US farmers given early warning about hungry crop pest

US farmers given early warning about hungry crop pest

Biologists say a destructive insect is likely to cause even more damage than usual as rising temperatures prompt leaves to sprout earlier.

LONDON, 24 May, 2015 − It is small, bright green and an unwelcome visitor. But global warming means that this particular agricultural menace arrives earlier than ever − and consumes more than ever.

New research has confirmed that the potato leafhopper now turns up to devour US crops on average 10 days earlier than it did 60 years ago.

Despite its informal name, Empoasca fabae is known to have developed an appetite not just for potatoes, but for anything from rhubarb to red maple trees.

It survives over the winter in the southernmost states, then moves north as the temperatures begin to rise and crops begin to sprout.

It has been observed to reproduce itself on around 200 plant species, and it also has a taste for apples, celery, beans, grapes, hops and the important perennial forage crop alfalfa, sometimes also known as lucerne.

Severe infestation

Three biologists from two US universities report in PLOS One, the Public Library of Science journal, that leafhopper infestation is more severe in the warmest years, and that the damage caused by the tiny insect is likely to increase as average temperatures continue to rise.

It arrives in the growing season and pierces the plant leaf tissue to get at the sap. Its saliva carries a toxin that can cause the leaf to dry, curl and rot, and the consequent damage is called “hopperburn”.

“You don’t realise they’re even there until you see the damage to the plants . . . By then it’s too late”

“Earlier arrival dates make it particularly important for farmers to get out early in the season and scout for leafhoppers,” says William Lamp, associate professor of entomology at the University of Maryland, and one of the three authors of the study.

“They’re tiny, flighty and very hard to see. You don’t realise they’re even there until you see the damage to the plants, which can take up to a week to manifest. By then it’s too late.”

The researchers combed the records between 1951 and 2012 to track the dates in which the pest was recorded in each of 19 affected US states, and matched this with weather records over the same timespan. Such a finding was  possible only because scientists had access to systematic data.

Dilip Venugopal, an ecologist, and colleague of Lamp at the University of Maryland, says: “The historical records on agricultural pests are a gold mine, made possible by decades of hard work by agricultural research and extension personnel who collect this data. There has been a decline in data collection activity over the past decade, and we would love to see an effort to ramp this up again.”

Global average temperatures have risen by 0.74°C since 1951, and the last decade has been the warmest since climate records began.

Changed behaviour

The leafhopper is only one of many long-distance migratory pests likely to change behaviour in response to climate change. Other researchers have already observed crop pests’ steady movement towards higher latitudes in recent decades.

“Climate change is not just costly because temperatures and oceans rise, but because it makes it harder to feed ourselves,” says report co-author Mitchell Baker, assistant professor of biology at Queens College, City University of New York.

“Increased pest pressure in agriculture is one of the complex effects of continued warming. Predicting arrival time and severity is critical to managing this pest and others like it.” – Climate News Network

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Rainforests are left on edge of destruction

Rainforests are left on edge of destruction

Eminent conservationist says climate change’s major threat to the world’s tropical rainforests comes not from heat, but from drought and uncertain rainfall.

LONDON, 23 May, 2015 – Rising temperatures will not themselves spell disaster for the world’s rainforests. It is the droughts and unpredictable rainfall patterns, which climate change is already worsening, that will settle the forests’ fate before the century ends, according to a new book.

Claude Martin, who has worked in tropical rainforest conservation since the 1970s, is author of On the Edge, commissioned by the Club of Rome, which published the seminal Limits to Growth report in 1972. Since then, nearly 50% of the world’s forest cover has disappeared.

Martin, a former director-general of WWF International, recognises that there are many drivers of forest damage and destruction − including the pressures of the global economy for animal feed and food for humans, and the worldwide demand for biofuels.

Essential ecosystem

Acknowledging the progress made in science and conservation, he reminds his readers that the forests are not just huge repositories of biodiversity, but an essential ecosystem providing everyone on the planet with fresh water, clean air and climate regulation.

Evaluating the impact of climate change on rainforests means focusing on the length of dry seasons and water stress, rather than temperature, Martin writes.

The likeliest cause of forest collapse and severe risks of reaching a tipping point is not temperature rise, but the change from the dependable rainfall patterns of the past, and the probability of increasing droughts and forest fires.

He sees a likelihood of drought and fires increasing − not least in the Amazon − because of the way in which climate change is fuelling El Niño and La Niña, the twin periodic temperature disruptions that occur every few years in the eastern Pacific Ocean.

