The Stratosphere - Water Vapor - Global Warming/Cooling: Is There a Connection?

You may have seen a reference to a recent National Oceanographic and Atmospheric Administration (NOAA) study about water vapor in the atmosphere and its impact on rising global temperatures.

The article: Stratospheric Water Vapor is a Global Warming Wild Card (01/2010) was published in the journal Science (01/2010). Susan Solomon was the NOAA senior scientist and first author of this study.

In a recent post, I offered information clarifying the fundamental differences between Climate and Weather. It seems that there is yet another influence that contributes to weather variability.

According to Solomon, “Current climate models do a remarkable job on water vapor near the surface. But this is different — it’s a thin wedge of the upper atmosphere that packs a wallop from one decade to the next in a way we didn’t expect.’

‘The stratosphere is a region of the atmosphere from about eight to 30 miles above the Earth’s surface. Water vapor enters the stratosphere mainly as air rises in the tropics. [This] new study is the first to relate water vapor in the stratosphere to the specific variations in warming of the past few decades.’”

There are some good details in the NOAA site link. I also refer you to the following link to the New York Times Dot Earth blog by Andrew Revkin. In his 01/29/2010 post, he offers the following: “short-term variability even on the scale of a decade (in either the hot or not hot direction) is a distraction if one is looking for evidence of human-driven warming or trying to build an argument for or against curbing emissions of greenhouse gases.'

'the science illuminating the extent of the human influence on climate is not “settled” for many specific, and important, points, even though the basic case for rising risks from rising concentrations of greenhouse gases is robust enough to merit a strong response.'”

The article: Less Water Vapor May Slow Warming Trends (01/28/2010) appears in New York Times/Environment section by Sindya Banyoo.

A study done by NASA GISS (Goddard Institute for Space Studies): Reaction of Ozone and Climate to Increasing Stratospheric Water Vapor by Drew Shindell was published way back in the dark ages of May 2001. It offers some clues to the importance and impact of Stratospheric Water Vapor. "The model indicates that increased water vapor accounts for about 40% of the ozone loss in the upper stratosphere, and about 20% of the overall loss to date. There are two driving forces behind the change in stratospheric moisture. Increasing emissions of methane are transformed into water in the stratosphere by chemical reactions. This can account for about a third of the observed increase in moisture there.'

'In addition, there is a greater transport of water from the lower atmosphere, which happens for several reasons. First of all, more water may be available in the lower atmosphere to be carried up. Warmer air holds more water vapor than colder air, so global warming will make the lower atmosphere wetter. Another possibility is that air is carried up more rapidly into the stratosphere.'

'Climate models indicate that greenhouse gases such as carbon dioxide and methane may enhance the transport of air from the lower atmosphere up into the stratosphere. Additionally, the coldest temperature through which the air passes could change, which would alter the amount of water that freezes out along the way. Though not fully understood, the increased transport of water vapor to the stratosphere seems to have been caused at least partially by human activities."

Now you know a little bit more about that Thin Blue Line that surrounds our planet.