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Science finds new routes to energy

April 17, 2014 in Agriculture, Biofuels, Carbon Dioxide, Energy, Technology

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The research opens the way to more nutritious soya beans grown with less water Image: H. Zell via Wikimedia Commons

The research opens the way to more nutritious soya beans grown with less water
Image: H. Zell via Wikimedia Commons

By Tim Radford

Scientists in the US have found new ways to make biofuel, increase crop yields and exploit carbon dioxide through novel applications of familiar materials.

LONDON, 17 April – While politicians posture, and climate scientists sigh sadly, researchers in laboratories continue to devise ingenious new ways to save energy, increase efficiency, and make the most of solar power.

Darren Drewry of the Jet Propulsion Laboratory in California and two colleagues from the University of Illinois have a computer model that could design soybean crops able to produce 8.5% more nourishment, use 13% less water and reflect 34% more sunlight back into space.

They report in the journal Global Change Biology that they can achieve all three goals by breeding for slightly different leaf distribution on the stalk, and for the angle at which the leaf grows, using a technique called numerical optimisation to try a very large number of structural traits to get the best results. “And surprisingly, there are combinations of these traits that can improve each of these goals at the same time,” says Dr Drewry.

In the great evolutionary challenge match, plants fight for the light and try to put each other in the shade. “Our crop plants reflect many millions of years in the wild under these competitive conditions,” said Stephen Long, a plant biologist. “In a crop field we want plants to share resources and conserve water and nutrients, so we have been looking at what leaf arrangements would best do this.”

Once future agricultural scientists have worked out what they most want from a crop – and in arid zones, water economy must rate highly – the programme can decide the best configuration of leaf. From that, future breeders could select traits from the enormous library of existing soybean variations.

Lomg-lasting benefit

They could reduce the canopy to let light through to lower levels to increase yield, or they could heighten the canopy to reflect light back into space and offset climate change.

“We can also model what these plant canopies can do in a future climate, so that it will be valid 40 or 50 years down the line,” says Praveen Kumar, an environmental engineer.

At Stanford University in California, other scientists have thought of a way to make biofuel without benefit of fields, plants or sunlight. They report in Nature that they have devised an oxide-derived copper catalyst that can turn carbon monoxide – the lethal gas in car exhausts and coal-burning power stations – directly into liquid ethanol of the sort now made from corn and other crops.

What’s more, they say, they can do this at room temperature and normal atmospheric pressures. The technique rests on the ability to turn copper oxide into a network of nanocrystals of metallic copper that would serve as a cathode in an electrolysis reaction and reduce carbon monoxide to ethanol.

Biofuel is expensive: it takes time, fields, fertiliser and water. It takes 800 gallons of water to grow a bushel of corn, which in turn yields three gallons of ethanol. The new technique could eliminate the crop, the time, and a lot of the water.

Ten-fold efficiency gain

And it opens another way to exploit captured CO2 as a power source. Carbon dioxide can be turned efficiently and easily into carbon monoxide. The new oxide-derived copper catalyst could then turn carbon monoxide into ethanol with ten times the efficiency of any normal copper catalysts.

The team would like to scale up their catalytic cell and see it powered by solar or wind energy. “But we have a lot more work to do to make a device that is practical,” said Matthew Kanan of Stanford.

Meanwhile, scientists in Oregon report in the Royal Society of Chemistry journal RSC Advances that they have tested a new way to tap the sun’s rays, and to use that power to make solar energy materials at the same time.

Once again, the match of nanoscience and copper has provided unexpected consequences. By focusing light continuously on a continuous flow micro-reactor, the researchers have synthesized copper indium nanoparticle inks that could make thin-film solar cells in minutes. Other processes might take hours to deliver the same materials.

“It could produce solar energy materials anywhere there’s an adequate solar resource and in this chemical manufacturing process, there would be zero energy impact,” said Chih-Hung Chang of Oregon State University. – Climate News Network

IPCC tries a gamble with shale gas

April 14, 2014 in Adaptation, Coal, Energy, Fracking, Greenhouse Gases, IPCC, Methane, Nuclear power, Renewables, Shale Gas, Solar energy, Wind power

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Non merci: A French protest against drilling for shale gas Image: Camster via Wikimedia Commons

Non merci: A French protest against drilling for shale gas
Image: Camster via Wikimedia Commons

By Alex Kirby

The latest IPCC report urges a dash for gas to allow us to reduce the burning of coal. And it accepts the use of shale gas, which threatens to be far more polluting than originally thought.

