Tuesday, 21 May 2019

I am now a Climate Science Believer!

I haven't been posting much over the last few days because I was busy reading lots of articles about Climate Science and watching YouTube videos, most were from Warmenists and a few from Deniers, for balance. No links, for the time being as I have dozens.

The Warmenist articles/videos look to be about 90% correct, but they all contain a couple of logical/mathematical errors, inherent contradictions or  over-simplifications, not to mention that they contradict each other. Most of the Denier articles and videos have similar inconsistencies.

What their explanation boils down to, having stripped away the errors and taking the rest at face value, is this:

1. The two main Greenhouse Gases are:
a) water vapour (not to be confused with condensed water droplets, which cool the atmosphere) at an average of 20,000 parts per million (within a wide range between zero and 40,000, that's the assumed average).
b) Carbon dioxide at an average of 420 ppm, up from 280 ppm in pre-industrial era.

Molecule-for-molecule, these have a very similar effect (AFAIAA). Water is self-regulating, as once it hits saturation point, it condenses and falls as rain or snow, removing itself from the atmosphere and cooling things down.

Carbon dioxide is not self-regulating, rain washes some of it out of the atmosphere, but it then most of it re-evaporates and only some goes into the oceans (which is where limestone cliffs come from) or into plants (which eventually die and rot again).

(The Warmenists shift the goal posts here a bit. Up to current CO2 levels, they accept that H20 is self-regulating and can be ignored (most of them do), but magically, if C02 increases, then H20 and C02 will interact and temperature increases due to the H20 element will somehow become self-reinforcing. This seems highly unlikely to me.)

2. The entire additional 33C average temperature of the earth's surface compared to what you'd expect from sunlight alone is down to greenhouses gases.

Apparently nitrogen and oxygen would have no such effect, we'd still get the steady fall in temperature with decreasing pressure/increasing altitude. This is the 'adiabatic lapse rate'. This gradient is much the same for all planets in the solar system, regardless of what kind of gas makes up their atmosphere.

3. If you increase greenhouse gas concentrations from average 20,280 ppm (average H20 plus pre-industrial C02) to 20,420 ppm (average H20 plus current CO2), that's a 0.7% increase in Watts being reflected back to each square metre of the earth's surface. Existing greenhouse effect is 33C, increase that by 0.7% = 33.23 = an extra 0.2C* compared to what it would be at 280 ppm C02, everything else being equal.

* The increase in surface temperature relative to increases in Watts/m2 is logarithmic not linear = 0.1C, so let's round that 0.23C down to 0.2C for sake of argument.

4. It appears to be accepted by both sides that global average temperatures go in lots of overlapping and fairly regular cycles. The most relevant one as at today is a roughly thousand-year cycle i.e. Roman Warm Period, Mediaeval Warm Period and Modern Warm Period.

That explains the rest of any increase since a randomly chosen starting point. Let's not  bicker about what a sensible starting point is.

Looking at the increase since the pre-industrial era means you are looking at the increase since the Little Ice Age, however defined, when temperatures were 1 or 2C lower than the very long run average, so of course we're 1C warmer than then.


decnine said...

2 points of detail:

1. When rain falls on calcium rocks, a little bit dissolves - hence limestone caves and hard water. The CO2 is re-mobilised mostly as bicarbonate.

2. The increased concentration of CO2 in the air is correlated with a significant greening of marginal environments especially at the northern limit of plant growth. There appears to have been a significant increase in plant biomass (biological capture of CO2) globally.

Mark Wadsworth said...

D, yes of course, but the rules are, you may only refer to Warmenist sources. They don't entertain the idea that CO2 levels are to some extent self-regulating.

Graeme said...

Ah but the problem is that the science is now used as a starting point for all sorts of batty initiatives. It's what the science is used for that matters rather than the science itself. So warmenists invent scare stories about melting glaciers and rising sea levels to justify building windmills. It's all bonkers and needs to be exposed as such. The scientists who go along with these stupid made up scare stories need to be exposed. Nothing that comes out of the Potsdam institute is actually science any more even though they claim to be scientists

Mark Wadsworth said...

G, that's the problem, isn't it?

Bayard said...

G, it's been that way for years, in all branches of science. Who do you think funds their research?