Lord Rooker, at 2nd Reading in the Lords set out the background - "The Intergovernmental Panel on Climate Change recently published its fourth assessment report, an authoritative analysis of the current state of knowledge on the subject. Its key conclusions remind us why the need for this Bill is so pressing.
The IPCC concludes that the climate is observably warming and that this is due much more to human activity than to any naturally occurring factors. Without effective international reductions in emissions, atmospheric concentrations of greenhouse gases will continue to grow and temperatures will rise by up to 4 degrees centigrade this century. Dire consequences for food and water resources, human health, infrastructure, biodiversity and economic activity worldwide will follow and the risk of abrupt or irreversible climate change will increase. To avoid the worst of this, global emissions must peak soon and then decline rapidly. We know that this can be done. The Stern report set out clearly that doing nothing would cost far more than taking action and that early action will be easier and cheaper than action taken later. Meanwhile, we must also adapt to unavoidable changes already in the system."