LONDON, 14 April – If you support fracking, you should be pleased with the latest report from the Intergovernmental Panel on Climate Change (the IPCC). It’s given the green light to the use of shale gas as a short-term way to slow climate change.

The report is the third and final part of the latest IPCC assessment on climate change (known as AR5). While it puts considerable emphasis on the need for more renewable energy – including solar, wind and hydropower – it says emissions of greenhouse gases can be cut in the medium term by replacing coal with less-polluting gas, though the gas will itself ultimately have to be phased out.

On shale gas, obtained by the controversial fracking process, Ottmar Edenhofer - co-chair of the working group that produced the report – said it was quite clear that the fuel “can be very consistent with low carbon development and decarbonisation”.

Among the objections to fracking is the fact the process releases quantities of methane, a greenhouse gas often reckoned to be at least 20 times more powerful than carbon dioxide at warming the atmosphere. That is the comparison we have often used in the Network’s reporting. It’s right, so far as it goes. But by some calculations it doesn’t go nearly far enough.

Own goal

Recently an observant reader pointed out that methane is 20 times more potent than CO2 when its impact is measured over a century. But in the short term it is a far greater problem. Over the space of two decades it is estimated to be at least 84 times more damaging than carbon dioxide.

Robert Howarth is professor of ecology and environmental biology at Cornell University. He and his colleague Drew Shindell of the US National Oceanic and Atmospheric Administration have predicted that unless emissions of methane (and black carbon) are reduced immediately, the Earth will warm by 1.5°C by 2030 and by 2.0°C by between 2045 and 2050, whether or not carbon dioxide emissions are reduced.

Professor Howarth puts the global warming potential of methane higher still. He has written: “At the time scale of 20 years following emission, methane’s global warming potential is more than 100-fold greater than for carbon dioxide (Shindell et al. 2009).”

Some critics will conclude that the IPCC’s search for a bridging strategy to move us rapidly to a world of clean energy has scored an own goal by failing to rule out a fuel which entails a large and avoidable increase in greenhouse emissions. The cost of the infrastructure needed to exploit shale gas on a large scale may also work to prolong its use.

Affordable transformation

Ironically, the clean energy world the IPCC seeks need be no more than 15 years away, according to one US expert. Mark Z Jacobson is professor of civil and environmental engineering at Stanford University, California, and director of its atmosphere and energy program. He believes that wind, water and solar power can be scaled up cost-effectively to meet the world’s energy demands, ending dependence on both fossil fuels and nuclear power.

Professor Jacobson described in Energy Policy in 2010 how he and a colleague had analysed “the feasibility of providing worldwide energy for all purposes (electric power, transportation, heating/cooling, etc.) from wind, water, and sunlight (WWS)”.

He continued: “We suggest producing all new energy with WWS by 2030 and replacing the pre-existing energy by 2050. Barriers to the plan are primarily social and political, not technological or economic. The energy cost in a WWS world should be similar to that today.”

It sounds like a less risky path to a world of clean energy than the IPCC is urging. Fifteen years to build a different way of fuelling society, or 20 years of watching spiralling methane emissions, seems a no-brainer. – Climate News Network

More CO2 limits plants’ protein output

April 12, 2014 in Agriculture, Carbon Dioxide, Soil, Uncategorized, Vegetation changes, Warming

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The Mojave desert: As CO2levels rose, it took up unexpectedly large amountsofthe gas Image: Rennett Stowe via Wikimedia Commons

The Mojave desert: As CO2 levels rose, it took up unexpectedly large amounts of the gas
Image: Rennett Stowe via Wikimedia Commons

By Tim Radford

With increasing warmth drying more of the Earth, arid soils may absorb more carbon dioxide – but that in turn is likely to limit protein production.

LONDON, 12 April – As global temperatures rise, more than one third of the land surface may become more arid. Although there will be changes in rainfall patterns, heat – and the attendant evaporation of the soil – could extend ever drier conditions to more and more farmland and cities, according to research in the journal Climate Dynamics.

The new study – which excludes Antarctica – is led by Benjamin Cook, a climate scientist both with the University of Columbia’s Lamont-Doherty Earth Observatory and the US space agency Nasa. It is based on climate simulation, and forecasts that 12% of the land surface will be subjected to drought by 2100 just through changes in rainfall. Throw in the increased heat, though, and the drying effect will be spread to 30% of the land.

Even those regions that might be expected to get more rain will be at greater risk of drought. This would be very bad news for the wheat, corn and rice belts of the south-western US and south-eastern China.

