Joe Romm has gone on the record at Climate Progress on April 13, 2009 that the “median” forecast was for warming in the US by 2100 of 10-15F, or 5.5-8.3C, and he made it very clear that if he had to pick a single number, it would be the high end of that range.
On average, the 8.3C implies about 0.9C per decade of warming. This might vary slightly by what starting point he intended (he is not very clear in the post) and I understand there is a curve so it will be below average in the early years and above in the later.
Anyway, Joe Romm is ready to put his money where his mouth is, and wants to make a 50/50 bet with any comers that warming in the next decade will be… 0.15C. Boy, it sure is daring for a guy who is constantly in the press at a number around 0.9C per decade to commit to a number 6 times lower when he puts his money where his mouth is. Especially when Romm has argued that warming in the last decade has been suppressed (somehow) and will pop back up soon. Lucia has more reasons why this is a chickensh*t bet.
Like most bullies, Romm is really in the chicken business.
An easy way to measure the climate sensitivity is to take the ratio of the outgoing surface energy to the incident solar energy. When the incident solar energy is adjusted for the albedo of about 0.3, we get 239 W/m^2. The outgoing surface energy at 288.5K is 392.8 W/m^2, resulting in a gain of about 1.6. We can also measure the dynamic gain by examining the response of the climate to the +/- 40 W/m^2 sinusoidal variability in solar energy that occurs between perihelion and aphelion. This is a little tricker because the global average temperature is actually about 4C colder in January (perihelion) than in Jun, instead of the 3-4C warmer that it should be. This is the result of Northern hemisphere ice and snow which reflects more energy and if not for the increased solar energy at perihelion, would be closer to 10C colder instead of just 4C. Another way to calculate this is from a theoretical basis, where dEsurface/dEsun is computed. All of these give a result consistent with 1.6.
For a climate sensitivity of 1.6, the 3.7 W/m^2 claimed for doubling CO2 (HITRAN simulations predict a smaller increase) becomes about 6 W/m^2. Starting from 392.5 W/m^2, 6 more makes it 398.8 W/m^2, which when back converted with Stefan-Boltzmann, results in a temperature of 289.6K, for a total increase of 1.1C. If you use the actual HITRAN data and compute the result for doubling CO2 from 280ppm to 560ppm, you get 1.78 W/m^2, for a rise of only about 0.5C. The HITRAN based simulation actually predicts the total energy absorbed by the atmosphere increases by 3.6 W/m^2 (probably the number that the IPCC metric was backed in to), but the atmosphere re-radiates it’s absorbed energy, half of which goes into space and the other half is returned to the surface.
George
Will you ever work out that the US is not the world? Comparing even a prediction for one with a prediction for the other would be pretty fucking stupid. Here, you’re comparing a prediction for one in 90 years time, with observations of the other over the previous ten years.
What would it take to get you to understand something?
Maybe it’s a chicken**** bet, but I would seriously consider putting down $500 or $1000 if the measure were something besides GISS. I don’t trust James Hansen one bit.
A fairer way to do the bet would be to look at the 4 leading global surface temperature measures; drop the highest and lowest trends; and average the other two.
Romm can’t explain the flood in the southeast this week. A certain river reached 29 feet in depth which he said was global warming. When It was the same depth in 1919, what was it then? Of course we have interstates and ditches that improve the velocity of water flowing to the rivers.
Yesterday he was aggitated about the dust storm in Australia. They have a dozen of those events over the past 100 years. I am sure his boss is busy defending the truthers over at ACORN. Podesta is the board member leading the investigation. Come on Joe r. soros can cover ya if you bet on 6 degrees in 50 years. You have power point presentations that promise it.
Brazil84,
I don’t trust Hansen either, but as I like to say, ‘When playing wack-a-mole with an AGW proponent, science is the best hammer and using their science is even better’.
You can find a summary of some of my findings on the climate at this URL.
http://www.palisad.com/co2/slides/siframes.html
It’s about 6 months out of date and I plan an update some time in the near future. It also identifies a clear anomaly in Hansen’s data which was left uncorrected (11/2001 when NOAA-14 was replaced with NOAA-16). When 5 year averaged anomaly analysis is layered on top of the data, it gives the false appearance of a warming trend in the years around 2001. This is a major flaw in anomaly analysis, where data anomalies are indistinguishable from anomalous trends. It’s no wonder that Hansen pushes this kind of analysis so hard.
