Getting past the politics, looking at the science
So far in this thread, just like in others that I've participated in, most of the arguments have been based in assertions about the uncertainty of the science, or the nature of science, or the political affiliations of one side of the argument or the other.
Yes, the role of skepticism in science is crucial, but there comes a time when the skeptics must be willing to yield to consensus. That time has arrived with this issue. And I tire of the argument that supporters are demopublicans, deniers are republicrats {yawn}. (For the record, I am neither, and in fact am as apolitical as one can get.)
There are allegations here that the GW supporters merely wish to increase their leverage for gun control, and that they are unwilling to accept nuclear power as an alternative to burning fossil fuels.
Several posters have danced dangerously close to
ad hominem, which is a sure recipe for getting this thread locked. (Art WILL get out a big padlock if that happens,
as he should. You can trust that. I only hope to get this lengthy essay posted before he does.)
But interestingly, with all the allegations of bad science, of uncertainty, of politics, etc, no one has bothered to look at what we do know, or site any sources of information about that.
This post is a step in that direction. I'd like to get past politics and name calling and get down to basic knowledge.
Below is a
partial list of what we know. All of it is published in peer-reviewed scientific journals. (Peer review processes include skeptics who rake a fine tooth comb over methods of experimental design, data analysis and conclusions searching for logical flaws in all.)
It is important to try to grasp that the Earth's climate regulation system is the single most complex issue that science has ever tackled, bar none. It involves physics, thermodynamics, fluid dynamics, chemistry, atmospheric sciences, oceanography, astronomy, ecology, geology, evolution, mathematics (much of it complex) and computer science. It is no wonder that many people have trouble grasping it; in many cases that includes the scientists themselves, many of whom are trained in only one or two of the requisite disciplines, and rarely in all of them.
For the record, I have a PhD in ecology, an MS in mathematics, and teach two college-level classes about this issue.
That doesn't make me any smarter than you. It doesn't make me an expert or an authority. (I don't believe in either.) It simply states that I've spent some time studying these issues (several hundred hours
at least just over the last three years) and have a bit of information about them. As a person with an interest in science, especially ecological dynamics and the evolutionary and geologic history of our planet, I find this at least an intellectually fascinating exercise. I have NO agendas in terms of solutions. Humanity will do what it will in terms of dealing with this, or not as the case will probably be. I am responsible only for myself.
I am
very open to
arguments in favor of nuclear fission (as a short term solution) and nuclear fusion (as a longer term solution). As a gun owner (4 presently {see user name}, working on #5: a SW 686+), I support RKBA and will resist use of GW arguments by any who try to take my guns away.
(As a matter of fact, I came to THR seeking advice on guns for my tool kit since, based on my knowledge of global warming and climate change, and the rapidity with which both can and do occur (a certainty from various studies including geology and - more importantly - ice core studies), I fully expect that the current bout of climate change will disrupt civilization as we know it within a decade or three, including agricultural production and water availability for hundreds of millions, and I intend to be ready for the ensuing criminal anarchy.)
As a student of the concept of ecological stability, I am also well aware that climate change IS the rule rather than the exception on this planet (and presumably others), and that the relatively stable climate of the last few thousand years (since the end of the last Ice Age after the
Younger Dryas event ended 11,200 years ago) has been an anomaly, and that our civilization has neither experienced large scale climate change, nor are we prepared to deal with it when (not if) it happens.
As oceanographer
Wally Broecker said as early as 1988, "The climate system is a capricious beast and we are poking it with a sharp stick. Expect surprises."
I strongly recommend a web site by
physicist Spencer Weart called The Discovery of Global Warming. IMO, it is the best source of the history and current state of the science of climate change on the web. It is clearly written for an educated lay reader; he sites references for every piece of data, every assertion and every conclusion (unlike many so-called "skeptics") and freely notes where uncertainties exist, but - importantly - explains the nature of those uncertainties [e.g., the important distinction between
qualitative statements (warming is occurring) v.
quantitative statements (X degrees of warming will occur in the next t years)].
To his credit, Weart divides most of his chapters into two unequal sections: what we thought we understood about this science
before 1988, including the confusion that existed in the climate change science community before data collection and computing power was sufficient to deal with the issue (e.g., yes, they did erroneously believe that global cooling was more likely in the 1970's, but he explains clearly why) and
after 1988 when the amount of data increased exponentially and computing power (especially the super computers of the 21st century) resulted in far better data analysis and modeling reliability.
I particularly recommend the following essays on Weart's site. For those trying to understand the scale and speed of the challenge before us, and why there has been such confusion in the scientific community about this issue that has fueled the skeptics, these are essential reading.
Note that each essay includes a summary at the top (minimum reading). If time is short, jump to the section of each entitled "After 1988".
