The growing gap between public support for action and the scientific evidence is driving senior scientists to distraction. [5 July 2011 | Peter Boyer]
Neither Al Gore nor yours truly seems to have much to say these days, lamented a recent Mercury correspondent. “Is it a sign that climate is as always was? Perhaps Mr Boyer should start a travel column.”
I should be so lucky. The promise of having a good time in exotic places at others’ expense might even persuade me that I shouldn’t have sounded off about air travel’s carbon footprint. Or maybe a TV travel show, which pays better. But it’s not going to happen.
Which leaves me with the reader’s other thought, that Al Gore and I are banging on about nothing. A growing number of people would seem to agree, if the Lowy Institute’s annual survey of about 1000 Australians, released last week, is anything to go by.
The Lowy poll finds that a decreasing number of people — only 41 per cent — think climate change is a serious and pressing problem. The figure has dropped by 27 per cent since a similar survey in 2006, the year Al Gore’s movie An Inconvenient Truth broke box-office records.
Over the same five years, support for the sceptical position that we should do nothing if there’s a cost involved has nearly tripled from 7 to 19 per cent. There’s a strong age difference here: 28 per cent of people aged 60 or more take this view, but only 11 per cent of young adults (up to age 29).
If only they were right. I’d cope with the egg on my face if it became clear that Earth’s atmosphere or oceans haven’t been affected by our release of 30 billion tonnes of fossilised carbon a year, and that its surface temperatures, ice sheets and sea levels remain “as always was”. If only.
If you think that the evidence for human-induced climate change is weakening, think again. Here’s what top-level overviews of current peer-reviewed science compiled last year and this year by the Australian Academy of Science and the Climate Commission are saying:
• The decade from 2001 to 2010 was the warmest in 130 years of global records, more than 0.46C above the average for the three decades to 1990. Australia’s average surface temperature has risen by about 0.7C since 1960, and its 10-year average has risen every decade since the 1940s.
• The number of heatwaves in Australia in the decade to 2010 was double the decadal average of the past 50 years, while the number of low-temperature extremes was the lowest on record.
• Sea-surface temperatures have warmed nearly everywhere over the past century. Around Australia they are now on average the highest on record.
• Satellite observations show that both the Greenland and West Antarctic ice sheets continue to lose ice at an increasing rate, and that Antarctica as a whole is losing ice. Mountain glaciers everywhere are getting smaller.
• The world’s sea level has risen on average by about 20 cm since the first global estimates in the 1880s. Sea level around Australia has risen about 1.2 mm a year since 1920, but over the past 20 years, relative to land, it has risen by 2 mm a year in the south-east and over 8 mm a year in the north-west.
• Studies of changing responses of biological species and ecosystems in Australia and globally, such as animals and plants becoming extinct or moving to new habitats, have yielded clear evidence of a warming climate.
• The concentration of carbon dioxide in the air has just passed 390 parts per million — about 40 per cent higher than the highest natural concentration over the 800,000-year ice core record. This has changed the acidity of oceans since 1880 at a rate unprecedented in 25 million years, putting exceptional evolutionary pressure on marine ecosystems.
• A long-term increase in the atmosphere’s average water vapour content, at a rate of about 1.5 per cent each decade, has brought more intense heavy rains in many regions.
• Science has found no natural basis for Earth’s warming. Solar cycles are the main short-term influence, but we’re now in the middle of a deep “solar minimum” which by itself would have a cooling effect. The only plausible evidence for warming — and it’s very strong evidence — is the rapid rise in greenhouse gases caused by fossil fuel burning.
All this and much more is telling us loudly, repeatedly and with increasing urgency that Spaceship Earth has a problem. Something new is happening to the climate, and the cause of it is clear. It’s us.
Getting our heads around the idea of a changing climate is hard, especially when we need to think globally and over decades, centuries and millennia. When winter chills seems to give the lie to global warming it’s an even bigger challenge. Perhaps Lowy should do a midsummer poll.
The lagging public support for action in the face of increasingly strong scientific evidence has led Australia’s Chief Scientist, Ian Chubb, to describe the current level of public debate as “appalling”. A failure to contain human emissions of greenhouse gases, he said, will bring us to a “tipping point” after which climate change will be unstoppable.
The spectrum of scientific opinion about the potential impact of our fossil-fuel emissions ranges from benign (a tiny minority of specialist scientists) to dangerous (a very large majority). We’d be fools to put all our eggs in the benign basket.