Known together as the El Niño-Southern Oscillation (ENSO), their impacts spread for thousands of miles.

“Lethargy of governments and the impotence of the intergovernmental system make it very unlikely that average global warming will be kept below 2°C

Martin is one of those scientists who are convinced that climate change will intensify ENSOs. As global warming effects become stronger, ENSO events become more frequent, rainfall drops further because of forest loss and fragmentation, and droughts are likely to become more common and more severe. And so the vicious circle becomes a constant downward spiral.

“When the 20th century’s strongest ENSO occurred in 1997/98,” Martin writes, “it was considered to be an unusual phenomenon. . . . [It] caused severe drought in Amazonia, Southeast Asia and Mexico, and had massive effects on the net primary productivity of forests, thus their capacity of carbon storage as well as forest fires.”

After another severe drought in 2001, following another ENSO event, about a third of the Amazon forests stored significantly less carbon and became vulnerable to fire. Two more droughts followed soon after, in 2005 and 2010. The first was estimated to be a once-in-a-century occurrence.

Fastest warming

Martin’s concerns are not confined to Amazonia. He cites modelling by the Intergovernmental Panel on Climate Change, which shows that Africa is expected to warm by 3-4°C by the end of the century − the fastest warming since the end of the last ice age around 11,500 years ago. This would expose the great Congo Basin forest to the risk of severe damage.

Globally, Martin is not hopeful. “The current rate of greenhouse gas emissions, the lethargy of governments and the impotence of the intergovernmental system make it very unlikely that average global warming will be kept below 2°C,” he says.

Under a mid-range emissions scenario, atmospheric CO2 concentrations are likely to rise by the end of the century to levels not seen in the last 50 million years. But he thinks the forest crisis will be developing uncontrollably some decades before then.

He predicts: “The decisive period for the long-term future of the rainforests . . . will be the second half of the century, when global warming is likely to exceed 2°C above the pre-industrial global average.

“It will be too late then to avoid a dangerous tipping point of self-reinforcing climate change.” – Climate News Network

  • On the Edge − The State and Fate of the World’s Tropical Rainforests. A Report to the Club of Rome, by Claude Martin (Greystone Books, £20/US$32.95).

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Cutting warming to 1.5°C could put food supply at risk

Cutting warming to 1.5°C could put food supply at risk

Scientists say meeting the tougher demands of many countries on limiting global temperature rise may be technically feasible, but would risk worsening world hunger.

LONDON, 21 May, 2015 – As world leaders try to agree how to prevent global warming from heating the planet by more than 2°C above pre-industrial levels, scientists have tackled an altogether thornier question: can we keep the rise below 1.5°C?

The lower target − demanded by more than 100 countries as a safer goal − is attainable, they say. But there will be little room for error, and getting there will mean not only cutting greenhouse gas emissions, but actually removing carbon dioxide from the atmosphere.

That is not possible with the technology now available. And even if it could one day be done, it would probably have forbiddingly harmful consequences for world food supplies.

However, limiting temperature rise by 2100 to less than 1.5°C is still feasible, say the researchers from the International Institute for Applied Systems Analysis (IIASA) in Austria, the Potsdam Institute for Climate Impact Research (PIK), Germany, and colleagues. They report their findings in the journal Nature Climate Change.

Similar actions

Not surprisingly, the answer includes doing more, and doing it faster. “Actions for returning global warming to below 1.5°C by 2100 are in many ways similar to those for limiting warming to below 2°C,” says IIASA climate researcher Joeri Rogelj, one of the lead authors of the report.

The authors accept that the economic, political, and technological conditions for achieving even 2°C are “substantial”. The negotiations to be held in Paris in December by member states of the UN Framework Convention on Climate Change (UNFCCC) may show what chance there is of meeting them.

The new study identifies key ways of reaching the 1.5°C target by 2100. One is a tight limit on future carbon emissions.

Gunnar Luderer, PIK senior researcher in sustainable solutions, who co-led the study, says: “In 1.5°C scenarios, the remaining carbon budget for the 21st century is reduced to almost half, compared to 2°C scenarios.

“As a consequence, deeper emissions cuts are required from all sectors, and global carbon neutrality would need to be reached 10-20 years earlier than projected for 2°C scenarios.”

Energy efficiency will also need to improve faster, he says.

“The scenarios we assess keep warming
to the lowest levels currently considered
technologically feasible”

But the study finds that staying below 1.5°C would require a radical step change: some time this century, carbon emissions would have to become negative at a global scale.

