The global carbon cycle. Analogy: We're filling the bathtub at a faster rate than it drains.

The global carbon cycle. Analogy: We're filling the bathtub at a faster rate than it drains. And the surplus keeps accumulating year after year.

Do human CO2 emissions (4%) have a different effect on the climate than natural CO2 emissions (96%)?

David Charles Leithauser, Technical consultant, writer, inventor (1980-present)

Answered Jul 19, 2018

The answer to your basic question is, “No, human CO2 emissions do not have a different effect on the climate than natural CO2 emissions.”

An important comment is that no, human emissions are not 4% of all emission (to be more precise, net emissions). Natural forces have a net NEGATIVE emission level. That is, all natural forces combined are currently taking more CO2 out of the air than they are putting into it. Without human emissions, CO2 levels would be dropping slightly, although this would stop and net emissions natural minus CO2 removal would be zero once they reached a new equilibrium. They would be in balance.

The claim that human emissions are just 4% of CO2 additions to the atmosphere is just one of many big lies put out by the fossil fuel companies. It is based on this.

Humans put 29 gigatons of CO2 into the air each year. (This information is slightly dated, it is actually slightly more now, but close enough to explain the point.) Decaying vegetation puts out 429 and the ocean releases 322. If you look only at these figures, you get humans putting out 4%. However, they conveniently ignore the fact that while decaying vegetation puts out 438 gigatons of CO2, GROWING vegetation takes in 450, and while the ocean releases 332 gigatons of CO2, it then reabsorbs that much plus another 6 gigatons. All told, vegetation and the oceans absorb all the CO2 they release, plus 17 of the 29 gigatons that humans release (without reabsorbing any of it back).

To be clear again, it does not matter whether the CO2 comes from humans or natural sources. They all have the same effect on the climate. What does matter is that the net amount of CO2 is increasing due to humans.

I would like to point out that this type of deception, citing some facts while leaving out important information that proves those facts are irrelevant, is very typical of the climate change denier misinformation campaigns. Be on the lookout for such misleading statements.

https://www.quora.com/q/climatechangediscussion/Do-human-CO2-emissions-4-have-a-different-effect-on-the-climate-than-natural-CO2-emissions-96?ch=8&share=ba55231e&srid=Oyud