Update: January 27 2011 – Mike Smith also has an excellent discussion of media misinformation regarding recent extreme weather in his post on his weblog Meterological Musings
There is a news article by CBS titled (h/t to Marc Morano)
In the past year, every continent except Antarctica has seen record-breaking floods. Rains submerged one-fifth of Pakistan, a thousand-year deluge swamped Nashville and storms just north of Rio caused the deadliest landslides Brazil has ever seen.
Southern France and northern Australia had floods, too. Sri Lanka, South Africa, the list goes on.
And while no single weather event can be linked definitively to global climate change, a growing number of scientists say these extreme events represent the face of a warming world.
“Any one of these events is remarkable,” said Jay Gulledge, senior scientist for the Pew Center on Global Climate Change. “But all of this taken together could not happen without the extra heat that’s in the ocean. It defies common sense to overlook that link.”
That link works more or less like this. Concentrations of greenhouse gases are the highest the earth has seen in 15 million years. These gases trap heat, warming both the air and the oceans. Warmer oceans give off more moisture, and a warmer atmosphere can hold more of it in suspension. The more moisture in the air, the more powerful storms tend to grow. When these supercharged weather systems hit land, they don’t just turn into rain or snow, they become cyclones, blizzards and floods.
“There is a lot of tropical moisture in the atmosphere that is getting transported over very long distances and is dropping out in various places around the world in dramatic fashion,” Gulledge said.
“Weather like this matches the predictions of numerous recent climate studies. In 2007, the Intergovernmental Panel on Climate Change noted that severe droughts and heavy rains were already on the rise in many parts of the world, and linked them to the surge in greenhouse gases. A study published last year by the National Academy of Sciences predicted an increase in heavy rainfall of somewhere between 3 and 10 percent for every Celsius degree of warming. Each additional degree would also cause the amount of area burned by wildfires in North America to double or quadruple, according to the same report.”
What does the actual data say.
The current sea surface temperature anomaly (which is the interface where ocean heat interfaces with the atmosphere) is presented below [from http://www.osdpd.noaa.gov/data/sst/anomaly/2011/anomnight.1.24.2011.gif].
The most recent global average lower tropospheric temperature anomaly is given below [from http://www.remss.com/msu/msu_data_description.html]
The water vapor anomalies, unfortunately, are not routinely, updated and made available to us. Nevertheless, papers such as
Randel, B. et al, 2004: Interannual Changes of Stratospheric Water Vapor and Correlations with Tropical Tropopause Temperatures. Journal of Atmospheric Sciences. 2133-2148
where the abstract reads [highlight added]
“Interannual variations of stratospheric water vapor over 1992–2003 are studied using Halogen Occultation Experiment (HALOE) satellite measurements. Interannual anomalies in water vapor with an approximate 2-yr periodicity are evident near the tropical tropopause, and these propagate vertically and latitudinally with the mean stratospheric transport circulation (in a manner analogous to the seasonal ‘‘tape recorder’’). Unusually low water vapor anomalies are observed in the lower stratosphere for 2001–03. These interannual anomalies are also observed in Arctic lower-stratospheric water vapor measurements by the Polar Ozone and Aerosol Measurement (POAM) satellite instrument during 1998–2003. Comparisons of the HALOE data with balloon measurements of lower-stratospheric water vapor at Boulder, Colorado (408N), show partial agreement for seasonal and interannual changes during 1992–2002, but decadal increases observed in the balloon measurements for this period are not observed in HALOE data. Interannual changes in HALOE water vapor are well correlated with anomalies in tropical tropopause temperatures. The approximate 2-yr periodicity is attributable to tropopause temperature changes associated with the quasi-biennial oscillation and El Niño–Southern Oscillation.”
Susan Solomon, Karen Rosenlof, Robert Portmann, John Daniel, Sean Davis, Todd Sanford, Gian-Kasper Plattner, 2010: Contributions of Stratospheric Water Vapor to Decadal Changes in the Rate of
Global Warming. http://www.sciencexpress.org / 28 January 2010 / Page 1 / 10.1126/science.1182488 (see)
where the abstract reads [highlighting added]
“Stratospheric water vapor concentrations decreased by about 10% after the year 2000. Here we show that this acted to slow the rate of increase in global surface temperature over 2000-2009 by about 25% compared to that which would have occurred due only to carbon dioxide and other greenhouse gases. More limited data suggest that stratospheric water vapor probably increased between 1980 and 2000, which would have enhanced the decadal rate of surface warming during the 1990s by about 30% compared to estimates neglecting this change. These findings show that stratospheric water vapor represents an important driver of decadal global surface climate change.”
The NASA water vapor dataset would help further diagnose the global atmospheric water vapor issue, but, as discussed in
while a preliminary study showed a (1988-1999) decrease in global atmospheric water vapor (see), an updated accurate NVAP data analysis will only be available in 2012 or 2013!
The available data shows that sea surface temperature anomalies show large spatial variations, including large areas of cooler than average conditions, the lower tropospheric temperature anomaly is only slightly warmer than the long-term average (and shows no statistically significant trend since 1998), and the global water vapor anomalies, to the extent we can determine from recent data, shows that it has not increased significantly in recent years. The tropical sea surface temperatures also show large areas of cooler than average conditions.
The conclusions in the CBS news article and the statements by those interviewed failed to examine the actual current values of key climate metrics.
My Recommendations are:
1. Make the latest global average sea surface temperature anomalies available along with the spatial map.
2. Make the latest global average sea surface temperature anomalies available along with the spatial map.
3. Make the latest global tropospheric and lower stratospheric water vapor anomalies available along with the spatial map.
With this information, claims such as made by CBS, and those who were interviewed, could be quickly confirmed or refuted.