That is the scientists’ way of saying that significant amounts of CO2 will have to be actively removed from the atmosphere. And there is at present no known way of doing that.

In theory, it is possible − for example, through bio-energy use, combined with carbon capture and storage. But that is a technology that so far remains untested on a large scale.

It would also increase hunger, as the crops needed to produce enough biofuel would compete for land with food plants.

Another idea is to grow more forests, which would sequester carbon in their trees, but this would be open to the same objection − that it would reduce cropland. The higher temperatures in prospect will themselves affect forest growth and health.

Lowest levels

Rogelj told the Climate News Network: “Increased temperatures can make afforestation efforts harder. However, the scenarios we assess here keep warming to the lowest levels currently considered technologically feasible, and this issue will thus have a relatively smaller impact.”

Whatever happens, the authors expect things to get hotter before they have any chance of cooling down.

Rogelj says: “Basically, all our 1.5°C scenarios first exceed the 1.5°C temperature threshold somewhere in mid-century, before declining to 2100 and beyond as more and more carbon dioxide is actively removed from the atmosphere by specialised technologies.”

Over 100 countries worldwide more than half the members of the UNFCCC, including the Alliance of Small Island States (AOSIS) and the Least Developed Countries (LDCs) have declared their support for a 1.5°C target. – Climate News Network

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Tree-based farming could deliver abundant benefits

Tree-based farming could deliver abundant benefits

In addition to mitigating the effects of climate change, forests can help alleviate hunger and provide a safety net for some of the world’s poorest people.

LONDON, 8 May, 2015 – Forests may be the green investment with the richest returns for humankind, according to new research.

While one study outlines the ways in which forests provide food, fuel, shelter and a safety net for more than a billion humans, a separate one confirms that a canopy of older, sturdier trees helps protect the saplings and juvenile growths against heat and drought.

An international team of more than 60 scientists collaborated on a report − Forests, Trees and Landscapes for Food Security and Nutrition: a Global Assessment Report − just published by the International Union of Forest Research Organisations (IUFRO).

“Large-scale crop production is highly vulnerable to extreme weather events, which may occur far more frequently under climate change,” says Christoph Wilburger, who co-ordinated the IUFRO initiative. “Science shows that tree-based farming can adapt far better to such calamities.

Key role

“We know that forests already play a key role in mitigating the effects of climate change. This report makes it very clear that they also play a key role in alleviating hunger and in improving nutrition.”

Climate scientists tend to consider forests as “carbon sinks” − agencies that soak up carbon dioxide from the atmosphere and that could help counter the rising levels of the greenhouse gas released by the burning of fossil fuels.

But forests also have a role in water storage and in protecting land from the forces of erosion.

Forest fruits and nuts are an important nutrition source for many. The iron content of the dried seeds of the African locust bean and raw cashew nut can, for instance, match the flesh of chickens. And forests are shelter for sources of wild meat, fish and edible insects.

“Extensive losses of forest canopy . . . will amplify the effects of climate change”

In developing countries, around 2.4 billion households use wood and charcoal for cooking and heating, and forests deliver a multitude of what are sometimes called ecosystem services − such as supporting bees and other crop pollinators, delivering fodder for village livestock, and protecting streams and watersheds.

Worldwide, the lower the levels of prosperity, the higher the dependence on forests. In the Sahel region of Africa south of the Sahara, trees contribute on average four-fifths of household income − mostly through shea nut production.

The report also points out that the expansion of agricultural land accounts for 73% of forest loss worldwide.

Increasing threat

But if forests keep people safe, what keeps a forest in leaf when drought, extremes of heat and the attrition of climate change are also an increasing threat?

Solomon Dobrowski, of the Forest Landscape Ecology Lab at the University of Montana, and colleagues report in Global Ecology and Biogeography that the regeneration of future forests could depend on shelter from the extensive canopy provided by the adult trees in mature woodland.

Juvenile trees are more shallow-rooted and more vulnerable to high winds, intense sunlight, high temperatures and extended drought. Without a shady, protective canopy, they could suffer. And without juvenile trees, a forest could only decline.

Professor Dobrowski warns: “Extensive losses of forest canopy from disturbances such as severe wildfire will amplify the effects of climate change.” – Climate News Network

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High anxiety that mountain peaks are warming faster

High anxiety that mountain peaks are warming faster

Scientists call for international efforts to determine why temperatures on high-altitude mountains appear to be rising faster than in nearby lowlands.

LONDON, 28 April, 2015 − Temperatures could be climbing on mountains − with new research suggesting that the highest altitudes may be warming at a rate greater than expected.

