Erratic Weather could be Linked to Global Warming

Scientists think recent odd temperatures trends may be related to global climate change.

Last week, we had another March heat wave sweep through the Northern states. But this week, a cold snap has brought on the lowest temperatures of the season. This trend of “weather-weirding,” in which temperatures lurch back and forth, is becoming more and more common in the Northern Hemisphere. It has led climate scientists to consider a possible link to global warming.

Scientists Still Have No Idea

Scientists are still developing the theories that would tie this erratic weather into global warming. They are focusing most of their attention on the drastic decline of sea ice in the Arctic, which is believed to be a direct consequence of the human release of greenhouse gases.

A link between global warming and three odd behaviors is suspected:

• ·         An increase in heat waves,
• ·         A rise in episodes of heavy rainfall and other precipitation
• ·         More frequent coastal flooding

The link between heat waves and global warming may be clear. However, the evidence is thinner regarding some types of weather extremes. Poor statistics have plagued tornado research. And researchers studying specific events, like the Russian heat wave of 2010, have often come to conflicting conclusions about whether to blame climate change.

Possible Human Link

Yet mainstream scientists are determined to figure out which climate extremes are being influenced by human activity, and their attention is increasingly drawn to the Arctic sea ice.

Dr. Jennifer Francis, of Rutgers, has presented evidence that this is affecting the jet stream, the huge river of air that circles the Northern Hemisphere in a loopy, meandering fashion. “This means that whatever weather you have today…is more likely to last longer than it used to,” said Dr. Francis.

Not all of her colleagues buy that explanation.

Martin P. Hoerling, contends that some researchers shouldn’t attribute specific weather events to human causes. Dr. Hoerling ran computer analyses that failed to confirm a widespread effect outside the Arctic from declining sea ice. “What’s happening in the Arctic is mostly staying in the Arctic,” he said. However, he also conceded that, “It’s been a stunning March.”