http://contemporarylit.about.com/cs/firstchapters/a/hegemony.htm the excerpt is:
A few years ago, one of the great figures of contemporary biology, Ernst Mayr, published some reflections on the likelihood of success in the search for extraterrestrial intelligence. He considered the prospects very low. His reasoning had to do with the adaptive value of what we call "higher intelligence," meaning the particular human form of intellectual organization. Mayr estimated the number of species since the origin of life at about fifty billion, only one of which "achieved the kind of intelligence needed to establish a civilization." It did so very recently, perhaps 100,000 years ago. It is generally assumed that only one small breeding group survived, of which we are all descendants.
Mayr speculated that the human form of intellectual organization may not be favored by selection. The history of life on Earth, he wrote, refutes the claim that "it is better to be smart than to be stupid," at least judging by biological success: beetles and bacteria, for example, are vastly more successful than humans in terms of survival. He also made the rather somber observation that "the average life expectancy of a species is about 100,000 years."
We are entering a period of human history that may provide an answer to the question of whether it is better to be smart than stupid. The most hopeful prospect is that the question will not be answered: if it receives a definite answer, that answer can only be that humans were a kind of "biological error," using their allotted 100,000 years to destroy themselves and, in the process, much else.
The species has surely developed the capacity to do just that, and a hypothetical extraterrestrial observer might well conclude that humans have demonstrated that capacity throughout their history, dramatically in the past few hundred years, with an assault on the environment that sustains life, on the diversity of more complex organisms, and with cold and calculated savagery, on each other as well.
 See e.g. "Global Warming Has Gone To The Bogs" (CSMonitor, 3/11/04)
"..Their results, published in Geophysical Research Letters, show Sweden's sub-arctic bogs are losing permafrost rapidly. It's completely gone in some areas. And Dr. Christensen says that, at the Stordalen site, methane emission is up "at least 20 percent, but maybe as much as 60 percent, from 1970 to 2000."
"His team report warns that if its findings are typical of the northern subarctic, global warming could accelerate as bogs thaw.
 "Earth Reveals Its Sensitive Side" by Stephen Leahy,
Which also notes,
"According to the 2001 report by the Intergovernmental Panel on Climate Change, a doubling of CO2 in the atmosphere would produce a global temperature rise ranging from 3 to 8 degrees F. This is too wide a range to be helpful in projecting what climatic changes are coming, however, so scientists have worked to refine this range. As recently published in Nature, they are beginning to settle on a likely rise of about 5 to 6 degrees F"
But what is 5.5F? It is 3 degrees Celsius, that is, a full 50% higher than the 2 degrees C we are told would take us past the tipping point.
See also the article,
Which notes, "A recent Nature study suggested that Greenland's ice sheet will begin to melt if the temperature there rises by 3 degrees Celsius (5.4 degrees Fahrenheit). That is something many scientists think IS LIKELY TO HAPPEN in another hundred years" [Emphasis added]
This National Geographic article also comes with a map of Florida showing what not 20 but "merely" 6ft would do: it would submerge a very significant part of Florida.
The complete melting of Greenland would raise sea levels by 7 meters (23 feet). But even a partial melting would cause a one-meter (three-foot) rise. A one-meter [not 20 feet but merely 3 foot] sea level rise WOULD WREAK PARTICULAR HAVOC ON THE GULF COAST AND EASTERN SEABOARD of the United States. [Emphasis added] "No one will be free from this," said Overpeck, whose maps show that every U.S. East Coast city from Boston to Miami would be swamped. A one-meter sea rise in New Orleans, Overpeck said, would mean "no more Mardi Gras."
And the related article
Which notes that perhaps it is not 500ppm but 450 ppm which is the "do not pass" line; "In the scientific community we think an atmospheric CO2 concentration of about 450ppm - the equivalent of a 2C rise in temperature - is about the most we can allow. Beyond that you start to reach the 'tipping points', the unpredictable areas where rapid changes can set in" and this comes from an _optimistic_ scientist; it's a story about how "affordable" cuts in climate emissions could be.
See also: Too Hot to Handle? Discussing Caltech Vice-Provost and physicist David Goodstein's Out of Gas. Excerpt:
"The planet Venus is a little closer to the sun than Earth is, but the physics should permit Venus to be very earthlike in temperature. But it's not.Venus has a runaway greenhouse effect and a surface temperature hotter than molten lead. As we have seen, distance from the sun is only one of several variables that determine habitability on Earth. At 93 million miles from the sun, our planet could be a frozen wasteland, or it could be a Venusian inferno. The fact is that it is neither. Instead it has this delicately balanced partial greenhouse effect that is ideal for creatures like us. We mess with that greenhouse effect at our peril."
 See e.g.
http://english.aljazeera.net/NR/exeres/8853FFB5-3368-44D1-82AE-4066D9FCEA09.htm and http://www.energypulse.net/centers/article/article_display.cfm?a_id=868
The [Kyoto] agreement aims to reduce emissions from industrialised nations only by around 5%, whereas the consensus among many climate scientists is that in order to avoid the worst consequences of global warming, emissions cuts in the order of 60% across the board are needed.
Industrialised countries cut their overall emissions by about 3% from 1990 to 2000. But this was largely because a sharp decrease in emissions from the collapsing economies of former Soviet countries masked an 8% rise among rich countries.
The UN says industrialised countries are now well off target for the end of the decade and predicts emissions 10% above [!] 1990 levels by 2010. Only four EU countries are on track to meet their own target
 The three main sources we are aware of are: Articles in Mother Earth News about houses for circa $10,000 including much build-it-yourself; the B.E.L.L. (Biogenic Ecodesic Living Lighthouse), BELL page and the tornado-proof "dome" homes starting at $10,000 at Monolithic.com and see the homes section and the gorgeous pictures at "best of both worlds?" article here