 The ocean and atmospheric climate and this is true climate and remember climate is the integration of weather over at least 25 to 30 years So if you can see trends over that kind of time interval, you've got real climate change just as an aside So we're now talking about data sets that go thousands of years to tens of thousands of years and in that time interval we talk about Milankovic cyclicity Now Milan Milankovic was a mathematician. He identified orbital cycles that show what happens with the Earth's tilt and how it sort of wobbles like a like a top and that's called precession and that's a 20,000 years cycle how much it leans on its axis and that's a 40,000 year cycle and that's a liquidy and Then eccentricity is how circular the Earth's orbit it so it goes from a circle to an ellipse and that's a roughly a hundred thousand year cycle and So people like me that do paleo-synography Data very very strongly Reflects those cycles because they're really really big changes and you know sea level changes by 120 meters from just 25,000 years ago the sea level was down that far and There was kilometers of ice over North America and Northern Europe all the way down to New York City New York City has glacial striations in Central Park which Indicate there was kilometers of ice there right that was sort of the end of it You have that kind of real dramatic changes in climate over these thousands of years time scale