By Michael Haughey, May 30, 2009
Rising, and warming, seas are personal – for the Silvertip. It is a family matter. His (her) cousin the Polar Bear is in serious trouble. Fishing is lousy, land habitat is disappearing, and ice floes are further and further apart, making hunting and survival very difficult. They are truly endangered. The Silvertip too has lost habitat, so he understands.
You may have noticed, as I have, that scientists are very clear in saying that the IPCC climate models did not include dynamic melting influences in the land-based ice sheets on Greenland, West Antarctica, or East Antarctica. Yet statements from scientists about future possibilities for melting of these ice sheets are hard to find. James Hansen wrote an article for New Scientist in 2007 (“Huge sea level rises are coming – unless we act now“) about the possibility of rather dramatic sea level rise in this century, or the order of about 16 feet, but at least a few meters. 20 feet of sea level rise is roughly what could happen if all the ice on Greenland or all the ice on West Antarctica, but not both, melted. Melting of the ice on this planet is increasing at an increasing rate. James Hansen gave us his educated guess at what may lie ahead for rising seas. Consider two excerpts from James Hansen’s article:
“As an example, let us say that ice sheet melting adds 1 centimetre to sea level for the decade 2005 to 2015, and that this doubles each decade until the West Antarctic ice sheet is largely depleted. This would yield a rise in sea level of more than 5 metres by 2095.“
“Sea level is already rising at a moderate rate. In the past decade, it increased by 3 centimetres, about double the average rate during the preceding century. The rate of sea level rise over the 20th century was itself probably greater than the rate in the prior millennium, and this is due at least in part to human activity. About half of the increase is accounted for by thermal expansion of ocean water as a result of global warming. Melting mountain glaciers worldwide are responsible for several centimetres of the increase.”
There is evidence of an accelerating rate of sea level rise, and there is ice core evidence of a precedent in similar and even lesser conditions.
Consider this excerpt from James Hansen’s article: “…the palaeoclimate record contains numerous examples of ice sheets yielding sea level rises of several metres per century when forcings were smaller than that of the business-as-usual scenario. For example, about 14,000 years ago, sea level rose approximately 20 metres in 400 years, or about 1 metre every 20 years.”
Note that by “forcings”, he means forces that result in melting of ice, such as the rise in average world-wide temperature.
One meter every 20 years is roughly 16.5 feet in 100 years. If all the ice on both Greenland and West Antarctica melts, that would result in about 40 ft of sea level rise in addition to the few meters form thermal expansion and the 10 meters or so from melting glaciers. But little is said about East Antarctica, which poses a possible addition of about 170 feet of sea level rise should all that ice melt. It is interesting to read the scientific summaries and articles because they are quite forthright in saying they simply do not know what is happening in East Antarctica nor what could happen. They also say that sea level rise from whatever might happen to the land-based ice sheets is not included in the climate models used to make the predictions. In fact melting from Greenland and West Antarctica is not included in the models used as input to the 2007 IPCC reports.
James Hansen explains that Earth is receiving 0.5 to 1.0 watts per square meter more energy from the sun than it is losing, and that amount of energy imbalance is enough to raise sea levels one meter per decade from the melting of ice, if all that energy only melted ice. It doesn’t all go to melting ice, of course, but it puts the present energy imbalance in perspective. This also contradicts the common misperception that sun-spot variations are driving global warming as those variations are much smaller over time. The 11-year sun spot cycle causes a variation of 1.3 watts per square meter reaching the earths outer atmosphere (see NASA data). 30% of that is reflected back to outer space, and 40% of what gets through to land is re-radiated back into space. The net is about 0.55 watts per square meter imbalance variation from peak to low, or 0.27 watts per square meter imbalance over the average of the cycle during the peak of the 11-year cycle. This causes a secondary sine wave imposed on the global warming trend. The positive feedback mechanisms that are occurring and about to occur will further raise the energy imbalance from the sun. It is not a constant value. It has increased or perhaps come into being due to the burning of fossil fuels and related positive feedback mechanisms and more is to come. In summary, Earth is getting hotter, faster, and sea levels will be rising faster and faster as a result.
The media event Earth 2100 (see the artice “A Glimmer of Hope Amidst the Fog” on this web site under the Media category) depicts part of a devastating possible result from about 6 feet of sea level rise. Comparatively, 20 feet to 50 feet of sea level rise would likely result in unimaginable catastrophe. So how do we feel about 220 feet? Sea level rise is, of course, only one of a vast array of mostly negative results to be expected from climate change. The list is frighteningly long.
