The past 10 years have been the hottest since measurements began, and climate scientists have long warned of the extreme weather still to come. Adam Morton reports.
Neville Nicholls is a climate scientist. He has long believed his role was research, not advocacy. But when he woke on the morning following Black Saturday, turned on his TV and caught his breath after witnessing the shocking aerial footage of what was once Marysville, he instinctively blamed himself.
"My initial thought was: is this my fault? Has this happened because I haven't been out there saying that this stuff is going to have catastrophic consequences for us?" he recalls. "It is the first time I have ever been shaken from my belief that I shouldn't be an advocate on climate change."
Nicholls — an Australian Research Council professorial fellow at Monash University and an author and reviewer with the United Nations Intergovernmental Panel on Climate Change (IPCC) — resolved to take more responsibility to be a public voice; not to lobby for a particular political response, but to explain and defend the science that is his life's work.
He wasn't alone. Increasingly, as the first decade of the century unfolded, Australia's most decorated scientists in climate fields were concerned that published evidence in their areas of expertise was being misused or ignored. Believing they faced a misinformation campaign driven by fossil-fuel interests and an intransigent political system, they formed Climate Scientists Australia as a means to improve the quality of public information and decision-making.
For some members, the challenge they faced was underscored in July when the Victorian Bushfires Royal Commission released its four-volume final report and made little reference to climate change.
It has been said so often that it should be well known by now: no extreme event can be definitively blamed on the surge in atmospheric greenhouse gases since industrialisation. But when events closely replicate what dozens of climate models have predicted will come, neither can they and climate change be divorced.
The 13 members of Climate Scientists Australia believe February 7, 2009, was such a case: 46.4 degrees in Melbourne — not just the city's hottest day on record, but more than 3 degrees warmer than February's previous maximum. Coinciding with turbulent winds and coming after a record 12 years of below-average rains, it added to an unprecedented score of 172 on the Forest Fire Danger Index, according to a report to the royal commission by Melbourne University fire ecologist Dr Kevin Tolhurst. Ash Wednesday in 1983 — the second-worst day for dangerous fire conditions — rated just 120, the devastating 1939 inferno 100.
In the October edition of the Bulletin of the Australian Meteorological & Oceanographic Society, Nicholls summarised: "A quantitative analysis leaves no doubt that the combination of weather conditions leading up to Black Saturday, and on the day, had not been observed previously in the 150 years of Melbourne instrumental weather data."
The commission, though, found neither the day nor the fires were unprecedented, accepting oral evidence from land and fuel management experts that the Black Saturday fires were not a shift from what had come before.
Nicholls, one of several scientists to lodge a submission with the commission linking the fires with human-induced climate change, was surprised. "I think a focus on the fact that we had not previously seen such extreme fire weather and climate conditions is important," he says.
"If we simply note that Black Saturday was just another instance of serious fires occurring in association with hot, dry, windy conditions, then we could lose sight of how extraordinary the weather conditions were, and we may not consider changes in strategy that could help us cope with even more extreme fires in the future."
The public debate over climate change has yielded its share of controversies, confected and otherwise, but in the eyes of leading scientists the royal commission's response is emblematic of the biggest of the past 10 years: the failure to convince policymakers and shapers to take the warnings of the world's most reputable scientific agencies seriously enough to respond effectively.
The global public's awareness of climate change grew significantly over the decade, but by this year, according to some polls, its acceptance of the science had diminished.
The decline was particularly marked in Britain and the US. Britain was home to the so-called "Climategate" affair, in which senior scientists were accused of manipulating data after ambiguous emails were leaked from the University of East Anglia. The scientists were exonerated of the most serious claims of dishonesty by a series of inquiries, but the damage was done — the findings clearing their names received only a fraction of the press coverage of the initial allegations. A separate investigation by the InterAcademy Council recommended changes to the IPCC, including greater care and transparency, but found its work synthesising published climate science was mostly successful.
In the US, there was a concerted attack from the resurgent Republican Party and influential parts of the media claiming climate science was a hoax and conspiracy. A University of Maryland study published this month found Fox News viewers were 30 percentage points more likely to incorrectly believe that most scientists do not agree that climate change is occurring, or that views are split.
The public mood was not helped by the debacle of the United Nations Framework Convention on Climate Change meeting in Copenhagen in December 2009, which left people with the not unreasonable perception that the world's leaders had no idea how to tackle the problem. The recent follow-up meeting in Cancun managed to glue the pieces of the broken talks back together, but left the most challenging issues in forging a new treaty to build on the Kyoto Protocol — which covers little more than a quarter of global emissions — to a later date.
Meanwhile, the claims made on climate change's behalf continued to mount. Delegates in Cancun were handed a report by aid agency Oxfam, quoting insurance agency Munich Re, which had linked 21,000 deaths in the first nine months of 2010 to climate change. It was twice the number of casualties caused by extreme weather in all of 2009. The mid-year floods that soaked a fifth of Pakistan alone killed about 2000 people and affected the lives of 20 million. The same weather system caused extraordinary summer heat in near-Arctic Russia that wiped out crops, caused rampant wildfires and doubled the usual summer death rate for Moscow. It rang alarm bells for those familiar with the IPCC's projection, based on more than 20 climate models that to date had proved remarkably accurate, that a significant temperature rise above pre-industrial levels would increase the likelihood of floods in southern Asia and the risk of heat waves and wildfires in Europe.
