Four degrees of warming 'likely'

[Lorenzo]

Well, this is first. I haven't yet met a scientist who is not at least remotely familiar with the GRIP and GISP core projects...until now. Try this for starters.

[bradhurley]

“Models are not perfect,” says Syd Levitus. “Data are not perfect. Theory isn’t perfect. We shouldn’t expect them to be. It’s the combination of models, data, and theory that lead to improvements in our science, in our understanding of phenomena.”[/list]

Exactly.

The climate system is complex, and I think we have centuries of discoveries and surprises ahead of us. My guess is that scientists won't have a truly complete and unassailable understanding of global climate and all its influences until the year 2270 or thereabouts. And even then there will be doubters, which is as it should be.

This gets back to the point I made that debating global warming is a bit like debating the existence of God. Many people claim to know that God exists, while many other people claim to know the opposite. But the only people who really and truly know are dead, and they aren't sending us data. If there's an afterlife, the question will be answered when you die; if there isn't an afterlife it doesn't matter. But either way, by the time you find out, it's too late to do anything about it. If you lived your life as if there were no judgment at the end you might find yourself in a hot spot if you turn out to be wrong.

It's the same with global warming: time will tell who's right, but by the time we find out for sure it'll be too late to do anything about it. The only people we know are wrong today are the people who claim to have the answers, the ones who "know" that global warming is happening and the ones who "know" that it isn't.

One cool thing about science is that it isn't done by vote: one person who is right is worth 10,000 who are wrong. If you look back at plate tectonics, for example, the theory was met with great skepticism when it was first proposed and was very much a minority view until enough evidence could be gathered to support it. It's entirely possible that one of the climate change skeptics could turn out to be right and everyone else was wrong all along. I certainly hope that ends up being the case. But I don't think we can count on it.

[I.D.10-t]

I haven't yet met a scientist...

Climatologist. People in science have fields, it is not an all knowing group.

[SteveShaw]

Well, this is first. I haven't yet met a scientist who is not at least remotely familiar with the GRIP and GISP core projects...until now. Try this for starters.

All I can find is reference to a 20-degree change at one end of a glaciation, and no time scale is mentioned for that change as far as I can see at first glance. Further, we are talking about an ice core in one location. Interesting and informative as that is, you can't extrapolate to a global picture of rapid warming from that at all, and that is what you're attempting to compare this with when you denounce my claim for an unprecedented rate of warming in recent decades. Apples and pears in other words. The tropics were relatively unaffected by the last glaciation, for example. So basically you've convinced me of nothing. Sorry about that.

[Lorenzo]

The Younger Dryas (YD) was the most significant rapid climate change event that occurred during the last deglaciation of the North Atlantic region. Previous ice core studies have focused on the abrupt termination of this event (Dansgaard et al., 1989) because this transition marks the end of the last major climate reorganization during the deglaciation. Most recently the YD has been re-dated using precision, sub-annually resolved multivariate measurements from the GISP2 core as a 1300+/-70 year duration event that terminated abruptly. This was evidenced by an approximate 7 °C rise in temperature and a two-fold increase in accumulation rate, at approximately 11.64 kyr BP (Alley et al., 1993). The transition into the Preboreal (PB), the PB/YD transition, and the YD/Holocene transition were all remarkably fast, each occurring over a period of a decade or so (Alley et al., 1993). [source]

Previous studies on two deep Greenland ice cores have shown that a long series of climate oscillations characterized the late Weichselian glaciation in the North Atlantic region1, and that the last glacial cold period, the Younger Dryas, ended abruptly 10,700 years ago2. Here we further focus on this epoch-defining event, and present detailed heavy-isotope and dust-concentration profiles which suggest that, in less than 20 years, the climate in the North Atlantic region turned into a milder and less stormy regime, as a consequence of a rapid retreat of the sea-ice cover. A warming of 7 °C in South Greenland was completed in about 50 years. [source]

The end of the Younger Dryas. Measurements of oxygen isotopes from the GISP2 ice core suggest the ending of the Younger Dryas took place over just 40 – 50 years in three discrete steps, each lasting five years. Other proxy data, such as dust concentration, and snow accumulation, suggest an even more rapid transition, requiring a ~7 °C warming in just a few years; the total warming was 10°±4°.

The end of the Younger Dryas has been dated to around 9620 BC (11550 calendar years BP, occurring at 10000 radiocarbon years BP, a "radiocarbon plateau") by a variety of methods, with mostly consistent results. [source]

[Lorenzo]

...until the year 2270 or thereabouts. And even then there will be doubters, which is as it should be.

...If there's an afterlife, the question will be answered when you die; if there isn't an afterlife it doesn't matter.

...One cool thing about science is that it isn't done by vote...

Re 2270 AD, I think I know how you came up with that one, but you may want to elaborate!

Re life after death, I recall a freind of mine, an archaeologist, when asked about his belief, said "surprise me." You'd think that all those people mentioned in the bible, who were resurrected, could have explained what death was all about to someone who could pass the "reality" on to the rest of us...but that might reveal too much I suppose.

Re voting, just what kind of people would subject science to a vote...hummm. Well, that's a whole other topic that deserves a look back in history, but I won't go there right now.

[bradhurley]

Re 2270 AD, I think I know how you came up with that one, but you may want to elaborate!

