Schwartz paper: http://www.ecd.bnl.gov/steve/pubs/HeatCapacity.pdf

and critisized e.g. here: http://www.realclimate.org/index.php/archives/2007/09/climate-insensitivity/

I personally find large parts of the critique to be invalid (e.g. pretending that a GCM is a “system” as the climate; it should be rather embarrasing for a scientist to use a model to falsify a model…), but never the less would not want to miss his answers.

Hmmmm.

The Pinatubo eruption injected some 20 million tonnes of SO2 directly into the stratosphere, where it stayed for 2-3 years (to make it convenient, let’s say 800 days). The total effect (including water vapour feedback) was a cooling of maximum 0.6 ºC. Humans emit around 80 million tonnes per year, mainly in the troposphere where it lasts for average 4 days. The direct effect of both (scattering on wetted sulphate particles) is virtually the same, which means that the direct effect of human made aerosols is around 0.025 ºC (including a 4-day accumulation). Tropospheric aerosols also have an indirect effect on clouds (more reflective, longer lasting). The IPCC gives a fourfold range increase for this forcing, compared to the direct effect. If we assume this is right, then the net effect of human made SO2 emissions would be 0.1 ºC.

That is only for cooling aerosols, but black carbon (coal) and the Asian brown cloud (wood, browncoal, peat), are warming the lower troposphere above India (and China?) + albedo changes over snow and ice fields…

Thus the net effect of all aerosols together may be positive, not negative…

Further detailed comments at RC, here and here, the latter without any reaction of the guest specialists in aerosols, Ron Miller and Dorothy Koch from NASA GISS.

1966-1975 +.00C anomaly trend (19.8%), +10 ppmv CO2
1996-2005 +.22C anomaly trend (94.5%), +20 ppmv CO2
1895-1904 -.16C anomaly trend (88.7%), +02 ppmv CO2
1986-1995 +.09C anomaly trend (78.9%), +14 ppmv CO2
1976-1985 +.12C anomaly trend (44.1%), +14 ppmv CO2
1956-1965 +.00C anomaly trend (06.6%), +06 ppmv CO2

What I wonder is what 2006-2015 is going to look like….

Lucia,

Yours is a very important question that must be answered in a straight way. Which one from delta T, F and S is well known? I always wondered why the modelers took the delta T of the 1870s like the “standard” when the most plausible delta T to be a “standard” delta T is that one corresponding to the last 12000 years. The problem with that ample delta T is that it is enough wide (some 3-7 K) as to blur the current “global warming”.

Hi Paul, I quote (in 37) from real climate’s dismissal of the paper, not the paper.

Real climate’s analysis of the paper concludes with the quote in #37 (as I read it) that the real climate’s estimate of the uncertainties in the observations used in the paper are too large to rule out the GCMs (with reasonable model uncertainty applied by real climate) fitting the observations.

That struck me as real climate applying Steve’s auditing principals that if the observations are uncertain and the models are uncertain, then the models have no prediction power.

So Steve is having more impact than imagined on real climate, they’re adopting Steve’s approach!

And it a further test of the predictive power of climateaudit.org that mentioning Steve on real climate results in immediate removal of the offending comment.