Additional lines of evidence
Beyond the thermometer we find several other lines of evidence that reinforce the notion that our planet has warmed.
Global Indicators
All of these indicators are consistent with a warming planet. Paramount to the western United States is the reduction in spring snow cover and depth in our mountains. Upwards of three-quarters of the water supply of the West is stored in mountain snowpack and released with the arrival of warmer temperatures in the spring and summer to meet the water demands of humans and the environment. Widespread observations show a reduction in the amount of snow water equivalent (water content of the snow) measured on April 1st since 1950.
Less snow, earlier melt
Changes in hydrology across western North American have also been reflected in a 1-2 week advance in the onset of snowmelt runoff timing. What are the consequence of more water arriving earlier and less runoff occurring in summer?
A comprehensive report by the EPA documenting climate indicators in the United States is available here.
A comprehensive report by the EPA documenting climate indicators in the United States is available here.
A time series of mean annual temperature in Idaho shows a long-term warming trend with the last 10 years being warmer than any other 10-year period since 1895. However, the warmest year on record in Idaho and many other western states remains as 1934.