Dire New Climate Warnings
A new study conducted by NASA, authored by 48 scientists, warns that the so-called tipping points for the Earth's climate are much closer than previously thought. The critical thresholds for atmospheric CO2 levels may be "much lower than 450 ppm", meaning that we may already be beyond the critical points, or may reach them within just a few years.
http://www.abcnews.go.com/Technology/story?id=3223473&page=1
Follow the links to pages 2 and 3.
There are many reasons why we are in much greater trouble with respect to the climate than is readily apparent. First, we are all aware of the large and growing extent to which humanity has increased CO2 levels (roughly 270 ppm to 383 ppm) and that we have similarly increased concentrations of methane (CH4) and nitrous oxide (N2O) dramatically, as well as the concentrations of many artificial greenhouse gasses.
Secondly, we are all aware that the rate of our own emissions is increasing and will increase more steeply in the not-so-distant future, as, for one thing, China continues to start the construction one new coal-fired power plant, on average, about every five days.
Thirdly, we see rapidly increasing awareness of the problem, and lots of talk and some action regarding the elimination of human additions of fossil carbon into the sky. It remains, however, highly unlikely that we could see reductions of as much as 90% in human fossil carbon emissions by 2050, however vital this goal may be.
So against this backdrop, we need to see the many reasons for urgent concern that I alluded to above:
1) We have set in motion a massive melting of the gigantic, white mirror on top of the planet which has for many millions of years been reflecting back into space nearly all of the sunlight which falls upon it during the summer half of each year. As each year goes by, the ice melts more, on average, and nearly half of the floating Arctic Ocean ice cap is already gone in late summer, compared to its extent as recently as 1979. According to the U.S. Navy, the ice is now about 7 feet thick, whereas it used to be about 10 feet thick. The areal extent of the ice has also fallen by roughly 20%, for a total volume loss of roughly 44%. Everyone acknowledges that the rest is going fast. This constitutes a massive, positive feedback loop, which we have set in motion and we can assume we may be unable to stop, even if we were to reduce greenhouse gas emissions to zero tomorrow. And of course, we won't be doing that. The arctic ice cap and the extensive snowy tundra lands of the arctic have never been pushed toward such a melting for at least a few million years.
2) We have also set in motion a massive melting of the huge regions of arctic permafrost across Siberia and Alaska in particular. The permafrost is an ancient accumulation of organic matter, which not only contains vast amounts of methane, but which, when melted will decay and enter the atmosphere as both CO2 and methane. The permafrost is likewise old, and constitutes a huge carbon sink that serves to keep the planet from warming greatly. Keep in mind that in the Earth's long history, climate has varied a lot, though over vastly longer time scales than the time scale of human civilization. If one goes back more than 100 million years, the average temperature on Earth was as much as 55 degrees F hotter than today, and the coolest place on Earth, Antarctica (Gondwanaland at the time), was so warm that temperate forests grew there. Our carbon sinks are vital features of the planet, because their continued existence prevents the planet from experiencing violent climate changes that our civilization is totally unable to cope with. The melting permafrost now includes an area of western Siberia the size of France and Germany combined. The long-frozen peat ground is turning into a gigantic, methane-belching soggy bog, and it is expected that all of the Earth's permafrost will be melted, at the rate we're going, by 2050. And that the amount of fossil carbon that it will add to the sky on our behalf is equal to the entire existing greenhouse blanket of the planet, exclusive of water vapor. This alone would drive the fossil carbon to levels equivalent to 750 ppm of CO2, roughly.
3) We have also set in motion a number of other massive natural positive feedback loops, which include: the loss of tropical forests, the loss of ancient peat deposits in the tropics to fires caused by deforestation, and, through our massive carbonation of the oceans, we have already reached a point where it is expected that the efficacy of the sea at scrubbing some of our fossil carbon emissions is going to fall, failing to keep up with future fossil carbon emissions to the same degree in which it has half kept up with our past fossil carbon emissions. And that is not to mention the extreme threat to the seas, which this carbonation and resultant falling pH presents. The pH has already fallen by one tenth of a unit, and early research shows that just one more tenth of a pH unit of fall will result in the widespread loss of calcium-shell-forming creatures' ability to survive. This includes coral, plankton, crustaceans, etc., and all the life forms which depend on them (that's nearly all life in the sea). We are currently on track to reduce the pH by three more tenths of a unit by the end of this century.
4) It turns out that there are massive deposits of methane hydrates in certain places in several oceans of the world. The magnitude of these deposits is said to be on the order of 100X the quantity of all fossil fuels remaining on Earth. And these deposits are fragile and subject to causing massive methane releases when disturbed by seismic events, volcanism, and/or warming. The Arctic Ocean is relatively shallow, is warming rapidly, and contains such methane hydrate deposits. Pray that we don't disturb any of them. Climatologists believe that in the fossil record they can see evidence of very sudden global temperature increases of as much as 12 degrees F, with no other known explanation except that a large methane hydrate release occurred. At least the life of methane in the atmosphere is only a few decades, unlike CO2, which lasts many times longer.
5) It is also true, that because the Earth has a large amount of thermal buffering, in the form of oceans covering 70 percent of its surface, that when the climate balance, or "forcing" is altered fundamentally, as we have been doing at a substantial level for a few decades now (and possibly at a significant level for over 10,000 years), the overall effects of the new greenhouse balance are not felt fully for between 30 and 50 years. In other words, if we could instantly stabilize atmospheric carbon (CO2 and methane mainly) at current levels, the planet would continue to warm for another 50 years or so, even without any positive feedback loops in effect.
