Few of the books and articles about climate change mention the role that the Earth’s topography, its set of mountains and valleys, plays in controlling weather and climate.
One of the most important players is the Tibetan Plateau. Its largest portion is located in the Chinese Province of Tibet (Xizang). Plateaus are usually flat, and this one is reasonably so. Most of its area is at elevations between 13,000 and 16,000 feet. If you climb the very imposing El Capitan mountain in California, you’re at about half that altitude. The 13,770 foot Grand Teton, Wyoming puts you on a level with the bottom of the Tibetan Plateau. The plateau rim, though, goes up into serious altitudes. There, the Himalayas chain rises into the 26,000 foot range with Annapurna, and monsters like K2 and Mount Everest go another 2,000 feet above that.
A 900-square mile chunk of bedrock like that loses massive amounts of heat during winter. A little farther up in the atmosphere is the jet stream, that fast storm track which separates colder air from warmer air. Because Tibet is now cold, the jet stream is displaced farther south into India. Climate change increases the differences between warm and cold areas, so the wave undulations of the jet stream can be expected to get stronger. The jet stream surrounds the globe in a steady wave pattern. Typically, one of the waves bottoms out in Eastern Europe. This opens the door for cold winter storms from Russia. A steeper wave, with the jet stream dipping farther south in Europe, can bring harsh “Siberian Express” outbreaks with deep freezes. Countries like Germany, Poland, Slovakia and others will not only get warming from climate change, but also some bitterly cold winters.
In the summer, the Tibetan Plateau heats up in the sunshine and becomes a heat source. This displaces the jet stream to its north and into Russia. South of it, the coast is then clear for storms from the warm Indian and Pacific Oceans. Storms drag moisture onto the land and produce weeks of rain, even outside the Monsoon season. I experienced it myself, slogging through endless rainstorms in eastern China a few spring seasons ago. With a greater bouncing of the waves in the jet stream, weather patterns are changing from Europe to the Pacific and onward into North America.
Rudi Kiefer, Ph.D., is a professor at Brenau University, teaching physical and health sciences on Brenau’s Georgia campuses and in China. His column appears Sundays and at gainesvilletimes.com.