Lucky Last – Mike Steketee puts it in perspective
Global warming is a real problem, despite the ill-informed claims of the climate deniers, shouts the headline in The Australian. A rare opinion piece in this last broadsheet bastian of climate deniers.
“IF in doubt vote no” may be the five most powerful words in politics. Those arguing against action on climate change certainly are entitled to think so, writes Mike Sketetee.
They have shifted public opinion merely by raising a few instances where claims about the effects of global warming have been exaggerated or not sufficiently documented, and by catching a few scientists playing politics. Heaven forbid that anyone involved in a highly charged political debate should sex up their case through the selective use of material and exaggeration. Nevertheless, while that is stock in trade for politicians, it is not a good look for scientists. But some perspective is in order.
Mike Steketee in The Australian (27 February 2010):
Global warming is a real problem, despite the ill-informed claims of the climate deniers
“IF in doubt vote no” may be the five most powerful words in politics. Those arguing against action on climate change certainly are entitled to think so.
They have shifted public opinion merely by raising a few instances where claims about the effects of global warming have been exaggerated or not sufficiently documented, and by catching a few scientists playing politics. Heaven forbid that anyone involved in a highly charged political debate should sex up their case through the selective use of material and exaggeration. Nevertheless, while that is stock in trade for politicians, it is not a good look for scientists. But some perspective is in order.
Two sentences in volume two of the four-volume 2007 report from the Intergovernmental Panel on Climate Change claim that the Himalayan glaciers could melt by 2035. This is not supported by the scientific evidence, including that in the rest of the IPCC report, which contains a 46-page chapter in volume one on glaciers, ice and snow. This covers scientific observations of melting and includes the comment that “reports on individual glaciers or limited glacier areas support the global picture of ongoing strong ice shrinkage in almost all regions”, although some glaciers had advanced or thickened, probably because of increased precipitation. Another chapter includes a projection of the future decline of glaciers but makes no predictions about their disappearance.
Apart from this, the errors in the IPCC report are hard to find. It says The Netherlands is highly susceptible to rising sea levels and river flooding because 55 per cent of its territory is below sea level. This figure was supplied by the Dutch Environmental Assessment Agency, which has since conceded that it should have said that 55 per cent of The Netherlands was at risk of flooding, with 26 per cent of the country below sea level and 29 per cent susceptible to river flooding. This does not change the IPCC’s conclusion about The Netherlands’ vulnerability. Even the figure it used is not necessarily wrong: the Dutch transport ministry has a measure of 60 per cent of the country lying below the high water level during storms.
Sceptics have challenged the IPCC’s statement that up to 40 per cent of Amazon forests “could react drastically to even a slight reduction in precipitation”. The reference cited is to a WWF report but this is based on a peer-reviewed study, the lead author of which has said that the IPCC statement is correct.
The IPCC has been accused of linking global warming to recent natural disasters. While it does refer to one study that found an increase in economic losses from natural disasters, it also mentions other studies that have not detected such a trend. All up, the IPCC’s 2007 report cites about 18,000 references and most of them are to peer-reviewed scientific papers. This is vastly more evidence than critics have been able to find to the contrary.
As for so-called Climategate — hacked emails from the University of East Anglia — this does show scientists behaving badly by withholding information and talking of manipulating data that did not suit their argument. But it does not invalidate the accumulating evidence for global warming.
Rather, it proves that the evidence is not all one way and that there is no absolute certainty in climate science, which is why the IPCC always talks in terms of probabilities.
None of these cases undermines the IPCC’s main findings. Are the glaciers melting? Not all of them and not uniformly, but overall, unambiguously yes. Are temperatures rising? You could be forgiven for thinking not, given the loudness of the claims that there has been no warming since 1998. How is it that sceptics can place so much importance on this short-term trend but ignore that 1998 was an unusually strong El Nino year, that the last decade in Australia was the warmest on record, that each decade since the 1940s has been warmer than the preceding one in Australia and that, globally, 14 of the 15 warmest years on record occurred from 1995 to 2009?
Far from the scientific community hyping up the case for human-induced global warming, arguably it has been too cautious and too slow.
Joseph Fourier first suggested in 1824 that gases in the atmosphere trapped heat. Thirty-five years later John Tyndall conducted experiments that found water vapour and CO2 were the two most important gases to create such a greenhouse effect. In 1896 Svante Arrhenius calculated that doubling the level of carbon dioxide would lead to temperature increases of 5C-6C. But he and others suggested this would not be a problem because the oceans would absorb most of the extra CO2 and additional CO2 would not trap more heat. This latter theory was not seriously challenged until the 1950s and it took until the 70s for a few scientists to start warning that global warming was a serious and urgent issue.
John Sawyer of the British Meteorological Office calculated in 1972 that increased greenhouse gases would cause warming of 0.6C by the end of the century. The actual increase was 0.5C. In areas such as the decline in sea ice and sea level rise, past IPCC projections have proven to be too low.
Although they are side issues, the doubts sown by critics, together with a few cooler winters, have led to a fall in public concern about global warming. A poll reported in the Guardian this week showed a drop from 44 per cent to 31 per cent in the past year in people in Britain who believe climate change is definitely a reality, although another 29 per cent agree that it could be. Almost 20 per cent say climate change is caused by human factors, while two-thirds say it is due to a mix of human and natural causes. The Australian’s Newspoll conducted a fortnight ago found a fall from 84 per cent to 73 per cent since 2008 in those who say climate change is occurring. Of these believers, 94 per cent say it is wholly or partly caused by human activity, two percentage points below the 2008 figure.
Of course, these figures demonstrate that we should not mistake those who make the most noise in the debate for the majority. They explain why Tony Abbott, while giving every impression to his conservative supporters that he is a sceptic, still subscribes to the government’s targets for emissions reductions, including the 5 per cent unconditional (we’re not waiting for the world) cut and feels compelled to offer his own, albeit partial, solutions. And although climate change may be a lower priority for voters, the polling suggests there is still mileage in Kevin Rudd campaigning on having superior credentials on the issue.
As it happens, public impressions about climate change are not that different from the views of those with professional knowledge on the issue. A poll of 3146 earth scientists at the start of last year found 82 per cent agreed that human activity was a significant contributing factor to changing mean global temperatures. Of the 77 climatologists actively engaged in research, 75 agreed. For any government to ignore these views would not just be courageous, it would be irresponsible. Tackling climate change remains, in the words of Ross Garnaut, a diabolical problem. An international emissions trading system may be the best solution in theory, but such an internationally binding agreement may be unobtainable and the scheme the Rudd government wants to legislate is so compromised as to render it ineffective. There are plenty of other options. Even if they are more expensive, as premiums for risk insurance they are well worth paying.
Source: www.theaustralian.com.au