Monday, August 3, 2009
Global Climate Change: A reality beyond debate
"Natural influences cannot explain the rapid increase in global near-surface temperatures observed during the second half of the 20th century."
- The American Geophyiscal Union
"...the warming of the climate system is unequivocal...human activity has very likely been the driving force in that change over the last 50 years."
- United Nations Inter-governmental Panel on Climate Change (IPCC)
Fourth Assessment Report February 2007
Writing as a non-scientist, one of the things that I have always respected about natural science is that here at least is a field of endeavor that is committed to rigorous objectivity, and to a reasoned and methodical assessment of facts entirely without reference to popular opinion, superstition or ideology. This aloofness of the scientific community toward the blatant subjectivity inherent in fields such as politics or religion is a feature of their discipline that I must admit I am rather attracted to - and even though I am a man of faith, I am also a man of reason and therefore one to take scientific conclusions very seriously. Given the nature of their profession it is therefore rare, if not almost unheard of, to hear scientists use language such as "unequivocal" when describing scientific results. Yet in the hotly debated political football that is the issue of global warming and climate change, that is the very term used by the IPCC (Inter-governmental Panel on Climate Change) an international body convened by the United Nations - with a contributory membership of thousands of the worlds leading scientists in a broad range of disciplines - to assess the causes and effects of Global climate trends. In 2007 this body was awarded the Nobel Prize for its published assessment-reports which concluded that a relatively recent and accelerating global warming trend is a fact and that the cause of this is "very likely" of human origin.
It must be emphasized that the IPCC does not take the alarmist position of predicting some sort of catastrophic "extinction-class event" such as depicted in the Hollywood film The Day After Tomorrow, or anything remotely like it. Such a melodramatic scenario of global warming rapidly impacting ocean currents and triggering an ice age in a matter of days or weeks strikes even a layman like me as pure science fiction - global natural processes just don't work that way. What the IPCC reports do say, is that average global surface temperatures have increased about 0.74 degrees Centigrade and that the "linear trend" since about the late 1950's of 0.13 degrees (Centigrade) per decade is nearly twice that for the past 100 years. Data from the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) fully affirm and substantiate these conclusions.
The UN panel report points out that this warming trend has not been globally uniform, for example the American Southeast (where I and most of my friends and family all live) has actually cooled some over the last century, but that the overall trend planet-wide, especially in the Northern Hemisphere above 40 degrees North latitude (essentially Canada, Russia and nearly all of Europe) has been a significant increase in average temperature. The 10 warmest years on record have all occurred since 1995, 7 of the 8 warmest since 2001. NASA satellites provide striking evidence of what is possibly the most alarming physical consequence of this warming trend, the decrease in the permanent Arctic sea-ice layer. Satellite imagery beginning from when large-scale satellite based measurements were possible in the late 70's to the present day, reveals that in a 30 year period nearly half of the North polar sea-ice layer then extant has since retreated, the most dramatic reductions having occurred since the 1990's. One serious result of ice-cap regression that not only could, but likely will, have grave consequences for the planet is that ocean levels are projected to rise anywhere from 7 to 23 inches by 2100. Worst-case scenarios - that seem increasingly probable to an overwhelming majority of earth scientists - predict flooding that would likely put many major relatively low-lying urban centers such as New York, London and Shanghai permanently under water (including I might add our own Tampa Bay metro area) within the current lifetime of some of us, and alter significantly the basic geography of the planet for the next several thousand years.
The above brief sketch of some of what is involved with climate change is an example of the information reported in a very prosaically worded technical document published by a highly respected, multi-national and strictly mainstream scientific source with no discernable political agenda or axe to grind. The reports of the IPCC also affirm the central conclusion of the world scientific community as to the primary cause of the current rapid climate change process - namely an acceleration of the so-called "Greenhouse effect" by increased concentration of greenhouse gases (GHG's) in the atmosphere.
