James Hansen and Daryl Hannah arrested in West Virginia mining protest We never said biochar is a miracle cure Nasa's James Hansen warns 'democratic process isn't working' in climate change fight Robert Bryce: James Hansen wants to close coal-fired power plants, but there's no good alternati... James Hansen: Coal-fired power plants are death factories. Close them Climate expert Jim Hansen snubs Heathrow runway protesters President Obama 'has four years to save Earth' Nasa climate expert makes personal appeal to Obama A letter to Obama Nasa's James Hansen warns Barack Obama on climate change US election: Climate scientist James Hansen aims to get 1m students to vote on John McCain and Barac... Brian Beutler: James Hansen's climate change activism is hurting his own cause Kate Sheppard: James Hansen's testimony on climate change should be a wake-up call to Congress James Hansen: Policy needs to keep pace with climate change science Twenty years later: tipping points near on global warming