The director of a NASA space laboratory will this week lead thousands of climate-change campaigners through Coventry in an extraordinary intervention in British politics.
James Hansen plans to use Thursday's Climate Change Day of Action to put pressure on Prime Minister Gordon Brown to wake up to the threat of climate change -- by halting the construction of new power stations and the expansion of airports, with schemes such as the third runway at Heathrow Airport near London.
The move by a leading American researcher is the highest-profile example to date of the way climate change is politicizing scientists.
It follows last week's climate science summit in Copenhagen where 2,500 leading climate scientists issued a stark warning to politicians that unless they took drastic action to cut carbon emissions, the world would face "irreversible shifts in climate."
They warned that global temperature increases averaging more than 7 Fahrenheit were now possible and that human-generated CO2 could also acidify the world's oceans, wiping out life forms ranging from tiny plankton to coral reefs.