Oh, I arrived at that number very scientifically. I sat looking at my computer screen thinking to myself, "think of a year far off in the future, long after all of us reading this forum are dead." I think I wrote 2200 first, but then thought all the questions might not be resolved by then so gave it another 70 years for good measure.

[SteveShaw]

Exactly, Lorenzo, a warming of seven degrees recorded for one location. That is not what we are supposedly talking about, is it. Hardly global warming, was it! And just a little way up the thread you were demanding corroboration for thousands of thermometer records!

[Lorenzo]

The rapid rise of temperature is believed to have been in the "North Atlantic region" and "higher latitudes of the Northern Hemisphere" if you reread the quotes and sources posted above, since airborne particles like lead from Rome, Greece, and other areas were found trapped in the ice...along with volcanic ash, pollen, dust from elsewhere around the world, and carbon from fires in Asia.

"Was the Younger Dryas global? Answering this question is hampered by the lack of a precise definition of "Younger Dryas" in all the records. In western Europe and Greenland, the Younger Dryas is a well-defined synchronous cool period. But cooling in the tropical North Atlantic may have preceded this by a few hundred years; South America shows a less well defined initiation but a sharp termination. The Antarctic Cold Reversal appears to have started a thousand years before the Younger Dryas, and has no clearly defined start or end; Huybers has argued that there is fair confidence in the absence of the Younger Dryas in Antarctica, New Zealand and parts of Oceania. Timing of the tropical counterpart to the Younger Dryas – the Deglaciation Climate Reversal (DCR) – is difficult to establish as low latitude ice core records generally lack independent dating over this interval. An example of this is the Sajama ice core (Bolivia), for which the timing of the DCR has been pinned to that of the GISP2 ice core record (central Greenland). Climatic change in the central Andes during the DCR, however, was significant and characterized by a shift to much wetter, and likely colder, conditions. The magnitude and abruptness of these changes would suggest that low latitude climate did not respond passively during the YD/DCR.

In western North America it is likely that the effects of the Younger Dryas were less intense than in Europe; however, evidence of glacial re-advance indicates Younger Dryas cooling occurred in the Pacific Northwest." (see above sources)

Again, there may be no such thing as uniform global warming, there may be, or may have been, warming in particular areas (deep sea, shallow sea, stratophere, land surface, airports, sub-land surface, etc) at certain times, and simultaneous cooling in other areas of earth.

This is science, not political science - where attempts are often made to twist things around beyond recognition. Try using the quote feature...and get it right!

[SteveShaw]

Your claim of a seven-degree rise in a very short period was set against my claim of an unprecedented rate of global rise, as measured by thousands of thermometers spread over the whole globe, over a very few decades. You have not demonstrated the truly global nature of the rise you claim, nothing like in fact, nor have you specified a time-span for your dramatic rise to compete with my single-century one. You can churn out as much technical stuff in long posts as you like in your attempt to obfuscate, as above, but frankly you need to admit that you got it wrong. I promise not to smirk publicly if you come clean.

[Lorenzo]

Have you read Mojib Latif? He's a IPCC member that says we may be in a cooling period that could last another 20 years. Latif is at the Leibniz Institute of Marine Sciences in Germany at Kiel University and is probably the world's top climate modeller.

As you probably relize, I just ignore all the political-science jive talk and stick with the science, BTW, the 7 degree rise in the North Atlantic and Europe is actually 7 deg. C, or about 14 dgrees F. Try using the quote feature instead of paraphrasing..what is this--some kind of religion?!

[mutepointe]

Thunderdome
Two Men Enter, One Man Leaves.

[hippiechick]

If there was no CO2 problem, would we be free of pollution ? No!
What about all the new GMO's, frankenfood, toxic chemicals, uranium waste disposal, fluoride, and other crazy stuff like cleaning your house with bleach ? How much longer are we going to put up with these gangsters disguised as businesses ?! Chlorine carries plenty germs and dangerous chemicals, they even put it in the drinking water. That's why we can't ignore anything. There is no need for all this, there are better and safer ways, a pollution-free world is possible. They want you to believe C02 is the only polluter, cause carbon taxes are big busine$$!

[hans]

Of course there is lots of other kind of pollution. I think nobody would deny this here. But if CO2 pollution would be curbed, I think humanity would have tackled many other kinds of pollution by the way. Perhaps not all, as we could go for nuclear energy in a big way, and end up with a massive disposal problem of spent nuclear fuel.

As to pollutants: perhaps humanity is the biggest pollutant on the planet.

As to carbon taxes: this is not a political thread, nor is this a political forum. So no comments on that. Let's just stick with looking and discussing evidence for global warming.

[SteveShaw]

Have you read Mojib Latif? He's a IPCC member that says we may be in a cooling period that could last another 20 years.

But we are not in cooling period. There a few like him. The oil companies would love to have him on board.

As you probably relize, I just ignore all the political-science jive talk and stick with the science, BTW, the 7 degree rise in the North Atlantic and Europe is actually 7 deg. C, or about 14 dgrees F.

Multiply Celsius by 9/5 to get Fahrenheit. This gives 12.6°F, not 14°, and avoids translator's inflation. Or join the human race and ditch Fahrenheit.

I see you are trying "warming creep," a well-known technique which extends the phenomenon well beyond the area in which observations were made or for which they are immediately valid. You haven't demonstrated a seven-degree rise in a very short period, as you originally claimed, at least certainly not for the suitably-vague "north Atlantic and Europe." There are some places on the planet even bigger than Texas, you know.