Anthropogenic climate variability

Climate shifts that are caused by human activity, in modern times usually equated with Global Warming, although e.g. in Roman times deforestation to get log for shipbuilding played a major role in a change of Mediterrenean[?] climate.

Because it is so difficult to decide what is natural climate variability and what is caused by humans, there are still many decisionmakers who maintain anthropogenic influences are minor or will even improve global climate. In scientific circles however, the often unfortunate influence of humans on climate has been widely accepted.