Professors plead with greens to accept nuclear power

Professors plead with greens to accept nuclear power

Academics argue that nuclear power is essential to save the planet from climate change, but critics say they seem to have forgotten the danger of a nuclear winter.

LONDON, 26 December, 2014 − Seventy-five professors from the world’s leading universities have signed a letter urging environmentalists to re-think their attitude to nuclear power as a way to save the planet from climate change and preserve its animals, plants and fish.

Ironically, it is two Australian academics who came up with the research. They come from a country whose government has repudiated the Kyoto Protocol, reversed measures to cut climate change, is one of the world’s biggest coal exporters, and has no nuclear power. Australia has just recorded the hottest spring since records began 100 years ago.

The two professors are Barry W. Brook, Chair of Environmental Sustainability at the University of Tasmania, and Corey J.A. Bradshaw, Sir Hubert Wilkins Chair of Climate Change at the University of Adelaide’s Environment Institute. Their backers include many leading experts on ecology, biodiversity, evolution and geography from the US, UK, China and India.

The letter is significant because previous pleas for a role for nuclear power have mostly come from physics professors, who could reasonably be said to love the technology for its own sake.

But this group has no stake in nuclear power, and their argument is based purely on the need to save the planet and its species from overheating and excess use of valuable land for renewables. Professors Brook and Bradshaw have had a paper published in the magazine Conservation Biology, in which they evaluated all possible forms of energy generation. Wind and nuclear power had the highest “benefit-to-cost ratio”.

“…we entreat the conservation and environmental community to weigh up the pros and cons of different energy sources…”

The letter urges environmentalists to read the paper, and says the two professors “provide strong evidence for the need to accept a substantial role for advanced nuclear power systems with complete fuel recycling − as part of a range of sustainable energy technologies that also includes appropriate use of renewables, energy storage and energy efficiency.

“This multi-pronged strategy for sustainable energy could also be more cost-effective and spare more land for biodiversity, as well as reduce non-carbon pollution (aerosols, heavy metals).

“Given the historical antagonism towards nuclear energy amongst the environmental community, we accept that this stands as a controversial position.

“However, much as leading climate scientists have recently advocated the development of safe, next-generation nuclear energy systems to combat global climate change, we entreat the conservation and environmental community to weigh up the pros and cons of different energy sources, using objective evidence and pragmatic trade-offs, rather than simply relying on idealistic perceptions of what is ‘green’.

“Although renewable energy sources like wind and solar will likely make increasing contributions to future energy production, these technology options face real-world problems of scalability, cost, material and land use, meaning that it is too risky to rely on them as the only alternatives to fossil fuels.

Conflict risk

“Nuclear power − being by far the most compact and energy-dense of sources − could also make a major, and perhaps leading, contribution. As scientists, we declare that an evidence-based approach to future energy production is an essential component of securing biodiversity’s future and cannot be ignored. It is time that conservationists make their voices heard in this policy arena.”

The letter has attracted a wide variety of comments. Some are supportive, but others say that the professors have ignored one of the greatest threats to the planet – a nuclear war.

Dr Jim Green, writing in the Ecologist magazine, makes the point that nuclear power and nuclear proliferation go hand in hand:  “Even a modest exchange of nuclear warheads could profoundly affect biodiversity, and large scale nuclear war certainly would.”

Dr Green also attacks the paper for endorsing fast breeder reactor technology as the solution to climate change. He says that the “fast reactor techno-utopia presented by Brook and Bradshaw is theoretically attractive”, but has already been tried unsuccessfully, and cannot be made to work in the real world. – Climate News Network

Share This:

Beavers damned for increasing threat from methane

Beavers damned for increasing threat from methane

The growth of the world’s beaver population to more than 10 million has led to a big increase in one of the main greenhouse gases that cause climate change.

LONDON, 21 December, 2014 − For a picture of industrious innocence, beavers are hard to beat. Yet they now find themselves facing a grave charge: they are, it seems, responsible for increasing greenhouse gas emissions.

The problem, Canadian scientists say, lies in the shallow ponds that form behind the dams the beavers build. The ponds are essential to the animals’ way of life. Unfortunately, they’re also good places for generating methane.

Methane is a powerful greenhouse gas, and in the short term it does much more damage than the far more abundant carbon dioxide. There is now international agreement that methane is 34 times more potent than CO2 over a century, but 84 times more over a much shorter timespan – just 20 years. And two decades can be crucial in trying to slow the rate of climate change.

