News Release: "Less Snow, Less Water" Report, continued

Key New Findings

For this report, RMCO analyzed temperature data from the National Oceanic and Atmospheric Administration (NOAA) and snowpack data from the Natural Resources Conservation Service (NRCS), for the upper portions of the Columbia, Colorado, Missouri, and Rio Grande river basins. Those are the West’s four largest rivers. The analysis provides new evidence that climate disruption is already underway in the West in ways that endanger the region’s snow and water resources.

First, in each river basin the most recent five years was the hottest such period in the last 110 years. Compared to the historical average temperature for each river basin over the period 1895-1990, the average 2000-2004 temperatures were:

• 1.5 ° F hotter than the historical average in the upper Columbia basin.
• 2.1 ° F hotter than the historical average in the upper Colorado basin.
• 1.5 ° F hotter in the upper Missouri basin.
• 2.5 ° F hotter in the upper Rio Grande basin.

Second, in each river basin, over the last 10 years (1995-2004), the greatest warming was in January, February, and March. This pronounced warming in winter and early spring is what scientists have predicted will happen with the greenhouse effect, and can be regarded as one signature of human-induced climate change. This also is when warming has the greatest effects on snowpack levels. January temperatures in the last ten years have averaged:

• 3.5 ° F hotter than the historical (1895-1990) average January temperature in the upper Columbia basin
• 3.7 ° F hotter than the historical average January temperature in the upper Colorado basin.
• 3.1 ° F hotter than average in the upper Missouri basin.

• 4.3 ° F hotter than average in the upper Rio Grande basin.