Maggie's Farm

DeGaulle: If they're right, in terms of the fundamental issue, how did they so spectacularly fail to see it coming, and what catastrophic unknown consequences of their 'solutions' might they be failing to perceive?

Interesting question actually. Turns out that scientists are not omniscient. Over a century ago, it was shown that if you increased atmospheric greenhouse gases significantly, it would warm the Earth's surface. What wasn't known was just how vast the amount of greenhouse gases humans would emit than was supposed at that time. See Arrhenius, On the Influence of Carbonic Acid in the Air Upon the Temperature of the Ground, Philosophical Magazine 1896.

DeGaulle: in terms of geological history, we are in an era of already very low temperatures and of low CO2 levels.

True, but ecosystems and human civilization are adapted to the current conditions. Rapid change will cause permanent damage to ecosystems and severely disrupt human civilization.

DeGaulle: That's what the scientists tell us.

Those crazy scientists! What will they come up with next?!

DeGaulle: The scientists' 'solutions' to a problem that doesn't exist might conceivably reduce temperature and carbon levels below that necessary for plant survival.

Huh? No one's proposing reducing atmospheric CO2 to below pre-industrial levels. Indeed, just keeping it from doubling from pre-industrial levels is taking quite a bit of effort.

DeGaulle: Perhaps, some of those scientists that you admit are not 'omniscient' might be claiming a doubling of CO2 levels.

Not sure how to parse that statement. Are you saying scientists have not accurately measured the concentration of atmospheric carbon dioxide? It’s a simple measurement. Or are you referring to climate sensitivity, the expected effect of a doubling of atmospheric carbon dioxide? Climate sensitivity is subject to some uncertainty, but several independent measures put the likely value between 2-4°C.

DeGaulle: If these levels are increasing so rapidly, why isn't Greenland well on its way to returning to the foliage that earned its name in the Middle Ages?

The Greenland Ice Sheet is more than 2 million years old. It’s estimated that warming of 3-5°C would eventually lead to the near complete melting of the Ice Cap, but it would take centuries for that to happen due to the high thermal mass. Partial melting in the shorter term would still cause significant sea level rise.

As for foliage, Greenland is greening primarily due to the retreat of glaciers. See Grimes et al., Land cover changes across Greenland dominated by a doubling of vegetation in three decades, Scientific Reports 2024.

Hmm. Forecasts vs. Observations

jack walter: It's just changes in planetary climate that happen over tens of thousands of years

Those crazy scientists! What will they come up with next?! Yes, climate has changed over Earth's geological history. However, the current warming trend is anthropogenic and anomalously rapid.

jack walter: You might have to adapt, but you don't need to worry about stopping it because you can't and shouldn't

Some global warming is inevitable, so adaptation is certainly part of the response. However, the longer it takes to mitigate the problem, the more costly it will be, and not just economically. Climate disruption will cause social and political problems, including mass migration. And the worse the warming, the greater the damage to humanity's shared ecological inheritance

In any case, the claim that "No climate alarmist prediction has ever come true" is false.

Anon: You’re asking that we believe that the observed temperatures shown in that graph are accurate.

Satellite measurements, surface data, and robotic ocean buoys; that is, different scientists using different methods; all show the same warming trend. We also have fundamental physics, which predict that an increase in greenhouse gases will warm the surface and cool the upper atmosphere, which is what is observed.

Anon: Only a fool . . .

Pointing to multiple, independent lines of evidence is a stronger argument than "Is not!" or even "Only a fool".

Jan Peter Blickenstaff: Climate is an abstraction (definition) based upon data/facts (weather, geography, biosphere) over a specified period of time.

Climate change is as real as any empirical phenomenon, like planets orbiting the sun or atoms combining into molecules.

Jan Peter Blickenstaff: For climate to change the weather data has to be trending up or down.

Anthropogenic greenhouse gases are warming Earth's surface.

Jan Peter Blickenstaff: Change is the only constant in the Universe.

Sure. But not all change is good for humans or inevitable. Anthropogenic global warming is neither good nor inevitable.

Jan Peter Blickenstaff: (environmental change is one spur of evolutionary adaptation)

You may not want to go there. One of the primary mechanisms of evolution is the extinction of species. Don't worry though. Humans are highly adaptable, so they should be able to not only adapt, but prosper. Of course, one reason humans are so adaptable is that they can project into the future, including any actions taken to respond, especially with modern science. However, the cost will be much higher (economically, politically, socially, ecologically) the longer it takes to mitigate the problem.

Jan Peter Blickenstaff: To say that climate change is helpful or harmful for survival (good and bad are moral terms) one must propose an optimum data point and optimum for who or what; individuals or populations or species?

That's easy. Human civilization and the world's ecosystems on which it relies developed over a relatively stable climate environment. The optimal for human civilization and the ecosystems on which it relies is the continuation of that stable environment. If the climate were changing naturally, then adaptation would be the only recourse. In this case, however, anthropogenic greenhouse gases are causing a rapid and anomalous warming of Earth's surface.