“For agriculture, moisture in the soil is what really matters,” said Cook’s co-author, Jason Smerdon. The research confirms previous studies, and the more recent warnings from the Intergovernmental Panel on Climate Change, and other studies, have predicted that extremes of temperature will be bad news for farmers anyway, with yields  likely to be affected.

But nothing in climate research is simple. The extra warming will be a direct consequence of ever-higher levels of carbon dioxide in the atmosphere. A study in Nature Climate Change has just revealed that arid zones offer an unexpected source of what engineers call negative feedback.

Carbon sink

A 10-year experiment in the Mojave desert in the US has shown that as carbon dioxide levels increase, arid areas take up unexpectedly large amounts of the gas.

“They are a major sink for atmospheric carbon dioxide, so as CO2 levels go up, they’ll increase their uptake of CO2 from the atmosphere. They’ll help take up some of that excess CO2 going into the atmosphere. They can’t take it all up, but they’ll help,” says Dave Evans, a biologist at Washington State University.

All land surfaces absorb some carbon. Until now, most attention has been paid to the role of forests as major “sinks” of carbon. But the US experimenters marked out nine octagonal plots of the desert and blew air with current levels of CO2 over three of them, and air with 550 parts per million of CO2, the expected level by 2050, over another three. Three received no extra air at all.

Then the researchers excavated the soils to a depth of a metre to measure the absorbed carbon and were surprised by the gain in carbon during a relatively short exposure in the plots exposed to the extra carbon dioxide.

Arid and semi-arid soils account for a large proportion of the planet’s land surface: overall, they could increase carbon uptake to account for between 15% and 28% of the amount currently being absorbed by land surfaces.

Less protein

This sounds like good news, on balance. It may not be, as far as food supplies are concerned. In the same issue of Nature Climate Change a second study reports on experiments into the effects of elevated levels of carbon dioxide on wheat.

Carbon dioxide is seen as a fertiliser of plants and indeed, without it, there would be no plants. But Arnold Bloom, a plant scientist at the University of California Davis reports that, according to his experiments, elevated levels of carbon dioxide also inhibit the conversion of nitrate into protein in crops.

Wheat provides nearly one fourth of all protein in the global human diet. Other studies have shown the same effect with wheat – and also with rice, barley and potato tubers.

“When this decline is factored into the respective portion of dietary protein that humans derive from these various crops, it becomes clear that the overall protein available for human consumption may drop by about three per cent as atmospheric carbon dioxide reaches the levels anticipated to occur during the next few decades,” Bloom said. – Climate News Network

Whale dumps temper Antarctic warmth

March 25, 2014 in Antarctic, Carbon, Deep Ocean, Global Ocean Commission, Marine ecology, Whales

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Whales play a key part in recycling iron and carbon in the Antarctic Image: US National Oceanic & Atmospheric Administration

Whales play a key part in recycling iron and carbon in the Antarctic
Image: US National Oceanic & Atmospheric Administration

By Alex Kirby

By enriching the seas with iron expelled from their digestive systems, sperm whales are helping to slow the warming of the Antarctic, scientists say.

LONDON, 25 March – There is plenty yet to learn about the causes and effects of climate change, and here is one fact you may perhaps not have known until now: defecating sperm whales are helping to slow the warming of the Southern Ocean.

A team of Australian scientists and colleagues based at Flinders University in Adelaide reported in Proceedings of the Royal Society B (in 2010) that the whales help to increase levels of iron in Antarctic waters (which are iron-deficient).

Iron is important for marine life, and the polar oceans are important for helping to regulate atmospheric CO2 levels. So the whales’ personal hygiene is helping vastly smaller lifeforms to thrive, which in turn keeps the ocean ecosystem in balance and able to recycle carbon safely to the seabed.

Scientists had believed that the whales’ breathing decreased the efficiency of the Southern Ocean’s biological pump by returning carbon from the depths to the surface and thence to the atmosphere, where it would add to the greenhouse gases already there.

But the Flinders team says that by consuming prey in deep water (the whales search for squid  at 1,200 metres or even further down) and then releasing iron-rich liquid faeces into the sunlit zone near the surface, the whales instead stimulate new primary production and return the carbon to deep water.

Damaged by whaling

“Primary production” is the scientific term used to describe the minute forms of life produced by the effect of light in the presence of nutrients and – crucially – iron.

The researchers say Southern Ocean sperm whales stimulate the return of 40,000 tonnes of carbon annually to the deep ocean but breathe out only half that amount. So by stimulating new primary production, the 12,000 Antarctic whales act as a carbon sink, removing twice as much carbon from the atmosphere as they add by their breathing.

