Trifling With Desert Climate Data, And Thinking About Global Warming

Last week, I was looking through some climate data from the deserts of Nevada (I think it may have been Pahrump, or vicinity), and was struck how it just doesn't get as cold there as it used to. Mean monthly minimum temperatures in the single digits could be observed a hundred years ago, but they never occur now.

I couldn't find that data set this week, but there is plenty of other data out there to look at.

Deserts are nice, because the greenhouse warming associated with water vapor is minimized in the deserts, so if you see any changes, it's likely carbon dioxide to blame, rather than any changes associated with the urban heat island effect, or changes in roughness associated with changes in land use, or first-order changes in water vapor. And minimum temperatures are where you would spot the change first, because turbulence is at a minimum for these mostly-stagnant conditions. Cooling occurs principally by radiation.

Using US HCN data for Mina, NV (on the road between Hawthorne and Tonopah), and looking at just the monthly mean minimum temperature for the month of April (a rather dry month), it's easy to spot the warming signal. And this particular data set ends in 1994, so recent warming isn't even on here.

Australia's BOM has a series of maps for the Outback showing pretty-uniform warming throughout the last century. It's the same phenomenon.

Yup, Global Warming is real!