@MontereyJack,
MontereyJack wrote:And incidentally way way back there I cited some actual research, just a small early smattering that does not IMPLY but SHOWS specifically that humans are mostly responsible for the CO2 increase. And if you deny that increase in CO2 causes more warming, you're overturning the last century of physics and chemistry.
"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"
http://www.sciencedaily.com/releases/2009/07/090714124956.htm
Kruimple says:
Quote: We have data that shows the last time CO2 levels were as high as they are today was about 15 million years ago. Humans have only been around for roughly 100 to 200 thousand years. In the reports that I have read, they state that the average temperatures were 5 to 10 degrees higher than they are today.
Good point, not very accurate, but your heart's in the right place. Your timeline is wrong, the concentrations were much higher, but yes the temperature was higher. See? High Co2 causes higher temps. Now consider that the average global temp during the ice ages is only about 5 or 6 degrees C lower than today, and think what a difference 6 degrees C is likely to make (it's not as simple as saying a June day would be 80degrees F instead of 70, global temp doesn't work that way).
It is also the case that the there were a whole lot of differences in what was going on in the world then than are going on today, one of them being that yhr most efficient biological CO2 sequesterers hadn't evoilved yet. So those conditions will not be replicated.
@Krumple,
Quote:
We have data that shows the last time CO2 levels were as high as they are today was about 15 million years ago. Humans have only been around for roughly 100 to 200 thousand years. In the reports that I have read, they state that the average temperatures were 5 to 10 degrees higher than they are today.
Using that logic then we didn't build the Hoover Dam because any instance of a river being dammed 15 million years ago never involved humans.
You are not using science Krumple, you are using faulty logic.
parados, I suspect Krumple will show us that anybody who suggests Hoover Dam wasn't built by beavers is just implying it and can't prove it.
@parados,
parados wrote:
Quote:
We have data that shows the last time CO2 levels were as high as they are today was about 15 million years ago. Humans have only been around for roughly 100 to 200 thousand years. In the reports that I have read, they state that the average temperatures were 5 to 10 degrees higher than they are today.
Using that logic then we didn't build the Hoover Dam because any instance of a river being dammed 15 million years ago never involved humans.
You are not using science Krumple, you are using faulty logic.
I can't help it that you are a moron.
Read your article again, Krumple. They say CO2 rise contributed about half of the temp rise. That's consistent with what current climate models, on today's conditions show. If there's a feedback loop that kicks in when CO2 increases that we don't know about because it hasn't happened near enough in time to us to find it, then things will be worse than the climate models say. If there's some other process going on, that is consistent with the obvious point that the world has not always been like it is today. In either case, it is consistent with the fact that increasing CO2 goes along with higher temps. And CO2 is unquestionably increasing.
@Krumple,
I can't help it you have to continually call me names rather than argue the actual science. It does however point to your lack of evidence that actually backs up your argument about the science.
@MontereyJack,
There are actually 2 issues there MJ.
A rise in temperature causes an increase in CO2. If a forcing other than CO2 causes warming CO2 will increase. The increase in CO2 will add to the warming in a feedback loop.
Because CO2 was not the first forcing in past instances of warming doesn't mean it isn't a forcing. Nor does it mean it can't be the first forcing today.
Well, speak of the devil. Look what just turned up in Science the journal this week.
Quote: WASHINGTON — The world's oceans are turning acidic at what could be the fastest pace of any time in the past 300 million years, even more rapidly than during a monster emission of planet-warming carbon 56 million years ago, scientists said on Thursday.
Looking back at that bygone warm period in Earth's history could offer help in forecasting the impact of human-spurred climate change, researchers said of a review of hundreds of studies of ancient climate records published in the journal Science.
Quickly acidifying seawater eats away at coral reefs, which provide habitat for other animals and plants, and makes it harder for mussels and oysters to form protective shells. It can also interfere with small organisms that feed commercial fish like salmon.
The phenomenon has been a top concern of Jane Lubchenco, the head of the U.S. National Oceanic and Atmospheric Administration, who has conducted demonstrations about acidification during hearings in the U.S. Congress.