6) As we have been polluting the sky so as to warm the planet, we have also been polluting the sky so as to cool it. Particulate emissions are now understood to have had planetary cooling effects probably equal to more than 60 percent of the warming effects we have caused! Our greenhouse pollution has been about 2.5X more powerful than we have been able to tell, because our cooling has been masking our warming. This means a couple of things. First, it means that the true effectiveness of CO2 and methane at warming the planet is much greater than climate models have generally assumed, and second, it means that in the future, our cooling will increasingly fail to keep pace with our warming, again causing warming to accelerate relative to past experience. The particulate emissions are so bad for our lungs and cardiovascular systems, and so destructive of rainfall patterns, that we cannot allow them to continue unabated, and indeed U.S. and European emissions, which are now thought to have been either a principle cause or the principle cause of the droughts of sub-Saharan Africa during the 1970s and 80s, have already been largely abated.
So, are you beginning to get the picture? We have used up our grace period. We are way, way further along with warming the planet than we can tell by looking at today's weather. We are pushing the planetary system over a cliff, the planet is picking up speed, and where it will end, if we can't stop it from continuing to fall over, is a place that you don't want to be. The current worst-case scenario I have heard, from British climatologist Peter Cox, is for 18 degrees F warming by the end of this century, and increasing most rapidly at that point, well on its way to 25 degrees F average increase -- or even hotter. This kind of rapid shift would mean the end of human civilization and almost certainly the end of our species altogether. One eventual consequence of this extent of warming is the seas turning largely anaerobic, with resulting huge emissions of hydrogen sulphide (H2S) from anaerobic bacteria in the ocean, which in turn poisons life on land directly and destroys most of the ozone layer, further insuring the end of most life on land. Recent science holds many unfortunate surprises regarding the consequences of our continued rape of the planet.
With increases of the CO2 concentration to just over 750 ppm, and sufficient time for the climate to stabilize thereafter, widespread melting of nearly the entire Antarctic ice sheet may ensue. Melting of nearly all of the land ice on Earth would raise sea levels by nearly 300 feet. Not only would every coastal city be completely obliterated, but a large percentage of the major inland cities of the world would be underwater as well. Of course there would be little food, hardly any life as we know it in the sea, and so on. No thank you.
So when you hear that once again, this year is the hottest year on record (yes, 2007) don't think for a minute that some modestly altered business-as-usual approach is going to do the trick. And don't buy another gas-guzzling car. In fact, don't buy any car until there is one that you like which is both ultra-efficient and which can run on biofuels and/or renewable electricity. We are in far deeper trouble than most people realize.
What does this mean? For one thing, the talk you hear about addressing climate change by cutting way back on fossil carbon emissions, e.g. 80 or even 90% in the U.S. by 2050, is not even close to being the complete remedy for the incredible threats we face, as the West Antarctic Ice Sheet and the Greenland Ice Sheet perch precariously at the edge of collapse from the increasingly rapid and unpredictable warming we have unleashed. Losing them would mean a sea level increase of over 40 feet, and we could very easily see this happen within the next few decades. Don't be fooled by the misleading opening statement of the IPCC on their prediction for sea level rise for this century -- what you didn't hear in most news stories about their recent reports is that their charter forbids them from "speculation", therefore they simply left out the prospect of melting land ice from their prediction altogether! Many glaciologists are very worried.
What I hope to point out, is that in order to actually get a grip on this crisis, we will have to not only make drastic and rapid changes to free ourselves of our addictions to fossil fuels, but we will also have to create and use methods to remove CO2 from the sky which is already there. As unlikely as this seems, it turns out to be -- probably -- possible.
Go to this page:
http://www.npr.org/templates/story/story.php?storyId=10621219
then click the Listen link in the top left, to hear the most recent interview with Dr. Klaus Lackner, a PhD physicist at Columbia University, about his project to scrub CO2 from the sky, with a realistic goal of getting the cost down to just $30 per ton (that's cheap). It would add just 25 cents to the cost of a gallon of gasoline, for example. I think we could afford $100 a ton to save ourselves, don't you? The dirty energy companies might even be all for it, since it could allow them to remain in business.
And write to your Representative and Senators and ask them to get with it, and start talking not just of putting the brakes on our rate of increase in atmospheric CO2, but also about bringing CO2 back down to a level that will help to tame the massive shifts which we have set in motion and which will continue to push us off the cliff, even if we push the brakes all the way to the floor.
If we melt it all, the Gulf of Mexico will nearly reach the southern tip of Illinois.
If we melt it all, the city of Fresno, California will be beachfront property.
Beijing. Paris. Rome. All gone. But L.A., the central Bay Area, Seattle, New York, Boston, Washington, D.C., Baltimore, Philadelphia, Miami, London, Copenhagen, Shanghai, Tokyo, Rio, etc., etc. will all be even longer gone.
And the sea level catastrophes will be a fraction of the impacts we will suffer.
I mention the possibility of actually melting nearly all of the land ice in Antarctica because research conducted by Robert M. DeConto and David Pollard strongly suggests to me that because they have concluded that the most likely trigger of the widespread formation of the Antarctic ice sheets was very slowly falling CO2 levels, about 34 million years ago, and that the point of the trigger was about 750 ppm, and that the current climate condition is one of warm austral summers (meaning the trigger now could be a climate which has settled in at less than 750 ppm of CO2), and because we are rapidly heading for CO2 levels greatly exceeding that level, that it is entirely possible that we could basically melt it all.
Our only hope to deal with this mess is to first see clearly how much trouble we are in. All avenues need to be explored. We must start working systematically toward a total solution. Today. It will not be easy, but a half-way solution will prove totally unacceptable.