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It might be a little premature to declare a primary tenet of global warming theory "invalidated" ...

Analysis of rainfall and surface moisture trends have led to a number of studies investigating whether the Earth has been undergoing drying, or whether drying is reversing.

Fellow DailyTech blogger Michael Asher recently reported on one study that analyzed historical rainfall data between 1900 to 2000, and using wavelet analysis concluded that droughts were decreasing, and that major drought events were decreasing as well.

Another study, released just days before by NASA's Goddard Institute for Space Studies (GISS), analyzed the data on rainfall and concluded that worldwide the Earth is undergoing significant drying effects.  In particular, much of the Mediterranean area, North Africa and the Middle East are rapidly becoming drier. 

The study goes on to use this data to predict current weather patterns.

This study continues a long chain of research which supports a unanimous conclusion that the Earth is experiencing significant drying.

In 2006, the British government funded a climate study carried out by the Met Office Hadley Centre for Climate Prediction and Research. 

Its conclusion: global drought increased 25 percent in the 1990s.

It also modeled possible future weather scenarios and found that indicated that extreme drought could affect 30 percent of the world's land surface, up from the current span of 3 percent.  Severe drought (the next worse) would rise from 8% land area to 40%, and mild drought would rise from 25% to 50%.

In 2005, the National Center for Atmospheric Research (NCAR), a U.S. government funded research center, released a study that the percentage of Earth's land area stricken by serious drought more than doubled from the 1970s to the early 2000s.

It also found that drought had increased and surface moisture had decreased, on average, worldwide.

Along the lines of the study mentioned in the other Dailytech article, it found that water vapor in the air and global precipitation have increased over the past few decades--however, warming caused the moisture to evaporate at a faster rate, and land moisture levels have been dropping, leading to droughts.

To examine how soil moisture has evolved over the last few decades, the NCAR researchers produced a unique global-scale analysis using the Palmer index, which for decades has been the most widely used yardstick of U.S. drought. The Palmer index is a measure of near-surface moisture conditions and is correlated with soil moisture content.

Interestingly, the study indicated that the U.S. has become wetter over the past 50 years, while most of the rest of the Northern Hemisphere has dried.

While rainfall has increased worldwide, the study found that it has decreased in Africa's Sahel and East Asia, leading to further expansion of dry soils.

The conclusions of these studies: the U.S. may be getting wetter, and rainfall may not be decreasing, but land moisture is definitely decreasing, due to increasing temperatures.  Decreased land moisture will lead to more droughts, and more extreme droughts, as the soil experiences further decrease in moisture.

While this is only one element of global warming and climate change theory, it certainly seems premature to declare it "invalidated," as some critics are inclined to proclaim.

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Related to Global Warming? Or other factors?
By geddarkstorm on 9/12/2007 5:04:11 PM , Rating: 3
I do have to disagree with the general interpretation of the studies, Jason. Mostly, in that soil moisture is affected by far more than precipitation: cloud cover, vegetative cover and composition, and soil composition are the three main forces I can think of. These factors are too important (all together more so than just temperature, as 'cold and sunny' gravel with no plant cover will retain no soil moisture as well) and no study that overlooks them can be taken very seriously. All of these interplay.

If precipitation is staying the same, other factors must be investigated instead of just saying there's a growing chance for drought and it's connected to growing temperatures. If the whole Mediterranean area is being over grazed, farmed, or clear cut, then there sure is going to be a growing possibility of drought. Only if all these factors are held constant can the effects of temperature on drought be reliably looked at.

