Scientists can't even be sure how high the land was before India crashed into Asia, obliterating the Tethys Ocean which used to separate them. Like western South America, the coast could have been lined by mountains.Some scientists have even suggested that the rise of the Himalayas could have triggered the Ice Age by increasing the total amount of global rain and removing vast amounts of carbon dioxide from the air.By pushing the Himalayas to their current altitude, more than 8,000m above sea level, and raising the Tibetan plateau to 5,000m, the detachment of the block was responsible for both the monsoon rains that make south Asia so fertile and the Gobi desert in central Asia. Warm winds blowing from the Pacific Ocean cool as they rise over the mountains, releasing the moisture they contain as torrential rains, leaving almost no water to fall on the arid interior of the continent.