This is an archived article that was published on sltrib.com in 2011, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

According to a new Bureau of Reclamation study ("Report: Climate change to sap Utah water supply," Tribune, April 26), the water supply of the Colorado Basin will shrink 8.5 percent by mid-century because of climate change.

For water aficionados, the only news here was that the bureau had finally joined the 21st century in acknowledging the likely effects of climate change. For years, the bureau refused to consider not only climate change but also tree ring studies in its projections for the Colorado. Tree ring studies give us a glimpse into the water history of the basin stretching back hundreds of years instead of the 100 of our instrumental record.

What tree ring studies reveal is that drought was a frequent visitor to the Colorado basin, about three times more frequent than today. Past droughts also tended to be longer-lasting and more severe. Unfortunately for us, it has been the instrumental record, not the sobering record of the tree rings, that planners like the bureau have used for their projections.

So, historically, our region has been drier than at present, and could, even without rising temperatures, return to its drier normal.

But now there's a new drought factor: climate change. The bureau's projection is an 8.5 percent drop in water by mid-century. True to form, the bureau is putting out a version of reality that is unrealistic. Others who have looked at the effects of climate change on the Colorado Basin put the number much higher.

A 2005 study in the journal "Nature," for example, projected that the decline in runoff could be 25 percent by mid-century.

This study is noteworthy in that it ran not just one but 24 different models, 86-97 percent of which agreed on a 25 percent drop for Utah. And that 25 percent is just the reduction we could see by mid-century. Climate change does not stop at 2050. Indeed, if we stay on our current trajectory, we'll see similar kinds of numbers mounting into the distant future.

The bottom line is that Utah is heading into a water crisis, and no one at any level of government here has a plan for dealing with it. In its 2010 plan for the Jordan River Basin (Salt Lake Valley), for example, the state doesn't even mention climate change or its likely effects. Nor does the state really take historic drought into account.

Nothing in state planning would prepare us to deal with a regimen of drought that was three times more frequent as well as more severe than what we've experienced since 1847.

The reason the state's not yet in panic mode is that it believes it has an ace up its sleeve, the water that is "banked" in agriculture, where 80 percent of our water is consumed.

The state believes that if we run short, we'll just farm less and take some of that agricultural water. Those wanting to develop water-intensive nuclear power and oil shale take the same view.

With massive projected drops in supply, and equally massive projected increases in use, this means the end of Utah agriculture.

The problem with this line of thinking is that climate change will be hammering our food supply as well, with 30-50 percent drops in productivity projected in many parts of the world, including the U.S.

We're going to need more, not fewer, farms in production to make up the difference. And they're going to need water.

Utah's failure to think clearly about the total climate change story is setting up our state for a perfect storm of disasters, all of them avoidable.

Ed Firmage Jr. is a Salt Lake fine-art photographer.