Clearly we as a society must find ways to work together collectively far beyond the economic restraints of “paybacks from energy cost savings”. Does anyone still believe that unregulated capitalism can provide the incentives necessary and in the time needed to avert such a catastrophe? A collective all-out effort planet-wide may not be enough, so clearly pure capitalism will not be the solution. Quite likely regulated capitalism can provide some very important incentives, and social-democratic mechanisms can provide many vehicles for mobilizing just about everyone toward mitigating this common threat. What else is needed? What else is there? We must put tremendous amounts of creativity to work in addressing the mitigation of the factors causing climate change. Not to do so would be to commit moral and criminal assault on future generations and likely many of the people living today. Some small communities are making significant progress. But none of the larger societies or nations on this planet are making anywhere near sufficient progress any where near fast enough. That includes capitalist, socialist, democratic, communist, dictators, theocracies, and all combinations of political systems. None of us have it right, so forcing our systems on other nations is not the answer. We must combine the best of each and create new possibilities. We must find a way to direct our efforts toward a common purpose using resource conservation far beyond what economists tell us is “economic”. All buildings, existing and new, from now on, must on average be net energy producers from renewable energy sources and from very aggressive energy conservation. All other aspects of our societies must likewise end the use of fossil and nuclear fuels and replace them with aggressive energy conservation and renewable energy sources. It must begin at that level now, and it must be competed very soon. Remember that the goal is to preserve the planet as a habitable place for humans. So the goal is not necessarily sacrifice, but rather wise abundance. Buildings are a great example. They can be more comfortable, more productive, healthier places to live and work, all the while producing more energy through renewable energy than the energy that they consume.
I say “we” and “all buildings” and such, because one person or one corporation making the necessary changes will probably just go out of business. But when we all act together, collectively, with a common understanding, then we all operate on a level playing field. Then, and only then, can we make the needed progress.
The hopeful side, and it is very hopeful, is that there is more than enough to be done to provide creative and productive work for everyone on the planet. We can solve many issues with this one effort. The first step is underway – the understanding of the extreme seriousness of the problem. Once the problem is fully understood, what we must then do will become quite obvious. Some of the next steps are also, simultaneously underway. We as a world-wide society are developing and deploying, although much, much too slowly, some of the technologies that will be a part of the solution as well as making some of the personal and societal changes that will also be needed.
Our primary goal is really very simple. We must stop and quickly reverse the increase in atmospheric CO2 levels before we are inundated with the positive feedback contribution from the methane release crisis. If methane release gets in full swing, we may not be able cope with the resulting climate change. It may be simply too much.
If you still do not believe that climate change is occurring and coming faster and faster, I urge you to study the information that is available and that is coming out of recent research. In the meantime, the rest of us have serious work to do. We can certainly use your help, and we urge you to consider that the worst that can come of our efforts is a better planet for humans and all of life. How bad can that be?
One area of research I suggest watching very closely is that studying the science behind the melting of the land-based ice on the three major ice sheets (Greenland, West Antarctica, and East Antarctica). It was only a few years ago that the moulins on Greenland were discovered and their process began to be understood. Rather than rivers of melt-water that flowed into the ice sheet and re-froze, it was discovered that they went all the way to bedrock. The melt-water not only didn’t re-freeze, but lubricated the underside of the ice sheets. The ice sheets began to slide more quickly toward the ocean. What else don’t we know about the physics of melting ice sheets? At what point do they begin to crack and fall apart, exposing more and more surface to warmer air and melting faster and faster? The planet is within 1 degree C of the warmest temperature in the last millions years. Again from James Hansen’s article: “There is strong evidence that the Earth now is within 1 °C of its highest temperature in the past million years. Oxygen isotopes in the deep-ocean fossil plankton known as foraminifera reveal that the Earth was last 2 °C to 3 °C warmer around 3 million years ago, with carbon dioxide levels of perhaps 350 to 450 parts per million. It was a dramatically different planet then, with no Arctic sea ice in the warm seasons and sea level about 25 metres higher, give or take 10 metres.”
The recent International Polar Year 2007-2008 expeditions (http://www.ipy.org/ ) are likely to ad to our collective knowledge. Reports are expected soon. Most likely there will be more questions than answers.
