[andre]

http://www.vancouver...9391/story.html

Quote

When a drought hit North America in the 1930s, creating a giant dust bowl and crippling agriculture from Saskatchewan to Oklahoma, it entered history as the Dirty Thirties. But University of Regina paleoclimatologist Jeannine-Marie St. Jacques says that decade-long drought is nowhere near as bad as it can get. St. Jacques and her colleagues have been studying tree ring data to uncover the reality of prairie droughts...cont'd

That's a message to think about. But this is also a message to think about:

Quote

"They could get worse under global warming, for all we know. And that's just it - we don't know."

If we don't know, why not equally validly state: "it could get less under global warming" After all, with higher temperatures, more convection should bring more water vapor in the atmosphere, generating precipitation. But apparantly there is still a dogmatic message to convey.

[ldavidcooke]

Hey Andre,

The reason the inverse can not be considered is that as both the GAT and CO2 have gone up so has the increase in polar sea ice melt along with cross-zonal covective heat flows. Meaning that a number of things appear to be changing which will directly relate to synoptics. It appears that with the change in both aquifer and precipitation resources, due to synoptics changes, the tendency for drought has been increasing in the US steadily since the 1970's. Frst California and the Folsom Lake region, through to the SE and Mid-West in the late 80's through 90's and now the US west from the State of Washington to the Sandi Mtns.

Hence, the actual patteren observation disallows a potential inverse condition. Thus supporting the hypothesis and intermediate conclusion that many have drawn. At isssue is the inability to describe how a change in one factor can result in a change in wide scale weather patterns. (Kind of like it takes a change in a large scale weather pattern to result in a change to a different weather pattern.) Though if either camp can demo how one effects the other and results in the observed pattern without parametric manipulation I am sure it will begin to get traction.