The science of forecasting solar cycles is nascent, burgeoning, and inexact. For example, predictions of the transition from cycle 23 to 24 ranged from the autumn of 2006 to March 2008; the event occurred in January 2008. (It was, as always, marked by the occurrence of a sunspot that has opposite magnetic polarity from any sunspots of the previous cycle.)
Predictions of a cycle's intensity are based on numerous formulas and methodologies. Expectations of cycle 24's intensity vary from big and intense to quiet. After lengthy study, NOAA's official prediction panel is split, while other forecasters see a decline in eruptive activity, citing a 25 percent decline in cycle 23's activity, the late start of cycle 24, and comparative studies of the 88-year (and longer) cycles.
Doug Hathaway, a solar physicist at NASA, believes that solar activity has diminished and will continue to do so for decades. In 2006, he predicted, based on observations of the slowing of the plasma flow on the Sun, that cycle 25 could be the quietest—thus, the coolest—in centuries. Also in that year, Khabibullo Abdusamatov, head of research for the Russian Academy of Sciences, issued an imminent mini-ice age warning based on expectations of a quieter Sun over the next 50 years. Our long-range forecasts also point toward cooling conditions.
These factors—the cooling Pacific, the yet-to-cool Atlantic, and the historical reduction in recent solar activity—suggest that a staggered cooling period could continue. Absent from most headlines about global warming is a discussion of measures suggesting that the warming has ceased and a cooling may have begun. For example, deep-ocean heat content has not increased during the past five years. Looking at just one year, from January 2007 to January 2008, we find that satellite-derived atmospheric temperatures indicate that Earth was about one degree Fahrenheit cooler at the beginning of 2008 than it was at the beginning of 2007. The United Kingdom's Hadley Centre ocean and land temperature records show cooling in the last seven to ten years.
During the past 100 years, while temperatures have risen and fallen and risen yet again, carbon dioxide has been on a steady climb (see graph)—and, for that, mankind does bear some responsibility. However, we would be wise to also consider the cycles and synchronicity of the Sun and oceans in any discussion of the causes of climate change.
Have you noticed changes in vegetation, animals—and even utility bills—that indicate climate change in your area? What do you think causes climate change? What are you doing about it? Share your thoughts in the comment box below.