Why the Cooling over the Last 50 Myr?
qThe collision of Indian and Asia happened around
40 Myr ago.
qThe collision
produced the Himalayas and a huge area of uplifted
terrain called the Tibetan Plateau.
qThe Himalayas Mountains provided fresh, readily erodable surfaces
on which chemical weathering could proceed rapidly.
qAt the same time,
the uplifting of the Tibetan Plateau create seasonal monsoon rainfalls, which provided
the water needed for chemical weathering.
qTherefore, the
collision of India and Asia enhanced the chemical
weathering process and brought down the atmospheric CO2
level to the relatively low values that prevail
today.
qThis reduced the
greenhouse effect and cooled down the climate over the last 50 Myr.
(from The Earth System)