Steve_American wrote:1] Lurkers, did you follow how TtP got from a "change in albedo from ~.3 to ~.9 in glaciated areas" to "A 1% increase in IR absorption would therefore equate to an albedo difference of ~0.006"? I could see no connection between those 2 statements that are back-to-back in his reply.
Albedo is inversely proportional to absorption of visible-spectrum energy by the earth's surface. GHGs increase temperature by absorbing and then re-radiating that energy when it is re-radiated from the surface as IR.
2] Lurkers, TtP seems to totally fail to grok that changes in IR absorption cause a tiny amount in cooling or heating each day for centuries. This goes on until a new equilibrium temp is reached. So, a tiny change can cause a large temp change over many decades.
No, because negative feedbacks force a new equilibrium very quickly.
3] Lurkers, TtP above wrote, "A 1% increase in IR absorption is insignificant because". I have not seen any attempt by TtP to support his claim that a 1% change in absorption is insignificant.
I explained it.
. . . This is my attempt to show that he is wrong using his own words. TtP asserts that the 280 ppm (IIRC) of CO2 in the air in 1850, will absorb all the IR light/heat in a few hundred meters.
In combination with the water vapor that makes up ~1%-4% of surface air, depending on various local factors. And the water vapor is far more important both because it absorbs IR better than CO2 and because it is far more abundant in surface air.
This is a lot of absorption. Yet TtP admits that IR light/heat still escapes into space, when he says energy in = energy out. Then he asserts that a 1% increase in the absorption of IR light/heat is insignificant.
Think of the blankets. The first blanket absorbs all the heat from your body, but then it transmits half of it to the next blanket, which absorbs it, and half back to your body, which is why you feel warmer. But then the second blanket transmits half of the heat it has absorbed from the first blanket to the third blanket and half back to the first blanket, and the first blanket transmits half of that back down to your body and half back out to the second blanket, etc., etc., for all 41 blankets. Each blanket blocks all the heat from the one below it, but then transmits half of that heat outward and half back in; in the end, each blanket ends up a little cooler than the one below it. Adding one cotton blanket to top of the stack has a large effect on the former top blanket, but almost no effect at the bottom.
. . . An analogy might be wealth, income, and spending. Here wealth = the energy in the air measured as its temp. Income is the rate at which the IR energy is absorbed. And spending = the rate at which the energy of that sample of air loses its energy by reradiating IR light/heat. OK, here we are talking about what effect changing the rate of change in the income has on wealth. That is, does a 1% increase in the rate of change in income have a significant effect on the accumulated wealth of the person? We know that there is a time lag between increasing the CO2 ppm and the temp of the air. That is the air takes time to increase its temp. You know this because when you cook and boil water, turning up the fire under the pot does not immediately make it boil. This means that the temp of our air below slowly heats up, and because the amount of IR being reradiated depends on the temp of the air the amount of IT reradiated lags behind the amount of IR absorbed. We need to assume that she was spending the same as her income, because before in 1850 the temp was not increasing much due to the CO2 in the air.
You are ignoring the negative feedbacks. When something warms up, it automatically radiates more energy, establishing a new equilibrium. In fact, the amount radiated is proportional to the fourth power of the absolute temperature, so the negative feedback is extremely strong. By contrast, people don't automatically spend any more when they have more income.
. . . Suppose, the person's income was $100K/yr. Her wealth was $0, and her spending was $100K. this means her wealth was not changing because she spent all her income. [In 1850 we are assuming that the temp was constant. We do this because we need to eliminate all other reasons why the temp will change to see the effect a 1% change will have if all other factors are equal.]
No, the temperature would be constant at equilibrium no matter how much CO2 there was in the air. The heating effect is transient.
. . . OK, her income was $100K. A 1% increase would make her earn $101K/yr. There is a lag in her increased spending. I'll assume for illustration here, that her spending increases by 0.06%, so 1.006 x 100k = $100.6k.
. . . Now, in the 1st year her wealth will increase by $101K - 100.6K = $0.4K. If her wealth is assumed to be 0 just for simplicity, then her wealth is now $0.4K.
. . . In the next year her income was $101K and it again increases by 1% so now her income is 101 x 1.01 = $102.01k. This year we'll illustrate by assuming her spending also increases by 0.06%, so she spends 1.006 x 100.6k = 101.20K. So, her wealth is now 0.4K + 102.01k - 101.20k = 1.21k
In each following year we multiply by the same 1% income increase and the same .6% spending increase, we get her wealth increased to $2.426k. After 7 years her wealth is now $11.564k. If we extend this to 100 years we can see that it is significant.
Again, you are assuming away the negative feedbacks that force equilibrium.
I redid the spread sheet and assumed that all her increased income was spent, but with a 1 year lag. In this case her wealth after 7 years was $12.365k. So, it was larger.
But there is no limit in your analogy! If you keep it going, she just gets richer and richer. That doesn't happen with temperature because it self-corrects to reach equilibrium.
We all know that TtP will reject this analogy. I hope the Lurkers can grok the point, that is "changing the rate of something is never insignificant if the time is long enough.
The physical system that determines a planet's equilibrium surface temperature includes strong negative feedbacks that your model does not have.
Before, I have shown that adding just 0.0001 deg.C each day over 3 decades adds just about 1 deg.C to the temp. Obviously, adding more per day makes the 1 deg.C increase happen sooner.
You haven't understood the concept of thermal equilibrium and how it is reached.
TtP might have thought that adding just 0.0001 deg.C to the temp per day was insignificant. But, you can see that it isn't.
Temperature doesn't just add and add and add, as assets do. The hotter something is, the faster it cools.
Also, because of the time lag of temp increase, if we stopped adding CO2 to the air today, by removing all of what we add, the temp would keep increasing.
Yes, but a new equilibrium would be reached fairly quickly. Temperature would not just keep increasing indefinitely based on a given added amount of CO2.
And worse, this would add more water vapor to the air, which is a much stronger GHG, so it would heat the Earth more & faster.
The amount of additional water vapor is so small, and its IR absorption already so thoroughly saturated, that it can't possibly have any significant effect. AGW climate models all assume absurdly exaggerated positive water vapor feedback because it is the only way to make them sensitive enough to CO2 to justify anti-fossil fuel hysteria. But there is no plausible physical mechanism behind such assumptions.
In this wonderfully rosy case, it would take decades for the temp to reach the new equilibrium temp, and it might be a 2 or 3 deg.C increase on top of our current 1.15 deg.C increase from 1850 temps.
Such sensitivity to CO2 is ridiculously exaggerated, and impossible given the earth's climate history.
This will be very bad. Even a 1 deg.C increase from now is very bad.
No, it is actually good -- comparable to the Holocene Optimum 6-8Kya.