Global Warming: Lessons from the Pliocene Warm Period shows some highly relevant things as far as climate change. It shows how the weather and the ocean currents have changed over the last 5 million years due to the plate tectonic spreading of the Atlantic and the Pacific Oceanic Plates. It is quite interesting to look at the solar flux cycles as an oscillating forcing function (about +/- 15 watts/m^2 at the equator) every 40,000 years due to the wobble in the Earth's axis and how the thermocline of the ocean (temperature gradient) controls the weather on the land via the bouyancy and temperature changes in the ocean. The question being posed here is whether or not the El Nino conditions are normal for us or not, and how future tectonic plate shifting (on the order of millions of years) will affect climate change.