Trapping limited

Colin J. Whitfield, of the University of Saskatchewan, led a study − published in the journal AMBIO − from which he estimated that beaver numbers in Eurasia and the Americas have grown so much that the methane emissions the ponds produce are now 200 times higher than in 1900.

Between the 16th and the 19th centuries, the fur trade nearly led to the beavers’ extinction worldwide. After trapping was limited and they were re-introduced to their natural ranges, the number of North American (Castor canadensis) and Eurasian (Castor fiber) beavers began to grow. The North American beaver has also been introduced to parts of Eurasia and South America.

“This suggests that the contribution of beaver activity to global methane emissions may continue to grow”

Beavers build dams in rivers to create standing open-water ponds and wetlands. The ponds are usually shallow, with dams seldom more than 1.5 metres high. The study found that carbon builds up in the oxygen-poor pond bottoms, and methane is then generated. Unable to dissolve adequately in the shallow water, it is released into the atmosphere.

The team estimated the size of the current global beaver population and determined the area covered by beaver ponds. They found that global beaver numbers have grown to over 10 million, damming more than 42,000 sq kms of aquatic pond areas, bordered by over 200,000 kms of shoreline habitat.

At the end of the 20th century, they say, beavers contributed up to 0.80 teragrams (or 800 million kilograms) of methane to the atmosphere annually. This is about 15% of the input from wild cud-chewing animals such as deer or antelopes.

“Continued range expansion, coupled with changes in population and pond densities, may dramatically increase the amount of water impounded by the beaver,” Whitfield says.

“This, in combination with anticipated increases in surface water temperatures, and likely effects on rates of methanogenesis, suggests that the contribution of beaver activity to global methane emissions may continue to grow.”

Copious amounts

Beavers are not alone in unwittingly worsening climate change. Ruminants − animals that chew the cud − emit copious amounts of methane, prompting concerns about the impacts on the atmosphere of an increasingly meat-based human diet.

Now comes news that another species may have to step up and accept some of the blame for a warming world.

Scientists from Woods Hole Research Center, in the US, told the American Geophysical Union fall meeting in San Francisco that Arctic ground squirrels may be playing a greater role in climate change than previously thought.

They say the animals are hastening the release of greenhouse gases from the permafrost, accelerating an existing positive feedback that means the warming temperatures help the frozen soil to thaw and emit still more greenhouse gas. − Climate News Network

Share This:

Loss of rainforests is double whammy threat to climate

Loss of rainforests is double whammy threat to climate

New research spells out the devastating impacts that complete destruction of tropical forests would have on global temperatures, weather patterns and agriculture.

LONDON, 20 December, 2014 − Tropical rainforests do more than just soak up carbon dioxide and renew atmospheric oxygen, they affect the weather in the rest of the world as well. And if the Amazon rainforest disappeared, the US Midwest could begin to dry up during the growing season.

In what is claimed as the most comprehensive analysis to date, US researchers report in Nature Climate Change that they used climate models to test the consequences of the complete devastation of the tropical rainforests.

They found that wholesale felling and clearing of the forests in Amazonia, Africa and South-east Asia would have consequences that extended far beyond the tropics, and could affect agriculture in North America, Europe and Asia.

“Tropical deforestation delivers a double whammy to the climate – and to farmers,” says Deborah Lawrence, an environmental scientist at the University of Virginia.

Rainfall patterns

“Most people know that climate change is a dangerous global problem, and that it’s caused by pumping carbon into the atmosphere. But it turns out that removing forests alters moisture and air flow, leading to changes – from fluctuating rainfall patterns to rises in temperatures – that are just as hazardous, and happen right away.

“The impacts go beyond the tropics – the UK and Hawaii could see an increase in rainfall, while the US Midwest and Southern France could see a decline.”

Although the research is based on computer simulations, there is already evidence that the disappearance of the tropical forests has begun to affect regional climates. The dry season in Thailand has become drier, and the rainy season in the Amazon has been delayed by up to two weeks, in those tracts that have been cleared. In the forested regions, the rains still arrive on time.

The tropical forests are under assault everywhere. Were they to disappear altogether, then planetary temperatures − soaring in any case because of climate change − would rise by an additional 0.7°C. This would double the warming observed since 1850.

