global warming

[DEDixon 39]

if actually caused by humans, it can't be stopped. no way, no how.

if just part of the earth's eco-cycle, it might correct itself or just continue on the same course.

[scandal 951]

if actually caused by humans, it can't be stopped. no way, no how.

if just part of the earth's eco-cycle, it might correct itself or just continue on the same course.

Um, ok.

What about this? The climate is a highly complex non-linear system with many interlinked variables. Any one particular variable can have a non-linear amplifying or dampening effect whose contribution can appear out of proportion to the scale of the variable. Hence relatively minor changes in atmospheric carbon can result in much larger changes in effects such as sea-ice and polar-ice cap formation and melting. Am I saying that is the case? No, I don't know the science well enough to comment. But I've worked with nonlinear dynamic systems enough to know that in certain cases you can achieve dramatic end results from apparently minor changes to input variables. That could (potentially) preclude your statements.

[DEDixon 39]

Um, ok.

What about this? The climate is a highly complex non-linear system blah, blah, blah.

i repeat, if human cause, absolutely without a doubt no way out of this.

[scandal 951]

i repeat, if human cause, absolutely without a doubt no way out of this.

Well thank you Professor Dixon for qualifying that. Your Nobel Prize will be in the mail within 4-6 weeks. Or you might just find it in a box of Cracker Jack.

[Trumplestiltskin 5,791]

Hmmm - the whole premise of this thread is to make some random, arbitrary and quite unsupported statements of opinion as if they are statements of "fact".

When did you last get an A in class for a 2 line essay?

[Obama 2012 1,714]

The OP is correct and false.

At the growing population rate, there's not a damn thing we can do about it if man is the cause.

Well, that is unless we embrace Eugenics....

[JohnSmith2007 353]

The OP is correct and false.

At the growing population rate, there's not a damn thing we can do about it if man is the cause.

Well, that is unless we embrace Eugenics....

Well, not without going back to the stone age anyway. For all the "promising" green tech coming out none of it will reduce the man made CO2 to any significant degree in time to alter the direction of the climate. As I see it we have only two options, give up all our modern energy sources now or prepare to live with whatever change is coming.

[DEDixon 39]

The OP is correct and false.

At the growing population rate, there's not a damn thing we can do about it if man is the cause.

Well, that is unless we embrace Eugenics....

bingo. we might be able to delay it a tiny little bit, but, the multiples, given the number of women on earth, professor dixon's research (lots of graphs and such) clearly indicates doomsday. kiss your children goodbye, china and the russians could at any moment launch nukes at us for their own survival. they will probably nuke pakistan and india too, just because their are a lot of people there. i think we should hit them first.

Well, not without going back to the stone age anyway. For all the "promising" green tech coming out none of it will reduce the man made CO2 to any significant degree in time to alter the direction of the climate. As I see it we have only two options, give up all our modern energy sources now or prepare to live with whatever change is coming.

option 3: we strike before they do.

[one...two...tree 2,762]

i repeat, if human cause, absolutely without a doubt no way out of this.

If you read or listen to what the actual climate scientists have to say - they aren't saying we stop Global Warming outright. The concern is over the accelerated rate it is happening because of CO2 emissions. Previous Global Warming periods happened over thousands of years, but we've managed to crank up the rising global temperature to a rate that will make it near impossible for life as we know it to continue.

[one...two...tree 2,762]

How long will global warming last?

The notion is pervasive in the popular and scientific literature that the lifetime of anthropogenic CO₂ released to the atmosphere is some fuzzy number measured most conveniently in decades or centuries. The reality is that the CO₂ from a gallon out of every tank of gas will continue to affect climate for tens and even hundreds of thousands of years into the future.

The U.S. Environmental Protection Agency Inventory of U.S. Greenhouse Gas Emissions and Sinks (2005) has the CO₂ lifetime listed as 5-200 years, for example [1]. I have seen "hundreds of years" in scientific manuscripts and in environmentalist literature. David Goodstein in his excellent book The End of the Age of Oil states, "If we were to suddenly stop burning fossil fuel, the natural carbon cycle would probably restore the previous concentration in a thousand years or so." I assume that Goodstein is conservatively applying several century-long e-folding times to derive his thousand years, but he implicitly assumes that the CO₂ will relax toward its 1750 concentration. The point is that it does not.

When you release a slug of new CO₂ into the atmosphere, dissolution in the ocean gets rid of about three quarters of it, more or less, depending on how much is released. The rest has to await neutralization by reaction with CaCO₃ or igneous rocks on land and in the ocean [2-6]. These rock reactions also restore the pH of the ocean from the CO₂ acid spike. My model indicates that about 7% of carbon released today will still be in the atmosphere in 100,000 years [7]. I calculate a mean lifetime, from the sum of all the processes, of about 30,000 years. That's a deceptive number, because it is so strongly influenced by the immense longevity of that long tail. If one is forced to simplify reality into a single number for popular discussion, several hundred years is a sensible number to choose, because it tells three-quarters of the story, and the part of the story which applies to our own lifetimes.

However, the long tail is a lot of baby to throw out in the name of bath-time simplicity. Major ice sheets, in particular in Greenland [8], ocean methane clathrate deposits [9], and future evolution of glacial/interglacial cycles [10] might be affected by that long tail. A better shorthand for public discussion might be that CO₂ sticks around for hundreds of years, plus 25% that sticks around forever.