It is important to point out that, in and of itself, the greenhouse effect is a normal and necessary natural process that has been part of planetary climate cycles since the beginning of the earth's natural history. Gases such as carbon dioxide and methane in the tropospheric layer of our atmosphere permit sunlight to reach the earth while trapping some of the heat, exactly like the glass paneling of a greenhouse, inhibiting it from radiating back into space - the formation of life on the planet would in fact have been impossible absent this process. However, the problem in the modern period has been that the burning of fossil fuels (namely coal and oil) and massive deforestation have caused the concentration levels of gases such as CO2 (carbon dioxide) to increase to a point apparently unparalleled in previous history. Climate models from NOAA, NASA and the IPCC predict that if GHG's continue to increase (as a result of for example CO2 emissions from automobile exhaust - only one of several major sources of atmospheric pollutants to increase substantially during the industrial age) that the average global surface temperature could increase from 3.2 to 7.5 degrees Faranheit by the end of the century. According to the website of the Environmental Protection Agency (EPA) "Scientists are certain that human activities are changing the composition of the atmosphere, [italics mine] and that increasing the concentration of greenhouse gases will change the planets climate. But they are not sure by how much it will change, at what rate it will change, or what the exact effects will be." A much stronger affirmation in this regard comes from the National Academies of Science which in a 2005 joint statement with the U.S. Academy of Sciences states: "The scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action. It is vital that all nations identify cost-effective steps that they can take now, to contribute to substantial and long-term reduction in net global greenhouse gas emissions."[italics mine]
It seems clear that a virtual scientific consensus exists with respect to the fundamental reality of global climate change and the strong likelihood (The IPCC reports this liklihood as greater than 90%) that people are causing it. Yet, notwithstanding the growing mountain of evidence and substantiating data from every reputable source around the world, there remains a persistent and indeed intractable mindset of denial from certain quarters of the body politic. This inclination toward denial is particularly evident within the political right wing of advanced industrial states like the United States. Some politically conservative elements, often in league with some of the worst offenders in the area of private-sector industrial pollution, continue to propagate the notion that there exists a scientifically credible alternative explanation to this phenomena and its causes. In some cases this belief in a so-called alternative explanation is genuinely motivated by political ideology, which advances an elaborate conspiracy-theory sort of argument that the whole concern re human causes to climate change is an alarmist liberal plot. In other cases it seems very obviously to be driven entirely by market interests (i.e. greed - for lack of a more appropriate term) on the part of certain industries and companies who fear the costs of increased environmental public-interest regulation.
At any rate, in doing the research for this post I failed to find any scientific argument from a recognized or academically reputable source to refute the apparent overwhelming mainstream position on this question. Everything I found seemed to substantiate everythig else, confirming my suspicion that for all intents and purposes the scientific community speaks with one voice with regard to at least the central issues involving this particular issue. There may be divergence on fine points and peripheral questions, but the main themes seem to remain the same from virtually every source I located. Such competing authentically scientific explantions as I was able to find - and they were few and well outside the mainstream - were all directly associated with the very industries that are most identified with the problem, or were sponsored by antagonistic conservative political groups. A fairly conscientious attempt on my part to find the relevant information I was searching for failed to produce any alternative explanations from a credible independent researcher untainted by an obvious ideological or industry-related bias.
As a concluding point, I must stress that I approached my subject with no particular bias (that is, other than a bias in favor of a purely objective scientific argument as opposed to anything tainted by ideological considerations of either the Left or the Right) on an issue about which, until very recently, I have not been all that terribly well informed. My own politics are actually very much a "mixed bag," as my profile states, I do not fit neatly into any ideological category or label but approach issues from a fiercely independent place that is rooted in a deep skepticism with regard to all totalistic ideological constructs. As it turns out, though I once indulged a very brief flirtation with socialist politics some years ago, I am today deeply critical of socialism, seeing in it an incipient tendency toward totalitarianism (and I am a confirmed anti-totalitarian) and in fact endorse a free-market system as likely the only viable rational alternative to state-socialism in modern economics. In brief, though I have reservations about capitalism I basically accept it - so long as it is subject to reasonable regulation commensurate with the aggregate public interest, and promotes responsible corporate citizenship with respect to the environment. So when it comes to the question of global warming or climate change, I have no explicitly "pro-Left" agenda to advance, I am interested only in facts and empirical evidence. To date the conservatives who would disagree with the position heretofore advanced have failed to supply me with any that I find particularly compelling.