The extent of the human contribution to modern global warming is a hotly debated topic in political circles, particularly in the US. During a recent congressional hearing, Rick Perry, the US energy secretary, remarked that “to stand up and say that 100% of global warming is because of human activity, I think on its face, is just indefensible”. However, the science on the human contribution to modern warming is quite clear. Humans emissions and activities have caused around 100% of the warming observed since 1950, according to the Intergovernmental Panel on Climate Change’s (IPCC) fifth assessment report.
Carbon Brief 13th Dec 2017 read more »