Drought May Threaten Globe Within Decades

August 5, 2010

Drought May Threaten Globe Within Decades

Aiguo Dai, PhD (Boulder, CO), National Center for Atmospheric Research. "Is climate change about to catch up to us?"

Dr. Dai, an Atmospheric Scientist, became interested in climate change when he moved to the US from China in 1990. He believes that climate is a global issue affecting nearly everyone.

Sharon Kleyne observed that climate is always changing and asked about the role of water in climate change. According to Dr. Dai, Earth's climate had been relatively stable for the last 10,000 years (Earth is four billion years old) but weather has been more active over the last 200 years, with rapid warming is rapid and changing atmospheric streams. Some wildlife species have been unable to adapt. It is unclear how much, if any, is human caused.

Mrs. Kleyne notes that we must live with Earth no matter what and that in general, humans are not good at this.

Dr. Dai notes that river flow volume is decreasing in many regions worldwide, creating water stress among most living organisms. With population growth, demand for fresh water is simultaneously increasing, particularly for drinking and agriculture.

Mrs. Kleyne believes that the solution is to educate the public about the needs for conservation and for human activities that are less environmentally damaging. Dr. Dai adds that the consequences of doing nothing are extremely dire and that the situation will not improve on its own. We must change our consumption habits, and we must store and conserve water.

Sharon Kleyne then asked Dr. Dai about the Yellow River in China. It is extremely polluted, often toxic and prone to immense flooding (for the last thousand miles, it flows between natural levees, at an elevation higher than the surrounding plain). It also feeds an extremely fertile region. Water flow in the Yellow River has been diminishing for 200 years. These problems are both human caused and natural.

Sharon wondered how China influences the rest of the world and if we in the US can help in any way. Dr. Dai noted that change in China is very slow and that they are beginning to ship water from the Yangtze, in the south, and to dig deeper water wells. He is an advocate of wind farms for power. There is much drift of China's polluted air to countries such as South Korea and Japan who have much stricter air quality standards.

Sharon noted that draught can contribute to air temperature, and to air and water pollution. Drought effect the amount of humidity in the air and the surface temperature of lakes and oceans, which affect the rate of evaporation. Theoretically, the cycle is self-correcting, since more evaporation means more rain.

Some polluted water may be OK for irrigation but not for drinking.

Conclusion: The United States has been fortunate in its weather for the past 50 years. That may change in the next 10 to 20 years as energy extremes. created by the increased weather activity, express themselves.