An interesting press release from the National Science Foundation states that when rain and snowfall have been factored out, the rise in global
temperatures has contributed significantly to the drop in soil moisture world wide. The study found that the amount of land suffering from very dry
conditions has at least doubled in the last 30 years.
ARLINGTON, Va.—Arlington, Va. --The percentage of Earth's land area stricken by serious drought more than doubled from the 1970s to the early
2000s, according to a new analysis by scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo. Widespread drying occurred
over much of Europe and Asia, Canada, western and southern Africa, and eastern Australia. Rising global temperatures appear to be a major factor, says
NCAR scientist Aiguo Dai.
The study was supported by the National Science Foundation (NSF), NCAR's primary sponsor. "The results reconfirm the complexity of the climate
system," says Cliff Jacobs, program director in NSF's division of atmospheric sciences. "We need to continue to develop a wide variety of research
tools to understand these changes."
Dai and colleagues found that the fraction of global land experiencing very dry conditions rose from about 10-15 percent in the early 1970s to about
30 percent by 2002. Almost half of that change is due to rising temperatures rather than decreases in rainfall or snowfall, according to Dai.
Even as drought has expanded across Earth's land areas, the amount of water vapor in the air has increased over the past few decades. Average global
precipitation has also risen slightly. However, as Dai notes, "surface air temperatures over global land areas have increased sharply since the
1970s." The large warming increases the tendency for moisture to evaporate from land areas. Together, the overall area experiencing either very dry or
very wet conditions could occupy a greater fraction of Earth's land areas in a warmer world, Dai says.
Please visit the link provided for the complete story.
Not being a scientist, I don't know how trustworthy the methods that were used are. However, if this is 'good science' this could actually be a very
good indicator that global warming is fact. The study attempted to isolate the affects of temperature increase only.
I feel the jury is still out on how much of global warming is attributable to human causes, and how much is natural climate change. Still, it would be
silly to think that humans have NO affect on the Earth and it's climate system. If anyone needed more motivation to do everything they could to reduce
greenhouse gas production, they should read this study report and think about what their backyard will look like in another 30 years if this trend
The map that is included in the page will be handy for those of us who may be considering a change of location in the near future.
For those who are not familiar with the NSF, this quote is from their site...
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of
science and engineering, with an annual budget of nearly $5.47 billion.