“We’re talking about conditions that are very different from anything humanity has ever experienced.”

So the moist, dense green cover that once screened vast areas of the equatorial belt is – like the oceans and the ice caps – a vital part of the climate machine.

Without the forests, the tropics would be significantly hotter. Because dense foliage turns ground water back into water vapour, it cools the air above it. Without the forests, temperatures would soar and large masses of air would start to rise as far as the stratosphere and start to ripple away to disturb weather patterns in the temperate zones.

The complete loss of tree cover in the Amazon basin – and a huge proportion has already disappeared – would reduce rainfall in parts of the US Midwest and Northwest and in the Southern states.

Were the Africa rainforests to vanish, there would be lower levels of rainfall in the Gulf of Mexico, in the Ukraine, and in Southern Europe. On the other hand, the Arabian Peninsula might benefit.

“In the last few centuries, the average global temperature has never varied by more than about one degree,” Professor Lawrence says. “Once we go above one degree – to 1.5 degrees or more – we’re talking about conditions that are very different from anything humanity has ever experienced.

“Farmers, so reliant on consistent and reliable growing conditions, could lose their bearings, and even their incomes, when facing these ups and downs in temperature and rainfall. While farmers may ultimately adapt to shifts in the season, it’s difficult, if not impossible, for farmers to adapt to increased floods or parched soils.”

Range of species

Studies such as these have their own uncertainties. However, the vital role of the rainforests as moderators of climate, as shelters for an extraordinary range of species, and as arbiters of the global water supply has been well established.

And as much tropical forest has already being cleared for cattle ranching and commercial agriculture, scientists have decades of data to work with.

The study found that the total loss of forests would also have direct local impacts, and people who cleared the forests for immediate gain would lose in the long run.

Without the forests in West Africa or the Congo, rainfall would drop by 40% or more, and temperatures would rise by 3°C. In the Amazon, if 40% of the forest was cleared, wet season rainfall would be reduced by 12% and dry season rainfall by 21%. – Climate News Network

Share This:

Sea urchins refine survival instincts as oceans change

Sea urchins refine survival instincts as oceans change

As climate change adds to the threat of extinction faced by many species, new research shows how sea urchins can adapt to the increasing temperature and levels of acidity in Antarctic waters.

LONDON, 17 December, 2014 − The sea urchins of the Southern Ocean could be safe from the threat of extinction. They may not enjoy global warming and the increasingly acid oceans, but new research indicates that they can adapt to climate change.

Researchers from the British Antarctic Survey and Bangor University in Wales − in what they describe as the largest study of its kind − collected 288 urchins of the species Sterechinus neumayeri from waters off the Antarctic Peninsula, carried them to Cambridge in the UK, and tested them in aquarium tanks over a two-year span, covering two full reproductive cycles.

During this time, they report in the Journal of Animal Ecology, they changed the water chemistry and turned up the temperature. The environment was made less alkaline and the thermometer notched up another 2°C − which are the conditions sea creatures could expect by 2100 if the world goes on burning fossil fuels and pumping greenhouse gases under the notorious business-as-usual scenario.

Intricate network

Research like this matters because it helps scientists to better understand the intricate network of environmental conditions that underwrite life on the planet, and because it provides answers to one of the big questions of climate change: how will it affect the estimated seven million species with whom humans share the planet?

According to the journal Nature, the lowest estimate is that 10 species become extinct every week, and the number could be as high as 690 a week. The uncertainty is an indicator of how little is known about the diversity of life on the planet.

The oceans, in particular, have been hard hit by human action. Other marine survival studies have not been encouraging: ocean acidification promises to be very bad news for corals, and therefore for the rich and diverse communities that depend on coral reefs. It also offers a survival threat to bivalves that exploit ocean chemistry to build protective shells.

Other experiments have shown that it can affect the survival behaviour of fish, and can even affect the lugworms that anglers favour as bait for fish.

But the news from the laboratory aquarium in Cambridge is encouraging. It took the sea urchins six to eight months to acclimatise and adjust to the new acidity levels and temperature − but they survived.

Artificial insemination experiments suggested that the urchins could spawn successfully under the new conditions, but to be sure of this, the researchers need more time. Antarctic invertebrates mature very slowly and sea urchins could live for 40 years or more.

