Those who urge taking action to avert climate change have had a bad couple of years. First, there was "Climategate" - the hacking of damaging emails from the Climatic Research Unit at the University of East Anglia, then the row over the use of a wildly inaccurate claim concerning the melting of Himalayan glaciers in a publication by the Intergovernmental Panel on Climate Change (IPCC) - the body tasked with reviewing and assessing research - and finally the failure of the 2009 UN Climate Change Conference in Copenhagen to reach a meaningful international agreement on addressing global warming.
This triple blow seriously damaged the public perception of the seriousness of the threat from climate change. Even worse, the global financial crisis and resulting economic fallout have convinced many people that there are far more important and urgent problems to throw resources at. This has all combined to undermine political support, as most clearly demonstrated by the increasingly sceptical public statements of the Republican candidates for next year's US Presidential election.
However, there has been more encouraging news recently. Most notably, the conclusions of the Berkeley Earth Project, which was set up in the wake of Climategate to take a fresh look at the evidence. As reported by the BBC, the project was established by a noted climate change sceptic, University of California physics professor Richard Muller, with the help of funding from sources which included charitable foundations maintained by the Koch brothers, the billionaire US industrialists who have donated large sums to organisations lobbying against acceptance of man-made global warming.
Despite these unpromising circumstances, Professor Muller's team conducted an exhaustive analysis of all of the available data from the three major centres for climate research, whose work had been decried as unreliable and shoddy in climate sceptic circles: the collaboration between the UK Met Office and UEA's Climatic Research Unit; the National Oceanic and Atmospheric Administration; and the National Aeronautics and Space Administration. The Berkeley Earth Project finally concluded that the research and analyses carried out by these three groups was fundamentally correct.
"Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the US and the UK," said Prof Muller.
"This confirms that these studies were done carefully and that potential biases identified by climate change sceptics did not seriously affect their conclusions."
This is worth emphasising: a thorough scientific study, funded with the help of climate sceptics and headed by a scientist who was himself a climate change sceptic, has concluded that those scientists warning about climate change were right all along. This deserves all the publicity it can get.
Next came calls for tougher action on climate change from big business in the form of The Corporate Leaders Group, a network of nearly 200 major companies spread over 30 countries, as described here.
This stance was supported by the Institutional Investors Group on Climate Change, representing more than $20 trillion in assets including banking giants HSBC and BNP Paribas, who argued that the governments which were acting quickly to implement tough climate policies would reap the biggest investments and the biggest rewards.
What Do We Know?
So what is the current state of scientific research into climate change? What is known and, of equal importance, not known? The New Scientist magazine has helpfully put together a simple guide to exactly that, here. To summarise very briefly:
We know that greenhouse gases are warming the planet, but we don't know how far the levels of these gases will rise.
We know that other pollutants are cooling the planet, but we don't know by how much.
We know that the planet is going to get a lot hotter, but we don't know how much hotter, nor how the climate will change in specific regions.
We know that the sea level is going to rise by many metres, but we don't know how quickly this will happen.
We know that there will be more floods and droughts, but we don't know whether there will be more hurricanes and the like.
Finally, we don't know how serious a threat global warming is to life, nor if and when "tipping points" (causing sudden accelerations in warming) will be reached.
It is of course frustrating that scientists cannot be more specific about what is going to happen where and when, but the massive complexity of the processes involved preclude this. Probably as a result, the public acceptance of the need for action - more specifically, the need for action which is costly now in order to stave off disaster later - is still not strong enough for most political leaders to take the action required. At the moment, the warming trends are steadily upwards, with the very limited reductions in carbon emissions achieved by the developed world swamped by the increasing industrialisation of the developing world - especially China and India - and the ever-growing global population which has now (more or less) reached seven billion and is projected to reach 9 or 10 billion by the middle of the century.
It is becoming ever more certain that we will not act effectively enough, quickly enough, to reduce our greenhouse gas emissions to the extent needed to prevent global temperatures from rising to dangerous levels by the end of this century. Can anything else be done? The obvious answer is geoengineering - technical fixes to counteract the rise in greenhouse gases - and it may be significant that public acceptance of such an approach seems to be growing as described here. However, as I have already discussed in this article, there are serious problems with this approach.
The path our generation takes now will decide what sort of future the next few generations will experience. At the moment, there appear to be few grounds for optimism. When faced with difficult and painful decisions, people are very prone to go through several stages (as governments have been doing over the current international financial crisis):
1. Denying there's a problem.
2. Hoping that it will go away if it's ignored for long enough.
3. Hoping that something will come up which will make hard decisions unnecessary.
4. Finally, reluctantly, taking the minimum action after waiting for as long as possible.
The problem with this tried-and-tested approach to muddling through is that the climate has enormous inertia. By the time the need for action has become obvious to all, the climate changes will have gathered such momentum that they will quite possibly be unstoppable. Humanity needs to fasten its metaphorical seat belt - we're in for a very rough ride.