The New York Times — a journal of influence not known for running hard on the science of climate change — responded by running front-page pictures of the Pakistani and Russian disasters alongside a shot of storms pummelling Chicago under the headline "In weather chaos, a case for global warming".
"The climate is changing," the National Climatic Data Centre's Jay Lawrimore told the paper. "Extreme events are occurring with greater frequency, and in many cases with greater intensity."
Munich Re reported that its database of natural catastrophes showed the number of extreme weather events such as windstorms and floods had tripled since 1980 "and the trend is expected to persist".
Not everyone working in the area is comfortable with linking the current shift in extreme events with greenhouse gases. There is disagreement in the scientific literature over whether extreme weather disasters have started to worsen. According to one view, there is little to no change in the proportions of people affected once population growth is factored in.
What does not remain a contested area in the scientific literature is that the planet is getting hotter. Analysing the data from the world's three temperature datasets, the World Meteorological Organisation last month reported that the past decade was the warmest since instrumental measurement began in 1850, and 2010 was on track to be the hottest year, and certainly in the top three, regardless of the extraordinary snow dumps clogging European and US cities over Christmas. (There is significant evidence to suggest that global warming is responsible for the extreme northern winters of the past two years. An increase in air pressure in the Arctic atmosphere caused by heat coming off a relatively ice-free ocean is pushing cold air south.)
Eighteen countries broke their records for the hottest day ever this year. Only one year in the 20th century — 1998 — was warmer than any so far in the 21st.
The noughties was the decade of the killer heatwave. Western Europe was hit in August 2003, when extreme heat was estimated to have contributed to the deaths of 46,000. About a third of the deaths were in France. Usually home to mild summers, it was unprepared for the impact on the weak and elderly of a week's worth of days hotter than 40 degrees. There were widespread crop failures and forest fires, particularly in southern Europe. About a tenth of Portugal's forests burned.
In Australia, Victoria had never had three consecutive days above 42 degrees until January , when there were three above 43 degrees. The horrendous bushfire death toll in early February was dwarfed by the "invisible disaster" of the January heatwave, which is estimated to have killed 500 people in Victoria, South Australia and Tasmania.
Perhaps the biggest step-change came in Russia this past northern summer, when at least five days in Moscow topped 100 degrees fahrenheit (37.78 degrees celsius) — a barrier that had never been crossed. An estimated 15,000 people died and the country's massive grain harvest was devastated by wildfire. According to Russian state weather service chief Alexander Frolov, it was the country's worst heatwave in a millennium. "Nothing like it can be seen in the archives," he said.
Nicholls says there are clear similarities between the three disasters, and others in Pakistan, Greece and California: "They have all been unprecedented, they all killed a lot of people and destroyed a lot of infrastructure."
Greenhouse gas emissions have continued to rise. Earlier this month the Mauna Loa Observatory in Hawaii showed that atmospheric carbon dioxide had reached 390 parts per million — a 40 per cent increase on pre-industrial levels.
All of this is in line with the IPCC's most recent assessment report, published in 2007, which found that there was at least 90 per cent certainty that most of the increase in the globe's temperature since mid-last century was due to the rise in industrial greenhouse gases. Even the world's most prominent climate sceptic, Lord Christopher Monckton, whose arguments have been shown by mechanical engineering professor John Abraham to repeatedly misrepresent the science he claims to be quoting, has acknowledged there is a greenhouse effect warming the planet, though he disputes its extent.
There is, of course, still significant uncertainty about the future impact of climate change. But the fundamentals predicted by climate models — marked declines in Arctic sea ice in summer, rising sea levels due to thermal expansion and glacier melt and increases in temperature — are being matched by observations.
That's the science. The response, the politics and economics, remain thornier still. The preferred model under the 1997 Kyoto Protocol is carbon trading, under which emissions are capped and pollution permits exchanged so that the cheapest way to meet the target can be found. This method has been adopted haphazardly across Europe, New Zealand and a band of US states, with more countries including Australia and China looking at signing up. There is near-universal agreement among economists that a carbon price is the most efficient way to reduce emissions, but carbon trading faces criticism that, while nice in theory, it is ineffective in the real world when it includes poorly policed offset schemes. For separate reasons, the US Congress has rejected a national trading scheme; Japan and South Korea have postponed a decision on theirs.
What are the hopes of a global solution to this diabolical problem? A recent prognosis by the Paris-based International Energy Agency found the national targets submitted under last year's loose Copenhagen Accord would put the world on a path of 3.5 degrees of warming by the end of the century. Even if you assume that countries introduce policies to back their international promises — Australia and the US, to name just two, currently have no way of meeting their targets — few scientists or policymakers expect the temperature rise to be kept within 2 degrees, the goal agreed under the UN process.
In Australia, next year will see a concerted effort from Labor, the Greens and significant parts of the business community to introduce a carbon price — most likely a tax that could evolve into carbon trading. If they succeed, attention is likely to turn to the challenge that has just begun to enter the public debate but will increasingly arise over the next decade: adapting to unavoidable change.