I am finding it increasingly difficult to maintain my optimism that we can stabilise global temperature increases below the "danger level" of 2°C. First, there is no sign that emissions are being reduced; rather, the opposite is happening. Second, it is becoming clear that the danger level for temperature increase is a good deal lower than 2°C.
The Arctic Sea ice cover is already approaching a new low. The new topic of speculation is not whether the Arctic ice will disappear completely in the summer months by 2080, but whether this will happen by 2018. An ice-free North Pole will have a significant effect on the planet's energy balance, given the important role this huge white "mirror" plays in reflecting incoming solar radiation. Once it is gone, the warming process can only speed up further. Already, a new study suggests that an ice-free Arctic Ocean will dramatically increase warming in surrounding land areas, accelerating the degradation of permafrost and resulting in huge releases of carbon and methane - driving yet more warming. Setting a danger level of 2°C, as the UK and EU have done, now looks dangerously optimistic.
The Intergovernmental Panel on Climate Change (IPCC) reported last year that emissions cuts within a decade could still keep temperature hikes below 2°C. But global emissions are rising year on year, not falling. Many climate models are underpinned by an assumption of 1.5 per cent increases annually in carbon releases. Instead, they have been running at more than 2 per cent.
In the words of the Tyndall Centre scientist Kevin Anderson: "Since 2000 the world has gone ballistic in terms of carbon emissions." Anderson has recently revised his projections for climate change and now thinks that the "best we can expect" is stab ilising atmospheric concentrations at 650 parts per million CO2 equivalent, equating to warming of about 4°C. He suggests we "mitigate for 2°, but adapt for 4°".
Adapting to 4°C of warming would be quite a challenge. With this level of temperature change, we can expect a huge increase in drought-prone zones, a mass extinction of half or more of the life on earth, hundreds of millions of refugees from areas deprived of fresh water or inundated by rising seas, and widespread starv ation due to food and water shortages.
The Stockholm Network's Carbon Scenarios report (which I helped draft) reaches a similar conclusion, projecting a warming of nearly 5°C if global policy on climate continues to fail. Against this terrifying backdrop, the denial lobby flourishes, its success almost calling into question the capacity of mankind for reasoned thought.
Nigel Lawson's dreadful book, laughably entitled An Appeal to Reason, has been riding high in the sales charts and is only one of several denialist tomes on global warming. The last time I looked, four out of five of Amazon's top sellers on climate were penned by deniers. And these are not just views from the fringe. A MORI poll reported by the Observer last month found six out of ten people think, wrongly, that "many scientific experts" disagree on whether human beings are causing climate change. Four out of ten people asked believed that the impact had been exaggerated.
Many climate-change sceptics like to think they are proudly independent people, refusing to be cowed by UN-sponsored orthodoxy from the IPCC. In fact, the arguments of climate sceptics have largely been moulded by a far more sinister force - the US-based conservative think tanks. A recent academic survey of environmentally sceptical books found that 92 per cent were linked with these think tanks, which include the Heritage Foundation, the Cato Institute and the Competitive Enterprise Institute. Since the early 1990s, these and other industry-funded front groups have been leading an anti-environmental backlash, changing the tenor of the political debate on environmental issues and bombarding the media and the public with disinformation.
The authors of the study, published in the June edition of a journal called Environmental Politics, argue that, far from being a true grass-roots movement, "environmental scepticism is an elite- driven reaction to global environmentalism, organised by core actors within the conservative movement". The "self-portrayal of sceptics as marginalised 'Davids' battling the powerful 'Goliath' of environmentalists and environmental scientists is a charade", given that the "sceptics are supported by politically powerful conservative think tanks funded by wealthy foundations and corporations".
Next time someone insists global warming isn't happening, ask yourself where their views come from - and whose interests they serve.