Cambodian and foreigner climate change activists stand surrounding Cambodia's biggest clock in the heart of the capital of Phnom Penh on October 21, 2009 as part of the Tck-Tck-Tck global campaign against climate change. The activists are calling for climate action. Cambodia is one of the most vulnerable countries to climate change impacts due to its low capacity and limited resources to address climate change. Cambodian Prime Minister Hun Sen on October 19, urged the world's rich countries to take more responsibility for climate change, saying the poor suffer for their carbon emissions 'sin.'