The team adds that the ability of the Southern Ocean to act as a carbon sink has been diminished by the large-scale killing of sperm whales during the era of industrial whaling, which reduced the global populations of many whale species to a fraction of their historic levels.

The researchers say the killing of the whales, by decreasing iron inputs to the surface zone, has had a serious impact. “This nutrient loss has undoubtedly altered the dynamics and food-web structure of these environments and this has decreased carbon export to the deep ocean”, they conclude.

Not unique

News of the researchers’ conclusions, which have so far gone largely unreported, was given to journalists covering a recent meeting in Hong Kong of the Global Ocean Commission by Professor Alex Rogers, of the Department of Zoology at the University of Oxford, UK.

Goodbye to all that? Whaling - still continuing in the Antarctic - disrupts the carbon recycling Image: Courtesy of the International Whaling Commission

Goodbye to all that? Whaling – still continuing in the Antarctic – damages the recycling process
Image: Courtesy of the International Whaling Commission

Asked by the Climate News Network whether the findings might apply to other whale species in other oceans, he said: “Not for iron, as the Southern Ocean is a high-nutrient low-chlorophyll area and thus primary production in this region is specifically limited by iron. In most other parts of the ocean it is limited by nitrates.”

But a similar paper had shown that before industrial whaling began whales had been the primary source of nitrates through the same process in Chesapeake Bay, on the US Atlantic coast. So fertilisation through defecation was likely to be a common mechanism, although different constituents of the faeces were important, and in the Antarctic krill might also be important in iron release.

Professor Rogers said whales made other useful contributions to human welfare. Taken together, the toothed whales – a group including sperm whales, belugas and narwhals – were thought to contribute 0.5-1.0% of all the energy needed  for ocean mixing. – Climate News Network

Bricks on wheels face road closure

March 23, 2014 in Carbon Dioxide, Economy, European Union, Road Transport, Safety, Technology, United Kingdom

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A brick on wheels? The traditional British lorry may before lone give way to a new and perhaps safer design Image: By Adrian S Pye via Wikimedia Commons

A brick on wheels? The traditional British lorry may before long give way to a new and perhaps safer design
Image: By Adrian S Pye via Wikimedia Commons

By Kieran Cooke

The European Parliament has voted in favour of changing the design of goods lorries throughout the EU – from their present brick shape to a more streamlined-looking vehicle. The idea is not only to increase fuel efficiency and cut back on CO2 emissions, but also to reduce accidents.

LONDON, 23 March – It’s one of those small steps that could help in the battle against greenhouse gas emissions and climate change.

Lorry design in the European Union at present is governed by legislation dating back to the mid-1990s, stipulating total maximum lengths for cabs and trailers.

This has resulted in the general adoption by road hauliers of a brick-shaped design for cabs on lorries: by making the cab more upright and shorter, transport companies have more space for goods.

But according to Transport & Environment (T&E), a Brussels-based group which campaigns for more sustainable and environmentally friendly transport policies within the EU, lorries have lagged seriously behind other vehicles in terms of environmental performance over the past 20 years.

“Whilst only three per cent of vehicles (in the EU), lorries account for a quarter of Europe’s road transport emissions. That share is expected to grow as traffic increases further”, it says.

Improving protection

T&E says the brick-shaped design is not only inefficient in terms of fuel consumption – it is also dangerous: “Lorries also have a dreadful safety record: every year 15% of all fatal collisions – around 4,200 deaths – involve lorries.”

About 75% of freight in Europe is delivered by lorry. Studies indicate road freight transport is one of the fastest-growing sources of CO2 emissions in the EU, with emissions from the sector likely to increase by more than 20% over the next 15 years. The EU imports 500 million barrels of oil each year, wortharound €60bn, to power its freight fleet.

European Parliament members say relatively simple changes in design can bring about advances in fuel efficiency and cut back on CO2 emissions. Under the Parliament’s proposals, the brick-shaped cab design would be replaced by a more streamlined, aerodynamic nose. The rear of the vehicle would also have aerodynamic flaps and shaping.

T&E says giving lorries a rounder front and putting in place other improvements could improve fuel economy by between seven and ten per cent. It says a more curved cab front would also give drivers greater visibility, eliminate blind spots and so avoid accidents.

Powerful backing

“Today is a good day for pedestrians, cyclists, drivers, hauliers and the environment”, said William Todts of T&E following the EU Parliament vote. “This vote brings the end of the brick-shaped cab closer. It’s a key decision that will reduce road deaths and kickstart progress on lorry CO2 emissions after 20 years of stagnation.”

