It’s been ten years since I addressed this issue in a specific blog post, so I thought it would be useful to revisit it. I mention it from time to time, but it is so important, it bears repeating and remembering.
Over and over again.
I continue to strive to simplify these concepts, so here goes another try.
What follows is as concise as I can make it.
- The temperature change in anything, including the climate system, is the result of an imbalance between the rates of energy gain and energy loss. This comes from the First Law of Thermodynamics. Basic stuff.
- Global warming is assumed to be due to the small (~1%) imbalance between absorbed sunlight and infrared energy lost to outer space averaged over the Earth caused by increasing atmospheric CO2 from fossil fuel burning.
- But we don’t know whether the climate system, without human influence, is in a natural state of energy balance anyway. We do not know the quantitative average amounts of absorbed sunlight and emitted infrared energy across the Earth, either observationally or from first physical principles to the accuracy necessary to blame most recent warming on humans rather than nature. Current best estimates, based upon a variety of datasets, is around 239-240 Watts per sq. meter for these energy flows. But we really don’t know.
When computer climate models are first constructed, these global-average energy flows in and out of the climate system do not balance.
So, modelers adjust any number of uncertain processes in the models (for example, cloud parameterizations) until they do balance.
They run the model for, say, 100 years and make sure there is little or no long-term temperature trend to verify balance exists.
Then, they add the infrared radiative effect of increasing CO2, which does cause an energy imbalance. Warming occurs. They then say something like, “See? The model proves that CO2 is responsible for warming we’ve seen since the 1950s.”
But they have only demonstrated what they assumed from the outset. It is circular reasoning. A tautology. Evidence that nature also causes global energy imbalances is abundant: e.g., the strong warming before the 1940s; the Little Ice Age; the Medieval Warm Period.
This is why many climate scientists try to purge these events from the historical record, to make it look like only humans can cause climate change.
I’m not saying that increasing CO2 doesn’t cause warming. I’m saying we have no idea how much warming it causes because we have no idea what natural energy imbalances exist in the climate system over, say, the last 50 years. Those are simply assumed to not exist.
(And, no, there is no fingerprint of human-caused warming. All global warming, whether natural or human-caused, looks about the same. If a natural decrease in marine cloudiness was responsible, or a decrease in ocean overturning [either possible in a chaotic system], warming would still be larger over land than the ocean, greater in the upper ocean than the deep ocean, and greatest at high northern latitudes and least at high southern latitudes).
Thus, global warming projections have a large element of faith programmed into them.
Read more at Dr. Roy’s Blog
So simply explained, so important, but so ignored by the media and lied about by the “climate scientists” like Michael Mann to push their climate apocalypse nonsense. And so many hundreds of billions of dollars wasted on pretending to try to stop the impossible.
Very well written, thanks!
The problem with the First Law of Thermodynamics is that these days Democrats and Liberals won’t accept any law they don’t like so obviously there is no such law or it’s made up and in either case invalid!
Exaggeration is a lie. AGW ,as predicted by some politicians, gets blown up into imminent catastrophe. That’s a BIG one.
Anyone who falls for it is an idiot.
Those who push it are crooked.
Most people are not changing their behaviour. The Duchess of Sussex flew to New York to watch her friend lose a tennis match that was televised worldwide. Hypocrisy for the everyone to see.
Climate change is like the weather…. everyone talks about it but no one does anything about it.
And I’ll say it since Dr.Spencer can’t. The propagation and accumulation of temperature measurement error is greater than the changes predicted by the worst case climate model forecast. Therefore the climate models are not fit to make forecast.
I still can remember all the stupid predictions about the Earth so Polluted we would be wearing Gas Masks and keep our cities under giant domes and none of this poppycock has happened or ever will happen the Fragile Earth and the Delicate Balance of Nature and two of the biggist scams ever
I want to see it snow a lot this coming winter i want to see some Eco-Wacko stranded at home without a snow shovel and no boots to keep their little toesies warm when it snows a foot or more
Warmists are indeed drunk with the Koolaid of faith because this is what they want to believe not because it is true. Faith has no place in science likewise politics which has infected the false global warming meme. The late Vincent Gray explained: The religious belief (from Genesis Chapter 1, verse 20) that humans have “dominion” over the earth is now extended so that humans take over the function of God and are responsible for all other creatures. Human influence is purely negative and destructive. The other creatures would be better off without us. We are destroying the planet. As this proposition is absurd, desperate attempts must be made to find evidence to support it. https://friendsofscience.org/assets/documents/GlobalWarmingScam_Gray.pdf