The advocacy group American Rivers didn't tell Utahns anything new when it tapped the Green River as No. 2 on its list of America's Most Endangered Rivers of 2012. Happily, though, the dangers to the river, which come from schemes to remove water from it, are prospective. They haven't happened yet. And if they don't, the river can be saved in all its majesty.

The Green is threatened by proposals to send its waters to Denver in a 500-mile pipeline, or use them to cool a nuclear generating plant in Utah. Because there already are many demands on the Green River, and because global climate change could dry up some of its waters, it doesn't make sense to build pipelines or reactors. The prudent thing is to call a halt to further development of its waters and leave them for the wildlife and humans who already depend upon them.

That will be difficult as the human population of the West continues to expand and the states of the Upper Colorado River Basin eye each other nervously as they consider proposals to develop the last drops of water to which they are legally entitled under the Colorado River Compact. Among those states are Wyoming, Colorado and Utah. Under this thinking, if you don't develop your water, it just flows downstream to someone else. Or, if the other guy develops his first, you lose out.

But the flip side is that you could tie your future to new pipeline or nuclear power projects that would not be feasible if the waters of the river decline as the Earth's temperature rises. The newest developments on the river would be least senior in terms of water rights, because they were built last, and they could be the first to lose their allocations during a water crisis.

That's the dilemma that political leaders face: develop or stand pat? We're in the stand pat camp. Preserve a resource that climate scientists say will likely shrink.

Developers aren't thinking in those terms. They are thinking about making money. One wants to send 250,000 acre-feet of water across Wyoming to the Front Range of Colorado. Fortunately, federal regulators have turned that down twice. Another wants 53,000 acre-feet to cool reactors near Green River, Utah. Others want still more water to process oil shale.

The Wyoming governor has taken a stand against the pipeline. Utah Gov. Gary Herbert has not, probably because Utah is toying with its own pipeline to take 70,000 acre-feet of water 140 miles from Lake Powell to St. George.

But Mother Earth is getting stingier with water in the West. We must pay heed and learn to get by on less.