Members of the Mountain Research Initiative collective report in Nature Climate Change that they found evidence that mountain peak regions were warming faster than the surrounding plateaus and lowlands.

The study − by Nick Pepin, leader of the Environmental Processes and Change Research Group at Portsmouth University in the UK, and colleagues from the US, Switzerland, Canada, Ecuador, Pakistan, China, Italy, Austria and Kazakhstan − comes with more than the usual set of health warnings.

The authors concede that the evidence is “extremely sparse”. But just as the Arctic region – the high latitudes of the northern hemisphere – is warming faster than anywhere else in the world, so the high altitude could also be at risk. The important thing is to find out.

No long-term data

There are few weather stations above 4,500 metres, and no long-term data for peaks higher than 5,000 metres anywhere in the world. The summit of Kilimanjaro, Africa’s highest mountain, has been monitored longest of all, but measurements have been recorded there on a systematic basis only for the last decade.

Other indications come from the Tibetan plateau, where temperatures recorded at 139 stations have risen steadily over the past 50 years, and the rate of change is accelerating.

“There is growing evidence that high mountain regions are warming faster than lower elevations,” Dr Pepin say. “Such warming can accelerate many other environmental changes, such as glacial melt and vegetation change, but scientists urgently need more and better data to confirm this.

“The social and economic consequences could be serious, and we could see much more dramatic changes sooner than previously thought”

“If we are right, and mountains are warming more rapidly than other environments, the social and economic consequences could be serious, and we could see much more dramatic changes sooner than previously thought.”

Kilimanjaro’s snow-covered peak in 1938. Image: Mary Meader/American Geographical Society Library via Wikimedia Commons

Kilimanjaro’s snow-covered peak in 1938.
Image: Mary Meader/American Geographical Society Library via Wikimedia Commons

There are two obvious causes for concern, the first being the simple problem of biodiversity. Plants and animals that occupy the highest elevations are at the optimum limits of their climatic tolerance, and if the climate gets warmer, they must move uphill to survive.

There is already evidence from alpine Switzerland that this is indeed happening. But those species already at the highest altitudes have nowhere else to go −  and so face extinction.

The second concern relates to an even more immediate impact. The highest mountain regions are glaciated, and this store of winter snow and ice becomes a source of spring and summer meltwater on which farmers, cities and even whole nations have grown to depend.

There is also good evidence that glaciers are in retreat, almost everywhere in the world. So the economic consequences could be considerable.

Endangered species

“This alone requires that close attention be paid to the issue,” the authors write. “In addition, mountains provide habitat for many of the world’s rare and endangered species, and the presence of many different ecosystems in close proximity enhances the ecological sensitivity of mountains to environmental change.”

In essence, the study incorporates a warning: more evidence is needed.

Raymond Bradley, who directs the Climate System Research Centre at the University of Massachusetts Amherst, spells it out: “We are calling for special efforts to be made to extend scientific observations upwards to the highest summits to capture what is happening across the world’s mountains.

“We also need a strong effort to find, collate and evaluate observational data that already exists wherever it is in the world. This requires international collaboration.” – Climate News Network

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Well drilling has deep impact on Great Plains’ health

Well drilling has deep impact on Great Plains' health

Loss of vegetation on North America’s vast rangelands as a result of a huge increase in oil and gas wells invokes memories of the 1930s Dust Bowl disaster.

LONDON, 27 April, 2015 − Oil wells and natural gas may have made individual Americans rich, but they have impoverished the great plains of North America, according to new research.

Fossil fuel prospectors have sunk 50,000 new wells a year since 2000 in three Canadian provinces and 11 US states, and have damaged the foundation of all economic growth: net primary production − otherwise known as biomass, or vegetation.

Brady Allred, assistant professor of rangeland ecology at the University of Montana’s College of Forestry and Conservation, and colleagues write in the journal Science that they combined years of high-resolution satellite data with information from industry and public records to track the impact of oil drilling on natural and crop growth.

They conclude that the vegetation lost or removed by the expansion of the oil and gas business between 2000 and 2012 added up to 10 million tonnes of dry vegetation, or 4.5 million tonnes of carbon that otherwise would have been removed from the atmosphere.

Loss of fodder

Put another way, this loss amounted to the equivalent of fodder for five million cattle for one month from the rangelands, and 120 million bushels of wheat from the croplands. This wheat equivalent, they point out, adds up to the equivalent of 13% of the wheat exported by the US in 2013.

Net primary production – the biomass that plants make from photosynthesis every day, all over the world – is the basis of all wealth and food security. It underwrites all other human and animal activity.