After a spate of fatal accidents involving lorries and cyclists, London’s mayor, Boris Johnson, has joined the call for changes in lorry design.

The era of more fuel-efficient, safer lorries in Europe is likely to be delayed for some time. Hauliers and truck manufacturers object to the costs of design changes.  To compensate for the haulage space lost due to any new shapes for lorries, the trucking industry is likely to press for bigger, longer vehicles.

The Parliament’s vote still needs to be confirmed by the full parliamentary body. It then goes forward to be considered by all member states. The brick on wheels could be charging down Europe’s roads for some time yet. – Climate News Network

Warmer freshwater emits more methane

March 20, 2014 in Greenhouse Gases, Methane, Warming, Water, Wetlands

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Swamps, marshes, rice paddies and all freshwater ecosystems are sources of methane Image: By vastateparksstaff (Uploaded by AlbertHerring) via Wikimedia Commons

Swamps, marshes, rice paddies and other freshwater ecosystems are sources of methane
Image: By vastateparksstaff (Uploaded by AlbertHerring) via Wikimedia Commons

By Tim Radford

Scientists think the amount of methane emitted to the atmosphere from freshwater ecosystems will increase as the climate warms, triggering further warming.

LONDON, 20 March – British scientists have identified yet another twist to the threat of global warming. Any further rises in temperature are likely to accelerate the release of methane from rivers, lakes, deltas, bogs, swamps, marshlands and rice paddy fields.

Methane or natural gas is a greenhouse gas. Weight for weight, it is more than 20 times more potent than carbon dioxide over a century, and researchers have repeatedly examined the contribution of natural gas emitted by ruminant cattle to global warming. But Gabriel Yvon-Durocher of the University of Exeter and colleagues considered something wider: the pattern of response to temperature in those natural ecosystems that are home to microbes that release methane.

They report in Nature that they looked at data from hundreds of field surveys and laboratory experiments to explore the speed at which the flow of methane increased with temperature.

Microbes, algae, freshwater plants and animals are all part of an active ecosystem and take their nourishment from and return waste to the atmosphere. Healthy plants take carbon dioxide from the atmosphere with photosynthesis. Most of the methane in freshwater systems is produced by an important group of microbes called Archaea that live in waterlogged, oxygen-free sediments and play an important role in decay.

Plant uptake of carbon dioxide is affected by temperature, and so is microbial methane production. Respiration also releases carbon dioxide. The questions the researchers set out to answer were: which gas is more likely to be released in greater quantities as temperatures rise? And is the outcome the same whether they examine the Archaea only, or all the microbes in an ecosystem, or the entire package of submerged freshwater life?

More heat, more methane

The answer is, the scientists say, that methane emissions go up with the mercury, and that the ratio of methane to carbon dioxide also goes up in step with temperature. And the result is the same whether you consider the microbes or the whole ecosystem.

“The discovery that methane fluxes are much more responsive to temperature than the processes that produce and consume carbon dioxide highlights another mechanism by which the global carbon cycle may serve to accelerate rather than mitigate future climate change,” says Dr Yvon-Durocher.

This is not the end of the story. All such studies raise as many questions as they answer, and more research is necessary. The next puzzle is how to fit such findings into models of climate change. However, the researchers feel they have cleared up one point. Dr Yvon-Durocher says:

“Our research provides scientists with an important clue about the mechanisms that may control the response of methane emissions from ecosystems to global warming.” – Climate News Network

Biofuels from waste ‘need EU backing’

March 3, 2014 in Adaptation, Agriculture, Biofuels, Business, Carbon Dioxide, Energy, European Union, Forests

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The bales head  for the farm: Straw is an agricultural waste suitable for making biofuel Image: Ian Kirk from Broadstone, Dorset, UK via Wikimedia Commons

The bales head for the farm: Straw is an agricultural waste suitable for making biofuel
Image: Ian Kirk from Broadstone, Dorset, UK via Wikimedia Commons

By Alex Kirby

The countries of the European Union could slash their greenhouse gas emissions and save significant amounts of oil by making fuel from waste, researchers say. But they think policymakers should give a lead.

LONDON, 3 March – Europe has the technology and the raw material to make a big cut in the amount of oil its transport uses, researchers say. But it will fail to reap the benefits on offer unless the European Union comes up with more radical policies.