“With predictions of warmer, more acidic waters in the future, this work shows how resilient these animals are to climate change,” said Melody Clark, project leader for the Adaptations and Physiology Group at the British Antarctic Survey.

“It also emphasises the importance of conducting long-term experiments in making accurate predictions. These animals live a long time, and so they do everything really slowly. They take around eight months to get used to new conditions, and two years to produce gonads (sexual organs). If we had stopped this experiment at three or even six months, we would have got very different results.”

Change habitat

Sea urchins cannot easily change their habitat: they must adapt or perish. But four-legged, warm-blooded terrestrial creatures have another option. In another instance of long-term research, scientists have established that small mountain mammals are prepared to move uphill as the climate warms.

Karen Rowe, biodiversity research fellow at Museum Victoria in Melbourne, Australia, and colleagues report in Proceedings of the Royal Society that they looked at records of observations of small mammals, made between 1911 and 1934 at 166 sites in the Californian mountains. Then, between 2003 and 2010, they surveyed the same species in the same locations.

Warmer winters are bad for hibernating mammals such as the chipmunk. Image: Vlad Lazarenko via Wikimedia Commons

Warmer winters are bad for hibernating mammals such as the chipmunk.
Image: Vlad Lazarenko via Wikimedia Commons

Altogether, they looked at 30,000 observations that recorded the foraging and breeding ranges of 34 species of chipmunk, gopher, pika, shrew, deer mouse, woodrat and squirrel at altitudes that varied from sea level to about 4,000 metres.

Moving uphill

Since the first, historic set of systematic measurements, the average temperatures in the region have climbed by 0.6°C, and many mammals have shifted their range accordingly – by moving uphill.

The pattern wasn’t consistent, but the researchers identified a problem for those animals that normally hibernate: warmer winters could be very bad news for creatures adapted to the chillier mountain slopes. And those animals that live at the highest altitudes might soon have nowhere to go.

“While mammals can avoid heat stress by behavioural means (such as shifting daily activity), warming winters lead to increased energy expenditures for hibernators and reduce the snow layer, which acts as insulation for non-hibernators,” they conclude.

“Global climate projections suggest that disappearing climates will be an increasing challenge for predicting future species’ responses.” – Climate News Network

Share This:

Tribal lands are vital for Amazon forest carbon sink

Tribal lands are vital for Amazon forest carbon sink

As land rights of indigenous peoples are increasingly being violated, new research shows that destruction of Amazon rainforest is a major threat not only to cultural identity but also to the global climate. 

LONDON, 5 December, 2014 − Scientists in the US and Latin America have once again confirmed the importance of the Amazon rainforest as a planetary resource and as a carbon sink to store carbon drawn down from the atmosphere. Sadly, they have also confirmed, once again, that it is at risk.

New research, released in time for the UN climate change conference being held in Lima, Peru, shows that 55% of the Amazon’s carbon is in the indigenous territories that are home to the regions’s 385 tribal peoples, or in formally-designated protected natural areas.

The forests are critical to the stability of the global climate, but also to the cultural identity of the forest dwellers of the region and the extraordinarily diverse ecosystems they inhabit.

Carbon-rich forests

“The territories of the Amazonian indigenous peoples store almost a third of the region’s above-ground carbon on just under a third of the land area,” said Wayne Walker, an ecologist and remote sensing specialist at the Woods Hole Research Centre, US, and lead author of a paper published in the journal Carbon Management.

“This is more forest carbon than is contained in some of the most carbon-rich tropical forests, including Indonesia and the Democratic Republic of the Congo.”

The authors also found that nearly 20% of tropical forests across the Amazon are threatened by legal and illegal logging, new roads, dams and the growth of agriculture, mining and the petroleum industries, at least in part because governments had failed to either recognise or enforce the land rights of indigenous peoples.

“Indigenous territories and protected areas are increasingly at risk, with potentially disastrous consequences”

The Amazon forest under study is a mosaic of 2,344 indigenous territories and 610 protected areas spread across nine nations. In terms of biological, cultural and linguistic diversity, these areas are exceptional.

They are also the cornerstone of conservation efforts. In this century alone, 253,000 square kilometres of Amazon rainforest – an area bigger than the UK − has been lost for a mix of reasons. And land rights of the indigenous peoples are also under attack, with more than half by area at risk.