Human wealth depends ultimately on what grows in the ground, or what can be dug from the ground, and most of the latter – such as coal, oil and peat– was once stuff that grew in the ground.

The same net primary production is the basis of what economists sometimes call ecosystem services on which all civilisation depends: the natural replenishment of the water supply, the pollination of crops, the provision of natural nitrogen fertilisers, and the renewal of natural habitat for wild things.

“It took catastrophic disruption of livelihoods and economies [in the 1930s] to trigger policy reforms that addressed environmental and social risks of land-use change”

And what worries the conservation scientists is that this loss of net primary production is likely to be “long-lasting and potentially permanent, as recovery or reclamation of previously drilled land has not kept pace with accelerated drilling”.

“This is not surprising because current reclamation practices vary by land ownership and governing body, target only limited portions of the energy landscape, require substantial funding and implementation commitments, and are often not initiated until the end life of a well.”

They say that the land actually taken up by wells, roads and storage facilities just between 2000 and 2012 is about 3 million hectares. This is the land area equivalent to three Yellowstone National Parks.

The hydraulic fracturing, or “fracking”, used to extract oil and gas is between 8,000 cubic metres and 50,000 cubic metres per well, which means that the total quantity of water squirted into the ground at high pressure during the 12 years to 2012 could exceed 33,900 million cubic metres. At least half of this was used in areas already defined as “water-stressed”.

New wells

The researchers considered the drilling of new wells in Alberta, Manitoba and Saskatchewan in Canada, and in Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah and Wyoming in the US.

Although there is legislation, it is limited to lands subject to federal jurisdiction, and 90% of all drilling infrastructure is now on privately-owned land − at least, in the US.

A tanker drives past a flaring oil well in North Dakota. Image: Tim Evanson via Wikimedia Commons

A tanker drives past a flaring oil well in North Dakota.  Image: Tim Evanson via Wikimedia Commons

The study’s authors want decision-makers to confront the challenges of this kind of ecological disruption. There are lessons from history in all this, they warn.

“In the early 20th century, rapid agricultural expansion and widespread displacement of native vegetation reduced the resilience of the region to drought, ultimately contributing to the Dust Bowl of the 1930s,” they write.

“It took catastrophic disruption of livelihoods and economies to trigger policy reforms that addressed environmental and social risks of land-use change.” – Climate News Network

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Investors chip in as renewables rise towards record level

Investors chip in as renewables rise towards record level

Climate-friendly boost for global energy mix as scientists say solar power alone could now meet the needs of California five times over.

LONDON, 12 April, 2015 − Carbon dioxide levels might be soaring, and governments might be slow to reduce fossil fuel emissions and contain climate change − but the smart money could nevertheless be going into renewable sources such as wind and solar power.

The United Nations Environment Programme (UNEP) says green energy investments rose by 17% in 2014 to reach a total of $270bn − the first annual increase in three years, and just 3% behind the all-time record set in 2011 of $279bn.

In 2014, renewable energies added 103 gigawatts to global capacity. This is roughly equal to the output of all 158 nuclear power reactors in the US.

Wind, solar, biomass, waste-to-power, geothermal, small hydro and marine power contributed an estimated 9.1% of world electricity generation in 2014. This also represents a notional saving in carbon dioxide emissions of 1.3 gigatonnes, which is about twice what pours from the exhausts of the world airlines.

Markets mature

“Once again in 2014, renewable made up nearly half the power capacity added worldwide,” said Achim Steiner, executive director of UNEP.

“These climate-friendly energy technologies are now an indispensable component of the global energy mix and their importance will only increase as markets mature, technology prices continue to fall and the need to rein in carbon emissions becomes ever more urgent.”

But, according to scientists backed by the Carnegie Institution, there is much more that could be done. A team led by Earth system scientists Rebecca Hernandez, now of the University of California Berkeley, reported in Nature Climate Change that solar energy alone could meet the demands of the state of California in the US up to five times over.

Solar power systems based on photovoltaics could generate up to 15,000 terawatts of energy a year. And mirror-driven concentrating systems could add another 6,000 terawatt hours.

California – now in the grip of a calamitous drought that has been tentatively linked to climate change triggered by human investment in fossil fuels – is the most populous state in the US. The researchers calculated that more than 27,000 square kilometres of land would be fit for photovoltaic solar construction, and more than 6,000 square kilometres for concentrating solar power.

