In an interview on the BBC4 Today’s Program, Professor Sir David King, the UK’s chief scientist, said that given current trends, a 550 parts per million concentration of CO2 in the atmosphere is optimistically the likely level at which the world can settle.
Such a concentration—roughly double the pre-industrial level—would likely result in an average global temperature rise in excess of 3º C (5.4º F).
An increase of that amount pushes the world into what the Exeter Conference categorized as dangerous climate change. An increase of 2º C, for example, is thought sufficient to melt the Greenland ice sheet. (Earlier post.)
There are no certainties here in terms of prediction, but if you ask me where we feel the temperature is likely to end up if we move to a level of carbon dioxide of 550 parts per million, which is roughly twice the pre-industrial level, and the level at which we would be optimistically hoping we could settle, that the temperature rise would be in excess of three degrees Centigrade...and yet we’re saying 550 ppm is probably the best we can achieve.—Sir David King
Professor Sir David King warned this would happen because world governments—notably the US and the developing countries of China and India—were failing to agree on cutting emissions of greenhouse gases. At the same time, countries such as the UK, which have signed the Kyoto Protocol, are failing to achieve their reduction goals.
The UK recently revised downward its internal target for CO2 reduction, although the country is still tracking toward meeting its Kyoto target. Increasing emissions from the transportation is one of the primary challenges. (Earlier post.)
An increase of 3º C over the coming century would, according to models, lead to a rise in sea levels and increase in desertification that will place 400 million people at the risk of hunger.
Developing countries will be the hardest hit, with between 20 million to 400 million metric tons of cereal production being lost, according to Sir David.
There are two parts to dealing with climate change. One is to reduce emissions. The second is that we must begin that whole process of adaptation.
What I want to stress is that we don’t have to succumb to a state of despondency...it is very important to understand that we can manage the risks to our population.
There is a difference between optimism [about the potential of technology] and head in the sand. Quite clearly what we have to do as we move forward with these discussions is see that the consensus position of the scientific community is brought right onto the table.