But a loss to the Amazon peoples would also be a loss to the planet. The Amazon rainforest is a unique resource in biodiversity and is also a carbon sink of global importance. Every tree is a reservoir of atmospheric carbon. Every felled tree or patch of burned forest is so much carbon dioxide back in the atmosphere, to fuel global warming.

Secure landscapes

The scientists warn that the carbon stored in these supposedly secure landscapes is enough to destabilise the planet’s atmosphere – or contribute to its stability.

“If all the current plans for economic development in the Amazon are actually implemented, the region would become a giant savanna, with islands of forest,” said one of the authors, Beto Ricardo, of Brazil’s SocioEnvironmental Institute (Instituto Socioambiental).

“A vast proportion of indigenous territories and protected areas are increasingly at risk, with potentially disastrous consequences, including 40% of indigenous territories, 30% of protected areas, and 24% of the area that pertains to both.” – Climate News Network

Share This:

Canada’s polar bears face food crisis by 2100

Canada's polar bears face food crisis by 2100

The survival of polar bears in Canada’s Arctic Archipelago may be in question in around 80 years’ time, because of the shrinkage of the sea ice.

LONDON, 30 November 2014 − The polar bears of the Canadian Arctic – at present they make their home in the nation’s huge, frozen archipelago – face starvation and reproductive failure by the close of this century.

New research in the Public Library of Science Journal PLOS One confirms that the continuing loss of sea ice in the Arctic ocean puts pressures on the region’s most iconic predator. By 2100, polar bears in the high Arctic may have to endure between two and five months without access to any sea ice.

Ursus maritimus has evolved under harsh circumstances, can swim huge distances, and can survive long periods without eating. However, it can only do so if it has been able to build up energy reserves and to do this, the bear needs access to a rich source of fat and calories.

So it hunts seals, and to hunt seals, it must be able to get onto the sea ice. The ice is where it hunts, where it mates and where it migrates.

No ice, no seals

Stephen Hamilton of the University of Alberta and colleagues used climate models to work out the likely pattern of sea ice in the Canadian Arctic during the rest of the century. The Canadian archipelago is home to at least seven populations of polar bear, a species already declared vulnerable.

Researchers have measured a steady shrinking of the north polar ice sheet over the last 30 years and have also found that the remaining sea ice is becoming thinner. By mid-century, according to some researchers, the Arctic could be navigable one summer in two.

This is not likely to be good news for an animal that needs the ice to hunt to gain fat and to provide the energy for the next breeding cycle. Hamilton and colleagues put their message bleakly:  “Under business-as-usual climate projections, polar bears may face starvation and reproductive failure across the entire Archipelago by the year 2100.”

“By 2100 all regions of the study area may cross the critical point-of-no-return”

This may not mean the end of the species, but there are only 19 populations of polar bears in the world, and the seven populations that hunt or den in the Canadian Arctic Archipelago make up probably a quarter of all the planet’s polar bears, even though the Canadian islands make up less than 10% of the polar bear’s range. So what happens in the Canadian Arctic could be critical.

What seems to govern polar bear behaviour is the concentration of sea ice: if the concentration falls below between 30 to 50%, the bears abandon the ice and move ashore to await the return of winter. The longer the bears stay ashore, the briefer the access to seal blubber.

At this point the extent of the ice-free period becomes critical. If the ice-free period lasts 120 days, two or three bears in every hundred could perish. If it lasts 180 days, then 20 out of 100 could starve. If the ice breaks up too early, between 55 and 100% of pregnant females could lose their cubs.

The scientists’ research is intended to help conservation programmes, but there may not be much future for the bears in the far north of Canada.

“By 2100 all regions of the study area may cross the critical point-of-no-return,” the authors say,  “putting the persistence of the Canadian Arctic Archipelago polar bear populations in jeopardy.” – Climate  News Network

Share This:

Saving forests not enough to stop carbon imbalance

Saving forests not enough to stop carbon imbalance

Creeping expansion of croplands into areas not previously covered with trees could undermine attempts by forest conservation schemes to address the problem of “carbon leakage” into the atmosphere.

LONDON, 21 November, 2014 − Foresters may be guardians of the planet, but they may need to think about more than just the forests to reduce the threats from climate change.

New research suggests that a policy that protects the planet’s forests from fire and the chainsaw must also deliver new ways of stopping the spread of agriculture into other habitats.