A report, Wasted: Europe’s Untapped Resource, says the continent has significant unexploited potential to convert waste from farming, forestry, industry and households into advanced low-carbon biofuels, saving more than a sixth of the EU’s expected total fuel consumption for road transport 16 years from now.

But it says the conversion will not happen unless EU policymakers give greater priority to sustainability and to the need to lower the dependence of transport on high-carbon fuels by 2030.

The research which produced the report was carried out by the International Council on Clean Transportation (ICCT) and NNFCC, a UK research consultancy. The project was supported by a group of companies interested in introducing new technology, including two airlines, British Airways and Virgin, and by WWF, BirdLife Europe and several other environment NGOs.

The report says that if all sustainable waste from farms, forests, households and industry is used for transport fuels, that could make enough to replace about 37 million tonnes of oil annually by 2030 – the equivalent of 16% of the EU’s road transport fuel demand by then.

Safeguards needed

It also says that so long as the new fuels came from sustainable sources, they would produce less than 40% of the carbon dioxide emissions from fossil fuels. Using them would inject up to €15 billion (US$21 bn) of extra revenue into the rural economy every year and create up to 300,000 new jobs by 2030.

The sorts of wastes that could be used include straw and other crop left-overs, forestry residues, municipal solid waste and used cooking oil.

But the report carries a warning too: safeguards would be needed to ensure the waste was obtained sustainably, including land management methods to protect biodiversity, water and soil.

And the benefits of biofuel from waste would have to be paid for. The report says some combinations of feedstock and technology would need short-term financial incentives, although others are already close to being competitive and would need little more than certainty about policy.

Easier challenge

The authors say cautiously that the research shows it is possible to develop a biofuel industry based on farm and forest wastes “which in the case of the cheapest feedstocks could become cost-competitive with only modest incentives…” Biofuel from other wastes might need different levels of subsidy.

Chris Malins led the analysis for the ICCT. He said: “Even when taking account of possible indirect emissions, alternative fuels from wastes and residues offer real and substantial carbon savings. The resource is available, and the technology exists – the challenge now is for Europe to put a policy framework in place that allows rapid investment.”

David Turley of the NNFCC, who led the economic analysis, said advanced biofuels from agricultural and forest wastes would require “little or only a modest additional incentive” to stimulate production at prices comparable to those of current fuels made from specially-grown crops.

The report concludes that while trying to use all the available waste might be thought optimistic, achieving just 2% of current EU road transport fuel use in 2020, as suggested by the European Parliament, would be less challenging.

Even that more modest aim, the report says, would still add about €163 million (US$224 m) in net revenues to the agricultural sector and €432 m (US$594 m) to the forestry sector. It would also generate an extra 37,000 permanent jobs in the rural economy, and 3,500 more in biofuel refineries. – Climate News Network

Tree roots ‘are natural thermostat’

February 18, 2014 in Carbon Dioxide, Forests, Mountains, Palaeoclimatology, Soil

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In sight of the Carpathians: Mountain forests can cool - and warm - the Earth Image: Horia Varlan from Bucharest, Romania, via Wikimedia Commons

In sight of the Carpathians: Mountain forests can cool – and warm – the Earth
Image: Horia Varlan from Bucharest, Romania, via Wikimedia Commons

By Tim Radford

Trees can influence the climate in unexpected ways, and British researchers say their roots are an important way of helping rocks to weather and drawing carbon dioxide from the atmosphere.

LONDON, 18 February – Trees have become a source of continuous surprise. Only weeks after researchers demonstrated that old forest giants actually accumulate more carbon than younger, fast-growing trees, British scientists have discovered that the great arbiters of long-term global temperatures may not be the leaves of an oak, a pine or a eucalypt, but the roots.

The argument, put by a team from Oxford and Sheffield Universities in the journal Geophysical Research Letters, begins with temperature. Warmer climates mean more vigorous tree growth and more leaf litter, and more organic content in the soil. So the tree’s roots grow more vigorously, say Christopher Doughty of Oxford and colleagues.

They get into the bedrock, and break up it up into its constituent minerals. Once that happens, the rock starts to weather, combining with carbon dioxide. This weathering draws carbon dioxide out of the atmosphere, and in the process cools the planet down a little. So mountain ecosystems – mountain forests are usually wet, and on conspicuous layers of rock – are in effect part of the global thermostat, preventing catastrophic overheating.

The tree is more than just a sink for carbon, it is an agency for chemical weathering that removes carbon from the air and locks it up in carbonate rock.

That mountain weathering and forest growth are part of the climate system has never been in much doubt: the questions have always been about how big a forest’s role might be, and how to calculate its contribution.