RE: Related to Global Warming? Or other factors?
By andrinoaa on 9/13/2007 6:22:28 AM , Rating: 2
Here in Melbourne, Australia ( not Austria ! ) we haven't had good rains in over 15yrs. The ice caps are melting, pacific islands are disappearing and Venice is sinking, just in case no one has noticed. If it rains more in the ocean but less on land,do we have a drought?
If the people who study these things say its us, I'm inclined to beleive them. After all, what part of science do you beleive and what part don't you beleive? If it is us and we do nothing, what kind of F&*&^%g animals are we? If its not us, what harm can we do? DOH. I for one am not inclined to put up my arms and say its too overwhelming.
We have the luxury to be smug in the "civilized west", but what will we do if humanitarian disasters occur globaly? This could affect half the global human population !! Are you going to stop 50 - 300 million refugees?
Think of the problem as an insurance risk. At what rate will your insurance company abandon your policy, 2%, 5% ?
Scientists are telling us the risk is greater than 10%
If this isn't food for thought, you ain't thinking but the bean counters are!
We don't have the luxury of waiting 50 yrs to see if its man made or natural cycles. Its do now while there is hope or do nothing because there is no hope. Which band are you in? We pray to god in hope for miracles ( the impossible we can do, miracles take a little longer lol lol ) but surely when hope is based on advantageous probability we fail to grasp it ?!?!?!
Where is my logic wrong?

RE: Related to Global Warming? Or other factors?
By masher2 on 9/13/2007 9:10:18 AM , Rating: 2
> "Venice is sinking".

Indeed it is. It's built on unstable marshy ground, and has been sinking for the past 1000 years. It's dropped 24 cm just in the past century. And it has nothing to do with global warming.

> "Here in Melbourne, Australia...we haven't had good rains in over 15yrs"

The drought Eastern Australia is now experiencing is not nearly as severe as the one which began there in the late 1930s. Australia is prone to droughts; this is a natural state of affairs.

> "what will we do if humanitarian disasters occur globaly? "

The planet warmed more in during the Medieval Climate Optimum than its expected to do over the next 100 years. No "disasters" were experienced by humanity; in fact, the climate was one of the most stable, salubrious periods in man's history.

> "Think of the problem as an insurance risk"

In this case, the cost of that insurance policy is far more expensive than any possible payoff, as many economists have pointed out. Kyoto, for instance, is estimated to cost the world up to one trillion dollars alone-- for a net reduction in world temperatures of 0.07 degrees over the next 50 years. That's IF the alarmists are correct and the warming isn't natural...if they're wrong, its zero reduction.

The difference between a world that warms 2 degrees and a world that warms 2.07 degrees is too small to measure. Far better to spend that trillion dollars actually helping people.

RE: Related to Global Warming? Or other factors?
By TomZ on 9/13/2007 9:40:00 AM , Rating: 2
The difference between a world that warms 2 degrees and a world that warms 2.07 degrees is too small to measure. Far better to spend that trillion dollars actually helping people.

And that's really the point of AGW skeptics - we should be devoting our attention, time, and money to something that is worthwhile instead. A lot of people in the world are suffering due to poverty, malnutrition, disease, etc - TODAY AS IN RIGHT NOW - and so I think it is pretty irresponsible that people accept this as the status quo and instead focus money on some possible future hypothetical problem. Imagine what kind of impact the "Kyoto trillion" could have in helping people in need in Africa for example.

RE: Related to Global Warming? Or other factors?
By sxr7171 on 9/13/2007 12:06:08 PM , Rating: 2
It's because we in the west have it too good. We sit here in our big-ass SUVs driving alone to the mall and worry about "Global Warming." We have too much free time on our hands and we'd rather spend billions of dollars on curbing some stupid crisis we imagined because we have nothing better to do than imagine up all sorts of disaster scenarios. How about spending that money on poverty right here in the US? How about that for a fucking "cause." We are so pompous as to think that what we can cause any more than a tiny dent in something so vast and dwarfing as GLOBAL climate patterns. How about spending money on something we actually have half a chance at actually affecting? The worst part of this is that we sit in our SUVs and expect developing nations to impede their progress so that we can feel better about doing "something" for the environment. This is all feel good bullshit by hypocrites.

By TomZ on 9/13/2007 12:25:28 PM , Rating: 2

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