Yup. It’s hot.

It’s going to stay hot—unseasonably hot, that is—until and perhaps past The Fourth.

We are used to hot summers here in Siskiyou County, not as hot as Redding or Sacramento and other spots in the Great Central Valley, but hot enough. This week of 100+ temperatures is notable for its high lows. Often in the summer here on the western edge of the Shasta Valley we can see 45-degree swings from day to night. It will be 95ºF in the afternoon and 50ºF in the early morning. When the temperature gets to three digits you can still get nice, cool mid-fifties temperatures to soothe your soul.

Not so this heat wave. It’s not dropping below 65ºF and in fact was almost 70ºF on our back patio this morning. If you don’t have A/C you need that big cooling drop so you can open up the house and get the hot, stifling overnight air out and the refreshing dawn air in. We are lucky and have excellent cooling, but we remember those days when we didn’t. If, god forbid, there was a power outage then we’d have to go back to our old rituals. Unfortunately the cooling would not be sufficient. I hope all my friends out there in hot places are doing OK!

Just a side note: the metric system blew it on temperature scale. You know it is hot when you go from 99 to 100 in Fahrenheit. In Celsius you go from 37 to 38! Boring. No one cares if you have a 99-degree fever but they get concerned if you hit 100. Fahrenheit has a nice, intuitive feel. Going from two digits to three just seems better. The same can be said for 100-mph. You know you’re rocking when you blast out of the nineties. It’s just not as exciting if it’s in kph, going from 160 to 161.

So, is climate change to blame? Is this heat wave evidence for global warming?

It’s easy to say “yes” but not all questions are meant to be answered in simple, binary fashion.

When scientists study things like gases they use statistical mechanics. This discipline (invented by an American, Josiah Willard Gibbs) views a gas as a gigantic ensemble of countless billions upon billions of molecules. Individual molecules are not important. The vast majority of molecules in the gas may be rising due to added heat for example, but any one particular molecule might be taking its own path. The mathematics of statistical mechanics smears out all those variations and makes probabilistic descriptions of the behavior of the whole mass. It’s the only way to accurately account for things.

Temperature, for example, is an average. If you knew the kinetic energy of every molecule of water in your teapot, you’d find that some were greater than others. Some molecules would be rushing about in a great frenzy, others languidly meandering. But by averaging that energy over the entire collection of molecules you can get a useful number—the temperature—that tells us something about the state of the system.

Just like our one lone molecule that is plunging downward when most of its buddies are racing upward from the added heat, any one particular weather event can be “disconnected” from the global climate. That is, even if humans had never added an ounce of carbon to the atmosphere, we could still get extreme weather events.

This is an extreme weather event. Climate science says we should see an increase in the frequency of extreme weather events.

If I reach into a box of hot air molecules, there’s a good chance the one I grab and measure will have a high kinetic energy. In fact, most of the ones I check with my instruments will confirm my observation. The gas is heating up and the molecules are getting energized and the whole mass is rising and pushing on the roof of the box. But I can still imagine the possibility that I will reach in a find a “cool” molecule that is not playing well with others! The odds of that occurrence are lower, much lower, but they are not zero. (Never mind that I can’t reach in and touch molecules, it’s just what Einstein would call gedanken, or thought-experiment.)

So is our Pacific Northwest Extreme Heat Wave the result of anthropogenic (human-made) carbon in the atmosphere? Is Global Warming the cause? Is it evidence of Climate Change?

Probably.

I told you that statistical mechanics was “probabilistic.” So are climate models. They are models after all, and we know that the map is not the territory. The climate is one thing, the models are another. The models are what we use to describe the global system, and if they are robust and have a good correspondence with the empirical evidence, we use them to make forecasts.

It turns out that the models are good. The great Swedish chemist, Svante Arrhenius, described the greenhouse effect in 1896 and postulated that the burning of fossil fuels by humans could raise global temperatures. That famous reactionary, Edward Teller, he of H-bomb fame (infamy?), spoke in 1959 about the possibility of melting the icecaps due to global warming. (Naturally he promoted nuclear energy as the alternative to fossil fuels.) The most famous climatologist, Charles Keeling, he of the Keeling Curve, was given the President’s National Medal of Science by none other than George W. Bush! Here’s what the award says:

“For his pioneering and fundamental research on atmospheric and oceanic carbon dioxide, the basis for understanding global carbon cycle and global warming.”

https://www.nsf.gov/od/nms/recip_details.jsp?recip_id=191

We all know what a snowflake liberal “Dubya” was!

So, yes.

Global warming and climate change are real phenomena. The models are good. They are giving us solid information to make decisions with. The political choices facing our society are one thing. The facts are quite another.

It’s no comfort. Whether this heat wave is a sure sign of climate change or not doesn’t make us any less hot.

But if we are looking for a “new normal” we’ve found it. We know there will be an increasing number of extreme weather events. That’s a fact. The next extreme event might not be a direct result of global warming, but you can bet there will be another, and it will be sooner than it ought to be.

Maybe that will get us to agree on some possible solutions.