Keeping climate stable

US scientists recently studied the rainy slopes of New Zealand’s Southern Alps to begin to put a value on mountain ecosystem processes. Dr Doughty and his colleagues measured tree roots at varying altitudes in the tropical rain forests of Peru, from the Amazon lowlands to 3,000 metres of altitude in the higher Andes.

They measured the growth to 30 cms below the surface every three months and did so for a period of years. They recorded the thickness of the soil’s organic layer, and they matched their observations with local temperatures, and began to calculate the rate at which tree roots might turn Andean granite into soil.

Then they scaled up the process, and extended it through long periods of time. Their conclusion: that forests served to moderate temperatures in a much hotter world 65 million years ago.

“This is a simple process driven by tree root growth and the decomposition of organic material. Yet it may contribute to the Earth’s long-term climate stability. It seems to act like a thermostat, drawing more carbon dioxide out of the atmosphere when it is warm and less when it is cooler”, Dr Doughty said.

If forests cool the Earth, however, they might also warm it up. A team from Yale University in the US has reported in Geophysical Research Letters that forest fires might have had an even greater impact on global warming during the Pliocene epoch about three million years ago than carbon dioxide.

Rapid rise expected

Nadine Unger, an atmospheric chemist, and a colleague have calculated that the release of volatile organic compounds, ozone and other products from blazing trees could have altered the planet’s radiation balance, by dumping enough aerosols into the atmosphere to outperform carbon dioxide as a planet-warmer.

In fact, the Pliocene was at least 2°C or 3°C warmer than the pre-industrial world. The Pliocene is of intense interest to climate scientists: they expect planetary temperatures to return to Pliocene levels before the end of the century, precisely because humans have cleared and burned the forests, and pumped colossal quantities of carbon dioxide into the atmosphere. The greater puzzle is why a rainy, forested and conspicuously human-free world should have been so much warmer.

“This discovery is important for better understanding climate change through Earth’s history, and has enormous implications for the impacts of deforestation and the role of forests in climate protection strategies”, Dr Unger said.

All this scholarship is concerned with the natural machinery of ancient climate change, and the Yale research was based on powerful computer simulations of long-vanished conditions that could not be replicated in a laboratory.

Meanwhile, ironically, forest scientists have had a chance to test the levels of volatile organic discharges from blazing forests because freakish weather conditions in Norway have seen unexpected wild fires in tracts of mountain forest. December was one of Norway’s warmest winter months ever. In one blaze, 430 residents were forced to evacuate. – Climate News Network

Carbon output ‘will climb 29% by 2035′

February 7, 2014 in Carbon Dioxide, Coal, Energy, Forecasting, Greenhouse Gases, Renewables, Shale Gas

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Spelling it out: A French "non" to the prospect of shale oil and gas Image: Eva Joly 2012 via Wikimedia Commons

Spelling it out: A French “non” to the prospect of shale oil and gas
Image: Eva Joly 2012 via Wikimedia Commons

By Alex Kirby

Climate scientists agree that global carbon dioxide emissions need to be sharply cut. A prominent player in the energy industry predicts they will go in the opposite direction.

LONDON, 7 February – The good news, from the climate’s standpoint, is that while global demand for energy is continuing to grow, the growth is slowing. The bad news is that one energy giant predicts global carbon dioxide emissions will probably rise by almost a third in the next 20 years.

The Intergovernmental Panel on Climate Change says greenhouse gas emissions need to peak by 2020 and then decline if the world is to hope to avoid global average temperatures rising by more than 2°C over pre-industrial levels. Beyond 2°C, it says, climate change could become dangerously unmanageable.

But BP’s Energy Outlook 2035 says CO2 emissions are likely to increase by 29% in the next two decades because of growing energy demand from the developing world.

It says “energy use in the advanced economies of North America, Europe and Asia as a group is expected to grow only very slowly – and begin to decline in the later years of the forecast period”.

But by 2035 energy use in the non-OECD economies is expected to be 69% higher than in 2012. In comparison use in the OECD will have grown by only 5%, and actually to have fallen after 2030, even with continued economic growth. The Outlook predicts that global energy consumption will rise by 41% from 2012 to 2035, compared with 30% over the last ten.

Nor does it offer much hope that the use of novel energy sources will help to cut emissions. It says: “Shale gas is the fastest-growing source of supply (6.5% p.a.), providing nearly half of the growth in global gas.”