“Their importance will only increase as markets mature, technology prices continue to fall
and the need to rein in carbon emissions becomes ever more urgent”

But there is a darker side to the story of renewable energy. On the other side of the Rocky Mountains, scientists have been working on the much more complex carbon budget of biofuels, which deliver energy in liquid form.

They count as renewable energy because, although they emit carbon dioxide when burned, they do not, overall, add to the levels of greenhouse gases in the atmosphere. That is because biofuel crops take carbon dioxide from the air to grow their tissues for conversion to fuel, and return the gas through engine exhausts.

But there have been persistent worries. One is that the conversion of food to fuel may not be the most efficient use of cropland.

Destroy ecosystems

The approach remains carbon neutral, as long as farmers exploit existing cropland. But the danger is that farmers might plough up existing grassland, destroy ecosystems, and release ancient stored soil carbon to the atmosphere, to make global warming worse.

Environmental scientist Tyler Lark and colleagues at the University of Wisconsin-Madison report in Environmental Research Letters that, between 2008 and 2012, US farmers ploughed seven million acres of new land for corn and soy for conversion to biofuels intended as renewable energy for motor transport.

In the course of doing so, they could have emitted as much carbon to the atmosphere as 34 coal-burning power stations in one year – or 28 million new cars on the road.

Nearly a quarter of the land converted came from long-standing prairies and ranges, much of it within the Central Plains, from North Dakota to Texas. And much of this was planted with corn intended for conversion to biofuels.

“It mimics the extreme land-use change that led to the Dust Bowl in the 1930s,” Lark says. “We could be, in a sense, ploughing up prairies with each mile we drive.” – Climate News Network

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Forests can soak up a third of carbon emissions

Forests can soak up a third of carbon emissions

Report commissioned by Prince Charles’s charity says protecting tropical forests could enable them to absorb billions of tonnes of the Earth’s emissions of carbon.

LONDON, 11 April, 2015 − Looking after the world’s tropical forests would be worthwhile in its own right, for the sake of their human and animal inhabitants and their wider effects on the natural world.

But researchers say it would also have a significant bonus. Properly cared for, the forests could cancel out between a quarter and a third of the planet’s carbon emissions.

They argue that it is not just outright destruction of the trees that is the problem, but the ways in which the forests become degraded by the incursion of different forms of development − logging, obviously, but also fires, mining, ranching, roads, and their effect in splitting the huge tracts of forested land into smaller and more isolated patches.

In a report commissioned by Prince Charles, the heir to the British throne, they say deforestation and degradation of the forests may account together for between 14% and 21% (1.4-2.2 gigatonnes of carbon, or GtC; a gigatonne is a billion metric tonnes) of all emissions of carbon, and perhaps even more if tropical peatlands and mangroves are included.

Atmospheric carbon

Against this, the forests absorb almost as much atmospheric carbon as they account for − an annual total of 1.2-1.8GtC, the authors say. But the report argues that simply offsetting the amount of carbon sequestered in this way against the amount emitted is insufficient, for two reasons.

The first is the evidence that human activities are responsible for a significant proportion of CO2 absorption. Second, total emissions are probably much higher than the traditional greenhouse gas (GHG) accounting approach allows.

Taken together, these two factors suggest that slowing damage to the forests and keeping them in the best condition possible is more important than many people have realised.

But the forests continue to suffer damage. The report says: “…it can be argued that the causes and consequences of tropical forest degradation have been given too little attention, with the science now pointing toward degradation being a very significant component both of greenhouse gas emissions and the weakening of forest ecosystems”.

We can act on forests now, therefore buying much-needed time to enable the transformation to a low-carbon economy

It paints a sobering picture of the present situation, saying there is “no sign yet that overall rates of deforestation or degradation are decreasing”. The report says the annual area of global forest lost is about 8.5m hectares.

Rising world demand for timber and wood products, and for farm produce, it says, “will significantly increase pressure on tropical forests over the next few decades”.

The report was commissioned by the Prince’s International Sustainability Unit. In a foreword, Prince Charles writes: “It is an alarming fact that rates of deforestation and degradation continue to rise, and that the underlying causes of this increase are set to become very much more acute…”

But he sounds an encouraging note: “We can act on forests now, therefore buying much-needed time to enable the transformation to a low-carbon economy.”

Considerable uncertainty

There is considerable uncertainty about how much the forests contribute to GHG emissions. In 2012, NASA said that tropical deforestation had accounted for about 10% of human carbon emissions from 2000 to 2005 − a much lower figure than previous estimates.

Forest degradation is often more difficult to detect than deforestation itself, and is almost invisible to satellite monitoring. Research in six tropical countries suggests that degradation by logging can cause significant damage, with GHG emissions on average about 12% of those caused by deforestation.

