I looked at the video.

I've been out of the U.S. for a few years, and didn't watch TV regularly for decades before that. But, by gosh, I hadn't realized that CNN had sunk so low. When I was watching them before, it was kind of a somber serious approach to most things. This one had fast music, constant change of scene, and an over-excited commentator swinging wildly in the general direction of facts. Occasionally he connects - but not too often.

Most of the "experts" he pulls out are the same old same-old: the half-dozen usual suspects. Christy is a real expert, but he doesn't say the really dumb stuff some of the others do.

What do I mean? Well, the usual "C-O2 doesn't cause high-T, high-T causes C-O2". This has been discussed and explained dozens of times. Unfortunately, it takes more than one logical step to understand, so the skeptics always hope nobody will remember. (They also always claim that Gore "missed" that problem. He didn't: In the film, he sidesteps it, to avoid the detailed reasoning, by saying "without getting too caught up in the details of the causation". It's slightly awkward, but I can understand why. It's a lot easier than saying, "In the past, higher temperature has indeed increased C-O2. However, the result of the increased C-O2 was a temperature that was higher than that which would have been produced by the original instigating cause. In those cases, C-O2 served as a positive feedback. However, in the present day, (and on a much smaller timescale), we are now producing from the combustion of fossil fuels C-O2 without having to wait for the stimulus of higher temperatures. Nevertheless, that C-O2 will have the same warming effect that it had before, when it extended the warming; but now it will be the main cause itself."

- I don't trust Horner's story on how the IPCC works. My understanding is that they generated first the body of the report, then the summary; then they vetted the summary with the policy-makers, to make sure the message was being heard as intended. They adjusted the language to get it clear; and then they went back to the main body of the report to make sure the terminology was consistent.

This isn't fundamentally different from developing technical documentation. You build the technical manual from the spec, and the user manual from the technical manual. You then make sure that the user manual can actually be understood by users. Then, if you're really doing a good job, you go back to the technical manual and make it consistent with the wording of the user manual - to avoid later confusion, if someone wants deeper information than provided by the user manual.

But everything ultimately comes from the spec (analogous to the scientific papers). You don't change the spec: it's for the programmers, anyway.

Lomborg: I've bought his book, but haven't had a chance to read it yet. From his interviews, my early judgment is that his methodology is inappropriate for evaluating earth-changing problems.

There's also a false "we can only do one thing at a time" assumption. Notice, for example, that the people saying that "AIDS/malnutrition/free trade/malaria/agricultural research are more important" are not, in generally, actually advocating SPENDING this money. They just want to stop spending on GW issues.

Like, "Don't buy a fire extinguisher. It's so much more cost-effective to buy aspirin. (But don't take that as permission to buy aspirin either!)"

One more thing I forgot to mention above:

As the presenter promised at the beginning of the "CNN Exposed" program, "This will NOT be a fair and balanced presentation." He got that right, anyway. Truth in advertising, if not in content.

At the close, he goes on to say, "Long live the debate!"

The problem with this so-called debate is the following: The scientists have had this debate over the last 100 years, and very intensively over the last 20 or 30. The issue is that the skeptics have lost that debate among the scientists. But instead of accepting that, they're going to "the court of public opinion". Why, because the general public will understand complex matters of climate-study evidence better than the experts? No, because they won't. By stirring up the pot of public debate, you get more delay. Another day, another dollar...

Neal,

"In the past, higher temperature has indeed increased C-O2. However, the result of the increased C-O2 was a temperature that was higher than that which would have been produced by the original instigating cause. In those cases, C-O2 served as a positive feedback."

I've been wondering since I first heard the positive-feedback explanation. If higher temperature causes CO2 release causes higher temperature ad infinitum, what stopped Earth from becoming like Venus from all that runaway greenhouse warming several eons ago? Or say, during the Medieval Warm Period? What are the current negative feedback mechanisms which halted and reversed the temperature rise, and do they exist today?

