Forty-seven percent of Americans say that if global warming is happening, it is caused mostly by human activities. This is the belief backed up by the scientific evidence; in the most recent report by the Intergovernmental Panel on Climate Change (IPCC) in September 2013, scientists agreed that it is "extremely likely" that human emissions of greenhouse gases are causing the planet to warm. Thirty-seven percent of Americans reject this consensus, saying that climate change is most likely caused by natural fluctuations. Boy, they really keep trying to hammer in that it's a fact, consensus, etc. angle, don't they?