Scientific Report: rock solid evidence for human-caused G.W.

[Medic]

In fact, to raise the surface temperature of the top 10% of that water only 1C would require only 11% of the Sun's yearly output on earth, as compared to 1,376
times our annual energy consumption which does tie in well with the explanation that a more active solar cycle is responsible for our temperature increases...not our puny efforts.

*snip paragraph 1*

Right now, there is without a doubt that there is a strong correllation between global average temperature and greenhouse gases in the atmosphere. That's something we can measure. There is also no doubt that we are producing greenhouse emissions, from industry, that dwarfs anything seen in at least 400,000 years. This is again something that can be infered from gathered physical data. Add two and two together there.

Moreover the effect of water as a greenhouse gas deserves to be mentioned because I saw the point raised in this same general debate (GW) as the crux of an anti-GW argument.

To quote ESPERE (Environmental Science Published for Everyone Round the Earth):

Due to the so called "greenhouse effect" - caused by atmospheric trace gases such as carbon dioxide (CO2), ozone (O3), and water vapor (H2O) - infrared radiation from the earth is stored temporarily in the atmosphere. Of all these trace gases, water vapor represents the most important constituent. It contributes to the natural greenhouse warming process by approximately 60%. Water vapor amplifies the anthropogenic contribution to greenhouse warming through a positive feedback. This amplification is counteracted by the increased reflection off clouds. How these two factors combine in the real atmosphere still remains an open question.

The point made against GW on this other debate was that therefore, it wasn't HUMAN's greenhouse gases at all that were causing it, but that isn't the understanding of water's role at all. What it IS is once we dumped other greenhouse gases in the atmosphere, it warmed the atmosphere gradually and that that increased evaporation of water and lead to a double whammy of a new greenhouse gas (humidity! gah!) and additional, heat-reflecting cloud cover over the earth.

Just in case Shep or anyone else had any serious doubts about just how comprehensive the scientific consensus is on GW.

[Alerik the Fortunate]

However, given it's seemingly too late already and even the strictest controls proposed by any gov't are hopelessly inadequate to keep levels from rising, letalone reduce them, well, it seems to me we're about to reap what we sowed.

Global revolution/war? Though it would have other aims, probably, but:
1) the initial ravage would stop the most notorious polluters from functioning at all
2) human population will contract, but in a struggle to _avoid_ demise, not walking to self-destruction like blind sheep
3) a real chance at installing a qualified technocracy in a short time (i.e. "now", instead of "after a 100 years")

And _perhaps_ this will preclude a future possibility of environmental global change harmful to humans, make them more concerned in general.

Global revolution will not usher in a technocracy; certainly not a highly qualified one. Those entities most likely to field war winning forces are those being run by short sighted plutocrats of one form or another who have intense political interest in denying the scale of the problem and obfuscating the issues to the ignorant and apathetic masses, who will not organize through political channels effectively enough to remove the entrenched oligarchy.

It is doubtful, to me at least, that the populations of major nations would organize as a revolutionary force coherently enough to affect anything, and the subsequent rapid stamping out of revolutionary forces by superior militaries of the ruling governments will most likely further cow the mainstream population that did not join in the movement. Revolutionary leadership would also be decimated, reducing popular agitation that much more.

Beyond that, it is much easier for popular forces, should they be raised somehow, to be led by charismatic religious fundamentalists, perhaps of an apocalyptic bent, catering to popularly indoctrinated religious hopes and bigotry. I doubt secular, scientific leadership will in the next decades develop sufficiently to inspire the masses. I really believe that mass movements are more likely to be anti-intellectual rather than techno-meritocratic. And war, would, of course, likely constitute a massive waste of resources.

[Darth Wong]

I would love to know how many of the people who have been running around "debunking" the IPCC report actually bothered to read it.

[Admiral Valdemar]

I would love to know how many of the people who have been running around "debunking" the IPCC report actually bothered to read it.

None, I should imagine. I've been dealing with several on various blogs and forums, some of whom oppose AGW solely on the basis of it having Gore as a vocal backer. That's right, they believe Gore is an authority on the subject (rather than speaking for these scientists to the public) and that alone is enough to invalidate the whole scientific community.

Then there are the thousands of "scientists" who dispute AGW, most of whom have Ph.Ds in business studies and poli-sci, and if that's not enough, you can always cite '70s alarmist American tabloid articles ranting about global cooling as evidence that scientists know not of what they speak and this is just another socialist, liberal trend to screw capitalism over through scaremongering.

