While the climate focus is often on gases like carbon dioxide, good old fashioned, dirty soot can also be behind extreme weather according to new research published in Atmospheric Chemistry and Physics.
Researchers at the Department of Energy's Pacific Northwest National Laboratory, the Universityof Michiganand NOAA looked at the effect of soot on the Tibetan Plateau in the Himalayasand found that soot is a worse offender in climate change than CO2.
'On the global scale, greenhouse gases like carbon dioxide cause the most concern related to climate change,'' said Yun Qian, the paper's lead author and an atmospheric scientist at PNNL. ''But our research shows that in some places like the Tibetan Plateau, soot can do more damage.''
Known as the Roof of the Earth, the Tibetan Plateau rises to altitudes of up to five miles and as well as a mystical magnet for travelers of all sorts it has a major effect on the weather of much of Asia. Here you'll find more ice than anywhere on earth apart from the two poles. As glaciers and snow melt they feed rivers like the Yangtze in Chinaand the Gangesin India.
As Chinaand India's economies become global challengers, the previously unspoiled plateau has been introduced to the dubious delights of development in the form of soot from industrial plants and burning fields.
The black soot soaks up heat and when the snow gets dirty it melts more quickly and, at such high altitudes, the effect is magnified.
Qian's team used a global climate computer model to play out a number of possible scenarios involving increased soot and carbon dioxide-related global warming.
Air over the Tibetan Plateau is the main driver of the characteristic monsoons of Asiaand this research suggests that soot will make monsoons earlier and stronger.
However, the team has acknowledged that the systems they are using are something of a blunt instrument and further research is needed to come up with more definitive answers about the weather effects of the Tibetan Plateau.
''The Tibetan Pla'' Qian said. ''Our research indicates that soot on snow can be a large player in the region's climate, but it's not the only factor. Many other elements need to be studies before we can say for sure what is the leading cause of snowmelt – which also contributes to retreating glaciers – on the plateau.''
Photo courtesy of Jan Reurink/PNNL