NASA has released a report indicating that this past decade is the warmest on record and that 2009 is the second warmest year on record (though actually THE warmest in the Southern Hemisphere).
2009 was tied for the second warmest year in the modern record, a new NASA analysis of global surface temperature shows. The analysis, conducted by the Goddard Institute for Space Studies (GISS) in New York City, also shows that in the Southern Hemisphere, 2009 was the warmest year since modern records began in 1880.
[…]
January 2000 to December 2009 was the warmest decade on record. Throughout the last three decades, the GISS surface temperature record shows an upward trend of about 0.2°C (0.36°F) per decade. Since 1880, the year that modern scientific instrumentation became available to monitor temperatures precisely, a clear warming trend is present, though there was a leveling off between the 1940s and 1970s.
The near-record temperatures of 2009 occurred despite an unseasonably cool December in much of North America. High air pressures in the Arctic decreased the east-west flow of the jet stream, while also increasing its tendency to blow from north to south and draw cold air southward from the Arctic. This resulted in an unusual effect that caused frigid air from the Arctic to rush into North America and warmer mid-latitude air to shift toward the north.
“Of course, the contiguous 48 states cover only 1.5 percent of the world area, so the U.S. temperature does not affect the global temperature much,’ said Hansen.
In total, average global temperatures have increased by about 0.8°C (1.5°F) since 1880.
Particularly distrubing, too, is that global temperatures are increasing despite the fact that the Earth is currently in a solar minimum–which typically result in cooler temperatures.
A deep solar minimum has made sunspots a rarity in the last few years. Such lulls in solar activity, which can cause the total amount of energy given off by the Sun to decrease by about a tenth of a percent, typically spur surface temperature to dip slightly. Overall, solar minimums and maximums are thought to produce no more than 0.1°C (0.18°F) of cooling or warming.
“In 2009, it was clear that even the deepest solar minimum in the period of satellite data hasn’t stopped global warming from continuing,” said Hansen.
Currently, global average temperatures are higher than they were during the Medieval Warming Period, and at the current rate of temperature rise, within the lifetime of many people reading this post the Earth will be at its highest average temperature since Homo Sapiens evolved. We already have an atmosphere that has about 30% more carbon dioxide in it then when Homo Sapiens evolved, and if current trends continue, by the end of the century the atmosphere will have enough carbon dioxide in it to begin exhibiting toxic effects on humans.
We are in the beginning stages of a grand biological experiment — can human beings, as a species, survive in atmospheric conditions in which they did not evolve? Perhaps we can.
Personally, though, I’d prefer to not conduct the experiment.
Image courtesy of NASA
