A Warming World

The Economist has a very clear and compelling chart up today showing how the world is warming.  This chart is taken from NOAA's just released report on "The State of the Climate, 2009".  The report was released yesterday, and it says that global warming is "undeniable" and that the 1990's were the warmest on record.  The chart below shows that unambiguously.

[Source and Credit: The Economist]

World Day to Combat Desertification Celebrated

Today is the World Day to Combat Desertification. Though this may not get the attention of such days as Flag Day (Monday), Chinese Dragon Boat Festival Day (yesterday), or Father's Day (this coming Sunday), this is an important subject that deserves our attention.  The UN Convention to Combat Desertification (UNCCD) entered into force in 1996. It calls for international cooperation to combat desertification and mitigate the effects of drought.

The process of changing grasslands into desert can be incredibly destructive to the societies that live there, and there is clear evidence that in extreme situations, it can cause conflict. The best example of that is in Darfur. Jeff Mazo explains how this happened in an excellent chapter in his book "Climate Conflict". Darfur can be delineated as a conflict between agriculturalists and pastoralists. As rainfall decreased, and the Sahara expanded, these two groups came into conflict over land rights. This led to the beginning of a destructive war. As quoted by Mazo's book, UNEP said "There is a very strong link between land degradation, desertification and conflict in Darfur."

Warming in the Arctic to Cause Colder Winters

In an ironic twist, a new study shows that rapid warming in the Arctic will make the weather in Northern Europe and Eastern North America much colder.  This was the weather pattern that prevailed in December and January of the past winter. The map below, from NASA, shows that temperature were much higher (red) than normal in the high Arctic, while much lower (blue) in Eurasia and North America.

At the International Polar Year Science Conference, currently taking place in Oslo, Dr James Overland of NOAA presented a study that says that a warming of the arctic will have significant impact on winter weather in Europe, Asia, and North America.  In fact, Dr Overland said "The exceptional cold and snowy winter of 2009-2010 in Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic."

The loss of Arctic sea ice has long been seen as one of the areas that will have major feedbacks on a changing climate.  However, so far as I know, the focus of worries about those feedback has been that a (darker colored) ice-free ocean would absorb more heat than the (lighter colored) ice does currently.  This would cause the Arctic to warm, and would prevent the re-building of ice.  According to Dr Overland, this is occuring, and that will cause the current warming to be permanent.  However, this is the first study I've seen that supposes any effects on global weather patterns of a warming Arctic, and it is disturbing. 

Last year, Time magazine ran an article "Is There a Climate-Change Tipping Point?" which said that before we hit a tipping point that the earth would see what was called 'squealing'.  I'll quote directly from the article:

In climate terms, squealing may involve increased variability of the weather — sudden shifts from hot temperatures to colder ones and back again. General instability ensues and, at some point, the center ceases to hold. "Before we reached a climate tipping point we'd expect to see lots of record heat and record cold," says Carpenter. "Every example of sudden climate change we've seen in the historical record was preceded by this sort of squealing."

These tipping points - which we won't know about unitl after they've passed - are scary.  Rapid, sustained changes in the climate are impossible to predict, and as I've said before, uncertainty should worry us.

Of course, the fact that global climate change could cause record levels of snowfall and cold is a level of complexity that will struggle to make it through the ADD political-media crowd.  No points for guessing who will build the next igloo on the Capitol lawn.  If it weren't so important, it would be funny that a symptom of a rapidly changing climate is being used as evidence that the climate isn't changing.