Figure caption: June 8 2011 (evening EDT) middle tropospheric 500 hPa height anomalies [which are proportional to lower tropospheric temperature anomalies] with higher heights being warmer and lower heights cooler than the long term average. The source of this figure is from http://www.rap.ucar.edu/weather/model/gfs000hr_500_del.gif.
The anomalies of the tropospheric 500 hPa heights associated with the heat wave in the eastern USA show that this is clearly NOT an unusual event in terms of tropospheric temperatures. This NOAA analysis places the current heat wave in its proper perspective. It is a regional event, NOT a global event, and not even extreme with respect to the troposphere [the effect of urbanization on the surface temperatures, likely explains the record temperatures].
There has, however, been considerable hype and erroneous statements regarding the current USA east coast heat wave. For example, the Daily Mail has a story by Mark Duell headlined
that has the text
“America’s extraordinary weather continued this week as much of the country sweltered in a record-breaking heatwave, while temperatures were expected suddenly to drop in places and a hurricane threatened to strike from the Pacific Ocean.”
The statement that “much of the country sweltered in a record-breaking heatwave” is a clear example of the misinformation presented in such “news” reports. Much if the USA is actually cooler or near the long term average temperatures for this time of year.
ABC News, in their report by Bill McGuire on June 8 2011
“……a new study published in the journal Climate Change today by Stanford scientists finds that large areas of the globe will warm up so quickly that even the coolest summers will be hotter than the hottest summers of the past 50 years. “
The ABC News article includes the text
“A study in this month’s issue of the journal Climatic Change predicts that much of the Northern Hemisphere is likely to experience an irreversible rise in summer temperatures within the next 20 to 60 years. The culprit, Stanford University scientists claim, is rising atmospheric greenhouse gas concentrations.”
“No need to wait long, the researchers said, because the heat is already here.”
“We find that the most immediate increase in extreme seasonal heat occurs in the tropics, with up to 70 percent of seasons in the early 21st century (2010-2039) exceeding the late-20th century maximum,” the authors wrote.”
The figure below from Roy Spencer’s weblog illustrates that the global average temperature anomaly is actually close to the long-term average. To relate the current heat wave in the eastern USA (or the fires in the southwest) to global warming is scientifically flawed.
The use of the eastern USA heat wave to claim evidence of an effect of global warming (when the lower troposphere is near its long-term average) is a clear example of the erroneous and misleading communication of climate science by the Stanford study. That study and the news reports are presenting misleading and erroneous information to policymakers and the public. The record heat wave surface temperatures, rather than being due to added greenhouse gases, may be due to the effect of the urban heat island in the eastern USA.