Category Archives: Mathematics

George Washington’s Winters

What is the right climate?

Why are we defining ‘dangerous climate change’ with respect to the climate of the 18th century, which was the coldest period in the last millennia, with wicked winters? Why not use a reference point of 2000 or 1970? The IPCC doesn’t provide a convincing explanation for the overall warming between 1750 and 1950; according to climate models, human causes contributed only a very small amount to the global warming to during this period (so presumably this overall warming was caused by natural climate variability). Co-opting the period between 1750 and 1950 into the AGW argument muddies the scientific and the policy waters.

It would make much more sense — from a scientific perspective, from the perspective of adaptation and engineering, and in the public communication of climate change — to refer to warming relative to a more recent reference period. Since the emissions reference periods are between 1990 and 2005, this also adds to the argument of citing a more recent reference period for defining ‘dangerous’.

The argument that human caused warming is already ‘dangerous’ — widely made by politicians, the media and some scientists — flies in the face of scientific evidence reported by the IPCC AR5 and SREX. Extreme weather events were worse earlier in the 20th century, and sea level has been rising for millennia, with recent rates of sea level rise comparable to what was observed in the middle 20th century.

It’s almost as though there’s some sort of political agenda at work.

Climate Models

Another example of their bogosity:

It occurs to me to wonder whether this error in the GISS-E2-R ocean mixing parameterisation, which gave rise to AMOC instability in the Pliocene simulation, might possibly account for the model’s behaviour in LU run 1. It looks to me as if something goes seriously wrong with the AMOC in the middle of the 20th century in that run, with no subsequent recovery evident.

But let’s make wealth-destroying policy based on this!

[Update on January 28th]

Insights from Karl Popper to break the gridlock in the climate debate.

It’s sad how so many people who (ironically) accuse me of being a “climate denier” or a “science denier” are so profoundly ignorant of how science actually works.


[Update a while later]

An analysis from Judith Curry and Nic Lewis on the latest climate crap from Mann et al:

As I see it, this paper is a giant exercise in circular reasoning:

  1. Assume that the global surface temperature estimates are accurate; ignore the differences with the satellite atmospheric temperatures
  2. Assume that the CMIP5 multi-model ensemble can be used to accurately portray probabilities
  3. Assume that the CMIP5 models adequately simulate internal variability
  4. Assume that external forcing data is sufficiently certain
  5. Assume that the climate models are correct in explaining essentially 100% of the recent warming from CO2

In order for Mann et al.’s analysis to work, you have to buy each of these 5 assumptions; each of these is questionable to varying degrees.

You don’t say.

Fossil Fuels

Matt Ridley on how they’ll save the world.
The conclusion:

The one thing that will not work is the one thing that the environmental movement insists upon: subsidizing wealthy crony capitalists to build low-density, low-output, capital-intensive, land-hungry renewable energy schemes, while telling the poor to give up the dream of getting richer through fossil fuels.

(Yes, behind paywall, but google the headline and you should be able to read it.)

[Update a while later]

I’m very sorry to hear about Piers Sellers’ illness, and hope for the best, but this NYT op-ed seems to me to be delusional:

All this as the world’s population is expected to crest at around 9.5 billion by 2050 from the current seven billion. Pope Francis and a think tank of retired military officers have drawn roughly the same conclusion from computer model predictions: The worst impacts will be felt by the world’s poorest, who are already under immense stress and have meager resources to help them adapt to the changes. They will see themselves as innocent victims of the developed world’s excesses. Looking back, the causes of the 1789 French Revolution are not a mystery to historians; looking forward, the pressure cooker for increased radicalism, of all flavors, and conflict could get hotter along with the global temperature.

Last year may also be seen in hindsight as the year of the Death of Denial. Globally speaking, most policy makers now trust the scientific evidence and predictions, even as they grapple with ways to respond to the problem. And most Americans — 70 percent, according to a recent Monmouth University poll — believe that the climate is changing. So perhaps now we can move on to the really hard part of this whole business.

I hope that will change next January. As Ridley points out (as does Alex Epstein), it is the poor who would be hit the hardest byaabandoning fossil fuels (particularly with plunging prices), much more so than by “climate change.”

Star Wars

…and the age of the fake nerd.

I suppose that’s still better than taking pride in your ignorance of math, as some do. As I noted on Twitter yesterday, it’s OK to like Star Wars, as long as you don’t delude yourself that it’s science fiction.

[Wednesday-morning update]

Star Wars TFA has a perfection problem. Note (FWIW) that Megan is married to SF film critic Peter Suderman.