July 05, 2006
Global cooling in the 21st century
Hans H.J. Labohm provides a cautious warning about our climate.
Earlier I wrote about the re-emergence of the global cooling hypothesis:
"Recently the astronomer Khabibullo Abdusamatov of the Pulkovo Astronomic Observatory in St. Petersburg declared that the Earth will experience a 'mini Ice Age' in the middle of this century, caused by low solar activity. Temperatures will begin falling six or seven years from now, when global warming caused by increased solar activity in the 20th century reaches its peak. The coldest period will occur 15 to 20 years after a major solar output decline between 2035 and 2045, Abdusamatov said. This view is shared by the Belgian astronomer, Dirk Callebaut, who expects a 'grand minimum' in the middle of this century, just like the Maunder Minimum (1650-1700), a period during which the Thames, the Seine and the Dutch canals were frozen in winter."
In the meantime a new study has appeared that seems to support this view. According to research by NASA's solar physicist David Hathaway, the Sun's Great Conveyor Belt has slowed to a record low crawl. This has important repercussions for future solar activity.
A related article talks about a recent slight cool-down, but puts that into context with the overall warming trend being observed:
The official thermometers at the U.S. National Climate Data Center show a slight global cooling trend over the last seven years, from 1998 to 2005.
Actually, global warming is likely to continue—but the interruption of the recent strong warming trend sharply undercuts the argument that our global warming is an urgent, man-made emergency. The seven-year decline makes our warming look much more like the moderate, erratic warming to be expected when the planet naturally shifts from a Little Ice Age (1300–1850 AD) to a centuries-long warm phase like the Medieval Warming (950–1300 AD) or the Roman Warming (200 BC– 600 AD).
Food for thought.