That CO2 you emitted last Tuesday: Is it coming back next month, next year, or in March 3011?
Tim Flannery makes it clear that CO2 circulates o-so-slowly, circa “a thousand years”. Remember that CO2′s “greenhouse” effect occurs at speed-of-light timescales, so if the temperature is affected, so must be the CO2 (according, at least, to the World of Flannery).
If we cut emissions today, global temperatures are not likely to drop for about a thousand years… Just let me finish and say this. If the world as a whole cut all emissions tomorrow the average temperature of the planet is not going to drop in several hundred years, perhaps as much as a thousand years because the system is overburdened with CO2 that has to be absorbed and that only happens slowly. [Thanks to Andrew Bolt]
There are a few clues that maybe CO2 doesn’t idle the centuries away aloft, and that (I know you’ll be shocked) the Climate Commission (and IPCC) have overstated things: If emissions are absorbed by the global system in a matter of months, it rather blows the idea that we have to act decades ahead to stop the catastrophe. If CO2 levels adjust quickly, our “sins” will be much more quickly forgiven, and we can wait and see.
The thousand-year time frame doesn’t fit very well with NASA’s official carbon cycle and the empirical evidence.
You can see below in the NASA diagram that plants absorb 16% of all the carbon dioxide in the entire atmosphere each and every year (121 Gt of the 750 Gt in the air), and oceans absorb 12%, meaning that 28% of all the CO2 in the global atmosphere is sucked down each year. Let’s call it one quarter.
If a quarter of all atmospheric CO2 is being turned over each year, this implies that if humans found the Fountain of Endless Energy and stopped emitting any CO2 tomorrow, within just four years, only about 30% of that CO2 would remain. Indeed 90% of all the emissions that we’d ever put up there since Cheops built a pointy rock house* would be gone by 2020.
Then there’s that point about global CO2 levels shifting twice a year:
Notice the bumpy ride of the CO2 graph? Each year CO2 varies by as much as 10ppm — 5 times the amount that humans are supposedly increasing it by per annum. CO2 levels peak at the start of the Northern Hemisphere summer as resurgent plants start to pull levels down. They’ll keep drawing out the CO2 until about November, when the cold shuts them down, and as they die or go dormant, they release CO2 back into the air. The reason the Northern Hemisphere dominates the plant growth cycle because of the large slabs of land in cold places which are alternatively covered with smothering snowcover or layered with carpets of hungry greenery. Though let’s not forget the Southern Hemisphere’s contribution: At the same time as hungry plants are starting to draw out the CO2 up in the North, the cooling southern oceans are soaking up the CO2 as well (colder water absorbs CO2 and warmer water releases it).
Craig Idso at CO2science.org points out that this seasonal swing has increased by nearly 20% since the 1950′s, probably because there is more CO2 in the air, and this helps plants grow faster.
And the main point about these seasonal details is that the entire planetary atmospheric CO2 level adjusts every month.
The system is responsive: When we add more CO2, it shifts a very big equilibrium ever so slightly.
Here’s another way of looking at those furious carbon flows:
Source: Columbia University Fig 11
Each week 600 mT of carbon dioxide are drawn out of the atmosphere by plants and oceans.
*King Tut apparently didn’t build much of a pyramid. The small tomb was buried. It’s important to get these things right.