A breath of fresh air in climate change debate

A new model of future greenhouse gas emissions suggests that it's not too late to reverse predicted climate change trends. In fact, the new study shows that the main greenhouse gas threats to Earth's future climate have yet to be built.

Writing in Science, Carnegie Institution-based researcher Steven Davis and his colleagues mathematically "froze" the Earth in its present state of emissions and asked what would happen if all of the present grenhouse gas sources on the planet were allowed to continue emitting for their working lifetime, but without any new CO2-sources being added. In other words, is there already sufficient climate-change inertia with the greenhouse-gas-producing infrastructure we already have to mean that it's too late to make a difference? Surprisingly, the answer that emerged from the analysis was no; in fact, the study shows that it's what we build next that matters most to the future of the planet. Reassuringly, the team found that our present CO2-producing capacity, in its working lifetime of up to about 40 years, would see the CO2 level stabilise at about 430 parts per million (ppm), some way short of the 450ppm viewed by many scientists as the point of no return.

But we cannot afford to be complacent, caution the researchers. According to co-author Ken Caldeira, "because most of the threat from climate change will come from energy infrastructure we have yet to build, it is critically important that we build the right stuff now - that is, low carbon energy technologies."