From Watts Up With That?

Guest Post by Willis Eschenbach  (@WEschenbach on eX-Twitter)

I see that Mad Keir Starmer, the frontman for the grunge rock band performing at the current UN Climate Conference Of The Parties under the name of “The UK”, has unilaterally declared that the UK will cut its CO2 emissions by 81% from 1990 levels by 2035. I do love that it’s 81% and not 80% … but I digress.

I also note that the UK Office of Budget Responsibility estimates that the UK getting to net zero by 2050 will cost £321 billion UK pounds (~ $410 billion US dollars) … and again, I gotta laugh that it’s not £320 billion, it’s £321 billion …

Now, I’ve said at various times that folks who propose big-dollar plans to attempt to reduce future temperatures should be legally required to calculate how much cooler the world will be in 2050 IF (and it’s a big if) the IPCC estimates of the effects of CO2 on temperature are accurate.

So lets take Mad Keir’s UK plan as a test case. Here’s a look at the UK CO2 emissions record.

Looks pretty impressive, all right. They’ve cut their emissions by half since 1975. Of course, in reality the reduction is much smaller. A lot of the emissions reductions resulted from the offshoring of UK manufacturing that’s hollowed out the UK economy, so the CO2 is produced in another country and UK folks get to feel all noble.

But Mad Keir’s not talking about that, so I won’t either.

However, here’s a bit of a different look at the exact same data. This shows the UK emissions as a yellow line as in Figure 1, and the rest of the world’s emissions (less the UK) as a red line.

Now, the IPCC says that the change shown by the red line of CO2 emissions has warmed the earth by about 1.4°C … so this gives us the first intimation that the temperature change from the UK emissions will be minuscule, trivially small.

In fact, that graph makes it clear that nothing the UK does will make a measurable difference in global temperatures.

But how small exactly? To estimate how much difference the UK sacrifices will make, here is a graph of a couple of simplified possible future UK scenarios.

The scenario shown in blue freezes the UK emissions at the current (2022) level. The red line drops emissions to 19% of the 1990 levels by 2035 and then to net zero by 2050.

Since some folks are allergic to math, I’ve put the actual calculations as an appendix. But the results are as follows:

The difference in CO2 emissions between the blue scenario and the red scenario is about 5.5 fewer gigatonnes (Gt) of CO2 emitted by 2050.

At 17.3 Gt of CO2 emissions per ppmv of atmospheric CO2 change, that’s a change of 0.32 ppmv of CO2.

So IF (and it’s a big if) the IPCC estimates of the effects of CO2 on temperature are accurate, then all of the time and effort and stacks of money expended by UK taxpayers will result in the earth being cooler in 2050 by …

…

… wait for it …

…

… a whopping 0.0007°C.

Seriously. All that wealth and human effort, all the government regulations and interference, all the suffering of the poor from skyrocketing energy costs, to MAYBE cool the world by seven ten-thousandths of a degree in 2050.

Call me crazy, but I think if everyone in the UK knew that all that Net-Zero 2050 would achieve is a POSSIBLE cooling of 0.0007°C by 2050, that idea would die instantly.

Now, Keir has said he hopes other countries will follow the UK’s lead and we can cool the world by a degree or so. To see if they’ll do that, let’s see how much it would cost to MAYBE cool the world by 1°C by 2050.

At a UK cost of $408 billion to make our lovely planet cooler in 2050 by 0.0007°C, making it 1°C cooler would cost $580 TRILLION dollars.

By comparison, the total of all the revenue collected (and often wasted or trousered) by all of the governments on this marvelous earth is about $15 trillion dollars per year … so even if every government everywhere spent every dime of their taxpayer’s money on the insane war against CO2 from today until 2050, we still wouldn’t cool it by 1° C.

And if Mad Keir thinks China, India, Russia, Brazil, or their like will sign on to that insanity, well, that’s why he’s Mad Keir. He likely thinks of it as insurance against disaster, but that’s like paying $2000 per year for years on an insurance policy that in case of catastrophe pays you $750 … just to pick a random payout number …

My warmest regards to all,

w.

THE USUAL: Please quote the exact words that you are discussing. I’m happy to defend my words. I can’t defend your re-statement of my words in a different form.

APPENDIX: First, here’s my usual trigger warning, Calvin regarding the mathiness.

With that settled, the total mass of the atmosphere is approximately 5.1 x 10^18 kg. 1 ppmv of CO2 in the atmosphere is equivalent to:

• 2.13 gigatonnes (Gt) of carbon
• 7.8 Gt of CO2 (as CO2 has a molecular weight 44/12 times that of carbon)

Approximately 45% of emitted CO2 remains in the atmosphere, while the rest is absorbed by oceans and land

So a 1 ppm increase in atmospheric CO2 ≈ 17.3 Gt of CO2 emissions. And the UK change of 5.5 Gt of CO2 converts to a 0.32 ppmv decrease in atmospheric CO2

Next, under a “business as usual” scenario, by the time we get halfway to 2050 the CO2 level will be ~ 450 ppmv. The 2022 level was 425.6. Per IPCC assumptions, the average change in forcing over the period is ~ log2(450/425.6)*3.7 W/m2. The change including the UK reduction is log2( (450-.32) /425.6)*3.7 W/m2. The difference between these is the change due to the UK reduction, which is 0.0009 W/m2

Finally, the IPCC assumes a climate sensitivity of 3°C per doubling of CO2, which is 0.8°C per additional W/m2. This gives us our final figure of a POSSIBLE change of 0.0007°C from the UK foolishness.