Green Revolution trebles human burden on planet

Green Revolution trebles human burden on planet

American researchers say seasonal swings in temperatures and CO2 levels are evidence of how agricultural advances and the population explosion have tilted nature’s balance.

LONDON, 22 November, 2014 – Humans are changing not just climate overall, but also the difference between seasons in any given year.

Researchers in the US believe they now know why global warming has begun to announce itself both in annual rises in temperature and in the seasonal records of carbon dioxide in the northern hemisphere − the same seasonal variation in atmospheric chemistry that also contains within it the signature of the Green Revolution and the 20th-century population explosion.

And it’s all because the natural swing from high carbon dioxide levels to low each year has become more dramatic in the last 50 years.

Each year, in the northern hemisphere growing season, the CO2 levels drop as plants grow and soak up the atmospheric carbon.

Inexorable pattern

Later in the year, as leaves fall, crops are harvested and consumed, and soil is freshly tilled, most of that CO2 gets back into the atmosphere. It’s an inexorable pattern that follows the seasons.

Systematic measurements of CO2 levels began in 1958, and they show that swings within each year from high to low, and back again, have increased in amplitude by 50%, and go on increasing by 0.3% every year.

Two groups of researchers report that they concentrated on the northern hemisphere because that’s the part of the globe where most of the continental landmass, most of the vegetation and the greatest part of the human population is concentrated.

And both groups identified the cause of the widening CO2 swing as being as mix of steadily higher temperatures and the Green Revolution – the dramatic advance in agricultural productivity that fuelled the trebling of the human burden of the planet in less than a human lifetime.

“Changes in the way we manage the land can literally alter the breathing of the biosphere”

Josh Gray, research assistant professor in the Department of Earth and Environment at Boston University, US, reports with colleagues in Nature journal that they have gone one better by identifying the crop that makes the biggest difference: maize, or corn.

Together, the world harvest of maize, wheat, rice and soybean grew by 240% between 1961 and 2008, increasing the uptake of carbon during that time by 330 million tonnes.

Maize, grown ever-more intensively in the mid-western US and in China, is responsible for two-thirds of this change, the researchers calculate. Dr Gray calls the super-productive croplands “ecosystems on steroids”.

Carbon cycle

Ning Zeng, professor in the Department of Atmospheric and Oceanic Science at the University of Maryland, US, and lead author of the other Nature paper, reports that he and colleagues devised a new model of the terrestrial carbon cycle to explore the increase in seasonal CO2 swings, and the role of the Green Revolution in these swings.

There are several reasons for the increasing swings: average temperatures have started to rise; there is the natural “fertilization” effect of carbon dioxide, as some plants respond well to higher levels; and as the Arctic regions have thawed, more growing land is available − and vegetation has been marching north.

But a fourth reason is that farmers are now producing more yield from the same land, and the same crops. Between 1961 and 2010, the area of land planted with the world’s great crops grew by 20%, but – with improved strains, better fertilizers, and more irrigation − yield grew threefold. So more CO2 was taken up each year, and more released.

“What we are seeing is the effect of the Green Revolution on Earth’s metabolism,” said Professor Zeng. “Changes in the way we manage the land can literally alter the breathing of the biosphere.” – Climate News Network

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Obama pledge gets dollars flowing into climate fund

Obama pledge gets dollars flowing into climate fund 

Many developing countries are already suffering the impacts of climate change, but a special fund to help them adapt to a warming world has been bolstered by promises of billions of dollars from wealthier nations.

LONDON, 20 November, 2014 − It’s been quite a week for those waiting for some action on climate change.

After US President Obama and China’s President Xi Jinping announced radical plans to cut back on greenhouse gas emissions, Obama then called on nations at the G20 summit in Brisbane, Australia, to agree to a new deal on climate.

And when he backed that up by pledging US$3 billion to the Green Climate Fund (GCF), set up in 2010 to promote low emissions and climate-resilient projects in the developing world, other countries quickly reached for their cheque books.

Paying their dues

Japan says it will be giving $1.5 billion to the GCF. Britain indicated it will be pledging a similar amount.  France and Germany have already announced they will be giving the $1 billion each. Sweden is pledging more than $500 million. And other countries in the developed world are lining up to pay their dues.

The GCF, which operates under the auspices of the United Nations Framework Convention on Climate Change, is holding a special High-Level Pledging Conference in Berlin today.

“This week’s announcements will be a legacy of US President Obama,” said Hela Cheikhrouhou, GCF’s executive director. “It will be seen by generations to come as the game‐changing moment that started a scaling‐up of global action on climate change.”

Obama said money paid into the GCF would help developing countries leapfrog some of the dirty industries that fuelled growth in the industrialised world, and will allow them to build clean-energy economies.

“Along with the other nations that have pledged support, this gives us the opportunity to help vulnerable communities with an early warning system, with stronger defences against storm surge, climate resilient infrastructure, to help farmers plant more durable crops,” Obama said.