Together, their impact is serious. The Global Forest Watch online monitoring network says that Brazil lost 5.9% of its forest cover between 2001 and 2012, while Indonesia lost 9.2% over the same timespan. − Climate News Network

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Woodlands revival adds new piece to carbon cycle puzzle

Woodlands revival adds new piece to carbon cycle puzzle

Growing number of trees on the world’s savanna grasslands helps offset carbon storage concerns caused by depletion of the great rainforests.

LONDON, 9 April, 2015 − Despite continuing concern about the fate of iconic rainforests, new research shows that the world’s forests have stored away an extra 4 billion tonnes of carbon in the last dozen years and the total amount of woodland has increased worldwide since 2003.

The encouraging news comes from Australian scientists, who report in Nature Climate Change that they used a new technique to analyse 20 years of satellite data, to estimate the overall pattern of growth in global vegetation.

The fate of the forests could hardly be more important. The world’s greenery is part of the natural atmospheric cycle, and the notorious greenhouse effect – the steady rise in carbon dioxide levels in the Earth’s atmosphere since the start of the Industrial Revolution and the use of fossil fuels to power economic growth – is in part also a response to land-use change and forest loss. Growth requires atmospheric carbon dioxide, and burning and land clearance releases it.

Biggest headache

So the study by remote sensing scientist Yi Liu, of the Climate Change Research Centre at the University of New South Wales, and colleagues becomes an important contribution to solving the climate scientist’s biggest headache: making sense of the carbon budget.

Accurate climate models depend on accurate assessment of the carbon cycle, and the forests play a critical role. Timber in the forests is essentially carbon in the bank.

And, for once, the news is encouraging. The great rainforests of the Congo and the Amazon may not be doing so well, but grasslands in other parts of the world have become increasingly more wooded, and there has been a massive expansion of forested land in China.

“The increase in vegetation primarily came from a lucky combination of environmental and economic factors, and massive tree-planting projects in China,” Dr Yi Liu says.

“Vegetation increased on the savannas of Australia, Africa and South America as a result of increasing rainfall, while in Russia and former Soviet republics we have seen the re-growth of forests on abandoned farmland. China was the only country to intentionally increase its vegetation with tree-planting projects.”

The Australian scientists are not the only researchers using instruments in high orbit to identify the green shoots of recovery.

“A lot rides on human decisions to slow
climate change. The clock is ticking
for the future of these forests”

Dmitry Shchepashchenko, a researcher at the International Institute for Applied Systems Analysis in Austria, and colleagues report in the journal Remote Sensing of Environment that a cocktail of remote sensing data, UN agency statistics and “crowdsourcing” – help from citizen scientists – has provided new high resolution maps of global forest cover.

This will serve as a basis for other studies, and for economic planning and policy-making. The maps are available on the Geo-Wiki website.

But the overall picture of a greener world remains uncertain. On the same day, scientists backed by the Carnegie Institution in Washington reported in Nature Geoscience that drought damage has already led to widespread forest death, and the toll could be much greater by the 2050s.

They based their study on the condition of the trembling aspen forests of the American southwest during the drought of 2000-2003.

Once again, their work is aimed at improving climate models and calculations of the response of forests to climate change, and could throw new light on the processes at work in forests subjected to water stress.

Drought damage

That is because the arboreal vascular system that transports water from the roots to the leaves is itself damaged by drought. But at what level would drought impose permanent damage on a tree’s physiology?

The Carnegie scientists were able to establish a drought threshold for the trembling aspen (Populus tremuloides), and the drought at the beginning of the century is known to have killed 17% of the species in Colorado.

The research is fundamental: just one study of one species in one region that provides a starting point for further studies, and thus for surer measures of vegetation response to climate change, and ultimately to a better understanding of the carbon cycle.

“Finding the thresholds in plant physiology, after which climate stress causes tree mortality, will allow us to resolve uncertainty over the fate of forest ecosystems in a changing climate,” says the study leader, William Anderegg, a researcher at Princeton Environmental Institute in the US.

“But, most importantly, a lot rides on human decisions to slow climate change. The clock is ticking for the future of these forests.” – Climate News Network

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“Water Man of India” makes rivers flow again

“Water Man of India” makes rivers flow again

Revival of traditional rainwater harvesting has transformed the driest state in India, and could be used to combat the effects of climate change across the world.