Renewables shine

Burning gas produces much lower CO2 emissions than using coal, but the sheer volume of shale production is expected to cancel out any possible emissions reductions. In fact the Outlook says of its predictions:  “…emissions [of CO2] remain well above the path recommended by scientists…Global emissions in 2035 are nearly double the 1990 level.”

An advantage claimed by some supporters of shale gas is that it will increasingly replace a much more polluting fossil fuel, coal. But at the moment many coal-producing countries are finding markets overseas for those they have lost to shale gas at home.

Oil, natural gas and coal are each expected to make up around 27% of the total mix by 2035, with the remaining share coming from nuclear, hydroelectricity and renewables. Among fossil fuels gas, conventional as well as shale, is growing fastest and is increasingly being used as a cleaner alternative to coal.

Bob Dudley, BP Group chief executive, said the Group was “optimistic for the world’s energy future”. Europe, China and India would become more dependent on imports, he said, while the US was on course to become self-sufficient in energy.

The Outlook does provide encouragement to the producers of renewables, which are expected to continue to be the fastest growing class of energy, gaining market share from a small base as they rise at an average of 6.4% a year to 2035. – Climate News Network

There’s no warming standstill says WMO

February 5, 2014 in Climate risk, El Niño, Temperature Increase, Warming slowdown

FOR IMMEDIATE RELEASE

Aerial fire-fighting in Australia, which in 2013 had its hottest year on record Image: Bidgee via Wikimedia Commons

Aerial fire-fighting in Australia, which in 2013 had its hottest year on record
Image: Bidgee via Wikimedia Commons

By Alex Kirby

The head of the World Meteorological Organization tells Climate News Network there is no standstill in global warming, which is on course to continue for generations to come.

LONDON, 5 February – The planet is continuing to warm, with implications for generations ahead, and temperatures are set to rise far into the future, the World Meteorological Organization (WMO) reports.

It says 2013 was among the ten warmest years since modern records began in 1850, equalling 2007 as the sixth warmest year, with a global land and ocean surface temperature 0.50°C above the 1961–1990 average and 0.03°C higher than the most recent 2001–2010 average.

Thirteen of the 14 warmest years on record have all occurred in this century. The warmest years on record are 2010 and 2005, with global temperatures about 0.55 °C above the long-term average, followed by 1998, which also had an exceptionally strong El Niño event.

El Niño events (which intensify warming) and cooling La Niñas are major drivers of natural climate variability. Neither occurred during 2013, which was warmer than 2011 or 2012, when La Niña exerted its cooling influence. 2013 was among the four warmest neutral years recorded, when neither El Niño nor La Niña affected temperatures.

“The global temperature for the year 2013 is consistent with the long-term warming trend”, said WMO Secretary-General Michel Jarraud. “The rate of warming is not uniform but the underlying trend is undeniable. Given the record amounts of greenhouse gases in our atmosphere, global temperatures will continue to rise for generations to come.

“Which standstill? The coldest year since 2001 is warmer than any year before 1998″

“Our action – or inaction – to curb emissions of carbon dioxide and other heat-trapping gases will shape the state of our planet for our children, grandchildren and great-grandchildren”, Mr Jarraud said.

Asked by Climate News Network how WMO regarded claims by some critics that there has been a “global warming standstill since 1997″, Mr Jarraud said: “Which standstill? The coldest year since 2001 is warmer than any year before 1998.

“Each decade is warmer than the previous one. There is global variability from year to year. You have to look at the longer period. If you do that, then the message is beyond any doubt…Despite the fact that there was no El Niño in 2013, it was still the sixth warmest year. This is significant.”

The WMO says surface temperature is just part of a much wider picture of climate change. “More than 90% of the excess heat being caused by human activities is being absorbed by the ocean“, it says.

It has released the temperature data in advance of its full Statement on the Status of the Climate in 2013, to be published in March. This will give more details of regional temperatures and other indicators.

Consistent findings

In contrast with 2012, when the US in particular experienced record high annual temperatures, the warmth in 2013 was most extreme in Australia, which had its hottest year on record.

WMO’s global temperature analysis is based mainly on three independent and complementary datasets. One is maintained by two UK centres, the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia. The other two are based in the US: NOAA’s National Climatic Data Center, and the Goddard Institute for Space Studies (GISS), operated by NASA.

Each dataset uses slightly different methods of calculation and so each gave 2013 a different temperature ranking, but they were consistent on the year-by-year changes and the longer warming trends globally.

WMO also uses reanalysis-based data from the European Centre for Medium-Range Weather Forecasts (ECMWF), which showed annual global land and ocean temperature to be the fourth highest on record. – Climate News Network