Temperature Trends

This image is a comparison of 10 different published reconstructions of mean temperature changes during the last 2000 years. The medieval warm period and little ice age are labeled at roughly the times when they are historically believed to occur. This plot demonstrates the range of reconstructions appearing in the published scientific literature.

The key to notice here is the current temperature anomaly (2004) is an abrupt and significant rise in temperature, significantly greater than the rise seen during the medieval warm period. And so far it shows no sign of leveling off.