[QUOTE=cheesehead;239562]Did you notice the key omission in the reasoning presented in the LA Times article? What key assumption is unstated? What flaw in the argument that "the main, [U][I]long term[/I][/U] solution for the GW problem is severely restricted global scale human population", as stated, so easily allows it to be twisted as was recently done in this thread?[/QUOTE]Let's analyze the effect of breathing, relative to atmospheric CO2 content.

Suppose all the carbon in one's body had come from food grown with no fossil-fuel-derived fertilizer and no fossil-fuel use in cultivation, harvest, transport or preparation. Then the CO2 in exhalations would simply be a return of carbon that had been captured from the atmosphere by plants in recent times, not extracted from underground fossil fuel. In this case, breathing doesn't cause a net increase in atmospheric CO2.

The only way that breathing would increase atmospheric CO2 would be for some carbon in the body to have been derived, one way or another (fertilizer, cultivation, harvest, transport or preparation of food plants and animals), from fossil fuel. This also applies to other uses of fossil fuels.

Thus the article's argument presumes, without explicitly stating so, that the human population's relative mix of overall fossil-fuel and renewable energy use remains unchanged. But the primary emphasis of other proposed mitigation is reducing our proportion of fossil fuel use relative to renewable energy use. We could cut our proportion of fossil fuel use by 50% [I]much[/I] more easily than we could reduce population by 50%.

[QUOTE=ewmayer;239488]Maybe you can get Interpol to go after Paul once they're done chasing down "most wanted international sex pervert and terrorist" Julian Assange.[/QUOTE]Sounds fair to me.

Paul

[QUOTE=cheesehead;240170]Let's analyze the effect of breathing, relative to atmospheric CO2 content.

Suppose all the carbon in one's body had come from food grown with no fossil-fuel-derived fertilizer and no fossil-fuel use in cultivation, harvest, transport or preparation. Then the CO2 in exhalations would simply be a return of carbon that had been captured from the atmosphere by plants in recent times, not extracted from underground fossil fuel. In this case, breathing doesn't cause a net increase in atmospheric CO2.[/QUOTE]
True enough, but the same argument also applied to animals raised as a food source.

The real issue is land-use changes needed for growing crops and raising livestock ... beyond a certain human population level (which is unknown, but I suspect we exceeded it a long time ago), neither the pure-vegan nor omnivore-oriented agricultural economic models can supply sufficient food without extensive land-use changes and fertilizer inputs, which almost inevitably lead to increased release of GGes. There may be relative differences - animal husbandry tends to require more land and produce more methane (though there is promising research in the latter area involving used of targeted methane-reducing commensal bacteria in livestock) - but massive overpopulation is the root cause. IMO the vaunted "green revolution", while appearing to be a great thing in terms of alleviated malnutrition, only made things worse in the long run, since global population is once again rapidly outstripping food supply, is now an order of magnitude larger, and global environmental degradation is that much worse than it was pre-green-revolution. If one fails to solve the root issue of humankind`s distressing habit of filling up all the available "food space" and more, providing more food solves nothing.

[QUOTE=cheesehead;240170]Suppose all the carbon in one's body had come from food grown with no fossil-fuel-derived fertilizer and no fossil-fuel use in cultivation, harvest, transport or preparation. Then the CO2 in exhalations would simply be a return of carbon that had been captured from the atmosphere by plants in recent times, not extracted from underground fossil fuel. In this case, breathing doesn't cause a net increase in atmospheric CO2.
[/QUOTE]
[QUOTE=ewmayer;240319]True enough, but the same argument also applied to animals raised as a food source.[/QUOTE]My term "food" includes animals, so of course it does.

However, only plants capture carbon from the atmosphere.

[quote]The real issue is land-use changes needed for growing crops and raising livestock ... beyond a certain human population level (which is unknown, but I suspect we exceeded it a long time ago), neither the pure-vegan nor omnivore-oriented agricultural economic models can supply sufficient food without extensive land-use changes and fertilizer inputs, which almost inevitably lead to increased release of GGes.[/quote]... only if current uses of fossil fuels and agricultural practices remain unchanged. Fertilizers don't necessarily have to come from fossil fuels.

The real issue I raised was that the population-decrease-is-[I]necessary[/I]-to-curb-AGW argument is flawed when it fails to take certain other things into account.

[QUOTE=ewmayer;198350]...except for the fact that they can't model clouds, you mean?[/QUOTE]So, you'll be interested in this item recently published in [I]Science[/I]:

"A Determination of the Cloud Feedback from Climate Variations over the Past Decade"

[URL]http://geotest.tamu.edu/userfiles/216/dessler10b.pdf[/URL]

[quote=A. E. Dessler]Estimates of Earth's climate sensitivity are uncertain, largely because of uncertainty in the long-term cloud feedback. I estimated the magnitude of the cloud feedback in response to short-term climate variations by analyzing the top-of-atmosphere radiation budget from March 2000 to February 2010. Over this period, the short-term cloud feedback had a magnitude of 0.54 ±0.74 (2 [sigma]) watts per square meter per kelvin, meaning that it is likely positive. A small negative feedback is possible, but one large enough to cancel the climate’s positive feedbacks is not supported by these observations. Both long- and short-wave components of short-term cloud feedback are also likely positive. Calculations of short-term cloud feedback in climate models yield a similar feedback. I find no correlation in the models between the short- and long-term cloud feedbacks.

. . .

For the problem of long-term climate change, what we really want to determine is the cloud feedback in response to long-term climate change. Unfortunately, it may be decades before a direct measurement is possible. In the meantime, observing shorter-term climate variations and comparing those observations to climate models may be the best we can do. This is what I have done in this paper. My analysis suggests that the short-term cloud feedback is likely positive and that climate models as a group are doing a reasonable job of simulating this feedback, providing some indication that models successfully simulate the response of clouds to climate variations. However, owing to the apparent time-scale dependence of the cloud feedback and the uncertainty in the observed short-term cloud feedback, we cannot use this analysis to reduce the present range of equilibrium climate sensitivity of 2.0 to 4.5 K.[/quote]

Dessler has a guest article on realclimate.org:

"Feedback on Cloud Feedback"

[URL]http://www.realclimate.org/index.php/archives/2010/12/feedback-on-cloud-feedback/[/URL]

[quote=Andrew Dessler]I have [URL="http://geotest.tamu.edu/userfiles/216/dessler10b.pdf"]a paper[/URL] in this week’s issue of [I]Science[/I] on the cloud feedback that may be of interest to realclimate readers. As you may know, clouds are important regulators of the amount of energy in and out of the climate system. Clouds both reflect sunlight back to space and trap infrared radiation and keep it from escaping to space. Changes in clouds can therefore have profound impacts on our climate.

A positive cloud feedback loop posits a scenario whereby an initial warming of the planet, caused, for example, by increases in greenhouse gases, causes clouds to trap more energy and lead to further warming. Such a process amplifies the direct heating by greenhouse gases. Models have been long predicted this, but testing the models has proved difficult.

Making the issue even more contentious, some of the more credible skeptics out there (e.g., Lindzen, Spencer) have been arguing that clouds behave quite differently from that predicted by models. In fact, they argue, clouds will stabilize the climate and prevent climate change from occurring (i.e., clouds will provide a negative feedback).

In my new paper, I calculate the energy trapped by clouds and observe how it varies as the climate warms and cools during El Nino-Southern Oscillation (ENSO) cycles. I find that, as the climate warms, clouds trap an additional 0.54±0.74W/m2 for every degree of warming. Thus, the cloud feedback is likely positive, but I cannot rule out a slight negative feedback.

It is important to note that while a slight negative feedback cannot be ruled out, the data do not support a negative feedback large enough to substantially cancel the well-established positive feedbacks, such as water vapor, as Lindzen and Spencer would argue.

I have also compared the results to climate models. Taken as a group, the models substantially reproduce the observations. This increases my confidence that the models are accurately simulating the variations of clouds with climate change.

. . .[/quote]

NASA's take is:

"Clouds Likely Created Positive Climate Feedback In Past Decade"

[URL]http://www.nasa.gov/topics/earth/features/amplified-warming.html[/URL]

[quote]A Texas A&M scientist's study of 10 years of NASA and other data found that clouds likely responded to carbon dioxide-induced global warming by amplifying that warming.

This amplified response is what scientists call a "positive feedback." The uncertainty about the feedback clouds will exhibit to increased greenhouse gases and a warmer climate remains one of the most difficult problems in long-term climate prediction. This new research, to be published Dec. 10 by Andrew Dessler in Science, is the first to look at real-world observations of global clouds at low and high altitudes. And when Dessler did that he found evidence of a positive feedback, and evidence that despite the uncertainty levels, current climate models are doing a reasonable job simulating cloud feedback.

. . .

... But for the first time on a significant time scale and a global spatial scale, a likely positive feedback from clouds has been observed, and not just seen in model results.

. . .[/quote]

As I'm coming to the issue of Global Warming rather late, I was
just wondering: if it is indeed a recent measurable phenomena,
(and the snows here today make that a question), wouldn't a
little global warming actually be a good thing for humanity?
Has anyone here discussed the benefits of global warming, and
instead of arguing over science and politics, present the issues
(perhaps briefly) from a humanity-based viewpoint? Or was this
already settled in this thread? Would be good to know, yes?

[QUOTE=davar55;243484]As I'm coming to the issue of Global Warming rather late, I was just wondering: if it is indeed a recent measurable phenomena, (and the snows here today make that a question),[/QUOTE]Global warming raises the average amount of water vapor in the atmosphere because of faster evaporation from ocean surfaces. So, global warming results in more precipitation in general.

GW also results in changes in ocean and atmospheric circulation. That will bring more precipitation to some areas, but less to others.

GW means an increase in average [I]global[/I] temperature. It does not mean that [U]every[/U] region will experience an increase! A cold and snowy Europe and/or North America is only one part of the global experience.

See "Does cold weather disprove global warming?" at [URL]http://www.skepticalscience.com/global-warming-cold-weather.htm[/URL] (Note that there is both a "Basic" explanation and an "Intermediate" explanation available by clicking on the tab beside "Select a level ..." just under the subheading "What the science says...")

Also, "Cold winter in a world of warming?" at [URL]http://www.realclimate.org/index.php/archives/2010/12/cold-winter-in-a-world-of-warming/[/URL] has more technical explanation.

[quote]wouldn't a little global warming actually be a good thing for humanity?[/quote]That's a typical question raised by newcomers to this subject.

1) "a little" -- How do we keep it from becoming "too much"?

2) There are many effects not obvious to a newcomer.

See "Positives and negatives of global warming" at [URL]http://www.skepticalscience.com/global-warming-positives-negatives.htm[/URL] (Again, there are both basic- and intermediate-level explanations.)

RealClimate.org is generally at a higher technical level than skepticalscience.com, but it does have a list of links to explanations for beginners:
[quote]NCAR: [URL="http://www.eo.ucar.edu/basics/index.html"]Weather and climate basics[/URL]
Oxford University: [URL="http://www.begbroke.ox.ac.uk/climate/interface.html"]The basics of climate prediction[/URL]
Pew Center: [URL="http://www.pewclimate.org/global-warming-basics/"]Global Warming basics[/URL]
Wikipedia: [URL="http://en.wikipedia.org/wiki/Global_warming"]Global Warming[/URL]
NASA: [URL="http://earthobservatory.nasa.gov/Library/GlobalWarmingUpdate/"]Global Warming update[/URL]
National Academy of Science: [URL="http://dels-old.nas.edu/climatechange/understanding-climate-change.shtml"]Understanding and Responding to Climate Change[/URL]
Encyclopedia of Earth: [URL="http://www.eoearth.org/article/Climate_Change_%28collection%29"]Climate Change Collection[/URL]
[URL="http://www.brighton73.freeserve.co.uk/gw/globalwarmingfaq.htm"]Global Warming FAQ[/URL] (Tom Rees)
[URL="http://www2.sunysuffolk.edu/mandias/global_warming/"]Global Warming: Man or Myth?[/URL] (Scott Mandia, SUNY Suffolk)[/quote]

Thank you.

Instead of asking where you think I should start, let me ask:

is this primarily a scientific issue or a political one (don't say both)?

If there is no serious problem, then clearly it's political.

[QUOTE=davar55;243614]Thank you.

Instead of asking where you think I should start, let me ask:

is this primarily a scientific issue or a political one (don't say both)?

If there is no serious problem, then clearly it's political.[/QUOTE]There is a serious scientific issue. Deciding what to do about it is a political problem. (Sorry, but that's how it is.)

Because the scientific issue challenges some basic parts of conservative worldviews (such as the notion that unfettered capitalism is sufficient to solve any problem, or the notion that God wouldn't allow humans to [I]really[/I] mess up things -- not after that promise to Noah), the political side is more contentious than it would be if it didn't challenge anyone's worldview.

Read this article to see a conservative's explanation, published in a conservative newspaper, for conservative resistance to acknowledging the validity of the scientific issue: [URL="http://fullcomment.nationalpost.com/2010/07/15/bad-science-global-warming-deniers-are-a-liability-to-the-conservative-cause/"]http://fullcomment.nationalpost.com/...rvative-cause/[/URL]

- - -

There are parallels between global warming and several previous issues. Each involved/involves a scientific issue and the political decisions on what to do about it:

The link between DDT (and other pesticides) and environmental harm, and what to do about it.

The link between tobacco smoking/chewing and cancer (plus heart disease, emphysema, and other health issues), and what to do about it.

The link between sulfur dioxide emissions from coal-burning powerplants and acid rain's damage to environment, and what to do about it.

The link between secondhand tobacco smoke and cancer, and what to do about it.

The link between chlorofluorocarbons and destruction of the ozone layer, and what to do about it. (This is the least contentious item on this list, as can be seen from the speed of international agreement on banning CFCs.)

Now, it's the link between manmade emissions of "greenhouse" gases (mainly carbon dioxide, but also methane, fluorocarbons, and some others) and global climate, and what to do about it.

As neither a conservative nor religionist, but merely an atheist,
I still have grave doubts about the political agenda of those
who think global warming is a pressing problem. Very long range,
it's worth thinking about. But any universal action at this point
is way premature. Some can recycle or conserve energy, and
unnecessary pollution is undesirable, but the danger if any is long
in the future and may be totally obviated by the continued
increasing enlightenment of humanity as science progresses
without the need for odious political actions now.

[QUOTE=davar55;243636]As neither a conservative nor religionist, but merely an atheist, I still have grave doubts about the political agenda of those who think global warming is a pressing problem.[/QUOTE]This touches upon the distinction between:

A) the scientific evidence that manmade GHGs have, in recent decades, been the principal forcing agent for global warming (which is very well settled),

B) predictions about the future climate changes that will result from manmade GHGs, each of which has to be based on some scenario about future GHG emissions (there's a wide range),

and

C) the political decisions (and technological possibilities) about what course of action to take.

[quote]Very long range, it's worth thinking about. But any universal action at this point is way premature. [/quote]You seem to be assuming that the future effects will be relatively mild, and that solutions will not require a long time to have significant effect.

How mild do you think the GW effects will be? Would you please list what you think would be the worst things that could happen in, say, 50 years and 100 years?

I think that most people underestimate the importance of lead times and time lags in general (such as in attributing the nation's economic changes to actions taken by a new President immediately after he takes office).

The effects of GHGs do not manifest themselves on short timeframes. (The carbon dioxide we're putting in the atmosphere now will be there for centuries.)

[quote]but the danger if any is long in the future[/quote]Will you define what you mean by "long in the future", please?

How did you already decide that, since you say you're a newcomer to the subject?

[quote]and may be totally obviated by the continued increasing enlightenment of humanity as science progresses without the need for odious political actions now.[/quote]Since you're a newcomer, it's possible you've seen mainly just one side's opinion about proposed solutions. Many possible solutions are not at all odious, but will take a long time to have an effect.

The idea that any and all solutions must be odious or totalitarian is simply false.

How about a government initiative to encourage and educate about the merits of better insulation? Odious? But just putting better insulation in some millions of houses could cut several percent off our GHGs that result from heating and cooling. It's unglamorous and decentralized; conservatives can't readily portray it as threateningly as other imagined measures, so instead they'd deride it as ineffective.

How about faster construction of power-producing windfarms, using new technology (waving stalks instead of rotating blades) that won't be as harmful to flying animals passing through?

There's a difference between effectiveness and scariness of solutions.