Not satisfied with mapping the past 1500 years of planetary climate, scientists have now been able to go back 11,000 years. they did it by using ice cores and layers of "foraminifera"- deposits of tiny shelled creatures on the ocean floor. how did they know to do this? hey fool, they are scientists, that is what they do. :)
results? after the end of the last ice age, the temperature of our planet inched upward with amazing slowness, around one degree over 5000 years. then it peaked, and inched downwards by the same amount over another 5 or 6 thousand years. then in the last 150 years, it jerked higher so that the temperature averages today are higher than they were at 75% of that past 11,000 years. and are poised to leave that chart behind and start a new one that goes almost straight UP.
if humans had never done that industrial revolution thing, our planet probably would have eventually ended up in another ice age in another 5000 years. But since we DID invent that fossil fuel burning thing, not really worth mentioning ice ages because they ain't gonna happen.
yeah I know you are really tired of hearing about the global warming hockey stick chart. But it is what it is. if you don't like hearing about it, don't read my stuff.