[Sivad]

However since early this century it has become possible to estimate climate sensitivity from observations as well. The method is very simple: one only needs the total amount of forcing increase, ocean heat energy increase and temperature increase between two periods. Several papers/letters have done this in the last year (Aldrin et al, Ring et al, Lewis, Otto et al) and they all conclude that climate sensitivity is somewhere between 1.5°C and 2°C.

This is really good news! Our climate definitely seems to be less sensitive than we thought for a long time. The range for climate sensitivity based on these observations is also much more constrained, somewhere between 1.2°C and 2.6°C. Note that the lower bound of this range falls outside the likely range that the SPM now gives of 1.5°C to 4.5°C.

The main reason that climate sensitivity has come down so dramatically is not the slowdown. It’s the fact that estimates for aerosol cooling have come down considerably since AR4 and as a result the total increase in anthropogenic forcing has increased considerably in only a few years. This was mentioned in the SPM:

The total anthropogenic RF for 2011 relative to 1750 is 2.29 [1.13 to 3.33] W m−2 (see Figure SPM.5), and it has increased more rapidly since 1970 than during prior decades. The total anthropogenic RF best estimate for 2011 is 43% higher than that reported in AR4 for the year 2005. This is caused by a combination of continued growth in most greenhouse gas concentrations and improved estimates of RF by aerosols indicating a weaker net cooling effect (negative RF). {8.5}

Now with considerably more forcing and no temperature increase, climate sensitivity has to come down! There is no other possibility. It is the only logical consequence. Unless…much more heat went into the ocean. Now the recent observationally based estimates for climate sensitivity take this into account. The increase of heat in the ocean is just by far not enough to compensate for the huge increase in the forcing.
https://www.destaatvanhet-klimaat.nl/20 ... cy-makers/

[Sivad]

Not to mention his claim that a doubling to (I assume) 550ppm of CO2 will lead to just a 3 deg. C increase in temp. if it is held at 550ppm for 100 years --- is IMHO bogus.

Your confusing transient sensitivity with equilibrium sensitivity. The IPCC estimate is for equilibrium sensitivity and Hansen puts the lag time to 60% equilibrium temp at between 25 - 50 years, not a century out.

[Hindsite]

Global warming caused by CFCs, not carbon dioxide, study says

WATERLOO, Ont. (Thursday, May 30, 2013) - Chlorofluorocarbons (CFCs) are to blame for global warming since the 1970s and not carbon dioxide, according to new research from the University of Waterloo published in the International Journal of Modern Physics B this week.

CFCs are already known to deplete ozone, but in-depth statistical analysis now shows that CFCs are also the key driver in global climate change, rather than carbon dioxide (CO2) emissions.

https://uwaterloo.ca/news/news/global-w ... study-says

[Pants-of-dog]

:lol: Which of those figures do you think are in dispute? They all come from NASA and IPCC. The problem we keep running into is you people just don't know anything about climate change.

Actually those figures are a bit dated. Atmospheric Co2 is now closer to 45% pre-industrial levels and the warming from anthropogenic emissions can't be more than .55C. I was actually being generous. That's why Curry, Lindzen, Bates, and other prominent climatologists have revised ECS down to between .5C- 1.65C. The IPCC estimate is way too high according to empirical reality.

Please provide a link to support your claim.

This is the second time I ask.

[Sivad]

Please provide a link to support your claim.

This is the second time I ask.

And this will be the second time I tell you that these are the official figures. I'm not hunting down trivial shit just because you don't know the facts. If you don't know how much CO2 has risen since 1880 or the GAT rise over that same time period then you just shouldn't have an opinion on any of this because you're not even qualified to casually discuss it on pofo.

[Sivad]

The alarmist over at Skeptical Science does the same math and gets the exact same result -

What Does This Tell Us About Climate Sensitivity?

So far, global surface air temperatures have increased approximately 0.8°C in response to these radiative forcings. Since we’re 0% to 66% of the way to the radiative forcing associated with a doubling of atmospheric CO2 (most likely value of 34%), the amount we should expect the planet to warm if CO2 doubles (also known as “climate sensitivity”) has a most likely value of 2.4°C, with a minimum of 1.2°C (because of the large aerosol cooling effect uncertainty and the fact that we may only be 0% of the way to the doubled CO2 forcing, we can’t place an upper limit on the climate sensivity parameter with this calculation). Using a much wider range of evidence, the IPCC puts the likely climate sensitivity range to a doubling of CO2 at 2 to 4.5°C with a most likely value of 3°C. Our calculation is consistent with the IPCC range.