Sadly, some of those people aren't even Republitard drones with a penchant for anti-logic or pro-Creationism. There are some atheists of supposed good rational thinking skills who argue at length over at IIDB.org, though the majority of those sceptics are being shouted down as more and more evidence mounts against them and they sound ever more desperate. One wacky in-duh-vidual even went so far as to call the delay for the AR4 report being released in full after the summary as being evidence of nefarious tinkering behind the scenes to make the thing sound more incredible and correct errors the media picked up on (which don't exist; they were misinterpretations).

[His Divine Shadow]

Can we the public read the full IPCC report ourselves yet by the way?

[Admiral Valdemar]

I believe another few weeks are in the way until the full report is ready. I anticipate the next part of the report that details the effects of the now confirmed AGW phenomenon.

[Sikon]

While the bulk of the new IPCC report isn't published yet, a detailed discussion of projected global warming and its anticipated effects is in the last report (2001), including the following quote from the summary here:

Projected adverse impacts based on models and other studies include:

* A general reduction in potential crop yields in most tropical and sub-tropical regions for most projected increases in temperature [4.2]
* A general reduction, with some variation, in potential crop yields in most regions in mid-latitudes for increases in annual-average temperature of more than a few °C [4.2]
* Decreased water availability for populations in many water-scarce regions, particularly in the sub-tropics [4.1]
* An increase in the number of people exposed to vector-borne (e.g., malaria) and water-borne diseases (e.g., cholera), and an increase in heat stress mortality [4.7]
* A widespread increase in the risk of flooding for many human settlements (tens of millions of inhabitants in settlements studied) from both increased heavy precipitation events and sea-level rise [4.5]
* Increased energy demand for space cooling due to higher summer temperatures. [4.5]

Projected beneficial impacts based on models and other studies include:

* Increased potential crop yields in some regions at mid-latitudes for increases in temperature of less than a few °C [4.2]
* A potential increase in global timber supply from appropriately managed forests [4.3]
* Increased water availability for populations in some water-scarce regions—for example, in parts of southeast Asia [4.1]
* Reduced winter mortality in mid- and high-latitudes
* Reduced energy demand for space heating due to higher winter temperatures. [4.5]

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The last report (2001) estimated a 1.4 to 5.8 degree Celsius increase in global average temperature for 2100 compared to 1990, along with a 0.09m to 0.88m rise in sea level.

A summary part of the new 2007 report is online here, mentioning that the best estimate for the low scenario is a 1.8 degree Celsius rise, while the best estimate for the high scenario is a 4.0 degree Celsius rise, for temperatures in 2090-2099 compared to 1980-1999. The model-based range for sea level rise excluding rapid dynamical changes in ice flow is 0.18m to 0.59m over that timeframe, from table SPM-3.

There is a lot more information even in that summary. One example is figure SPM-7 for projected change in rainfall and other precipitation, in this case illustrating for June to August:



The above is for the A1B scenario, one with much increased future energy consumption and intermediate between a more ideal scenario eventually without much fossil fuel use (A1T) and a worse scenario remaining most fossil-fuel intensive (A1FI). And there are more scenarios considered.

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The figure above from the preceding is a better chart than I have seen before.

If one considers "best estimate" values of the information aside from the uncertainty ranges, in W/m^2, the average source of pollution causes warming of 1.66 from carbon dioxide, 0.48 from methane (cows, etc.), 0.35 from tropospheric ozone, 0.34 from halocarbons (spray cans, etc.), and 0.33 from other warming pollution. Meanwhile, such also typically causes ~ 1.2 W/m^2 of cooling from the direct and cloud albedo effects of aerosols, plus ~ 0.05 W/m^2 of cooling from stratospheric ozone. Overall, the effect is net warming.

But notice something about the preceding. Individual sources of pollution differ from the average. For example, if a particular pollution source emitted CO2 but relatively little CH4, tropospheric ozone, halocarbons, etc. while having a proportionally larger than usual amount of aerosol emissions, it might cause much less warming than the usual polluter, possibly even net cooling in some cases.

Obviously, it is desirable to reduce pollution in general for multiple reasons. However, it is interesting to observe that factors like the CO2 to aerosol ratio may matter more for the net effect on global warming of some particular pollution sources than their CO2 emissions alone.

From the standpoint of mitigating global warming, the most effective measure might not only be to cut warming pollution but also to make up for the practical side-effect of drops in cooling aerosol pollutants by sulphate injection or other particulates.

Of course, that is not the actual policy of governments and may or may not ever become such, but a combination of effectively keeping the cooling radiative forcing while reducing the emissions causing warming would theoretically cause the greatest mitigation, if ever implemented.

[Sikon]

EDIT: Minor typo error:
The "average source of pollution" is meant to mean all sources of pollution combined.