Sunspots may be related to Global Cooling (which is dangerous) and Global Warming, which is not.
At least, sunspots always were in the past.
Sunspot cycles may hold key to global warming, cooling
The 2008 winter was the coldest in 40 years for the upper Midwest, Plains states and most of Canada. Minnesota newspapers report that this year’s opening of the locks to Mississippi barge traffic, delayed by three weeks, was the latest since the modern waterway opened in 1940.
Eau Claire, where “old-fashioned winters” have been a thing of the past, recorded 43 days of below-zero temperatures, while folks down in Madison shoveled away at a 117-year record snowfall throughout the season, as did many in New England and Canada.
Rare snowfalls struck Buenos Aires, Capetown, and Sidney during their mid-year winter, while China continually battled blizzards. Even Baghdad experienced measurable snowfall.
Antarctic pack-ice far exceeded what Captain Cook saw on his 18th century voyage into the Southern Ocean. On the continent itself the miles-thick ice continues to accumulate despite peripheral melting along the Antarctic Peninsula and occasional calving of an ice block. At the opposite pole, flow-ice once again spans the entire Arctic Ocean, and by April it had extended into the Bering Strait, making up for the much heralded melt-back last summer.
From January 2007 through the end of January 2008, the average global temperature fell by nearly a degree Fahrenheit, based on data obtained by the MET Office in Great Britain and other international temperature monitoring networks.
What are we to make of this? The recent climate conference held in New York City, sponsored by the Heartland Institute, provides some answers. Several hundreds climatologists in attendance dispelled notions that the global warming debate is over. Most attendees, who readily acknowledge the existence of post-Little Ice Age warming, believe man-made emissions are unlikely to cause major climate change and signed a declaration to that effect.
Bill Gray, dean of hurricane forecasters, attributed short-term climate change to slow-moving deep ocean currents that result from variation in the salinity of water sinking near the poles and ultimately welling up again along the coast of South America. These fluctuations account for the comings and goings of the familiar El Nino/La Nina cycles and the longer Pacific Decadal Oscillation that stretches over a large area of the eastern Pacific.
Solar experts highlighted how sunspots, and associated magnetic storms on the Sun’s surface, affect Earth’s weather and climate. The previous (very strong) 11-year sunspot cycle, associated with the recent warmth, ended in 2007, after having peaked in 2002. The new cycle should have already begun, but hasn’t yet.
In the absence of sunspots, solar flares are minimal. Flares eject massive streams of electrons and protons outward from the Sun. A portion of this stream, called the “solar wind”, bathes our planet producing the aurora and interfering with communications. The solar wind, as it interacts with Earth’s magnetic field, also protects us from the harmful effects of cosmic radiation.
During periods of weak solar activity – as at present – cosmic rays (high-energy protons originating in interstellar space) penetrate through the troposphere and ionize oxygen and nitrogen molecules. The ions become nucleating sites for water vapor that condenses into clouds. And when sunspots are at a minimum, more clouds form and correspondingly more sunlight is reflected back into space. The enhanced reflectance (albedo) cools the Earth. We all have experienced how quickly the temperature drops when the sun ducks behind a puffy white cloud on a warm, dry afternoon.
Past cool periods, identified with the late stages of the “Little Ice Age” and with the Maunder and Dalton climate minima, closely correlate with low sunspot numbers (astronomers have kept close tabs on sunspots since Galileo’s time). Some solar-physicists are now saying if the current cycle doesn’t begin to produce spots soon, we can expect a cool-down like the 19th-Century Dalton minimum – or worse. Decades-long cooling in the past brought crop failures to Europe from repeated summer frosts and restricted growing seasons.
With grain shortages already staring us in the face, we’d be advised to begin thinking about a global cool-down instead of a warming that may or may not continue. We might consider ways to transform semi-desert into arable land and to develop seed with shorter maturing cycles suitable for a sub-boreal grain belt. If cooling should begin in earnest, we will quickly forget global warming as we face the new challenges ahead.
Balgord, a consultant and writer, heads Environmental and Resources Technology in Middleton.