From Climate Scepticism

BY JIT

Just how fast is the climate “crisis” accelerating?

If the mainstream media is to be believed, the climate “crisis” is accelerating fast. Everything is so much worse than last year, and next year will be much worse than this year, and so on.

But just how much more potent is the greenhouse effect now than last year? It’s something that is not made obvious in discussion of emissions (globally seemingly flatlining according to EDGAR) or even as reflected in CO₂ concentrations in the atmosphere.

The consequences of climate change arise downstream of the physical drivers. The most important driver of present interest is CO₂ concentrations, to which global atmospheric temperature increases are related by a logarithmic function. As we know, CO₂ concentrations are inching up year by year, but the thing that is dinned into us more often than anything else is the importance of the CO₂ emissions themselves, in other words our current account spending, when the problem is in fact the overdraft.

This way of thinking only gets you so far, because if this “pollutant” was cleansed from the atmosphere, every living thing on Earth would die. Some pollutant. Situation “normal” we consider to be 280 parts per million of CO₂ in the atmosphere by count of molecules, and it is against this benchmark that the climate “crisis” is judged.

Well, I decided to crunch the numbers to find out just how objectively worse this year’s climate is compared to last year’s in terms of the potency of the CO₂ in the atmosphere.

I also wanted to answer a subsidiary question: How much better would things have been this year, if the UK had not existed at all?

Some interesting numbers 1: the mass of the atmosphere

According to Wiki, the mass of the atmosphere is 5.15*10¹⁸ kg, or 5.15 petatonnes. Of that, about 3.13*10¹⁵ kg is CO₂, or 3.13 teratonnes. [Remembering that CO₂ is heavier than the other molecules.]

In Denierland, I said that the present mass of C [not CO₂] in the atmosphere is 850 Gt, which equals 3.12*10¹⁵ kg CO₂, close to Wiki’s figure.

Allowing 0.04 % CO₂ to equal this figure, you get 1 ppm CO₂ ≈ 8 Gt (billion tonnes).

Some interesting numbers 2: global emissions of CO₂

According to EDGAR, the total quantity of CO₂ emitted globally in 2022 was 38.5 Gt. This is 3.85*10¹³ kg, or roughly 1% of the quantity of CO₂ already in the atmosphere.

However, not all our emissions end up getting added to the atmospheric stock. Again referring to Wiki I find that 57% of humanity’s emissions were absorbed in 2012. I’m going to say that is reduced to 50% today, which is the same figure I used in Denierland (benefitting the alarmist case). So of the 38.5 Gt emitted, 19.25 Gt net is added to the atmosphere.

Net added last year / Existing stock = Proportion added last year

19.25 / 3120 ≈ 0.006

This is about 1 part in 167, so it would take a further 167 years for CO₂ levels to double from today’s, given no change in our behaviour. [We are already well on the way to doubling from 280. This illustration would take us from 420 to 840 in 2190 AD, although we would probably run out of fossil fuels before then.]

We already have the estimate that 1 ppm CO₂ ≈ 8 Gt, so we estimate too that the 19.25 Gt we added last year would have increased the CO₂ concentration by 19.25 / 8 ≈ 2.4 ppm.

In May last year (Wiki again) the concentration of CO₂ was 421 ppm. So on these numbers, it should now be 423.4 ppm.

What about the UK’s contribution to this increase? According to EDGAR, the UK emitted 0.34 Gt CO₂ last year. This is 0.88 % of global emissions, meaning that we are responsible for 0.0088 * 2.4 ppm, or 0.0212 ppm out of the increase of 2.4 ppm.

Some interesting numbers 3: global temperature change

We know that every time you double the CO₂ concentration, you get the same increase in global temperature. What this means is that every ppm you add is worth less in terms of warming potential than the previous. It also means that, if you have a baseline level of CO₂ (280 ppm) it is easy to calculate the temperature difference resulting from any other concentration of CO₂, with a couple of caveats.

Caveat 1: you have to put in a number for transient climate response (TCR). TCR is the fast-acting part of climate change, the bit that is relevant to a human timescale, before long-term feedbacks have reached equilibrium. Lewis & Curry (2014, ?Climate Dynamics) estimated this to be 1.33 K per doubling using an energy budget approach. Big computers give higher numbers. I’m very generously (for the alarmist case) going to call TCR = 2 K here. However, TCR is not instantaneous; it’s relevant to 2100. So the temperature change reported here would be in train but not wholly realised.

Caveat 2: there are other things going on other than CO₂ concentrations going up. There are other greenhouse gases (in particular methane), and natural cycles, volcanoes, etc. This elementary analysis ignores all those.

The function you end up with (I don’t know if this is standard, or idiosyncratic) to calculate the temperature change from the baseline is:

Or in words, the temperature change from the baseline equals TCR times the logarithm base 2 of the present CO₂ concentration divided by the baseline concentration (280 ppm).

We can now estimate the temperature increase from the baseline by plugging in TCR = 2 K and CO₂ = 423.4. The answer you get is that the global climate should be an average of

1.193 K

warmer than it was in the pre-industrial baseline situation (or it will be once the short-term feedbacks are settled).

If you plug in last year’s concentration (421 ppm) you get

1.177 K

So the annual increase in temperature in this idealised situation would be 0.016 K between 2022 and 2023, or a sixtieth of a kelvin.

What about the UK’s contribution to the temperature increase over the baseline? What if we had disappeared last year? What if, in 2022, the UK’s 0.34 Gt had not been emitted?

With the UK, the estimated increase over the baseline was 1.193 K. Without the UK, the estimate is

1.193 K

(Yes, it’s the same number because of insufficient significant figures.) In fact, on these estimates, the UK’s contribution to climate change last year was:

0.00014 K

Or roughly 1/7000^th of a kelvin.

Bottom line

Although temperatures are rising, they (or the part driven by CO₂ emissions at any rate) are rising at a non-threatening and incremental rate. With parameter estimates favouring the alarmist cause, the effect of CO₂ emissions last year was of the order of a sixtieth of kelvin. The UK’s contribution to global warming from CO₂ emissions last year was about 1/7000^th of a kelvin, again with parameter estimates favouring alarm.

If these temperature changes drive other variables and give rise to dangerous weather etc, then it seems unlikely that any such changes would be noticeable on a year-to-year basis.

The climate “crisis” is not accelerating.

Editorial

Oh, for a leader who would stop dictating every aspect of our lives, and let us get on with them.