In the past, calls for cash to support the Fund’s activities in the developing world have been largely unsuccessful. Now the mood seems to have changed.

“It will be seen by generations to come as the game‐changing moment that started a scaling‐up of global action on climate change”

In the US, the Republicans – who now control both houses of Congress – are for the most part firmly opposed to Obama’s new-found zeal for action on the climate.

The White House feels that public attitudes on climate change issues are changing, both within the US and around the globe, but a brave new, fossil fuel-free world is still a long way off.

There are big questions about how the emissions reductions announced in the US-China agreement are to be achieved.

And the pledges to the GCF look impressive, but leaders of the wealthier nations have a tendency for making grand monetary gestures at international gatherings –then not following through with the cash.

Despite this, climate change has been put firmly among the top items on the international agenda. Momentum has also been built towards achieving a new global deal at the UN Climate Change Conference in Paris late next year.

Clear message

The past week’s events have also sent a clear message to the fossil fuel industry, and to investors in the sector: many of the most powerful countries in the world now agree that greenhouse gas emissions have to be cut.

The message has not gone down well with Tony Abbott, the Australian prime minister, and host of the G20 summit.

Although Australia is considered by scientists to be one of the countries most vulnerable to global warming, the Abbott government has made known its scepticism on the issue and has rolled back various measures aimed at combating changes in climate.

It has also strongly backed the development of several large-scale coal mining operations on the east coast, adjacent to the waters of the Great Barrier Reef. – Climate News Network

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Fall of ancient civilization offers climate warning

Fall of ancient civilization offers climate warning

Prolonged drought – a familiar climate-related issue in the modern world – is believed by scholars to have been a key factor in the implosion of the powerful Assyrian empire 2,700 years ago.

LONDON, 19 November, 2014 − Two scholars have a new explanation for the collapse of one of the great Bronze Age civilizations. The Assyrian empire of the 7th century BC – based in Nineveh, in what is now northern Iraq – may have collapsed at least in part because of a population explosion and climate change in the form of sustained drought.

And, they point out, there are lessons in ancient history for the modern world as well.

Adam Schneider, an anthropologist at the University of California, San Diego, and Selim Adali, of the Research Centre for Anatolian Civilizations at Koç University in Istanbul, Turkey, put forward their proposal in the journal Climatic Change.

They say that demographic and climatic factors played an indirect but significant role in the collapse of a civilization chronicled not just in clay tablets and archaeological marvels but in the Hebrew scriptures and the Christian Old Testament.

Historic links

The climate change theory of history is now well established. In the last two years, researchers have linked both the dissolution of the Minoan empire in the ancient Mediterranean and the collapse of Levantine civilizations of the near East and the Harappan civilization of the Indus Valley to sustained drought.

Others have identified seasons of plentiful rainfall as the impetus for the conquest of Russia, China and Persia by the Mongol horsemen of Genghis Khan.

The connections with modern conflict, too, have been made before. In 21 studies of upheaval and conflict in modern societies, researchers have found clear links with rises in temperatures.

And just days after the Assyrian study was published in Climatic Change, research in the Proceedings of the National Academy of Sciences identified a link between temperature and rainfall anomalies in sub-Saharan Africa and violence in the region during the last 30 years.

“Hindsight . . . allows us to piece together from the past what can go wrong if we choose not to enact policies that promote longer-term sustainability”

Schneider and Adali looked through what climate scientists call “proxy evidence” of rainfall patterns in the Tigris Valley of northern Iraq more than two and a half millennia ago.

They considered the evidence of lake sediments and confirmed that many parts of the region experienced a “short but widespread dry phase” during the mid-to-late 7th century BC.

They also unearthed written evidence from 666 BC that welcomed “copious rains, huge floods, a fine rate of exchange…” to mark a new accession to the throne. But by 657 BC, another letter stated that “this year’s rains were diminished and no harvest was reaped”.

In fact, Assyrian engineers had established an impressive series of canals, waterways, cisterns and reservoirs to conserve water, and archaeological finds reveal that the imperial farmers grew barley and wheat, grapes, cucumbers, pomegranates, flax and cotton among many other crops.

But demand, too, was on the increase. The empire of built by Sennacherib, a king identified in biblical chronicles, had ambitions for the local populations. In at least 20 known acts of mass deportation, half a million people were resettled in the heartland.

Nineveh grew fivefold in area, and the population growth, the scientists think, placed significant strains on the immediate supplies of food in the region.

Conflict and insurrection

Within five years of the 657 BC drought, the Assyrian economy was struggling, and conflict and insurrection had broken out. By 609 BC, a remarkable civilization had been destroyed.

A multi-year drought, the researchers argue, “would have placed serious stress on the agricultural economy of the Assyrian state and, by extension, upon the imperial political system”.

