Showing posts with label Sirius. Show all posts

Written by fatih al-farahat in , ,


Climate Catastrophe with David Friedman


David makes the point that regardless of the theory and various claims, that a 2 degree warming stretched out over a couple of centuries will not be a catastrophe. There will be ample time to adjust and also exploit the situation.

Even now we have brave souls planting grapes in locales that were clearly impossible a mere twenty years ago. Now we both know that that is a case of wishful thinking overcoming common sense. Such a locale must face reversions that will destroy the plants.

In fact we know that within the past 100,000 years, we survived a two thousand year close encounter with the Sirius cluster that increased global temperature by ten degrees (at least at the poles) and have done this repeatedly before. I am sure it created quite a mess, and modern humanity arose since.

What that all makes clear is that Earth is quite adept at handling a major increase in received heat and maintaining all life on Earth. The Amazon clearly did not catch fire and drive million of species to extinction.

In fact, it is my contention that better heat retention on Earth would be welcome. Restoring woodlands to the Sahara would capture more heat and warm the Northern hemisphere to conditions resembling the Bronze Age. That would also restore woodlands and rainfall throughout the Middle East. What part of this is a bad idea?

In fact, what I am saying is that we are about to begin the long road of terraforming the Earth and that broadly means collecting and retaining more solar energy and fairly distributing the results to optimize the climate. An optimized climate allows a huge human population to live in harmony with nature.

Sunday, July 05, 2009

Does Climate Catastrophe Pass the Giggle Test?

http://daviddfriedman.blogspot.com/2009/07/does-climate-catastrophe-pass-giggle.html


The argument for doing drastic things to prevent global warming has two parts. The first has to do with climate change, with reasons to think that the earth is getting warmer and that the reason is human action, in particular the production of CO2. The second has to do with consequences of climate change for humans.

Most of the criticism I have seen, in comments to this blog and elsewhere, has to do with the first half, with critics arguing that the evidence for global warming, or at least the evidence it is caused by humans and will continue if humans do not mend their ways, is weak. I don not know enough to be sure that those criticisms are wrong; pretty clearly climate is a very complicated and not terribly well understood subject. But my best guess, from watching the debate, is that the first half of the argument is correct, that global climate is warming and that human action is at least an important part of the cause.

What I find unconvincing is the second half of the argument. More precisely, I find unconvincing the claim that climate change on the scale suggested by the results of the IPCC models would have catastrophic consequences for humans. Obviously one can imagine climate change large enough and fast enough to be a very serious problem—a rapid end of the current interglacial, for example. And if, as I believe is the case, climate is not very well understood, one cannot absolutely rule out such changes.

But most of the argument is put in terms not of what might conceivably happen but of what we have good reason to expect to happen, and I think the outer bound of that is provided by the IPCC models. They suggest a temperature increase of about two degrees centigrade over the next hundred years, resulting in a sea level rise of about a foot and a half. What I find implausible is the claim that changes on that scale at that speed would be catastrophic—sufficiently so to justify very expensive measures now to prevent them.

Human beings, after all, currently live, work, grow food in a much wider range of climates than that. Glancing over a U.S.
climate map, it looks as though all of the places I have lived are within an hour or two drive of other places with an average temperature at least two degrees centigrade higher. If people can currently live, work, grow crops over a temperature range of much more than two degrees, it is hard to imagine any reason why most of them couldn't continue to do so, about as easily, if average temperature shifted up by that amount—especially if they had a century to adjust to the change. That observation raises the question with which I titled this post: Does climate change catastrophe pass the giggle test? Is the claim that climate change of that scale would have catastrophic consequences one that any reasonable person could take seriously?

I can only see two ways of defending such a claim. The first is some argument to show that present arrangements are, due to divine intervention or some alternative mechanism, optimal, so that any deviation, even a small one, can be expected to make things worse. The second, and less wildly implausible, is the observation that people have adapted their activities—the sort of houses they live in, the varieties of crops they grow—to current conditions. Put in economic terms, we have sunk costs in our present way of doing things. Even if the planet has not been optimized for us, we have optimized our activities for the planet, with the details depending in part on the local climate. Hence any change in either direction can be expected to be a worsening, making our present way of doing things less well adapted to the new conditions.

That would be a persuasive argument if we were talking about a substantial change occurring over five or ten years. But we aren't. We are talking about a not very large change occurring over a century. In the course of a century, most existing houses will be replaced. If temperatures are rising, they will be replaced with houses designed for a (slightly) warmer climate. If sea levels are rising, they will be replaced, in low lying coastal areas, with houses a little farther inland. Over a century, farmers will change at least the varieties they are growing, very possibly the kind of crop, multiple times, in response to the development of new crop varieties, shifting demand, and similar changes. If temperatures are rising, they will gradually shift to crops adapted to a (slightly) warmer climate.

