Hansen’s arrest was no surprise – in fact, it was deliberate. Hansen was taking part in a civil disobedience action at the White House organized to halt the approval of the Keystone XL pipeline, which will bring dirty oil from the Canadian tar sands down to US refineries in the Gulf. Hansen is just one of more than nearly 1000 protesters who have been arrested since the action began on August 20 (it continues through September 3 – you can learn more about it attarsandsaction.org).
Also, for those interested, Hansen has posted a collection of remarks, notes and powerpoints explaining how greenhouse gas emissions associated with the pipeline and the development of unconventional fossil fuels risk breaching tipping points in the global climate system. The collection also includes Hansen’s “conservative climate plan” to avoid such a scenario.