They see parallels with today, as the fate of the Assyrian empire offers lessons for modern society about the hazards of valuing short-term economic growth over long-term security and sustainability.

“The Assyrians can be ‘excused’ to some extent,” they conclude, “for focusing on short-term economic or political goals that increased their risk of being negatively impacted by climate change, given their technological capacity and their level of scientific understanding about how the natural world works.

“We, however, have no such excuses, and we also possess the additional benefit of hindsight, which allows us to piece together from the past what can go wrong if we choose not to enact policies that promote longer-term sustainability.” – Climate News Network

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Diet’s effects on emissions give food for thought

Diet's effects on emissions give food for thought

American researchers confirm that a shift to vegetarian, Mediterranean or fish-based diets would cut greenhouse gases, conserve forests and savannah, and have a big impact on obesity-linked health problems.

LONDON, 14 November, 2014 − The worldwide trend towards a Western-style diet rich in meat and dairy produce will lead to an 80% increase in greenhouse gas emissions (GHGs) from agriculture.

And since agriculture already accounts for 25% of all emissions, two US scientists argue in Nature journal that a shift away from the trend towards steak, sausage, fried potatoes and rich cream puddings offers tomorrow’s world three palpable rewards.

  • Greenhouse gas emissions would be reduced.
  • There would be less pressure to clear forests and savannah for farmland, so biodiversity would be conserved.
  • There would be lower rates of disease linked with obesity and cardiovascular hazard.

“The implementation of dietary solutions to the tightly-linked diet-environment-health trilemma is a global challenge, and opportunity, of great environmental and public health importance,” the report’s authors say.

For example, GHGs from beef or lamb per gram of protein are about 250 times those from a serving of peas or beans.

Rise in diabetes

And in China, the shift from traditional cuisine towards a Western-style diet rich in refined sugars, refined oils, meat and processed foods led to the incidence of type II diabetes rising from less than 1% in 1980 to 10% in 2008.

To put this greener, more sustainable world on the scientific menu, David Tilman, professor of ecology at the University of Minnesota, and Michael Clark, graduate science student at the Bren School of Environmental Science and Management, University of California Santa Barbara, simply looked at the already published evidence.

They identified 120 separate analyses of the GHGs from the entire life cycle of crop, livestock, fishery and aquaculture, all the way to the farm gate.

These analyses embraced a total of 550 studies, involving 82 types of food plant and animal products, and from all this they were able to calculate the diet-related emissions per gram of protein, per kilocalorie and per serving.

To confirm the connection between diet and health, they looked again at 18 studies based on eight long-term population studies that incorporated 10 million person-years of observation. They used 50 years of data about the dietary habits and trends in 100 of the world’s most populous nations to see the way food consumption patterns were changing.

“Dietary changes that can add about a decade to our lives can also prevent environmental damage”

And they confirmed something that nutritionists, health chiefs and medical advisers have been saying for decades: that a shift to vegetarian, traditional Mediterranean or fish-based diets could only be good.

“We showed that the same dietary changes that can add about a decade to our lives can also prevent massive environmental damage,” Professor Tilman said.

“In particular, if the world were to adopt variations on three common diets, health would be greatly increased at the same time global GHGs were reduced by an amount equal to the current GHGs of all cars, trucks, planes, trains and ships.

“In addition, this dietary shift would prevent the destruction of an area of tropical forests and savannahs of an area half as large as the United States.”

Such a shift away from the calorie-rich Western omnivore diet could reduce the incidence of type II diabetes – a condition notoriously linked to diet and obesity − by about 25%, cancer by about 10%, and death from heart disease by about 25%.

The close link between meat production and GHGs has been reported before.  Researchers have also stressed the environmental value of a diet rich in grains and legumes. rather than meat and dairy.

Not everybody will agree with the detail of their analysis. Other scientists have argued that − in the US, at least − healthy diet recommendations may not make a big difference to GHGs, or might even lead to an increase in them.

Acidic oceans

And because the authors specifically identify trawling for fish as wasteful, destructive and costly in emissions, and because ocean waters are becoming more acidic because of GHG emissions, a planetary switch to a pescatarian or fish and seafood diet is likely to be problematic.

But the two scientists nevertheless are clear on the main point. GHGs are, they say, “highly dependent on diet”.

Between 2009 and 2050, the global population will increase by 36%. People will also become better off, and their appetites and demands will grow. “When combined with a projected increase in per capita emissions from income-dependent global dietary shifts,” they say, “the net effect is an estimated 80% increase in global greenhouse gas emissions from food production.”

This 80% would represent 1. 8 billion tonnes per year of carbon dioxide or its equivalent − which was the total emissions from all forms of global transport in 2010.

“In contrast,” they say, “there would be no net increase in food production emissions if, by 2050, the global diet had become the average of the Mediterranean, pescatarian and vegetarian diets.” – Climate News Network

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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

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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

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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

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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

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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

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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

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