Sunspots get the blame and credit for a lot of things that happen on Earth. The regular cycles of these short-lived solar magnetic storms have been used to forecast human fertility, the stock market, weather conditions and agricultural production. That doesn't include the numerous earthly, and extraterrestrial, activities linked to sunspots by the supermarket tabloids.
So when astronomer Sallie Baliunas of the Harvard-Smithsonian Center for Astrophysics suggests that sunspot cycles may be the mechanism behind global warming, you can see the collective eyebrows rising.
Sunspots signal changes in the sun's brightness or energy level, which in turn may regulate the Earth's temperatures, she explains. Sunspot cycles appear to be mirror images of warming and cooling periods on Earth.
That's a direct threat to the environmental orthodoxy that man's insatiable lust for carbon combustion is the primary cause of the "greenhouse effect" and global warming.
Dr. Baliunas is not only challenging the science of the Greenhouse Gang, but their sacred political credo as preached by high priest Al Gore, who calls global warming "the highest risk environmental problem the world faces today."
That's the urgency behind the White House's wide-ranging program to curb human energy consumption and combat the potential threat of global warming. The assumption is that man is largely responsible for a half-degree (0.5) Celsius increase in average global temperatures over the past century. Industrial and automotive burning of fossil fuels has accelerated the accumulation of carbon dioxide in the atmosphere.
Dr. Baliunas is one of a number of scientists who are questioning the political rush to judgment on global warming. Wait another five years, as more reliable satellite weather data become available for analysis, she urges, before making costly and restrictive policy decisions on energy use.
Scientists generally agree that the average temperature of the Earth, based on actual readings around the globe, has risen by a half-degree between 1890 and 1990. They know that carbon dioxide has been accumulating in the atmosphere over that time and that these gases trap heat, creating a "greenhouse" that prevents heat from radiating out into space, warming the Earth's surface instead. Other human-generated greenhouse gases, of
much smaller proportion but also increasing, include methane (landfills, livestock), nitrous oxide (combustion) and chlorofluorocarbons (refrigeration, aerosol propellants).
