I am a Climate Change (human caused) agnostic.

[Quixote1818]

112. Do you know why this cooling occurred?

Snip> Plate collisions disrupt these carbon fluxes in a variety of ways, some tending to elevate and some tending to lower the atmospheric carbon dioxide level. It has been suggested that the Eocene, the early warm trend 55 million years ago, was caused by elevated atmospheric carbon dioxide and that a subsequent decrease in atmospheric carbon dioxide led to the cooling trend over the past 52 million years. One mechanism proposed as a cause of this decrease in carbon dioxide is that mountain uplift lead to enhanced weathering of silicate rocks, and thus removal of carbon dioxide from the atmosphere.

In addition, the collision of India and Asia led to the uplift of the Tibetan Plateau and the Himalayas. While topography may not be enough to explain the cooling trends, another mechanism may account for changing climate. The uplift may have caused both an increase in the global rate of chemical erosion, as well as erode fresh minerals that are rapidly transported to lower elevations, which are warmer and moister and allow chemical weathering to happen more efficiently. Through these mechanisms, then, it has been hypothesized that the tectonically driven uplift of the Tibetan Plateau and the Himalayas is the prime cause of the post-Eocene cooling trend.
http://www.pbs.org/wgbh/nova/earth/cause-ice-age.html

This cooling took MILLIONS of years! We are seeing all this wiped away in a decade!