The Modern Temperature Trend
Rapid Climate Change
The Carbon Dioxide Greenhouse Effect
Aerosols: The effects of haze and cloud
Biosphere: How Life Alters Climate
Changing Sun, Changing Climate?
Ocean Currents and Climate
Simple Models of Climate Change
Chaos in the Atmosphere
General Circulation Models
I may or may not continue to participate in this thread. Honestly, I've grown bored of the argument now, having seen so much
ad hominem and so many of the tired old bits of misinformation trotted out again and again and again. These days, I generally only engage in discussion with those who have at least read Weart's pages in which he addresses the arguments that have now been debunked by sound, peer-reviewed published science so that we are not "talking past one another". And, I'm pretty busy with work, and my main reason for being on THR is to learn about guns and tools, not to debate this issue.
And, it is, after all, a testable hypothesis: regardless of arguments on either side, nature will do what it will, and we will know "the answer" to this debate, most likely within a couple of decades. I find myself increasingly willing to sit back and wait for the answer rather than wade through endless debates among people who often haven't really studied the issues.
I wish you all well in what seems to be coming our way.
Nem
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Here is what we know with great certainty. Note that most of this is based in direct observation.
Those denying the reality of global warming and climate change on the Earth now must provide refutation of each of these bits of information, including references to published data serving to refute them. (I have little doubt that some will attack the sources of some of these stories; readers should be aware that regardless of the story source, there is published data to back it up.)
Those wishing to understand the issue need to focus NOT on any single bit of information in this list, but instead attempt to develop a gestalt of all of it, how they fit together as a coherent whole suggesting that we have a serious problem.
The crux of the issue is this: if melting of the northern polar ice cap (both the Arctic ocean sheet and the Greenland cap) cannot be stopped and reversed, then heating of that region will continue its upward spiral. The models have predicted (accurately) from the beginning that the poles would heat disproportionately fast, and that warming in that region would seriously impact climate changes in other regions. That is indeed occurring.
Yet, even though every single positive feedback process known to be involved in rapid climate change has now engaged, we know of no negative feedback processes that can now stop the melting of that northern ice cap.
1.
Global average temperatures have accelerated during the late 20th century & early parts of the 21st. 2005 (tied with 1998) was the hottest in at least 400 years, & possibly 1000 years. This is not a one-off event; 11 of last 12 years are among 12 warmest on record worldwide. 2006 was the hottest year on record for the US (sixth hottest worldwide). 2007 is projected to be the hottest year on record globally.
2.
The end-of-summer Arctic ice has decreased 20% in less than 3 decades. The rate of melting is accelerating. Ice accumulation decreased by 6% in the last two winters. Alaska has heated more & faster than other place on Earth (2oC).
3. Greenland's ice sheet is melting twice as fast (conservatively) than it was only five years ago, as confirmed by
NASA satellite studies.
4. Loss of the northern ice cap will accelerate warming by loss of
albedo. Ice reflects more than 80% of solar radiation, cooling a region; dark ocean water absorbs more than 80% of solar radiation. Absorption of heat, therefore, accelerates ice loss, a
positive feedback process.
5. From
ice core data: CO2 levels are already significantly higher now than in the last 800,000 years. (Previous high: 300 PPM; now: 379 ppm).
6. The CO2 increase is accelerating. Past increases never exceeded 30 ppm/1000 years, yet CO2 increased 30 ppm in the last 17 years.
7. Cycling times (“pump down”) for CO2 operate on the order of 50 years; thus, the CO2 in the atmosphere now, & any added to it from now, will remain in the atmosphere for at least 50 years, even if we minimize emissions now.
8. Ocean heating is causing
a decrease in population sizes & northward redistribution of marine phytoplankton that play a MAJOR role in absorption of CO2 and production of clouds that reflect sunlight, cooling tropical oceans. This is another
positive feedback.
9. From ice core data:
methane is also at a record high levels: 1780 ppb vs. 650 ppb in average interglacial. Though far lower in concentration than CO2, methane is 23X more powerful, molecule per molecule. It oxidizes (compared to CO2) quickly (~ a decade) to H2O + CO2.
10. Vast regions of permafrost near the Arctic are thawing, methane increase is 5X what was expected just a few years ago, & threatens to engage another
positive feedback process accelerating heating. This issue has been called "
a sleeping giant” by those studying it.
11. There is a 50 year
lag time (committed heating or oceanic inertia) between stabilization of gases & cessation of heating.
12. We are being cooled by sulfur
aerosols in the atmosphere, mostly resulting from burning fuels. Under proper conditions (e.g., an economic decline), aerosols would wash out of the atmosphere in
several weeks, significantly enhancing the heating effect by 2-3oC.