By the end of today, we will have seen two significant developments in the political landscape of climate change. First, the UK has indicated for the first time that it believes serious money will be needed from developing countries at Copenhagen.

Secondly, today will also see a vote in the US House on the Waxman-Markey bill [1], Obama's re-engagement of the US with climate. You may have seen Joss on Newsnight on Wednesday [2], arguing that the bill doesn't go anywhere near enough what we need to see from the US, and that Obama had effectively dropped the ball on the climate, but even if inadequate, it is still groundbreaking.

A good moment to get an insight into the interaction between science and politics over the pond. For the first of the Greenpeace meets series, occasional interviews in which we'll hook up with (hopefully) interesting authors, activists, scientists and policy wonks to download their wisdom, I went and had a coffee with veteran US environmental guru Bill McKibben.

Bill has spent the last twenty years writing, agitating and organising to make governments take strong action on climate change. His take is very much that until there is a mass movement that both gives politicians the space to act, and forces them to do so, change will be halting.

With that in mind, he's currently crossing the globe organising for 350.org [3] - the campaign group he founded, which calls for climate targets to be focused on lowering the amount of carbon dioxide in the atmosphere to a level of no more than 350 parts per million. (Hence the name. We're currently at 388.)

The podcast goes in-depth on the science behind 350.org, Bill's take on what Copenhagen will deliver for the global climate movement, and 350.org's plans for a global day of action on October 24th.