Question: Would the climate have been habitable for human life 3 million years ago and if it was what would living conditions have been like?

James Pope answered on 25 Jun 2012:

Hi musicallyhappy4968,

About 3 million years ago, our ancestors, a species called Australopithecus roamed aroiund Africa. They were a form of hominid, which is the genus or animal family we come from, called the ‘Homo’ genus (we are Homo Sapians). The most famous of the Australopithecus’ is Lucy and she was found in Ethiopia.

Generally, the climate was on average about 3°C warmer than today 3 million years ago, in an era we call the Pliocene. The image at the link below shows you the change in temperature (left hand map) and rainfall (right hand map) for a difference (we call it an anomaly) between the Pliocene and the Modern day. So the difference is basically created by a subtraction of Modern day values from Pliocene ones.

This image, which is from my work shows you that it was about the same as the modern day at the equator, but up to 10°C warmer at the poles. The image shows you that the world was also a bit wetter, with some more rainfall. The higher polar temperatures caused some big changes such as the amount of sea ice that could form, and the ice sheets were a bit smaller, so sea level was 25 metres higher than today as well.

However, it would definitely have been habitable for Humans, which is good news as the temperatures for the Pliocene are were we appear to be heading due to climate change by 2100, that is one of the reasons it’s such an important period of time to study and for us to understand, which is why I work on it!