The trick − according to a report by Alexander Popp, a senior researcher at the Potsdam Institute for Climate Impact Research, Germany, and colleagues − is to be sure to reduce carbon emissions, rather than just displace them.

The researchers argue in the journal Nature Climate Change that while forest protection schemes could, by 2100, prevent 77 billion tonnes of carbon dioxide from escaping into the atmosphere, the same policies could trigger cropland expansion into areas that were not forested.

This, in turn, could release 96 billion tonnes of CO2 over the same timescale. The researchers call this “carbon leakage”.

Changes in land use

That is because around a tenth of emissions of greenhouse gases (GHGs) arise from changes in land use, and the worst of these changes − in terms of GHG releases − is from tropical forest to agricultural cropland.

So any forest policy focusing on saving emissions must also embrace strategies for using existing farmland more efficiently and productively.

Greenhouse gas emissions from fossil fuel combustion provide the chief cause for alarm about climate change, and a switch to renewable sources such as wind, hydro and solar power remains an important part of potential strategies to reduce the hazards of global warming.

“A central challenge is the avoidance of international carbon leakage if forest conservation is not implemented globally”

But, in a whole range of ways, agriculture is responsible for about 25% of all emissions, and in a world certain to reach a population of nine billion this century – and possibly 11 billion − the demands and the impacts of agriculture are likely to increase.

The Potsdam scientists warn: “A central challenge is the avoidance of international carbon leakage if forest conservation is not implemented globally.”

But, they add, even global forest conservation schemes will fail to contain such leakage if croplands expand into areas that may not be forested, and are not protected from development in some way.

Overall, in recent decades, the planet’s lands have soaked up more carbon than they have released. Plants take up CO2 from the atmosphere, and although some of them are harvested, and others are burned or decomposed, a proportion of this sequestered carbon stays in the soil.

Woodland, heath, marsh, savannah and even mature meadow and grazing lands have reached some sort of equilibrium: they remain as carbon sinks.

Disturbed equilibrium

But change, in the form of a farmer’s plough, disturbs this equilibrium. Between 1990 and 2010, say the researchers, 12% of all emissions came from changes in land use and changes in the vegetation that covered the land.

So the Potsdam researchers took a hard look at a UN-proposed strategy called REDD –Reduced Emissions from Deforestation and Degradation – which is likely to remain an important part of all future climate treaty negotiations. The conclusion: it is not enough just to preserve forests alone; nations have to look at the bigger picture too.

“The results show that the largest benefits for climate change mitigation could be achieved by a full participation of all countries in a forest conservation scheme and the inclusion of other land types with high carbon content, such as wet savannahs,” Dr Popp says.

“While protecting forests to abate climate change is definitely worthwhile, our results illustrate for the first time that forest protection policies alone will not be enough.” – Climate News Network

Share This:

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

Share This:

Research spanner thrown into coal’s publicity machine

Research spanner thrown into coal’s publicity machine

Australian thinktank’s data challenges coal industry claims that it drives economic growth, is a key element of alleviating ‘energy poverty’ worldwide, and improves quality of life.

LONDON, 10 November, 2014 − The coal industry has many friends in high places, and none more so than Tony Abbott, prime minister of Australia − one of the world’s major producers of a fuel that earns the country billions from exports.

“Coal is vital for the future energy needs of the world,” Abbott said recently. “So let’s have no demonisation of coal – coal is good for humanity.”

But a new report by researchers in Australia seeks to debunk what it considers to be myths promulgated by the powerful worldwide coal industry and its allies.

The report by the Australia Institute, an independent public policy thinktank, says claims by lobbyists that coal is a main driver of economic growth are false.

Slower growth

Data shows that coal use has grown much slower than global economic growth, says the report, “All Talk and No action: The Coal Industry and Energy Poverty”.

It points out that “developed countries have reduced coal use while economic growth has been unaffected. Developing countries are now the major users, but with alternatives becoming cheaper, they are likely to reduce coal use much earlier in their development.”

“Coal use is often associated with lower life expectancy due to health impacts”

The report also attacks industry claims that coal use increases life expectancy and quality of life. “On the contrary,” it says, “coal use is often associated with lower life expectancy due to health impacts of indoor and outdoor air pollution and the global health impacts of climate change.”

The study says that although access to electricity might initially improve quality of life, once basic electricity facilities are in place there is little correlation between increased electricity uptake and improved living conditions.

