Alex Kirby

Taxpayers Give Billions in Fossil Fuel Subsidies, Lose Trillions to Related Health Costs

Health campaigners said the energy policies of the world's richest countries are inflicting a double burden on their citizens, not only using their taxes to pay fossil fuel subsidies, but also loading huge health costs on them.

Keep reading... Show less

Permafrost Thaw Threatens Dangerous Flood of Emissions

Permafrost, the layer of permanently frozen ground that lies just beneath the Earth’s surface in the polar regions, has been found to be more sensitive to the effects of global warming than climatology had recognised.

Keep reading... Show less

Agriculture Is Likely Cause of Rapid Surge in Methane Emissions That Threatens Paris Climate Agreement Targets

A little over a year ago, with huge relief, scarcely able to believe their achievement, world leaders finally agreed to reduce emissions of carbon dioxide.

Keep reading... Show less

How 19th-Century Whaling Could Help Predict the Climate of the Future

People from all walks of life with an interest in climate change and Arctic marine mammals are working with maritime historians and scientists to examine records of polar weather.

Keep reading... Show less

We're Running Out of Time: Ocean Acidification and Greenhouse Gas Emissions Soar

The World Meteorological Organization (WMO) reports that the amounts of atmospheric greenhouse gases reached a new high in 2013, driven by rapidly rising levels of carbon dioxide.

Keep reading... Show less

Lakes Raise New Question on Arctic Warming

Scientists say there is uncertainty over a previously unquestioned assumption about the way in which temperatures are rising in the Arctic.

New research, supported by the US National Science Foundation (NSF), suggests that a rethink is required on the widely-held scientific view that thawing permafrost uniformly accelerates atmospheric warming.

Instead, the scientists say, their findings show that one type of Arctic lake stores more greenhouse gases (GHGs) than it emits into the atmosphere.

But they say the effect is unlikely to be permanent, because increasing Arctic warmth will probably lead to the renewed release of the gases stored in the lakes.

Melted fresh water

The study, published in the journal Nature, focuses on thermokarst lakes, which appear as permafrost thaws and create surface depressions that fill with melted fresh water, converting previously frozen land into lakes.

The research suggests that Arctic thermokarst lakes are “net climate coolers” when observed over millennial timescales.

The Arctic is one of the fastest-warming regions on Earth. Sea ice has been retreating in the last 30 years or so by 12% a decade, NASA says, and spring and autumn on the Greenland icecap have warmed by more than 3°C.

But the new research suggests the lakes have not been contributing to this recent warmth, although thousands of years ago they did release GHGs.

“Until now, we’ve only thought of thermokarst lakes as positive contributors to climate warming,” said lead researcher Katey Walter Anthony, who is associate research professor at the University of Alaska Fairbanks Institute of Northern Engineering.

“It is true that they do warm climate by strong methane emissions when they first form, but on a longer-term scale they switch to become climate coolers because they ultimately soak up more carbon from the atmosphere than they ever release.”

The team found, thermokarst lakes in ice-rich regions of North Siberia and Alaska began cooling about 5,000 years ago. They stopped emitting methane and carbon dioxide, and instead started storing CO2 from peat-rich sediments.

The researchers used published data, their own field observations of Siberian permafrost and thermokarsts, radiocarbon dating, atmospheric modelling and spatial analyses to study how thawing permafrost is affecting climate change and GHG emissions.

Over the millennia, they say, several factors stimulated high rates of carbon deposits in lake sediments. These included thermokarst erosion and accumulations of organic matter, nutrient release from thawing permafrost, and slow decomposition in cold lake bottoms that lacked oxygen.

Carbon uptake

The study’s co-author, Miriam Jones, of the US Geological Survey, said: “These lakes are being fertilized by thawing yedoma permafrost [a type of permafrost rich in organic material]. So mosses and other plants flourish in these lakes, leading to carbon uptake rates that are among the highest in the world, even compared to carbon-rich peatlands.”

The study also found that when the lakes drain, previously thawed organic-rich lake sediments freeze again, storing a large amount of carbon processed in and under thermokarst lakes.

But the researchers say the new carbon storage will not last indefinitely. Future warming will probably start re-thawing some of the permafrost and release some of the carbon it contains.

Roughly 30% of global permafrost carbon is concentrated within 7% of the permafrost region in Alaska, Canada and Siberia. The study has expanded estimates of how much carbon the circumpolar peat stores in permafrost regions by more than 50%.

And it leaves scientists puzzling over a further question. The thermokarst lakes, according to this study, have been storing GHGs, not emitting them. So what else, despite that, is continuing to warm the Arctic faster than most of the rest of the planet?

Scientists Discover Mysterious, Harmful CFC Gases In the Atmosphere

Twenty-five years after the world first moved to protect the ozone layer, British scientists have found three new potentially damaging gases in the atmosphere. While they do not expect the gases to do much damage to the ozone layer, think they may add to global warming.

The scientists, at the University of East Anglia (UEA), in the UK, have found two new chlorofluorocarbons (CFCs) and one new hydrochlorofluorocarbon (HCFC). Their research, published in the journal Atmosphere, appears shortly after the same team found four other man-made gases in March this year.

They made the discovery by comparing samples of today’s air with samples collected between 1978 and 2012 in the unpolluted air of Tasmania, and samples taken during aircraft flights. Their measurements show that two of the new gases have reached the atmosphere in recent years.

Harmful effects

Ozone protects living things against the harmful effects of ultra-violet radiation from the sun, which can cause cancer and blindness in humans, as well as harming crops and wildlife on land and at sea.

Scientists discovered in 1985 that CFCs − the man-made gases used mainly in refrigerants and aerosols − were damaging the Earth’s protective layer of ozone over the Antarctic, thinning it and causing what has become known as “the ozone hole”. A similar, but less marked, weakening occurs over the Arctic as well.

That led to the world’s governments agreeing the Montreal Protocol in 1987. The production of all CFCs was banned in 2010, and the prediction was that, if countries observed the Protocol strictly, the damage to the ozone layer would be repaired by mid-century.

Dr Johannes Laube, from UEA’s school of environmental sciences, said: “Two of the gases that we found earlier in the year were particularly worrying because they were still accumulating significantly up until 2012.

“Emission increases of this scale have not been seen for any other CFCs since controls were introduced during the 1990s, but they are nowhere near peak CFC emissions of the 1980s.”

He said the three gases that had now been identified were in much lower concentrations than the ones found in March, so they were unlikely to threaten the ozone layer. But the findings strengthened the team’s argument that there are many more gases in the atmosphere that still await identification, and which together might well have an impact.

Corinna Kloss, who undertook the research while at UEA and is now at the Jülich Research Centre in Germany, said: “All seven gases were only around in the atmosphere in very small amounts before the 1980s, with four not present at all before the 1960s, which suggests they are man-made.

Possible sources

“Where these new gases are coming from should be investigated. Possible sources include industrial solvents, feedstock chemicals, and refrigerants.”

But there is a further concern over the chemicals that destroy the ozone layer, and that is their ability also to intensify global warming.

Dr Laube told the Climate News Network that the concentrations of all three newly-discovered gases were about one-tenth of those found in March. None seemed to have drastically increased in concentration in recent years, so he thought they were unlikely to be a problem to the ozone layer in the foreseeable future.

On global warming, however, one gas (HCFC-225ca) had been estimated as being 127 times stronger than CO2 on a per kg basis. This, Dr Laube estimated, meant an impact equivalent to about 50,000 tons of CO2 for 2012.

“For the two CFCs, global warming potentials are currently unknown,” he said. “If we look at other similar CFCs, they are likely to be 5,000 to 10,000 times more effective than CO2.”

This meant a best estimate for 2012 of emissions by one gas equivalent to 50,000 to 100,000 tons, and of 40,000 to 80,000 tons of carbon dioxide by the other gas.

For comparison, global CO2 emissions in 2011 were estimated by the Netherlands Environmental Assessment Agency at 34 billion tons.

How Whale Feces Slows Down Ocean Warming

LONDON — 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 meters or even further down) and then releasing iron-rich liquid feces 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 tons 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.

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 fertilization through defecation was likely to be a common mechanism, although different constituents of the feces 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.

Drought Makes the Amazon Forest Emit Carbon

Scientists think there is growing evidence to show that the Amazon forest is less effective at absorbing carbon dioxide than previously thought. Instead, they say, it may often be releasing huge quantities of CO2 to the atmosphere, acting not as a carbon sink but as a source.

Their reasons for this potentially significant rethink were published in two reports in the journal Nature. The first describes the results of researchers who sampled the amount of carbon in the air at four points over the Amazon, to build up a more comprehensive picture of the forest's response to both light and water.

Starting at up to 4.4 kms above the Earth, the researchers' aircraft collected 17 samples at each point and analysed them for concentrations of five different gases: CO2, methane, nitrous oxide, carbon monoxide and sulphur hexafluoride. They did this in 2010, a year marked by severe drought in Amazonia, and in 2011, which had above-average rainfall.

The drought, obviously, reduced plant production and limited the amount of carbon stored in vegetation, while at the same time large amounts of carbon were released by fire during the dry year. But in 2011 the region was effectively carbon-neutral, experiencing reduced carbon loss from fires and increased carbon uptake by vegetation.

The website Science for Brazil says: "The vegetation managed to absorb not only all the CO2 emitted through natural processes but also the emissions resulting from human activities, including fires."

'Far from reality'

The researchers found that the burning of vegetation linked to land use and a reduction in photosynthesis (the process used by plants and other organisms to convert light into chemical energy) meant about 0.48 petagrams (one petagram equals 1,000,000,000,000,000 grams) of carbon were lost from the forest in 2010, against 2011's carbon neutrality.

As temperatures were similar in both years they say that it was a lack of moisture that lowered photosynthesis rates, not greater heat. Their conclusion is that what the forest really needs is enough water. So the effects of drought and fire together can combine to make the forest a carbon source, not a sink.

The main author of the study is Luciana Vanni Gatti of Brazil's Nuclear Energy Research Institute (IPEN). She said: "...the lack of rainfall modifies the dynamics of the forest and the carbon balance in the region. Therefore... precipitation is a factor that scientists working with climate forecasting will have to take into consideration in their models. If not, the results will be very far from reality.”

If she and her colleagues are right, and if other forest regions react in the same way, the global consequences could prompt a drastic revision of the forests' ability to moderate global warming.

Not so green

Support for her team's conclusions comes in another Nature report, this time dealing with an apparent flaw in one of the reasons why scientists had believed the Amazon forest remained healthy during droughts.

They believed this because the forest appeared green. So, they concluded, it must be absorbing carbon dioxide. But Douglas Morton of the NASA Goddard Space Flight Center and colleagues say the apparent greenness was what Nature calls "an optical artefact of the observation method".

Satellite measurements in 2003 appeared to show that the Amazon canopy grew more strongly during a drought. As New Scientist reported, young leaves are greener - and reflect more infra-red light - than old foliage, so scientists assumed this was evidence that rainforests grew better during dry years.

It reports that Morton's team used alternative sensing methods to show that during droughts "NASA's sensors were not seeing a greener canopy at all. It was a trick of the light - perhaps because fresh foliage growth casts more shadows in the canopy and so absorbs more infrared light".

Morton told New Scientist: "Seasonal moisture availability governs the balance between photosynthesis and respiration in Amazon forests." In other words, it concludes, rainforests thrive in the rain. And water availability, rather than light, is the main driver of plant productivity in Amazon forests.

Katrina 'Could Soon Happen Every Other Year'

LONDON, 19 March - Extreme storm events on the scale of Hurricane Katrina which caused widespread damage in the Gulf of Mexico in 2005 will occur far more often because of climate change, a new study says.

Keep reading... Show less

Thanks for your support!

Did you enjoy AlterNet this year? Join us! We're offering AlterNet ad-free for 15% off - just $2 per week. From now until March 15th.