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mikk0384 t1_ir4ypo6 wrote

No. Other than the factors mentioned by u/CrustalTrudger, there are other things that are guaranteed to happen even if the CO2 content stays at the current level.

For instance, the increase in temperature means that the ice coverage is shrinking. Ice is really good at reflecting the light that hits it back out to space, so the more the ice shrinks, the more sunlight gets absorbed and heats the planet instead. It takes a while for the ice to melt, so the temperature will keep climbing for decades after the CO2 content is fixed.

There are other factors that play a role in the same manner. A lot of methane is trapped under the permafrost in many places, and methane is 25 times more potent as a greenhouse gas than CO2. This means that as the permafrost melts, more greenhouse gasses will be emitted to the atmosphere, with increasing temperatures to follow.

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onlinefunner OP t1_ir6bvdy wrote

>n the same manner. A lot of methane is trapped under the permafrost in many places, and methane is 25 times more potent as a greenhouse gas than CO2. This means that as the permafrost

Great info, thanks!

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CrustalTrudger t1_ir4v74i wrote

Let's rephrase the question to, "If global CO2 concentration in the atmosphere was constant, would global average temperature stay constant?" Considering even moderately long timescales (e.g., a few thousand years), the answer would be no because even hypothetically if CO2 concentration stayed exactly the same (which itself is basically an impossible hypothetical considering any part of Earth history if considering more than a few hundred to thousand of years), the amount of incoming solar radiation would change because of a variety of changes in Earth's orbital parameters (e.g., eccentricity, obliquity, precession). These orbital induced changes in solar radiation (i.e., insolation) are typically described in the context of Milankovitch cycles and are broadly the main drivers of most (but not all) climatic changes on millennial timescales with CO2 largely acting as a reinforcing feedback on these timescales. On longer timescales (e.g., several million to hundreds of millions of years), the amount of CO2 in the atmosphere represents a primary driver for climate with orbital changes influencing smaller scale variations (both in terms of magnitude and time scale). So broadly, major and long-lived changes in CO2 concentration (that reflect long-term balances between carbon stored in the atmosphere/hydrosphere vs lithosphere/mantle) drive transitions between Icehouse vs Greenhouse climates where as Milankovitch cycle type controls drive things like interglacial-glacial transitions within an Icehouse climate (i.e., what we have now). Both of these are discussed in significantly more detail in a variety of places, like this FAQ entry.

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mfb- t1_ir52cd8 wrote

OP asked about constant emissions not constant concentration, so it would be even worse - constant emissions (assuming we use present-day values) make the concentration rise for a long time.

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phdoofus t1_ir6jq3z wrote

Another factor playing in to other answers is that even if we cut off additional CO2 production *today* the oceans have so much additional heat stored in them from the last 100+ years of fossil fuel burning that the atmospheric temperatures would continue to rise for several hundred years.

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CrateDane t1_ir6oln0 wrote

Well, one "good" thing about the oceans is that they still lag behind on equilibrating with the CO2 concentration in the atmosphere, so in the absence of more emissions the oceans would actually suck a fair bit of CO2 out of the atmosphere.

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