Talk in the coal industry about tackling energy poverty is just public relations spin, says the report, and it questions whether the coal industry itself believes its own claims.

It is significant, the study says, that coal concerns that choose to become involved in electricity and poverty alleviation schemes in poorer parts of the world support projects connected with solar technology or small hydro and gas-fired facilities, rather than with far more expensive coal-fired power installations.

Polluting gases

The report also takes issue with claims by the coal industry that coal is becoming cleaner. What is meant by clean coal varies widely: although many power plants and other enterprises have reduced coal-related emissions of sulphur oxide and nitrogen oxide, coal still releases into the atmosphere enormous amounts of CO2 − by far the most polluting of greenhouse gases.

Meanwhile, progress on carbon capture and storage (CCS) – the process through which emissions from coal-powered plants and other industrial concerns are captured and stored deep below the Earth’s surface – has been slow.

There are only 13 such projects in operation, and together they are capable of sequestering only 25 million tonnes of carbon dioxide per year – less than one percent of the world’s total annual emissions.

To put this in perspective, the report says, 33,376 million tonnes of CO2 were emitted worldwide in 2011, with the US emitting 5,420 million tonnes, and Australia – which has a much smaller population − emitting 400 million tonnes.

It concludes: “Addressing the challenges of energy poverty will become even more difficult if public relations campaigns are able to influence government policies away from genuine solutions towards spending that benefits the coal industry. The real solutions to energy poverty do not focus on coal.” – Climate News Network

Share This:

World’s wetlands play key role as carbon sinks

World’s wetlands play key role as carbon sinks

Areas of wetlands drained for human habitation and agriculture have been identified by scientists in California as sources of carbon dioxide being released into the atmosphere.

LONDON, 2 November, 2014 − Researchers in the US propose yet another way to reduce greenhouse gas emissions, and at the same time prevent soil subsidence − by preserving and even restoring the world’s wetlands.

Jaclyn Hatala Matthes, a geographer at Dartmouth College in New Hampshire, US, reports in the journal Global Change Biology that she and colleagues from Californian universities measured carbon dioxide and methane from a pasture, a cornfield and a flooded rice paddy, all in the Sacramento-San Joaquin delta in California, which was drained more than a century ago and was settled for agriculture and human habitation.

The researchers found that the drained areas of land were carbon sources − that is, they released carbon dioxide into the atmosphere and added to the greenhouse effect. The flooded region, conversely, turned out to be a carbon sink that took more carbon from the atmosphere than it released.

They also found that the region is literally going down in the world, as soil subsidence rates are almost the highest on the planet.

Short-lived

The picture wasn’t quite perfect: the soggy soils also released methane, which is a greenhouse gas that, molecule for molecule, is 20 times more potent than carbon dioxide. It occurs in much lower concentrations, and is short-lived, staying in the atmosphere for years rather than tens of years. But it does add to global warming.

“However, we do expect that the methane emissions will stabilise over time,” Dr Matthes says. “We’ve seen that emissions tend to increase over the first few years, and that this increase is correlated with an increase in wetland plant growth and spread during this time.”

Researchers have already warned that, in any case, methane emissions are likely to increase as the world warms, with methane-emitting microbes inevitably flourishing in warmer waters. But, overall, there remains a case for preserving or restoring wetlands.

According to the WWF (formerly the World Wildlife Fund), the planet’s freshwater marshes, deltas, swamps, bayous and wetlands are home to 40% of all the world’s species and 12% of animal species.

Important buffers

Deltas and mangrove swamps also provide an important buffer to protect coasts – and coastal settlements – from storm surges, cyclones and even tsunamis, and their annual value in ecosystem services and as protective zones has been measured in trillions of dollars.

The World Resources Institute calculates that, ultimately, 90% of the ocean’s fish depend on deltas, estuaries and coastal wetlands as nursery and spawning grounds, as well as sources of nutrient. The loss of coastal wetlands has been linked to an increase in oceanic “dead zones”.

So the case for wetland restoration is a strong one, even on climate grounds. It soaks up carbon dioxide, and skilful plant management might, according to Dr Matthes, reduce the methane problem.

“It’s a little bit tricky in ecosystem engineering,” she says “but we are hoping to learn some things about how people might plan wetland vegetation in order to maximise carbon dioxide uptake, but to minimise methane release.” – Climate News Network

Share This: