Friday, December 9, 2011

Butterfly effect flags climate chaos

Jo Chandler 
The Age, December 10, 2011

Any regular observer of the annual international climate talks that have become a fixture on the Yuletide calendar over the past 17 years will be aware that these events create their own extreme weather. Conference rooms heavy with hot air are suddenly lashed by tornadoes of frenzied resolve and energy, most of which blow themselves out. Then there are the thunderous exchanges, frosty relations, occasional showers of aspiration, and the dustclouds of vanished hope.

What it all means it's often hard to say, the 10,000-plus players from 195 nations having evolved a banal language of negotiation that is near impenetrable to the uninitiated. One might be forgiven for thinking they are talking about someone else's planet.

But from outside the artificial atmospheric bubble of the UN climate talks, this planet continues to issue statements more eloquent, powerful and enduring than any of the human chatter. Its voice can be found in the volumes of scientific journals and expert reports as new pages are added to the evolving 150-year-plus archive of climate knowledge.

This year, the 12 days of Durban talks coincided with a torrent of new science, much of it timed to exploit piqued interest in climate issues (not always successfully). It began with a blast from the wild ocean waters south of the Roaring Forties, and finished on butterfly wings in the gardens of Great Britain. Links are included below.

November 29: The morning after South African President Jacob Zuma opened the Durban talks with the declaration that ''for most people in the developing countries and Africa, climate change is a matter of life and death'', scientists at the Antarctic Climate and Ecosystems Cooperative Research Centre in Hobart published an analysis collating the latest findings on the Southern Ocean, one of the most powerful players on global and regional climate.

Over the past 50 years its cold, deep waters have gulped down the lion's share of the heat and CO2 being pumped out by human enterprise, its mighty currents ploughing more than 40 per cent of the extra carbon dioxide into the deep water. As a consequence, the ocean is becoming more acidic - the upshot of an intense chemical attraction: CO2 loves H2O, and vice versa. The chemistry plays out in a lowering of the pH of seawater, eroding the capacity of the tiny organisms at the bottom of the marine food chain to build shells and skeletons. The timing of the threshold at which the Southern Ocean waters actually become corrosive to shells has been brought forward from around 2050 to around 2030.

Salinity is also changing. Samples hauled up from the abyss four kilometres down find the waters are both freshening (less salty) and warming.

The southern waters are warming faster than other oceans, the temperature rise trickling down to greater depths. Water temperature around Antarctica has a critical influence on ''the largest single uncertainty in estimating the future range of sea level rise … the question of what's going to happen to the ice sheets of Antarctica and Greenland'', says ACE CRC Oceans program leader Dr Steve Rintoul.

November 30: As the World Meteorological Organisation releases news that 2011 has been one of the warmest years on record despite the moderating influence of a cooling La Nina event (, Australia's Climate Commission publishes the latest of a series of reports on The Critical Decade, shifting discussion from broader environmental concerns to more intimate questions of human health.

The report declares climate change to be one of the most serious threats facing Australians' health, due to the increased risk of death or injury during extreme weather events, and an expected rise in infectious disease and mental illness. No one is immune, the report warns, but the most vulnerable will suffer disproportionately - children, the elderly, the sick, the poor, remote indigenous communities.

December 1: With Arctic temperatures rising at almost twice the average rate of the planet, the permafrost - the vast frozen tundra that holds about 1700 billion tonnes of organic matter accumulated in soils over thousands of years - is thawing. ''That is about four times more than all the carbon emitted by human activity in modern times, and twice as much as is present in the atmosphere now,'' say the authors of a commentary published in Nature, informed by a survey of 41 permafrost scientists from around the world.

In recent years there have been reports of ancient carbon and methane bubbling out of lakes and igniting tundra fires. ''Carbon released into the atmosphere from permafrost soils will accelerate climate change,'' the article states. How much of an effect the thaw will have is highly uncertain. But the scientists do anticipate it will be faster than the models suggest. They calculate that permafrost thaw could, over this century, put as much carbon into the atmosphere as deforestation (if forest loss continues at current rates), making it ''cause for serious concern''.

Their fears are compounded by the observation that permafrost emissions include significant quantities of methane, which is a much more potent greenhouse gas than carbon dioxide.

The survey, they say, ''outlines the additional risk to society caused by thawing of the frozen north, and underscores the urgent need to reduce atmospheric emissions from fossil-fuel use and deforestation. This will help to keep permafrost carbon frozen in the ground.''

December 2: The powerful role of carbon dioxide as a regulator of Earth's climate over deep history is further exposed in an analysis of ancient algae found buried in seabed cores. It reveals that a drop in atmospheric carbon dioxide of about 40 per cent appears to have been the driving force behind the formation of the Antarctic ice sheet 34 million years ago, say US scientists at Yale and Purdue universities in a paper in Science. ''The evidence falls in line with what we would expect if carbon dioxide is the main dial that governs global climate; if we crank it up or down there are dramatic changes,'' said Purdue's Professor Matthew Huber. ''We went from a warm world without ice to a cooler world with an ice sheet overnight, in geological terms, because of fluctuations in carbon dioxide levels.''

While the study sheds new light on the consequences of a moment one scientist described as ''the mother of all climate tipping points'', the factors that drove the fall in carbon dioxide levels remain a mystery.

December 4: At the heart of scientific investigation and public discussion about climate change is how much warming is influenced by humans, and how much is the consequence of natural variation. A fresh investigation of this question by Swiss climate modellers, using new methodology, concludes that natural factors are extremely unlikely to have contributed more than about one-quarter of the temperature rise observed in the past 60 years. Since 1950, the average global surface air temperature has increased by more than 0.5 degrees celsius. To distinguish between human and natural causes of warming, the scientists analysed changes in the balance of heat energy entering and leaving Earth. Their findings, in Nature Geoscience, echo other investigations, and lead to ''an even higher confidence about human influence dominating the observed temperature increase since pre-industrial times''.  

On the same day, two other papers explore different facets of the changing marine environment.

One looks at oxygen levels in the tropical north-east Atlantic Ocean. Fish need to swim - and breathe. Global warming is believed to be influencing the expansion of areas of the ocean in which dissolved oxygen levels are declining. A collaboration of American, German and Canadian scientists used individually tagged fish as part of their exploration of Atlantic waters. Their work plots a decrease in upper layer oxygen levels, and concludes that oxygen depletion and the expansion of the deep oxygen minimum zone may reduce the habitat of some fish species. This, combined with overfishing, may threaten the sustainability of valuable fisheries, they warn.

Meanwhile, anyone fishing for some good news might find a skerrick of it in a paper out of Queensland's James Cook University. The scientists set out to study the capacity of species to adapt to warmer waters. The team found that one species of common tropical reef fish was able to acclimatise within a couple of generations. The spiny damselfish didn't like being suddenly moved into warmer waters, explained Professor Philip Munday, but its descendants coped. Munday was not as reassured by his results as some media commentators. ''This is just one fish,'' he told the ABC. ''It is a complicated story. This is just one little piece of good news in that otherwise very worrying story.''

December 5: A week into the talks in Durban, and news breaks that global emissions of carbon dioxide from the burning of fossil fuels jumped by the largest amount on record over 2010. After a two-year slump in emissions during 2008 and 2009 as a result of the global financial crisis, emissions rose 5.9 per cent last year according to the analysis of the Global Carbon Project. ''There's no evidence that this trajectory we've been following the last 10 years is going to change,'' observed a leader of the analysis team, Dr Glen P. Peters of the Centre for International Climate and Environmental Research, Oslo. 


December 7: The UN Food and Agriculture Administration (FAO) issues its first report on the State of the World's Land and Water Resources. Between 1961 and 2009, cropland grew by 12 per cent, but agricultural production expanded by 150 per cent, thanks to yield increases in major crops. But the rates of growth are slowing, and the report plots an increasing imbalance between availability and demand for land and water resources. The number of areas reaching the limits of production capacity is fast increasing, the report warns.  

On the same day, the US National and Oceanic Atmospheric Administration reports that in 2011 the US experienced a record 12 separate billion-dollar weather/climate disasters, with an aggregate damage total of about $US52 billion ($A50.7 billion).

Meanwhile in Britain, data published from the biggest ever survey of butterflies shows that nearly three-quarters of butterfly species that breed in the UK have declined in numbers over a decade. Richard Fox, lead author of the survey, told the Guardian that the results were ''significant, worrying and depressing''.

He described butterflies as the canaries in the coalmine of the environment, the health of their populations providing a telling narrative stretching back - in the context of Britain - to the 1600s. ''We have just gone through a decade which has had the highest levels of public awareness about wildlife and conservation and effort and public money gone into the landscape for wildlife: in that context it's pretty bad news.''

December 8: As Durban negotiators entered the last phase of talks, Dr James Hansen, the director of NASA's Goddard Space Institute - and the scientist who first raised concerns about global warming before the US Senate in 1988 - had a message for them. If the world begins reducing CO2 emissions by 6 per cent a year starting in 2012, atmospheric levels can return to the "safe" level of 350 ppm that he and others have long called for. "If the world waits until 2020 to begin, it will need to reduce CO2 by 15 per cent a year to reach 350 ppm. We are out of time."

Jo Chandler is a senior writer.

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