Hey, global warming skeptics, take your heads out of the sand

Column: New report reinforces import of climate change.

UN Secretary General Ban Ki-moon has seen the meltdown of the Arctic for himself. Alarmed at the changes, he warned that "our foot is stuck on the [climate change] accelerator and we are heading towards an abyss."

It might be easy to dismiss this as more alarmist hype except for the coincidental publication of a major Arctic climate study. This latest research makes it crystal clear that the forces of human-driven climate change have overwhelmed the natural forces that had put Arctic climate on a long-term cooling trend.

Mr. Ban, who recently visited the Arctic, was addressing a 150-nation climate conference in Geneva on Sept. 3. The research, published the next day in Science, backs up his concern point by point. Led by Northern Arizona University (NAU) and the National Center for Atmospheric Research (NCAR) in Boulder, Colo., this five-year international study reconstructed 2,000 years of Arctic summer temperatures. Until now, the record extended back only 400 years. The research team combined data from lake sediments with previous data from ice cores and tree rings to build the longer record.

Ban noted that "the Arctic is warming faster than anywhere else on Earth." The study shows the Arctic is warming two to three times faster than anywhere else at a time when it should be cooling down. Natural changes in Earth's orbit vary our distance from the Sun over a 21,000 year cycle. The closer we are, the warmer the Arctic and vice versa. Right now, we're in the cool down part of that cycle. The study confirms a cooling trend over the past 2,000 years until it reversed about a century ago. The Arctic summer now is about 2.5 degrees warmer than it should be.

In an announcement of this result, team member Nicholas McKay explained that, "The 20th century is the first century for which how much energy we're getting from the Sun is no longer the most important thing governing the temperature of the Arctic." His co-author, Caspar Ammann at NCAR, said, "This study provides a clear example of how increased greenhouse gases are now changing our climate."

Climate theory predicts that the Arctic should warm faster than elsewhere. Loss of reflective ice and snow cover lets the region absorb more solar heat. Mr. Ban emphasized this point in Geneva. The new study confirms this so-called "Arctic amplification" of global warming.

Ban also noted that methane, a greenhouse gas 20 times more heat-trapping than CO2, is escaping from reservoirs in melting permafrost and from the sea bed. In a study of such emissions published Aug. 29 in the Journal of Geophysical Research, a research team by the Massachusetts Institute of Technology, underscored this. It concluded "that we may be greatly underestimating the methane fluxes presently occurring in the ocean and from underground into Earth's atmosphere." If so, this could drive global warming even faster than anticipated.

The Secretary General warned that, if you add this prospect to the Arctic warming signal, it looks like "we are certainly going to face a dire crisis, if not a catastrophe, across the world." He worries about sea level rise, unprecidented regional droughts, and the like. While this may sound alarmist, it's sobering to realize that ongoing climate research increasingly backs up such concern.