This is the most striking proof that fossil fuels are causing global warming I have ever read: simple energy conservation thermodynamics principal. The fossil fuels store energy from the sun of ancient times. Think of them as batteries with high energy density. Combustion releases that energy in form of carbon that prevents a proportion from the energy coming from the sun from being reflected back into space as infrared waves. Basically it’s like releasing the heat (the energy) from the sun of ancient times and preventing it from escaping into space at the same time. Basically the earth has become a pressure cooker.
That’s not evidence of global warming, you’d have to prove the energy released is large enough and not radiated away / stored back in some other way.
Unfortunately global warming is real and there’s plenty of evidence for it. Your mechanism isn’t really the issue though, it’s the greenhouse gases trapping new energy from the sun which is the basic root cause.
It is interesting to consider just how much excess energy it would take to directly upset Earth's thermal balance. In 3001: The Final Odyssey, Arthur C Clarke predicted a thermal crisis caused by abundant free energy. Is it plausible?
Total solar insolation is in the region of 1.8x10^17 W, which is some 10,000 times greater than the total energy use of humanity. This is not so far out when you consider our exponential energy use over the past few centuries! If growth does not slow (which it must), we could expect to use that much energy in about 4 more centuries.
But we could expect to hit problems before then. What percentage of disruption to Earth's energy budget leads to visible effect? Our current imbalance due to greenhouse gases amounts to roughly 1 Watt per square meter, or 0.1%. At our current rate of growth we'll reach that in a mere century! So even if we switch entirely over to nuclear power starting today, and continue along our merry way safe in the knowledge that we're producing no greenhouse gases, in 100 years we'll have a similar warming problem from energy alone.
Isaac Arthur on YouTube talks about this quite a bit.
Given limitless cheap energy like nuclear fusion, the ultimate limit on human population is not land or water but the waste heat that we generate. We're very far from that being an issue today, but in some dystopian future where we turn earth into Coruscant, that could be a thing.
I hope instead we stabilize our population or move to settlements in orbit. I'd like to see the land we currently use for food to be rewilded in a world where we can grow food in orbit and in vertical farms / artificial food factories. It would be nice if future humans mostly lived in cities or space habitats and the earth mostly went back to nature.
You might be interested in the book “ethnobotany: people, plants, and culture” to learn why leaving nature alone is not the best option, that biodiversity and rich ecosystems can come from human interference - weeding plants that are taking over, spreading seeds of food and medicine, intentionally building the soil - after a few thousand years you end up with the Amazon rain forest. It doesn’t happen on its own, humans are a part of it. To have this mind of leaving earth alone and even leaving it behind is leaving a lot of good food on the table, I wouldn’t want to live among the factory farms in space.
I don't buy that the Amazon is meaningfully a consequence of human activity. The sheer biodiversity on display is not something I can imagine evolving in just a few thousand years.
I’m probably being misleading since it’s not my field, but a quick Google suggests that the forest has changed over the past few thousand years - I didn’t mean to suggest that the forest wouldn’t be there without us, but that the ecosystem is richer and more complex because of our interference.
Just one source that talks about the changes over the past couple thousand years:
"These indigenous systems were highly sophisticated...There are over 80 domesticated or semi-domesticated crops in the Amazon," he said. "In Europe at the time they were working with about six."
I don't know if 100 years is "very far". It's not implausible that someone develops a practical fusion plant this decade, and at that point we're well on our way. We don't even need to turn the planet into Coruscant - by the maths I just spelled out, we're only a factor of 10 away from noticeable warming! A bit more population growth, a few lifestyle upgrades for the global south, and we're there.
Im skeptical that fusion will be a silver bullet for our problems. While I agree that producing lots of clean energy is the solution we need for many things, im not sure fusion is going to scale very easy when it is becomes practical for power generation. The sun is only producing thermal power per volume equivalent to a pile of manure, so even if we manage to increase that an order of magnitude, we will need an astronomical amount of plants and infrastructure to make it a primary energy source. And with such scales needed, we could have already done the same thing using other sources including fission.
Right, the point was simply to provide a plausible mechanism by which we could continue to increase our energy consumption exponentially, for the sake of argument. The thought experiment of "global warming from pure energy expenditure" doesn't work if the energy source is solar, because that energy offsets insolation.
I'm not particularly bullish on fusion power, though we can dream.
We may well need to deploy configurable sunshade at the earth - sun Lagrange point or something similarly drastic to keep the climate in a hospitable band.
Unfortunately not. All waste heat is already radiated into space, and there's no way to make it go faster. Heat always flows from hot places to cold places, unless you put energy in - so we can't gather all of our waste heat into one place for disposal, without creating more waste heat. It's the second law of thermodynamics, I'm afraid.
Even though GP's mechanism doesn't explain global warming, it does explain the nigh-impossibility of developing technology that can carbon-capture us out of this mess.
Biomass is basically solar-powered carbon sequestration.
If each year of fossil fuel consumption corresponds to the energy of 400 years of biomass, and we've been burning "too many" fossil fuels for 50 years, then to get out of this mess we would have to cover 50x400 = 20,000 Earth's with solar panels hooked up to carbon capture machines.
It's way worse, if course, because photosynthesis is more efficient than solar panels, and there's inefficiencies in carbon capture, but you get the idea!
We've used up way, way, WAY too much energy making tiny explosions and now we have to undo each and every one of them.
Your example incorrectly assumes the entire solar constant went toward carbon sequestration and this is obviously not the case.
The overall energy efficiency of the natural photosynthesis to sequestered carbon process is not inherently more efficient than man-made alternatives. The efficiency of the PV cell is just one small factor.
A much more accurate way to calculate sequestration potentials is to measure their energy cost and multiply by available energy.
It's just a Fermi estimate. Feel free to multiply/divide by ten (or even 100!) in either direction. The main point is that we're not going to carbon capture our way out of this--at least not with anything resembling modern technology.
But your estimate is demonstrably off by at least a factor of ten thousand.
The thrust of this paper is that it takes 90 tons of ancient biomass to result in 1 gallon of gasoline. This is a reduction of 30,000 to 1. This is the opposite of an efficient system. The vast majority of solar input and related carbon captured from the atmosphere by ancient plant matter is not being utilized by modern fossil fuel systems.
The point of this paper is that the ancient photosynthesis to fossil fuels process is incredibly inefficient. The "400 years" isn't indicative of the energy we're consuming today -- it's indicative of the extremely low percentage of solar energy that ends up captured inside fossil fuels.
We absolutely can carbon capture our way out of this. Again, you can do some pretty basic math on known sequestration techniques to disprove your conclusion.
I'd put my money on directly modulating incoming solar radiation instead
From the first time I saw the animations of the planned Starlink fleet, I started wondering if one could use a satelite fleet to manage incoming solar radiation.
There are some regulators at play too. Higher carbon+heat leads to better conditions for plant, which absorbs carbon and generates swamp... Which will be pulled underground to make more oil. We have overwhelmed such systems but they can correct our actions if given time.
Also higher carbon and heat seem to cause the ice caps and the glaciers to melt down faster than plants can absorb the excess heat. You could also say that it’s a regulator but I’m not sure it’s good the humanity in any way.
And more and warmer oceans provide more space for plankton to eat carbon. Nature almost always a regulatory process at the ready. The question is only its capacity.
Sure life will adapt or change or not. But I am not sure we will. We have now reached the point where we can stop using fossil fuels and dumping carbon into the atmosphere.
I am sure the earth will have time to adjust but not « us ». That was my understanding of the phenomenon at play. I may be wrong but it don’t understand the downvote. My comment wasn’t political.
