Record highs, recod lows – not a good ratio

Weather Channel asks, “July in April?” – Record smashing heat-wave hits nation
[Via Climate Progress]

CP: So it’s friggin’ hot in DC and much of the country.

Audience: How hot is it?

CP: It’s so hot that:

  • I saw a dog chasing a cat and they were both walkin’.
  • The robins are laying their eggs sunny side up.
  • I saw squirrels fanning their nuts.
  • Even meteorologists are doing stories about human-caused global warming.

Settle down, anti-science disinformers who try to shout down any talk of a link between climate change and extreme weather — these are only jokes. We all know that you can’t use a single weather event as evidence for or against climate change — unless of course that weather event is a big snowstorm [see “Massive moisture-driven extreme precipitation during warmest winter in the satellite record — and the disinformers say it disproves (!) climate science].


Luckily, the Pacific Northwest has been on the opposite temperature track for some time. When it was snowing in the East, it was warm back here. Now that it is frying in the East, we are actually starting to get our snowpack closer to normal levels.

But the figure above is a useful one and is an interesting way to visualize the data. Here is another attempt, from a paper that put his all into perspective:

The data in the top graphic might remind you of this figure from a must-read 2009 study led by National Center for Atmospheric Research (see “Record high temperatures far outpace record lows across U.S.“):


This graphic shows the ratio of record daily highs to record daily lows observed at about 1,800 weather stations in the 48 contiguous United States from January 1950 through September 2009. Each bar shows the proportion of record highs (red) to record lows (blue) for each decade. The 1960s and 1970s saw slightly more record daily lows than highs, but in the last 30 years record highs have increasingly predominated, with the ratio now about two-to-one for the 48 states as a whole. (©UCAR, graphic by Mike Shibao.)

In the 90s, the ratio of record highs to record lows was higher than any previous decade. In the last decade, this had increased, resulting in twice as many record highs as record lows. Not a good trend.
But the paper also states this:

The modeling results indicate that if nations continue to increase their emissions of greenhouse gases in a “business as usual” scenario, the U.S. ratio of daily record high to record low temperatures would increase to about 20-to-1 by mid-century and 50-to-1 by 2100.

Now, you can just away the models for no really good reason but they indicate pretty extreme changes in the weather well within the lifetimes of many of us today.

I feel that even if there is only a 5% chance that the models are right, we should take action now because the terrible effects on humans will be much more expensive than any adaptations we have to make in our economy.

What probability of the models being right do you feel should result in taking real action?