Chennai, 6 April, 2015 − School textbooks in India have been telling children for generations that Rajasthan is an inhospitable state in the northwest of the country, constrained by the hot, hostile sands of the Thar Desert.

But the driest state in India has a softer, humane face as well – that of Rajendra Singh, known as the “Water Man of India”, whose untiring efforts in water conservation in arid Rajasthan have led to him being awarded the Stockholm Water Prize, commonly referred to as the Nobel Prize for Water.

Singh did not attempt to design a new technology to address Rajasthan’s water problems. He began simply by de-silting several traditional surface level rainwater storage facilities – called “johads” in the local Hindi language − that fell out of use during British colonial rule. And, in doing so, he has quenched the thirst of villages that were dying.

Thousands of villages followed his example, and so much water was captured and soaked into aquifers that dry rivers have begun to flow again.

Water wars

Singh believes that water conservation is vital to combat the effects of climate change and to avoid “water wars” in the future.

And such is his reputation on water issues that he received a call from Prince Charles, heir to the UK throne, seeking advice on how to handle the devastating summer floods in England in 2007.

In an interview with Climate News Network, Singh recalled how he began making water flow again in perennially dry Rajasthan by inculcating do-it-yourself initiatives in the villagers.

He explained: “I imbibed Gandhian ideals during my school days that emphasised working for empowerment of villages.

“As an Ayurvedic (traditional medicine system in India) doctor, I went to the Alwar district of Rajasthan early in 1982 to start a clinic and spread awareness among youth about health and hygiene.

“I was perturbed because the majority of young men had already left the village, and the rest were about to leave for green pastures in the cities as they were unable to battle the water scarcity. Besides, they also wanted to earn good money.

“Women, old people and children were left behind in the village. I reworked my doctor plans to address the water scarcity, as that would actually save people from several diseases.

A village johad in arid Rajasthan. Image: LRBurdak via Wikimedia Commons

A village johad in arid Rajasthan. Image: LRBurdak via Wikimedia Commons

“Along with the support of the villagers, I de-silted a couple of johads in Alwar. When rains filled them, people in neighbouring villages trusted my initiative and over 8,000 johads are renovated now.

“Hordes of youth have returned to their villages as water filled tanks and the standard of living in hamlets rose in a big way.”

He said that five rivers in this region had revived and started to flow again.

Johads are simple tanks built across a slope, with a high embankment on three sides and the fourth side left open for rainwater to enter. They hold water during rains and recharge the aquifer below to ensure continuous water supply to the neighbourhood in the dry season.

“Community-based water management yields
long-lasting results and is the only solution for water shortages”

But Singh explained: “After the advent of bore wells and pipelines connecting every hamlet in India, we forgot the traditional water conservation facility used by our ancestors.”

Having won the Stockholm prize, what does the future hold for the Water Man?

“My immediate plans are to take up a global-level campaign on water conservation and peace,” he said. “As predicted by several experts, the next world war will be for water. Unless every one of us starts at least now to save water and protect the water bodies, we face severe conflicts − apart from suffering climate change impacts. I will be leading the global water walk in the UK in August 2015.

“During his two visits (2004 and 2006), Prince Charles told me that he was impressed by the johad model of conservation. He then called me in 2007 to be part of his team of water engineers to work out all possibilities to address the crisis during the floods in England. They listened to my suggestions on creating the johad model on hilltops and downhill to arrest water in the hills and prevent floods in the future.”

In India, however, he is not confident that the government has the right ideas. “Our government is pushing a different idea of inter-linking of rivers, which will only politicise the water crisis. I was part of the national-level body to clean up the holy Ganga River from 2010 to 2012, but I quit as there was lack of accountability and it ended up as a toothless organisation.

“Inter-linking of rivers is not a solution for flood and drought. As far as India is concerned, it will result only in inter-linking of corruption and politics.

Hearts and brains

“What we need is inter-linking of the hearts and brains of people to take up water conservation in their homes and community. If exploitation of river water and polluting the river are stopped, every river will flow. Water engineering should be focused on conservation of each drop, and not on changing the course of rivers, which are designed by Mother Nature.”

Singh is also against the idea of privatising water supplies, and does not believe it would result in people using water more judiciously.

“Water is not a commodity,” he said. “In my own example, johads are de-silted by the people and used by people. Community-based water management yields long-lasting results and is the only solution for water shortages.

“When people realise their need and de-silt lakes and ponds as a group, they can use the water without having to pay for it. Right to water is every man’s right, and monetising water will increase conflicts in the society.

“Helping a community to have access to clean and safe water means helping the community to have a dignified life.” – Climate News Network

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