The sticking-around-forever idea is not new, and the picture has not changed by very much since the effect was first predicted back in 1992 [2]. You can estimate the magnitude of the effect pretty well just using CO₂ thermodynamics and the back of an envelope. It could be argued (by someone with a cruel heart) that since we don't understand why CO₂ was lower during the last ice age, we ought not go around making forecasts for the future. Well, OK, but I would point out that CO₂ in the past appears to act as an amplifier for orbitally forced climate change, so if anything, we might expect the carbon cycle in the future to amplify our own climate forcing, rather than counteract it. If the past is any guide, CO₂ surprises in the future, in the long run, seem unlikely to help us out.

A long lifetime for CO₂ adjustment is also consistent with an isotopic event in the deep sea sedimentary record from 55 million years ago, the Paleocene/Eocene Thermal Maximum event. The record tells the story of the sudden release of an isotopically light source of carbon, triggering a fast warming in the deep sea of about 5 degrees C. Both the carbon isotope signal and the temperature (inferred from oxygen isotopes) then relaxed back toward their initial values in about 100,000 years. If the released carbon were initially in the form of methane, it would have been oxidized to CO₂ within a few decades, but as CO₂ it apparently stuck around, warming the deep ocean, for a long time before it went away.

The shortest lifetime estimates, such as EPA's 5-years, derive from the exchange flux of CO₂ between the atmosphere and ocean, which is about 200 Gt C/year (1 Gt C is 10¹² kg of carbon) in each direction. Because the exchange flux is back-and-forth, it has nothing to do with the net uptake by the ocean of new CO₂ to the system, which relies on the imbalance between the upward and downward exchange fluxes. That imbalance is only about 2 Gt C/year.

Even the present-day net flux tends to underestimate the real lifetime of global warming. The atmosphere contains about 160 Gt more carbon than it did then. If we divide this number by the CO₂ invasion flux into the ocean of 2 Gt C/year, we get an apparent uptake time scale of 80 years. This result is shorter than model air/water equilibration time scales by a factor of four or so. I believe the problem is with the simple calculation. The CO₂ concentration of the atmosphere is going up continuously, and so it invades the ocean as it equilibrates with warm surface waters. If atmospheric CO₂ were not going up, the warm surface waters would saturate in a year or two, the overall ocean invasion rate would decrease, and the lifetime estimates by this method would increase. Different parts of the ocean equilibrate with the atmosphere on different time scales, ranging from a year for the tropical surface ocean to a millennium for the deep sea. Overall, model experiments show a CO₂ equilibration time of a few centuries [5, 6, 11, 12]. The other problem with both of these conceptions is that they implicitly assure us that the CO₂ concentration is going back to its initial concentration, which it will not.

link

Edited April 5, 2010 by Galt's gallstones

[JohnSmith2007 353]

If you read or listen to what the actual climate scientists have to say - they aren't saying we stop Global Warming outright. The concern is over the accelerated rate it is happening because of CO2 emissions. Previous Global Warming periods happened over thousands of years, but we've managed to crank up the rising global temperature to a rate that will make it near impossible for life as we know it to continue.

The warming period that happened a thousand (medieval warming period?) years ago didn't take more than a few tens of years to come about.

[JohnSmith2007 353]

Lovelock: 'We can't save the planet'

Professor James Lovelock, the scientist who developed Gaia theory, has said it is too late to try and save the planet.

The man who achieved global fame for his theory that the whole earth is a single organism now believes that we can only hope that the earth will take care of itself in the face of completely unpredictable climate change.

Interviewed by Today presenter John Humphrys, videos of which you can see below, he said that while the earth's future was utterly uncertain, mankind was not aware it had "pulled the trigger" on global warming as it built its civilizations.

http://news.bbc.co.uk/today/hi/today/newsid_8594000/8594561.stm

[one...two...tree 2,762]

The warming period that happened a thousand (medieval warming period?) years ago didn't take more than a few tens of years to come about.

Source? (What I mean by source - from an actual body of science that studies climate)

[PhiLandShiR 18]

The OP is correct and false.

At the growing population rate, there's not a damn thing we can do about it if man is the cause.

Well, that is unless we embrace Eugenics....

We could start banking away CO2...

Store it deep in the oceans. It should stay there for a long time.

[JohnSmith2007 353]

Source? (What I mean by source - from an actual body of science that studies climate)

I don't know who this Hoffman guy is but he is quoting a study from the journal "Science" which is a reputable source. The graph at the botom gives the timelines.

Medieval Warm Period Rediscovered

Submitted by Doug L. Hoffman on Tue, 04/07/2009 - 12:38

A recent article in the journal Science has provided a new, detailed climate record for the Medieval Climate Anomaly (MCA), also know as the Medieval Warm Period. It was the most recent pre-industrial warm period, noted in Europe and elsewhere around the globe. The researchers present a 947-year-long multi-decadal North Atlantic Oscillation (NAO) reconstruction and find a persistent positive NAO during the MCA. The interesting thing is that the MCA had basically been removed from the climate record by Michael Mann's infamous “hockey stick” history graph that was adopted by the IPCC a decade ago.

More interesting, Trouet et al., based their work in part on a tree-ring–based drought reconstruction for Morocco (1049–2002) and a millennial-length speleothem-based precipitation proxy for Scotland (900–1993), a methodology similar to Mann's work. Unlike Mann, these researchers found significant climate warming during the MCA. According to the report: “The Morocco and Scotland reconstructions contain substantial multi-decadal variability that is characterized by antiphase oscillatory behavior over the last millennium.” Their reconstruction can be seen in the figure from the article seen below.

http://www.theresilientearth.com/?q=content/medieval-warm-period-rediscovered