Each of these efforts is significant. They include such key goals as those of Sweden, which aims for an oil-free economy by 2020, and the Global Warming Solutions Act in California, which aims to reduce greenhouse gas emissions from the entire state economy by 25% over the next two decades.

Even the US president, Bush, has said some of the right words. In his 2006 State of the Union Address he said: "America is addicted to oil." That line became the most quoted aspect of his speech. On 22 January a powerful and diverse group of industry leaders (termed the US Climate Action Partnership and including General Electric, Alcoa, Duke Energy and others) called for federal action to address climate change meaningfully. The partnership also urged for discussion of a cap and trade system.

Since then there have been two further critical announcements.

First, the Intergovernmental Panel on Climate Change declared unequivocally that the world is heating up beyond any natural cyclical variations and that there is more than 90% certainty that the phenomenon of climate change is caused by humans. The nail is now firmly in the coffin of the debate over global warming, no matter what a few well paid nay-sayers may say.

The issue now turns to who will lead, how we will collectively address the problem, and how quickly we will find efficient ways not only to address it but also to turn it into an opportunity to make our economies stronger and more equitable (Kammen 2006). This is important because global warming is only one of many reasons to support the transition to a clean, renewable energy future. A compelling case can also be made on the basis of economic development, energy security or other environmental benefits (Kammen, Kapadia and Fripp 2004).

Second, in the same week as the IPCC announcement, BP ("Beyond Petroleum" to some) announced that our team at the University of California, Berkeley; Lawrence Berkeley National Laboratory; and the University of Illinois at Urbana-Champaign won a $500 million 10 year award to develop biofuels to address global warming and local environmental concerns. The consortium has formed the Energy Biosciences Institute (EBI) to take on this challenge.

There will be a great deal of attention and discussion about EBI in the coming months and years. It’s a major endeavour – in fact the largest university research grant ever – and is aimed squarely at what has been the most challenging greenhouse-gas issue – liquid fuels. The project also presents a tremendous opportunity.

In January 2006 my research group published a paper in Science (Farrell et al 2006). This provided an energy-content comparison of gasoline, corn-based ethanol and cellulosic-ethanol. The research found that the benefits of a transition to cellulosic ethanol can be dramatic in an effort to reduce greenhouse gas emissions. A simple expansion in corn-based ethanol use, however, produces only very modest greenhouse gas benefits. That said, it could be used as a first step to move to clean biofuels more widely, and corn ethanol can be justified by an energy security argument as a way to offset gasoline.

Put more simply, ethanol made from corn by refining in a plant run on coal can actually be worse for the environment than using regular gasoline. But cellulosic materials turned into ethanol in a plant run by natural gas or, far better, wind power or the plant’s own waste energy and heat are much, much better for the planet than gasoline.

The EBI effort represents a chance to generalize on this result: not all fossil fuels, nor all biofuels, are "created equal" or are equally good or bad for the environment. What is needed now is the sophistication to work towards low-carbon fuels. California has adopted this in Executive Order 1-07, the Low Carbon Fuel Standard, which will be implemented statewide through a series of "early actions", to begin this July, and then through a longer-term planning process to be coordinated with the Global Warming Solutions Act.

What we need next is a series of regional or national efforts to examine what the lowest-carbon fuels are for different regions: plug-in hybrid vehicles running off a clean grid; clean biofuels; high-efficiency vehicle standards; etc. The new EBI can bring the intellectual muscle of a globally focused but locally based research team in California, a global leader in environmental legislation and a major agricultural research centre in Illinois jointly to bear on the pressing issues of carbon emissions reductions. The time to act is now.