…and dishonesty. More is beginning to leak out, this time from of all places the UN. That august body’s IPCC has had leaked a draft of its latest “study” on the man-caused disaster in climate, and it isn’t a pretty example of the outcome of climate “scientist” incestuousness.
High points on the leak are from Matt Ridley, in The Wall Street Journal, and they concern a “pollutant” that our present administration is going after, and damn the economy—and damn the
poor people whose lives are being ruined by high food and energy prices caused by the diversion of corn to biofuel and the subsidizing of renewable energy driven by carboncrats[.]
The question at hand:
How much warming will a doubling of atmospheric carbon dioxide actually produce?
Ridley’s information comes from Nic Lewis.
A semiretired successful financier from Bath, England, with a strong mathematics and physics background, Mr Lewis has made significant contributions to the subject of climate change.
Per Lewis [emphasis added]:
[T]he latest observational estimates of the effect of aerosols (such as sulfurous particles from coal smoke) find that they have much less cooling effect than thought when the last IPCC report was written. The rate at which the ocean is absorbing greenhouse-gas-induced warming is also now known to be fairly modest. In other words, the two excuses used to explain away the slow, mild warming we have actually experienced—culminating in a standstill in which global temperatures are no higher than they were 16 years ago—no longer work.
Thus [again, emphasis added],
We can now estimate, based on observations, how sensitive the temperature is to carbon dioxide. We do not need to rely heavily on unproven models. Comparing the trend in global temperature over the past 100-150 years with the change in “radiative forcing” (heating or cooling power) from carbon dioxide, aerosols and other sources, minus ocean heat uptake, can now give a good estimate of climate sensitivity.
The conclusion—taking the best observational estimates of the change in decadal-average global temperature between 1871-80 and 2002-11, and of the corresponding changes in forcing and ocean heat uptake—is this: A doubling of CO2 will lead to a warming of 1.6°-1.7°C (2.9°-3.1°F).
This is much lower than the IPCC’s current best estimate, 3°C (5.4°F).
In the end,
A cumulative change of less than 2°C by the end of this century will do no net harm. It will actually do net good—that much the IPCC scientists have already agreed upon in the last IPCC report. Rainfall will increase slightly, growing seasons will lengthen, Greenland’s ice cap will melt only very slowly, and so on.
There’s more to this climate pseudo-science failure, and it flows from the CO2 interactions via alleged feedback loops [emphasis added]:
A little warming (from whatever cause [including atmospheric CO2]) heats up the sea, which makes the air more humid—and water vapor itself is a greenhouse gas. The resulting model-simulated changes in clouds generally increase warming further, so the warming is doubled, trebled or more.
[The problem is,] water vapor may not be increasing. A recent paper from Colorado State University concluded that “we can neither prove nor disprove a robust trend in the global water vapor data.” [On top of that], as one Nobel Prize-winning physicist with a senior role in combating climate change admitted to me the other day: “We don’t even know the sign” of water vapor’s effect—in other words, whether it speeds up or slows down a warming of the atmosphere.
One reason for the uncertainty of the sign is that atmospheric water vapor means more clouds, and clouds reflect inbound sunlight while trapping outbound heat. Which has the greater effect—reducing the inbound inputs or holding onto the outbound outputs? Only a climate pseudo-scientist claims to know at this point in the data collection and analysis. Especially given the…quality…of their data and of their models.
There’s a whole lot more at the Watts Up With That? site, both on the present topic and on anthropogenic climate change, generally.