How Much Warming Should We Have Seen?

We can also flip the calculation backwards, assuming the IPCC most likely climate sensitivity of 3°C for a doubling of atmospheric CO2 and using the numbers above. In this case, we should have seen from 0% to 66% of 3°C, or about 0 to 2.0°C. Clearly the amount of warming we have seen so far is well within this range. Additionally, the most likely amount of warming is 34% of 3°C, which is 1.0°C. In other words, we have seen very close to the amount of warming that we “should have” seen, according to the IPCC.
https://thinkprogress.org/the-sensitivi ... 8094e28cd/

There are three problems with his conclusion, 1) that "much wider range of evidence he refers to is just model output and models are not reliable, 2) that .8C is .2C too low for a 3C equilibrium so the sensitivity can't be more than 2.4C according to empirical observation) , and 3) we know all of that .8C is almost certainly not 100% anthropogenic because we're still well within the range of natural variability and we're emerging from the little ice age(there are other reasons also like the 1940's blip but that probably gets too far into the weeds for this crowd).

So based on that, actual sensitivity is probably right around 1.6C with 2C being the unlikely upper bound.


Believing Six Impossible Things before Breakfast, and Climate Models. Christopher Essex, Ph.D.

[Pants-of-dog]

And this will be the second time I tell you that these are the official figures. I'm not hunting down trivial shit just because you don't know the facts. If you don't know how much CO2 has risen since 1880 or the GAT rise over that same time period then you just shouldn't have an opinion on any of this because you're not even qualified to casually discuss it on pofo.

Please provide a link. This is the third time I ask.

If you do not provide a link, I will assume that you actually have no evidence to supoort these numbers and I will dismiss your claim as unsupported.

[Sivad]

[Pants-of-dog]

So we can assume that you conceded the point and that the numbers are not as you describe.

[Hindsite]

So we can assume that you conceded the point and that the numbers are not as you describe.

The numbers keep changing because that is how normal climate change works.
Nothing to be disturbed about, so have a good nights sleep and stop worrying about it and praise the Lord.

[Sivad]

So we can assume that you conceded the point and that the numbers are not as you describe.

Actually the numbers are linked about 4 posts up, but it's pretty funny that you even questioned them in the first place. You know literally nothing about this subject, you haven't even taken the time to find out how much the average surface temp has risen. It's always pretty talking to you but this one in particular has been

[Pants-of-dog]

You mean the part where the increase in temperature is within the range of the IPCC’s claims about climate sensitivity?

I thought you were arguing that the IPCC got it wrong.

[Sivad]

You mean the part where the increase in temperature is within the range of the IPCC’s claims about climate sensitivity?

I thought you were arguing that the IPCC got it wrong.

His math is right, his analysis is fucking stupid. The math does not confirm the IPCC estimates.

[Pants-of-dog]

It certainly seems to.

Temperatures have increased 0.8 degrees Celsius.

If we assume that we are 1/3 of the way to doubling, as you claimed, then the sensitivity should be about 2.4, which is in the most likely range of possible numbers.

[Sivad]

It certainly seems to.

Temperatures have increased 0.8 degrees Celsius.

If we assume that we are 1/3 of the way to doubling, as you claimed, then the sensitivity should be about 2.4, which is in the most likely range of possible numbers.

It's not my claim, that's your god saying that. 2.4 is not 3, 6/10 of a degree makes a huge difference. And there's no way all of that is anthropogenic forcing, a generous estimate would be 2/3 anthropogenic(the IPCC only says more than half), so the estimate should be 1C - 2.4C. That's way lower than the IPCC range. The honest estimate is still cause for some concern and good reason to implement some precautionary measures, but alarm is definitely not warranted and forcing the world off fossil fuels in a very short span of time would be genocidal insanity. You people have gotten caught up in a mass hysteria and you've gone way off the deep end in your reaction to this manufactured crisis.

