The Greenhouse Effect (Science Impact Books)

Rating:
Summary: Very interesting predictions for weather patterns
Review: In 1980 Harold Bernard published his research into natural cycles and the dust bowl era in the US during the 1930s, which lead to his prediction of an even worse dust bowl era around 2020, unpredictable weather patterns around the turn of the century, and serious implications for agriculture and feeding the growing world population.

His predictions are based on the greenhouse effect superimposed upon natural cycles, the dominant one of which has a period of 180 years. The cold part of the cycle appeared in the 1890s and 1980s while the warm part of the cycle appeared in the 1930s and is due to reappear about 2020. Industrialization and the emission of CO2 took off after the Second World War so man's influence on the 180-year cycle was minimal up to that time. However, the greenhouse effect superimposed on the trough of the cold cycle lead to temperatures in the 1970s being slightly higher than were predicted for the natural cycle alone. As the year 2000 roughly marks the mid point between the cold trough and the warm peak the ever-increasing greenhouse effect will be added to the natural warming part of the cycle producing much higher temperatures than would otherwise have been true.

A long succession of record high temperatures throughout the US, coupled with low precipitation, strong winds and poor agricultural practices, resulted in the 1930s dust bowl era when 350 million tons of the world's richest top soil decimated agricultural production and brought great hardship. However, Bernard's detailed analysis of weather patterns over the United States during the 1930s showed that local communities and large regions of the US suffered anomalous weather patterns bringing record low temperatures or very high rainfall. High air temperatures warmed the oceans causing record levels of hurricane activity, the northward migration of fish and the opening of the far-northern ice pack to shipping. Higher and very intensive rainfall caused many homes to be lost and roads and bridges to be washed away. During the 1930s almost every spot in the US suffered record-setting extremes of weather which caused property damage and lowered agricultural production.

As Bernard could foresee even worse times in the new century, the book was written as a plea to governments to take immediate action to reduce fossil fuel use, lower the CO2 -induced global warming and thus forestall the hardship that lay ahead. However, anticipating that his words would fall on deaf ears he predicted that the CO2-produced climatic warming would begin to accelerate at the turn of the century and that in the period 2010-2020 we would go into a climate warmer than anything humankind has experienced in the last 1000 years. We can expect higher temperatures than when England and East Prussia grew grapes, glacier boundaries were 500-600 feet higher than today, and sheep and woodlands were found in southwest Greenland. Warmer summers, however, can be offset by bitter winters and we can anticipate lower temperatures than those which brought harsh frosts to the Mediterranean and caused the River Tiber and the River Nile to freeze over. In the past there was moisture in the Sahara and a 200-year drought in North America where summer temperatures on the Great Plains reached 120F so we must expect similar occurrences anywhere in the world. Climatic warming is magnified in the polar regions so we must expect ice sheets to slowly disintegrate.

Because of the speed of change, we will have immense difficulty adjusting and agriculture will struggle with the vastly altered patterns of temperature and rainfall. In 1976 world grain reserves had dwindled to 31 days while the difference between a good and bad harvest (such as 1972 and 1974) amounted to about 10% or 36 days of annual world consumption. He points out that the grain-producing areas of the world, including the US, have been drawing down their water tables at unsustainable rates and that if the US were to lose its capacity to export grain about 21% of total exports would be wiped out, with grave implications for feeding the growing world population and the US economy.

In closing, he emphasized that the key issue is the enormous consequences we face when the greenhouse threat becomes a reality - especially the consequences for world agriculture. The cause of the problem is our dependence upon fossil fuels and the build up of CO2. We must reduce our dependence upon petroleum, develop renewable energy sources and make the switch to renewables as soon as possible.
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