Climate aside, we do not live in a static world—consider the changes that have occurred over the past century. The shifts we can expect to occur due to technological progress alone, even without allowing for political and demograpic shifts, are much larger than the shifts required to deal with climate change on the scale I am discussing.

My conclusion is that this version of climate catastrophe, at least, does not pass the giggle test. There may be other versions, based on more pessimistic predictions of climate change, that do. But the claim that we now have good reason to expect climate change on a scale that will produce not merely problems for some but catastrophe for many is one that no reasonable person should take seriously.

posted by David Friedman @
8:59 AM

Written by fatih al-farahat in , ,


Palaeocene-Eocene Thermal Maximum (PETM)

The problem with PETM is the apparent 10,000 year period of high temperatures. This article gets it backwards again. The CO2 is easily explained as a consequence of the extreme warming of the Earth. The problem is explaining 10,000 years of hot climate.

We already have evidence of this exact same behavior been repeated every 100,000 years for 1000 years as a consequence of our long orbit through the Sirius cluster. It is important to note that the temperature effect is about the same and should not be considered a coincidence.

My conjecture is that 55,000,000 years ago, our solar system entered the Sirius cluster which contains a rich emitter in the ultra violet and entered a close but unstable orbit around the cluster for 10,000 years until it was flung out on its present far more stable orbit.

This conjecture nicely uses up the available facts and explains the increase in CO2 as a bonus

Global Warming: Our Best Guess Is Likely Wrong

http://www.terradaily.com/reports/Global_Warming_Our_Best_Guess_Is_Likely_Wrong_999.html


Based on findings related to oceanic acidity levels during the PETM and on calculations about the cycling of carbon among the oceans, air, plants and soil, Dickens and co-authors Richard Zeebe of the University of Hawaii and James Zachos of the University of California-Santa Cruz determined that the level of carbon dioxide in the atmosphere increased by about 70 percent during the PETM.

by Staff Writers
Houston TX (SPX) Jul 16, 2009

No one knows exactly how much Earth's climate will warm due to carbon emissions, but a new study this week suggests scientists' best predictions about global warming might be incorrect.

The study, which appears in Nature Geoscience, found that climate models explain only about half of the heating that occurred during a well-documented period of rapid global warming in Earth's ancient past. The study, which was published online today, contains an analysis of published records from a period of rapid climatic warming about 55 million years ago known as the Palaeocene-Eocene thermal maximum, or PETM.

"In a nutshell, theoretical models cannot explain what we observe in the geological record," said oceanographer Gerald Dickens, a co-author of the study and professor of Earth science at Rice University. "There appears to be something fundamentally wrong with the way temperature and carbon are linked in climate models."

During the PETM, for reasons that are still unknown, the amount of carbon in Earth's atmosphere rose rapidly. For this reason, the PETM, which has been identified in hundreds of sediment core samples worldwide, is probably the best ancient climate analogue for present-day Earth.

In addition to rapidly rising levels of atmospheric carbon, global surface temperatures rose dramatically during the PETM. Average temperatures worldwide rose by about 7 degrees Celsius - about 13 degrees Fahrenheit - in the relatively short geological span of about 10,000 years.

Many of the findings come from studies of core samples drilled from the deep seafloor over the past two decades. When oceanographers study these samples, they can see changes in the carbon cycle during the PETM.

"You go along a core and everything's the same, the same, the same, and then suddenly you pass this time line and the carbon chemistry is completely different," Dickens said. "This has been documented time and again at sites all over the world."

Based on findings related to oceanic acidity levels during the PETM and on calculations about the cycling of carbon among the oceans, air, plants and soil, Dickens and co-authors Richard Zeebe of the University of Hawaii and James Zachos of the University of California-Santa Cruz determined that the level of carbon dioxide in the atmosphere increased by about 70 percent during the PETM.

That's significant because it does not represent a doubling of atmospheric carbon dioxide. Since the start of the industrial revolution, carbon dioxide levels are believed to have risen by about one-third, largely due to the burning of fossil fuels. If present rates of fossil-fuel consumption continue, the doubling of carbon dioxide from fossil fuels will occur sometime within the next century or two.

Doubling of atmospheric carbon dioxide is an oft-talked-about threshold, and today's climate models include accepted values for the climate's sensitivity to doubling. Using these accepted values and the PETM carbon data, the researchers found that the models could only explain about half of the warming that Earth experienced 55 million years ago.

The conclusion, Dickens said, is that something other than carbon dioxide caused much of the heating during the PETM. "Some feedback loop or other processes that aren't accounted for in these models - the same ones used by the IPCC for current best estimates of 21st Century warming - caused a substantial portion of the warming that occurred during the PETM."