The article describes how recent studies have shown that increased levels of CO2 make plants absorb less water so that they are predicting more flooding as global temperatures rise. It's interesting to note that they don't discuss what effect this is going to have in terms of water vapor. Most people don't realize that water vapor accounts for the vast majority of all greenhouse effect, but this is largely ignored in pop science. The cycle of water vapor in the atmosphere is such that the average atmospheric life is less than a year while that of CO2 is in the hundreds of years, meaning that it is much more difficult to reduce the global level of CO2 once it is there than it would be to reduce the Water Vapor levels. Because of this, Water Vapor is seen as largely influenced by the other global warming factors rather than as a driver in itself. However, this report is essentially saying that less water will be removed from the ground and evaporated into the air as a result of an increase in CO2. But there are only a couple options: 1) this amount is so insignificant that it won't cause any flooding or major change in the balance of water on and around earth 2) It will change the way that water is evaporated with less coming from vegetation and more coming from surface water with a net effect of no flooding and no atmospheric water vapor changes 3) Less water will be evaporated in total as a result of vegetation-based evaporation (as the article suggests). However, if the last part is true then the effect is that earth will serve as a sink of water, reducing the amount of water vapor in the atmosphere and greatly reducing the greenhouse effect, cooling the earth. So my conclusion to this fear-mongering is that either flooding will increase (as they report) but the earth will cool as a result or nothing will drastically change...
Granted, I'm not a climatologist but neither is the reporter who is selectively quoting the scientists...
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