Saturday, February 17, 2018

Cool Integral

From KarlMagnus Petersson‏ on Twitter:


In the same way, you can show (I think) that


which is also cool, but not as cool, since "3" is not as cool as "e."

Note: 1/3 < 1/e. This makes sense, since for 0 < x <1, sqrt(x) < cuberoot(x) < fourthroot(x), etc.

Note II: Speaking of e, one of my best friends, a colleague in graduate school (we had the same advisor, and have gotten even closer since), once wrote a paper that contained the number e^e, which I think is about the coolest thing ever published in physics. I wrote about it here for Physics World.

Wednesday, February 07, 2018

Global Warming in Ursula Le Guin's 1969 Novel "The Left Hand of Darkness"

The science fiction writer Ursula Le Guin recently died (she lived in Portland, Oregon for decades), and since I hadn't read anything by her I thought I better get started. So I picked The Left Hand of Darkness, her breakthrough book published in 1969. She was on the ball, because even then she knew about CO2 and global warming. Here she writes about her fictional planet of Gethen.
Eskichwe rem ir Her hypothesized that the volcanic activity in N.W. Orgoreyn and the Archipelago has been increasing during the last ten or twenty millennia, and presages the end of the Ice, or at least a recession of it and an interglacial period. CO2 released by the volcanoes into the atmosphere will in time serve as an insulator, holding in the longwave heat-energy reflected from the earth, while permitting direct solar heat to enter undiminished. The average world temperature, he says, would in the end be raised some thirty degrees, till it attains 72°. I am glad I shall not be present. Ai says that similar theories have been propounded by Terran scholars to explain the still incomplete recession of their last Age of Ice. All such theories remain largely irrefutable and unprovable; no one knows certainly why the ice comes, why it goes. The Snow of Ignorance remains untrodden.
It's interesting that she associated CO2 warming with the Ice Ages, as science did for a good while back then, I think, while it grappled with understanding the Pleistocene.

More Humor from SpaceX

(Besides the orbiting red roadster, I mean)

Saturday, February 03, 2018

Saturday, January 27, 2018

Ocean Heat Content Reaches Record Highs

We all know by now -- or should know -- that ocean heat content (OHC) is easily the best metric of a global energy imbalance -- about 93% of the trapped heat goes there.

At least, The Guardian has caught on.

The OHC data for 4Q17 are in, and it shows that in 2017, the OHC of the top sixth and the top half of the global ocean both reached record annual values:


In 2017, the heat uptake for the 0-2000 m region -- the top half of the ocean -- was 1.6 W/m2 relative to 2016, and its acceleration, in just 12 years of data recording, is 0.039 ± 0.018 W/m2/yr.

Tuesday, January 23, 2018

Guesses for the New Doomsday Clock Setting?

Update 1/25: The Clock was set forward by half a minute, "amid increasing worries over nuclear weapons and climate change," so it's now at two minutes to midnight. Trump has at least 3 more years in office, so if this trend continues the Clock would be at a half a minute to midnight at the end of his first term. The fate of the world might hinge on defeating his bid for reelection (or on his impeachment and conviction -- one can always hope).

"'This is the closest the Clock has ever been to Doomsday, and as close as it was in 1953, at the height of the Cold War,'” said Rachel Bronson, president of the Bulletin of the Atomic Scientists." 

I certainly worry about nuclear Armageddon -- though not as much when I was younger, where for a few years after graduate school I would sometimes wake up screaming in the middle of a night after a dream -- but I don't think climate change will be "catastrophic." Difficult, costly, tragic in some situations -- but not catastrophic. By the 22nd century humans will probably know enough to do responsible geoengineering and prevent the 40 to 60 meters of sea level rise that would otherwise be coming over several millennia. Half of Florida might be gone by then, though. That alone is gonna cost trillions.

--

The Doomsday Clock is currently set to 2.5 minutes before midnight. It's maintained by the Bulletin of the Atomic Scientists, and will be reset this Thursday at 10 am ET, 7 am PT, 15:00 GMT. (No adjustment is also possible, as was done last year.) Watch online.

Any guesses on the new setting? I'm guessing 1.5 minutes before midnight, based solely on the fool now in the White House. (He'll probably consider this a positive sign of his worldwide fame.) A substantial jump forward, but still not too close to pure panic.

1.5 minutes before midnight would be the Clock's more dire setting ever. Here's its history:

Monday, January 22, 2018

Climate Models Are Doing Great

After 2017's annual temperatures came in, Gavin Schmidt posted this on Twitter:

Here, historical forcings are used prior to 2000 -- the actual GHG concentrations, volcanic eruptions, etc. After 2000 the comparison uses the old IPCC Scenario A1B -- "...very rapid economic growth, global population that peaks in mid-century and declines thereafter, and the rapid introduction of new and more efficient technologies." (Truth is, there isn't much of any difference in these old AR4 scenarios by this time.)

Looks equally good with the CMIP5 models.

The model/observation difference varies depending on the particular year (or couple of years), but over the long-term it's looking pretty good.

Certainly good enough to see that we have a big AGW problem on our hands.