The United States has abandoned comprehensive greenhouse-gas curbs, but California is pressing ahead. Mary Nichols is leading the fight against emissions.

Goes for auto emission cuts from far behind in the race us president Barack Obama has set in motion a national policy that is expected to make cars and trucks in the country 30 per cent more fuel efficient by 2016. The policy is also expected to cut 900 million tonnes of greenhouse gas (ghg) emissions from vehicles between 2012 and 2016. This is equal to taking 177 million cars off

Ten capital cities and the Californian government have recently signed up to a greenhouse gas inventory system that will help ciies and regions make deep cuts in their emissions.

For all its economic capacity, population size, and resource base, California remains only one among the 50 United States and, essentially, is a subnational actor attempting to play a role in the climate change policy arena on par with the nation-states of the world. This raises a series of questions about the substance and breadth of the state's new policy and what has motivated it.

Measuring the costs and benefits of projects intended to offset the emission of greenhouse gases is one of many thorny issues that the state of California must tackle as it begins drafting a cap-and-trade system of carbon credits.

This study looks at trends in GHG emissions in different regions across the world, and analyses the major drivers. It provides an overview of the policies, strategies and measures being adopted and planned worldwide to combat climate change. It compares the different approaches adopted in different regions and the reasons for differences in emphasis. It assesses the measures in terms of their expected impacts on the key WEC objectives of energy accessibility, availability and acceptability.