I also did not know about any straight-out debate over global warming, particularly anthropogenic and CO2-driven. Mostly what I read from skeptics is that no debate was ever held - the IPCC roped in the scientists who agreed with AGW theory and formed their autoritative conclusion. Can you inform more about how the debate took place and was settled, perhaps links? Thanks.

Scott,

- C-O2 feedback: The impact of increased C-O2 is logarithmic, so the feedback doesn't lead to a runaway. (You're probably thinking about a feedback loop, such as the microphone near the speaker, where the gain in the loop is greater than one. That leads to a runaway.

- C-O2 removal: There are natural processes that act over longer periods to remove C-O2 from the atmosphere. The main one is the biological pump: C-O2 dissolved in the upper surface of the ocean being taken up by foraminafera (tiny ocean critters with shells) that make up their shells using the carbon from the C-O2. When they die, they sink to the bottom of the ocean, and take the carbon with them. The timeframe is generally cited as being a few thousand years (there are different timeframes for different degrees of completeness: this seems to be a complicated process, not quite exponential).

- Scientific "debate": This is just a term of discussion, scientists hardly ever debate. What happens is that they have conferences, discuss papers and evidence, and form their opinions. Over time, the folks that are skeptical have found themselves in the tiny minority, because their arguments and evidence don't stand up. As Max Planck (the first Quantum Mechanic) pointed out, a scientific revolution is complete, not when there's nobody fighting it, but when all the ones against it have retired, and their students are not willing to continue the discussion.

" I worry about the Yellowstone caldera. It is 40,000 years overdue and will take out a significant fraction of the world when it goes and almost all the USA."

This is where living in PA (access to coal mines ... Thank you Dr Strangelove) comes in handy. Invest in coal mining, or die.

Neal, ask your personal opinion:

1) Do you think that a rise of several degrees Celcius will have negative enough effects to justify action?

2) Do you think that carbon taxes and caps are the best way to counter CO2 emissions?

3) Do you feel that the high cost of Kyoto and etc is justified, or that there is a better method?

1. The CNN show is entertainment - it's not news. To delude ourselves into thinking otherwise only exposes a complete misunderstanding about the current state of affairs.

2. What is the point of the argument? That man is/is not blamed for something that may/maynot be happening? This is ridiculous. The point is here that mankind needs to understand the impact on the world - that if we continue to unsustainably strip the Earth of its resources, we will have greater problems than some rising sea levels - mainly resource wars, climate refugees, energy cutbacks, the whole enchilada. (http://www.americanprogress.org/issues/2007/07/climate_debt.html),

3. If we begin to take steps to reduce our emissions output (not just carbon, not just sulfur dioxide everything), it will create new industry, new jobs, new ideas about how to connect people, how to interact with the natural world - how to become better stewards of our environment. It's going to cost money - but to cry out against the change would be Luddite.

4. On another level - we are the top-level predators, and so we have a vested interest in keeping our food supply diverse and healthy. We are not doing that now either. The amount of natural diversity is falling.

5. If you want reasoned debate on both sides that is well-informed and away from the political arena, then head here: http://blogs.nature.com/climatefeedback/

6. I heard it best on NPR from and ethicist. Currently, it is illegal (and for good reason) to walk up to someone's lawn and go to the bathroom on it (#1 or #2) for a variety of reason, including health reasons. Why would it not be the same for the crap that we spew out into our communities?

7. What do we have to loose becoming better stewards of our earth? What do we have to gain. That is the argument, and that is decision.

mdmhvonpa,

1) Yes, I think that a rise of several degrees Celsius is definitely something to worry about. The average global temperature was only about 5 degrees cooler than it is today during the heart of the last Ice Age.

2) I think carbon taxes point the incentives in the right direction. Carbon cap & trade is a bit tricky to get right, and the system can be "gamed" (either deliberately or accidentally).

3) High cost of Kyoto: The likelihood is that the Kyoto protocol is not enough. From my point of view, it represents first baby-steps towards moving us to a renewables-based energy supply system.