George
To George White- there are additional factors you have to take into consideration in getting that
1.6 figure. The average incoming radiation from the sun is 342 watts/ square meter. A large part of that 30% albedo is negative feedback from clouds.
When you look at Trenbeth’s figures
http://stephenschneider.stanford.edu/Climate/Climate_Science/EarthsEnergyBalance
The actual magnification is from 235 watts to 492 watts once you take latent heat and convection into consideration, for a magnification of 492/235 = 2.09. The EFFECTIVE radiation is
390/235 = 1.66. 43/109 = just about 40% of the greenhouse effect goes into convection and latent heat. Why shouldn’t the same ratio, or maybe an even greater ratio, apply to that 3.7 watt increase?
Originally I did the same 390/235* 3.7 watts = 6.14 watts at the surface as you did, but after reading some on the “Voigt” profile, and scare stories regarding increases in hurricane frequency, increased climate variability, etc. I’ve reconsidered. Now I think the net effect of doubling
CO2 will more likely have an effect of 393.7/390
Alan,
All greenhouse gases do is delay the release of surface energy, which is primarily a diurnal effect. Consider radiation cooling on a clear winter night. The energy entering the system is from the Sun and only the Sun. You can’t count greenhouse gas energy the same as energy from the Sun, at least with regard to forcing the system. This energy already forced the system when it arrived from the Sun. Counting it again is a violation of COE, at least relative to the top level energy balance and the closed loop gain of the system. The energy from GHG is not new energy, but energy from the past that just hasn’t made it out of the system yet. Counting GHG energy as new energy is why so many models diverge and predict nonsense like run away effects. GHG concentration changes only affect the response of the system. Water vapor is a special case with a wide synamic range, effectively making it a control variable for the system, primarily through the effects of clouds.
Similarly, you can’t count latent heat and convection as inputs to the system. These just are part of the systems response to incident energy, who’s effect is already accounted for by the closed loop ratio between surface energy and incident energy.
Voigt profiles don’t make a difference. The integral over all wavenumbers is always unity, independent of whether you are using the Lorentz, Doppler or Voigt shapes for the absorption line. The Voigt line profile is difficult to model analyticity, so approximations are often used. If the approximation doesn’t maintain a unit integral over all wavelengths, even by a small amount, it will overestimate the effect of the line and produce incorrect results. All this does anyway, is move energy from the peak of the absorption line into the wings. There are so many lines, with so much overlap, and most of the relevant CO2 absorption wavelengths are so saturated, that it hardly matters which you use, relative to the energy balance. Most of this only matters in the upper stratosphere and above, where Lorentz shapes get real narrow and Doppler broadening starts to become important. Because the lines are so broad near the surface, underestimating their width in the upper atmosphere is inconsequential.
You should also notice where the 3.7 W/m^2 comes from. My HITRAN based simulations show a total increase of 3.6 W/^2, however, half of that goes into space and only half is returned to the surface. Technically, only 1.3 W/m^2 is subject to the same amplification as post absorption incident solar energy on the surface. About half of the incident energy is absorbed, so the post absorption gain is about 2x, or about 3.2, however, this 2x gain is applied to 1/2x energy, so it’s a wash.
As for hurricane frequency, have you noticed that the number of hurricanes has been abnormally low recently? This year has been especially slow. This is likely the result of the significantly lower than normal Sun spot activity we have been experiencing. UV flux has been very low lately. While the upper atmosphere blocks most UV, that energy still enters the system, even if captured by the atmosphere. Hurricanes are the climates way of ridding the system of excess energy. Something that few understand is that as the planet gets warmer, it gets increasingly difficult to maintain that warmth, let alone get even warmer.
Another point to consider, is that to get the magic 3C sensitivity, the power gain of the system must be greater than 16! There’s no physical mechanism, real or imagined, that can do this and is the Achilles heal of the AGW argument.