[Sivad]

Kerry Emanuel, after much hemming and hawing, admits the models are inaccurate and have all projected too much warming.

Kerry Andrew Emanuel (born April 21, 1955) is an American professor of meteorology currently working at the Massachusetts Institute of Technology in Cambridge. In particular he has specialized in atmospheric convection and the mechanisms acting to intensify hurricanes. He was named one of the Time 100 influential people of 2006. In 2007, he was elected as a member of the U.S. National Academy of Sciences.

[Citizen J]

The United States is not going to help deal with climate change because of a much more fundamental problem in the United States. That problem has several names - propaganda, manufactured consent, public relations, I'm sure others can think of other names for it. It's all referring to the same machine. While it exists in all nations, it's especially large and ubiquitous in the United States. And as long as it keeps churning out contradictory information, it will continue to divide Americans on the subject - effectively paralyzing us.
This very thread is a reflection of that propaganda machine at work. Either there is consensus, or there is not - both cannot be correct. Either it is real or it is not - both cannot be correct. Both sides of the issue are certain of their conclusions, yet both sides cannot be simultaneously correct.

I believe this polarization does not exist anywhere else in the world on the same scale as it exists in the United States. In pretty much the rest of the world, the general gist of this issue is largely settled. The rest of the world believes there is consensus among scientists. To my knowledge, no other nation's leadership has expressed doubts about the very existence of climate change.

This is entirely due to the strength of the American propaganda machine. As long as it is in play, there may never be consensus among Americans, nor the political will to act on it. In that regard, the actual facts, truth, or importance of global climate change is irrelevant. Real or not, the United States will never have the political will to act until the American propaganda machine either changes its message or is dismantled.

[Sivad]

Either there is consensus, or there is not - both cannot be correct.

There is not. There's a majority opinion but once you take the sociological factors into account even the majority opinion doesn't carry the kind of rational weight the alarmists think it does.

Either it is real or it is not

Wrong. The question isn't whether it's real or not, it's a question of degree and likelihood. The alarmist overstate both.

Both sides of the issue are certain of their conclusions, yet both sides cannot be simultaneously correct.

There's not just two sides. There are deniers and alarmists, but there are also people like me who accept that the global average temperature has gone up, that human activity has significantly contributed to that, and that it could possibly lead to serious problems. The alarmist call anyone a denier who doesn't mindlessly accept the bogus claim of consensus on catastrophic global warming and isn't hysterically demanding the immediate decarbonization of the global economy.

The rest of the world believes there is consensus among scientists.

Then the rest of the world has been snowed by bullshitters.

In that regard, the actual facts, truth, or importance of global climate change is irrelevant.

Tell me about it, people are way up their own asses on both sides of every issue, this one is no different.

[Citizen J]

@Sivad,
So now you must determine how much of your information and opinion is the result of true research and factual information, and how much is the result of propaganda. Good luck with that. Estimating that 99.99% of the American population can't tell is being generous about the number who can.
Even I can't tell, and I think I've spent over a hundred hours trying to figure out which is which.

Most people's standard for distinguishing truth from propaganda is hardly more than their own confirmation bias.

[Sivad]

@Sivad,
So now you must determine how much of your information and opinion is the result of true research and factual information, and how much is the result of propaganda. Good luck with that.

You're assuming there isn't a copious amount of bullshit and propaganda coming from the scientific establishment itself. You're assuming there are no political or financial agendas in science and that scientists don't bring their ideological baggage into the science.

We know that's not true, we know that science is just another human institution and like all human institutions it has been compromised and corrupted to some significant extent by various outside influences and by its own internal politics. To think otherwise would not only be extremely naive but it would be a form of science denial in itself.

Aside from outside influences and internal politics, science can be undermined by simple social-psychological phenomena like groupthink or pluralistic ignorance. And there's also just the fact that science has acute technological, epistemic, and cognitive limitations relative to the scale and complexity of nature. There are some questions it just can't definitively answer.

So there is no information or opinion that's free of bias or outside influence, everything has to be taken with a large grain of salt. There are very few if any propositions that are beyond rational doubt and the establishment position on CAGW certainly isn't one of them.