National action holds key to global climate treaty

The Intergovernmental Panel on Climate Change (IPCC) has released the most comprehensive study ever on global warming, prepared by more than 200 scientists over two years. It concludes that, if the world continues to emit greenhouse gases at current rates, we will face warming of more than 2 degrees Celsius, compared with pre-industrial levels, within two to three decades. This is hugely significant because all countries have agreed that temperature rises should be restricted to no more than 2 degrees, thus increasing prospects of preventing "runaway" climate change.

The study also concludes that it is "extremely likely" that human activity has caused most of the increase in global temperature in recent decades.

The report will be welcomed by many, at a time when it may seem hard not to be pessimistic about the global battle to manage the huge risks of climate change. Moreover, in some places, climate change sceptics appear to be winning the battle for public opinion.

However, there are signs we may be reaching a turning point. If one examines what is already happening at national and sub-national level across the world, a relatively encouraging picture emerges.

Domestic laws and regulations are being passed at an increasing rate - in stark contrast to the pace of progress in UN-driven international negotiations. In 2012 alone, according to a report published by Globe International, 32 of 33 surveyed countries (which account for over 85 per cent of global greenhouse gas emissions), including the US and China, have introduced or are moving towards significant climate or climate-related legislation and regulation.

This is nothing less than game-changing.