George
Alan,
I want to amend what I said about the post absorption gain. It’s not 2x, but only about 1.1x. Less than 10% of the incident solar energy is absorbed while about half of the outgoing surface energy is absorbed. The long term (12 month+) closed loop (i.e. post feedback) gain is about 1.6, which can be unambiguously applied to solar energy and changes to solar energy. Whether or not the same gain can be applied to reflected GHG energy may be subject to debate, but in any event, the gain will not be any greater than 1.6 when applied to the GHG energy that is directed back to the surface.
George
In reply to CO2 is not evil:
“All greenhouse gases do is delay the release of surface energy, which is primarily a diurnal effect. Consider radiation cooling on a clear winter night”
That I agree with 100%. Note that the surface temperature can drop 10 C or more from max to min over the course of a day, while total atmospheric change is on the order of less than 1%, or less than 3C. That results in temperature inversions on clear nights. Obviously that means much more radiation is lost to space directly from the earth’s surface than from the atmosphere, implying that greenhouse gases other than H20 have a minor effect of surface temperatures.
The major effect on climate and weather is from Water, its high specific heat, and the fact that it exists in three phases on earth; solid, liquid, and gas. Measuring and predicting weather and climate is mostly trying to determine how water in its various phases will continue to transport heat from the equator to the poles.
I disagree with you on latent heat, though. Surface temperatures would average about 305 K rather than 288 K if that heat weren’t being carried away from earth’s surface by conduction and convection. You’ve got to take that into consideration when computing the greenhouse effect.
As to the Voigt profile, that was an aside, thrown in with hurricane frequency, etc. Note that the AGWers throw in scare stories about increased hurricane frequency without taking into consideration that increased hurricanes imply increased clouds, and increased rain, which would increase earth’s albedo and take up additional latent heat in evaporation of seawater.
Those powerful negative feedbacks would put a strong damper on any increase in hurricanes. My point was that the AGWers are making up worst case scenario scare stories. Those scare stories also apply to the broadening of
absorption bands with increasing temperatures and pressures. Maybe I’ll post more on that later
Alan,
Yes, I agree that latent heat is important to the system, but my point is that it’s already accounted for by my metric of gain, which is the ratio of measured surface energy to measured incident energy.
The point of this metric is that it’s simple to understand and exactly quantifies the sensitivity of surface temperature to changes in incident energy. The gain based on my latest analysis of 25 years of satellite data is 1.63 +/- less than 2.5%.
What the metric shows is that the equivalent power gain required to support the IPCC claim of 3C warming for 3.7 W/m^2 of additional forcing is so much larger than the measured gain, it’s completely unsupportable by any means. The current average surface energy @ 288.5K is 392.82 W/m^2. If the surface was 3C warmer, the energy at 291.5K is 409.42 W/m^2, for a total increase of 16.6 W/m^2. Considering a 3.7 W/m^2 increase, this represents a gain of about 4.5 which already is 2.75 larger than the system supports. However, 3.7 W/m^2 is the approximate increase in total absorption according to HITRAN data (3.6 W/m^2 actually). Half of this is re-radiated back into space and only half finds it’s way back to the surface, so 1.85 W/m^2 of additional surface energy input is somehow resulting in 16.6 W/m^2 of surface energy output, at least, according to AGW theory. 1.85 W/m^2 of additional surface energy is equivalent to about 2 W/m^2 of additional solar energy (<10% of incident solar energy is absorbed by the atmosphere). Converting to a required gain is, 16.6/2 = 8.3, which is over 5 times larger than the system demonstrates.
George
Have you seen this?
http://jennifermarohasy.com/blog/2009/09/why-i-am-an-anthropogenic-global-warming-sceptic-part-3/
(Apologies if you have already posted about it.)
Alan,
I want to amend what I said about the post absorption gain. It’s not 2x, but only about 1.1x. Less than 10% of the incident solar energy is absorbed while about half of the outgoing surface energy is absorbed. The long term (12 month+) closed loop (i.e. post feedback) gain is about 1.6, which can be unambiguously applied to solar energy and changes to solar energy. Whether or not the same gain can be applied to reflected GHG energy may be subject to debate, but in any event, the gain will not be any greater than 1.6 when applied to the GHG energy that is directed back to the surface.
George