Say we use massive carbon-sequestration machines to suck all the excess carbon out of the atmosphere (we’ll ignore all the stuff like cost, labor, practicality, NIMBY, just focus only on the science). “Excess” meaning, well, all the carbon emissions we put in the air that we shouldn’t have (let’s not be too pedantic.)
Does Earth then cool back down a few degrees Celsius to a more ideal temperature, and if so, by how much?
I read somewhere that, if the concentration of CO₂ in the atmosphere were 0 ppm, the Earth would turn in to an iceball.
While not directly a relevant answer. Maybe the ethanol/vodka producers would go out of business.
Right, we wouldn’t want to remove all of the carbon dioxide, because we do depend on some level of greenhouse effect to keep the temperature at a level livable for humans. But that’s not what the OP is asking: He’s asking about just bringing it back down to the immediately pre-industrial level.
The naive answer is that it would bring temperatures down to pre-industrial levels, too. But that might not necessarily be true: There may be some climate phenomena with multiple stable equilibrium points, which have been switched by our activity, and which might not switch back. Though I’ll leave the details for someone more knowledgeable.
Also:
It’s not so much a matter of the temperature itself being ideal or non-ideal (as long as you avoid the extremes like snowball Earth). Take the planet at any temperature, and with time, life (both human and otherwise) will find an equilibrium at that temperature. The big problem with what’s going on now is that the temperature is changing, far too rapidly for humans or anything else to adapt. So even if we had unicorn-powered technology to directly affect the carbon dioxide level at whatever level we want, it might still be prudent to merely stop the increase, or to reduce it to pre-industrial levels only gradually.
This was cited many moons ago, many times before, in climate change threads:
From the source:
https://climatechange.chicago.gov/climate-change-science/causes-climate-change
Models that account only for the effects of natural processes are not able to explain the warming observed over the past century. Models that also account for the greenhouse gases emitted by humans are able to explain this warming.
At a glance, human released warming gasses from the start of the industrial revolution, increased the natural temperature by about 1 degree Fahrenheit (.56 Celsius) by the year 2000.
More recent checks (2017) show that the increase is now close to 1 full degree Celsius (1.8 degrees Fahrenheit)
I would be curious about the response rate.
Unless we’re magically sucking thermal energy out of the environment the same time we’re sucking CO2 out, the atmosphere will still be as warm as it was an instant before the Big Suck. How would the temperature curve respond to the sudden loss of an excess of greenhouse gases?
I wonder if this has ever been modeled, even speculatively? I wouldn’t expect this exact thing would ever have been published, simply because it depends on a magic premise.
So, apparently, if we suck out all the excess carbon, we don’t actually cool the planet, we merely stop the additional warming. Cooling would require going above and beyond and actually generating a deficit of carbon?
No I don’t think so. Carbon is a greenhouse gas. That means it traps the heat in the atmosphere. If you removed the excess, the Earth would radiate away the heat. Almost all the heat the Earth gets comes from the sun directly, or indirectly from fossil fuels which originally are due to the sun. I’d think at a warmer temperature it would radiate faster until it returned to an equilibrium. But this would also depend on how much excess is dumped into the atmosphere by burning more fossil fuels.
It’s hard to say how it would play out. It would probably not cool off as fast as it warmed up, but it would eventually cool to a lower equilibrium point.
Are we magically sucking this carbon out of the ocean too? If not, then just as the ocean has been absorbing a fair amount of what we have emitted, it will start off gassing as we pull it from the atmosphere.
The ocean is not only a massive carbon sink but also a huge thermal reservoir, and most of the excess thermal energy that released carbon dioxide has been trapping has gone into the ocean. Even if we could return the radiative balance back to pre-Industrial levels and maintain it in equilibrium, the ocean would still reject heat back into the atmosphere and power tropical depressions into powerful storms.
Less than a watt per square meter might seem like a small change, but multiplied by the surface area of the ocean (more than 360 million square kilometers), that translates into an enormous global energy imbalance. It means that while the atmosphere has been spared from the full extent of global warming for now, heat already stored in the ocean will eventually be released, committing Earth to additional warming in the future.
The carbon cycle in the oceans is very complex because of both the multiple layers that uptake and transfer carbon dioxide in different ways, and because how living organisms both sequester carbon and are affected by the excess of it.
There are, of course, significant ancillary effects in the melting of ice caps and continental glaciers, thawing of permafrost, and the release of gases such as methane that are stored in benthic clathrates, none of which are going to be reversed by simply removing excess carbon dioxide. Those people promoting the notion that some hypothetical future technology will be developed to suck excess carbon dioxide out of the air (implausible at the scale required to significantly reduce atmospheric carbon) are ignoring that the delicate balance of the current global climate system has already been perturbed by the release of carbon that has been naturally sequestered for hundreds of millions of years in the span of less than two centuries, and there is no stuffing of that genie back into its bottle.
People tend to think of the climate as a relatively static system with minor fluctuations around a stable set point, like a house with a furnace and thermostat, but in fact it is a highly dynamic system in constant flux that has only been moderated to equilibrium by the presence of an extensive biome via the hydrologic cycle and the energy stored and released in periodic snow and ice. The system is big enough that it is hard for a single even or factor to radically shift it for more than a few months (e.g. a volcanic eruption or major firestorm), but the release of such much carbon dioxide in such a short period of time is a global effect that will take centuries or millennia for the climate system to come to a new dynamic equilibrium. The observed instability in the polar vortex, weakening of the jet streams, and presence of persistent regional “heat domes” are only the proverbial tip of the iceberg in terms of potential long term effects. Disruption of ocean gyres could have profound impacts upon both the climate and hydrologic cycle as well as ocean species dependent upon the stability they provide, and marine ecologists can only guess at what the resulting changes could be.
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