have been put forward as to why, over a period of about 200 years from 750 to 950AD, the Mayans abandoned their way of life. Research on the subject by Sigma Xi, The Scientific Research Society, says that a series of droughts caused by local climate change was the cause.

With the latest report of the Intergovernmental Panel on Climate Change predicting a faltering of the monsoon that is vital for the Indian sub-continent’s ability to feed itself, it seems as though history could repeat itself. Certainly, some people in India believe it could happen unless action to curb climate change is taken.

Environmental refugees in Africa are also seen as victims of changing weather patterns, and California is suffering a three-year drought that is badly affecting water supplies in this most prosperous of American states. – Climate News Network

Warming threatens to cut crop yields

Warming threatens to cut crop yields

The odds on food production being unable to meet the needs of an expanding population are hard to predict, but a new study shows that the risk increases dramatically when man-made climate change is factored in.

LONDON, 2 August, 2014 − Projecting the impact of climate change on global food production is no easy task. A warming climate might result in better crop yields in one region, but cause drought and crop failure in another.

A new US study, published in the journal Environmental Letters, assesses the odds of a major slowdown in global food production over the next 20 years.

Overall, the study’s authors say, the likelihood of a sharp drop in yields of crops vital to food supply, such as wheat and maize, is “not very high” − but global warming does markedly increase the chance of such events happening. The risk to global food supplies is about 20 times greater when man-made climate change is taken into account.

“Climate change has substantially increased the prospect that crop production will fail to keep up with rising demand in the next 20 years,” says Claudia Tebaldi, a research scientist at the National Center for Atmospheric Research and a co-author of the study.

Climate trends

Tebaldi, together with David Lobell, an associate director of the Center on Food Security and the Environment at California’s Stanford University, used computer models of global climate trends, together with data on weather patterns and crops, to calculate the odds of a major downturn in food supplies.

“I’m often asked whether climate change will threaten food supply, as if it’s a simple yes or no answer,” Lobell says.

“The truth is that, over a period of 10 or 20 years, it depends largely on how fast the Earth warms, and we can’t predict the pace of warming very precisely. So the best we can do is try to determine the odds.”

Yields of crops such as maize and wheat have typically increased by between one and two per cent a year over recent decades. This trend, says the study, needs to be maintained to cope with population growth, greater per capita food consumption, and the increased use of crops for biofuels.

The authors of the study – which was funded by the US government’s National Science Foundation and the US Department of Energy − found that under what they term natural climate shifts, the odds on that trend slowing up to 2030 were only 1 in 200.

Global food supplies

However, when human-induced global warming is taken into account, the odds shorten to one in 10 for a slowing in yields of maize and one in 20 for wheat production. Such cutbacks, says the study, would have a major impact on global food supplies at a time when demand is growing sharply.

Tebaldi and Lobell say an increase of 1˚C in temperature is capable of slowing maize yields by 7% and wheat yields by 6%, although there are regional variations to these figures.

The study says a slowdown in yields of maize and wheat could, in theory, be offset by shifting planting to cooler regions, but there is little sign that such shifts are happening – at least not quickly enough to take account of warmer temperatures.

“We can’t predict whether a major slowdown in crop growth will actually happen, and the odds are still fairly low,” says Tebaldi.

“But climate change has increased the odds to the point that organisations concerned with food security or global stability need to be aware of this risk.” − Climate News Network

New seeds of hope for Nepal’s farmers

New seeds of hope for Nepal’s farmers

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.

Rising heat hits Indian wheat crop

Rising heat hits Indian wheat crop

Satellite imaging highlights 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.

LONDON, 28 July, 2014 − Researchers in the UK have established a link between changing climate and agriculture that could have significant consequences for food supplies in South Asia.

They have found evidence of a relationship between rising average temperatures in India and reduced wheat production, which was increasing until about a decade ago but has now stopped.

The researchers, Dr John Duncan, Dr Jadu Dash and Professor Pete Atkinson, all geographers at the University of Southampton, say an intensification is predicted for the recent increases in warmth in India’s main wheat belt that are damaging crop yields.

The greatest impact that the hotter environment has on wheat, they say, comes from a rise in night-time temperatures.

Vulnerability

Dr Dash said: “Our findings highlight the vulnerability of India’s wheat production system to temperature rise. We are sounding an early warning to the problem, which could have serious implications in the future and so needs further investigation.”

The team is the first to use satellite imagery to establish the link between warming and crop yields. The images were taken at weekly intervals, from 2002 to 2007, of the wheat-growing seasons to measure the “vegetation greenness” − an indicator of crop yield.

The imagery, of the north-west Indo-Gangetic plain, was taken at such a high resolution that it was able to capture variations in local agricultural practices. The plains stretch over much of northern and eastern India, and into parts of Pakistan, Nepal and Bangladesh.

The data was then compared with climate and temperature information for the area to examine the effect on growth and development of the crop.

The study, published in the journal Global Change Biology, found that warmer temperatures reduced crop yield. Greater warmth during the reproductive and ripening periods, in particular, had “a significant negative impact on productivity”. But it was the warmer nights that did the greatest harm.

In some parts of the Indian wheat belt, growers have been advancing their growing season to make sure that the most sensitive point of the crop growth cycle falls within a cooler period. But in the long term, the researchers say, this will not help, because of the high average temperature rises predicted.

Dr Dash said farmers would have to think seriously about changing to more heat-tolerant wheat varieties. “Currently in India, 213 million people are food insecure and over 100 million are reliant on the national food welfare system, which uses huge quantities of wheat,” he said.

Regular data

“We hope that soon we will be able to examine agricultural practices in even greater detail, with the launch of the European Space Agency’s Sentinel satellites, which will provide regular data at even higher spatial resolution.”

In 2012, India was the world’s second largest wheat producer, with 94.9 million tonnes. It was self-sufficient and able to sell some wheat overseas, although the government has now limited exports.

India’s production was exceeded only by China’s. But China is building up its reserves of wheat, and is now widely seen as working more energetically than many developing countries for an ambitious global climate change agreement.

Dr Dash told the Climate News Network: “Ten years ago, India’s yield of wheat was increasing. Today, it’s stagnant − and the predictions are that, by 2050, average temperatures will be 5% higher than they are now. This is a wake-up call for the whole of South Asia.” − Climate News Network