Climate change is now one of the greatest challenges facing humanity, but it seems that we have been here before; if we look at the world's climate over a much longer period than 150 years.
During the Paleocene-Eocene Thermal Maximum which occurred 50m years ago, the poles were ice-free tropical regions, with very high carbon levels, and temperature increases of as much as 5 degrees.
I am just wondering if what we are currently seeing was going to happen anyway? Has the discovery of oil, and the resultant human activity just accelerated an already inevitable outcome?