Two Degrees of Misrepresentation

COPENHAGEN -- The United Nations-led climate change conference in Bali will be remembered less for the “road map” that it eventually created than for a messy collision between the United States and much of the rest of the world that kept onlookers transfixed. Environmental campaigners vilified America for resisting European Union pressure to pre-commit to specific temperature targets – namely, that global warming should be limited to no more than 2°C (3.6°F) above pre-industrial temperatures.

This target has become a veritable commandment of campaigners since the EU embraced it in 1996. The media often refer to it, sometimes saying that unless it is met, climate change would be very dangerous for humanity. In fact, the target is not scientifically backed, and the suggestion that we could achieve it is entirely implausible.

Stopping temperatures from rising by more than 2°C would require draconian, instant emission reductions – for the OECD the reductions would have to be between 40-50% below their expected path in just 12 years. Even if political consensus could be found, the cost would be phenomenal: one model estimates that the total global cost would be around $84 trillion, while the economic benefits would amount to just a seventh of this amount.

The suspiciously round figure of 2°C provides one clue to the fact this target is not based in science. The first peer-reviewed study that analyzed it, published in 2007, scathingly described it as being supported by “thin arguments, based on inadequate methods, sloppy reasoning, and selective citation from a very narrow set of studies.”