What percent have we raised CO2?

Dirac

The question is somewhat ambiguous. The number of moles of CO2 in the atmosphere have gone up (400-280)/280 x 100 = 43% The molar percentage has gone from 0.028% to 0.040%, an increase of 0.012% The percentage by weight has gone up about 44/29 x 0.012% = 0.018%, since CO2 is heavier than most other gases in the atmosphere. For the greenhouse effect, though, it's not the atmospheric fraction, it's how much CO2 there is along a vertical column and how it is distributed vertically (higher means more greenhouse effect). In comparison, water vapor has a molar percentage of about 0.4%, or about 10 times as much. "Anonymous" points out that CO2 has a diminishing warming effect as its concentration increases, that is true for CO2 and for all the other greenhouse gases present in the atmosphere (at least in the concentrations currently seen). That's why methane is sometimes misleadingly referred to as a "stronger" greenhouse gas, it's not that it's stronger on a molecule by molecule basis, it's just that it's present in much smaller concentrations, so you don't have to add as much to get a big change.

Jim

Dirac is correct, except that the question is not ambiguous. Percent cahange is always the ratio between the change and the initial value, multiplied by 100%.

Daro

Gov. wants to keep the issue as vague as possible. Simplified "give us your money or dies". Hence the continued calls for a global tax collected by the U.N. Purely political issue.Earth has warmed many many times before, and CO2 has been at dramatically varied levels, far above the paltry numbers they are trying to scare us with. The Yellow vests indicate that even hardcore socialists are not impressed with the supposed "solutions". .

JimZ

We don't really know since it may have warmed without our CO2 emissions. Warming tends to cause the ocean to emit more CO2 than it absorbs increasing the atmospheric concentration. It went from about 300 to 400 which an increase in 33 percent. I have read that about 40% of what we have emitted is absorbed by the ocean so even though the oceans should emit more with warming, our emissions of CO2 into the atmosphere has the effect of increasing the amount the CO2 absorbs into the ocean so there are conflicting processes going on there. Climates weren't stable before humans came around so it is hard to know for certain. I believe we have emitted enough to cause the increase. I just can't say what the concentration of CO2 would have been if humans didn't exist. That isn't a problem for alarmists because they like to blame things on humans and admitting that they don't know ruins their ability to exaggerate. For those that suggest methane is a problem, they should read this article and explain why. https://wattsupwiththat.com/2014/04/11/methane-the-irrelevant-greenhouse-gas/ If you add a gas (methane) that is already masked by another gas (water vapor), adding more probably won't do much according to Dr. Tom Sheahen

Anonymous

Atmospheric carbon dioxide (CO2) is a mild greenhouse gas that exerts a diminishing warming effect as its concentration increases. Doubling the concentration of atmospheric CO2 from its pre-industrial level, in the absence of other forcings and feedbacks, would likely cause a warming of ~0.3 to 1.1°C, almost 50% of which must already have occurred. At the current level of ~400 ppm we still live in a CO2-starved world. Atmospheric levels 15 times greater existed during the Cambrian Period (about 550 million years ago) without known adverse effects.