Warming from CO2 increases in the atmosphere is potentially catastrophic, and yet that may not be the worst of what is about to happen. It is the positive feedback mechanisms that frighten most. One of the most recently discovered is truly the most potentially catastrophic. That is the release of methane that has been sequestered for thousands and millions of years.
Sarah Simpson’s article in Scientific American “The Arctic Thaw Could Make Global Warming Worse” tells the story of courageous and hardy Katey Walter, who discovered a new methane release mechanism during her doctoral research in the Siberian Arctic tundra.
Lakes in the Arctic could release 50 billion tons of methane (there are about 5 billion tons of methane in the atmosphere now accounting for a third of the current global warming trend), per Sarah’s article. She points out that “…the Siberian shelf alone holds an estimated 1.4 trillion tons of methane in the form of gas hydrates.” That alone is “equivalent to the newest estimates of the total greenhouse gases that would be released during a complete permafrost thaw”. It is particularly worrisome because the impact could be huge and previously it had mostly been considered too small to be a factor: “Conventional wisdom long held that permafrost should take thousands of years to melt away, so researchers expected it to play a negligible role in climate change. But recent findings – Walter’s lake discovery in particular – have wrecked that prediction.” The decayed plant matter in the permafrost has been sequestered for thousands of years and has contributed to previous post-ice age warming. The methane hydrates that are sequestered below the permafrost, however, have been sequestered for millions of years. If those begin to release, the global warming impact could be monstrous.
There are at least three significant carbon stores in the Arctic. The permafrost contains carbon in the form of CO2 that is the result of decomposition of plant matter in the presence of oxygen. Under lakes in the Arctic are stores of methane within the permafrost that formed from decomposition of plant matter largely in the absence of oxygen due to the presence of overlying water. Below the permafrost are stores of frozen methane hydrate that also formed by decomposition of plant matter largely in the absence of oxygen.
To summarize, in order of increasing potential global warming impact: first is CO2 primarily from human impacts (direct, indirect, and from positive feedback mechanisms); second would be methane released from permafrost; and third, and most worrisome, would be the release of methane from the frozen methane hydrates below the permafrost. A number of factors have not yet been included in the global models that once included will doubtless move the computer predictions toward more rapid warming and faster sea level rise. Will we experience the worst case scenarios predicted for a few hundred years hence within our lifetimes?
We are entering uncharted territory at an unprecedented speed. It is not known exactly what will happen, but how often can you enter uncharted territory at an unprecedented speed and not have something very unexpected happen? Will we be lucky, or will we be reciting our full repertoire of four-letter words? Do you feel lucky? Do people in the path of a hurricane or flood feel lucky? Will we as the human race soon be wishing that hurricanes and floods were the worst we have to worry about?
Sea level rise by itself gives us a lot of reasons to worry. The fair weather sea level is one part of the problem. It can have many effects that are somewhat understood and probably more that are not understood yet. Salt water will penetrate into previously fresh water supplies. The increased weight of the water might cause seismic activity (earthquakes). Then there are the stormy weather impacts. Storms, especially hurricanes, bring what is called storm surge. The combination of wind and low atmospheric pressure in a storm raises the ocean height, similar to the pull of the moon during high tide, from a few feet to perhaps 20 feet or more in a strong hurricane. When the sea starts out higher, this storm surge will now travel much further inland. The flatter the land, the further it will travel. In addition, ocean features like barrier reefs and coastal wetlands that used to protect land near the ocean will be under water. Will they provide protection then or will the storm surge just roll by? Many of the most densely populated areas on the planet as well as productive agricultural land will eventually have to be abandoned. The immigration “problem” of today will be a fond memory by comparison.
We are not helpless or without hope. We can change our energy consumption efficiency and sources of energy without degradation of quality of life. We can probably capture and do something with the methane that is being released from the Arctic lakes since, so far, it seems to come up in discreet locations (although lots and lots of locations).
Yet will we, the human race, act in time? Waiting for this crisis would be to act too late. The Silvertip, looking down from the mountains, sees a self-centered human race that seems only to react to crises. He has serious doubts that we will act in time or with sufficient resolve. Is he right?
Copyright 2009, Michael D. Haughey. Some rights reserved.
Copyright 2009: Creative Commons CC BY-SA
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