But if you're looking for hard statistics, the trouble is there aren't many around and they're pretty old.
Around 10 years ago, the World Health Organisation published research saying that the impacts of climate change since the mid-1970s may have caused over 150,000 deaths in 2000, and that a further 5.5 million healthy years of life were lost worldwide due to debilitating diseases caused by climate change. It warned that the death toll could double again in the next 30 years if trends were not reversed.
Since then, there has not been an official update.
A 2009 report from the now-defunct Global Humanitarian Forum (GHF) calculated that climate change already kills about 315,000 people a year through hunger, sickness and weather disasters, and the annual death toll is expected to rise to half a million by 2030 - but its methodology was widely questioned.