Oceans get more acidic when more carbon gets into the atmosphere. In pre-industrial times, that occurred periodically in natural pulses of carbon that also pushed up global temperatures, the scientists wrote.
Human activities, including the burning of fossil fuels, have increased the level of atmospheric carbon to 392 parts per million from about 280 parts per million at the start of the industrial revolution. Carbon dioxide is one of several heat-trapping gases that contribute to global warming.
To figure out what ocean acidification might have done in the prehistoric past, 21 researchers from the United States, the United Kingdom, the Netherlands, Germany and Spain reviewed studies of the geological record going back 300 million years, looking for signs of climate disruption.
.Those indications of climate change included mass extinction events, where substantial percentages of living things on Earth died off, such as the giant asteroid strike thought to have killed the dinosaurs some 65 million years ago.
The events that seemed similar to what is happening now included mass extinctions about 252 million and 201 million years ago, as well as the warming period 56 million years in the past.
The researchers reckoned the 5,000-year hot spell 56 million years ago, likely due to factors like massive volcanism, was the closest parallel to current conditions at any time in the 300 million years.
To detect that, they looked at a layer of brown mud buried under the Southern Ocean off Antarctica. Sandwiched between layers of white plankton fossils, the brown mud indicated an ocean so acidic that the plankton fossils from that particular 5,000-year period dissolved into muck.
..During that span, the amount of carbon in the atmosphere doubled and average temperatures rose by 10.8 degrees F, the researchers said. The oceans became more acidic by about 0.4 unit on the 14-point pH scale over that 5,000-year period, the researchers said.
That is a fast warm-up and a quick acidification, but it is small compared with what has happened on Earth since the start of the industrial revolution some 150 years ago, study author Baerbel Hoenisch of Columbia University's Lamont-Doherty Earth Observatory said by telephone.
During the warming period 56 million years ago, known as the Paleocene-Eocene Thermal Maximum, or PETM, and occurring about 9 million years after the extinction of the dinosaurs, acidification for each century was about .008 unit on the pH scale, Hoenisch said.
Back then, many corals went extinct, as did many types of single-celled organisms that lived on the sea floor, which suggests other plants and animals higher on the food chain died out too, researchers said.
By contrast, in the 20th century, oceans acidified by .1 unit of pH, and are projected to get more acidic at the rate of .2 or .3 pH by the year 2100, according to the study.
The U.N. Intergovernmental Panel on Climate Change projects world temperatures could rise by 3.2 to 7 degrees F this century.
"Given that the rate of change was an order of magnitude smaller (in the PETM) compared to what we're doing today, and still there were these big ecosystem changes, that gives us concern for what is going to happen in the future," Hoenisch said.
Those skeptical of human-caused climate change often point to past warming periods caused by natural events as evidence that the current warming trend is not a result of human activities. Hoenisch noted that natural causes such as massive volcanism were probably responsible for the PETM.
She said, however, that the rate of warming and acidification was much more gradual then, over the course of five millennia compared with one century.
Richard Feely, an oceanographer at the U.S. National Oceanic and Atmospheric Administration who was not involved in the study, said looking at that distant past was a good way to foresee the future.
"These studies give you a sense of the timing involved in past ocean acidification events - they did not happen quickly," Feely said in a statement. "The decisions we make over the next few decades could have significant implications on a geologic timescale."
Copyright 2012 Thomson Reuters.
So Krumple was making a big deal of the PETM. Notice that they think that was caused by massive vulcanism. Obviously that's not causing ocean acidification this time around. Natural causes were slow in comparison with what's happening now. What's happening now is US. WE are causing the increased CO2, not volcanos. And the natural causes then led to mass estinctions, and this time around we're showing nature to be a piker in comparison. Thanks for bringing up the topic that shows we'd beter get our ases in gear quick, before it's way to late, Krumple.
@MontereyJack,
Quote: Human activities, including the burning of fossil fuels, have increased the level of atmospheric carbon to 392 parts per million from about 280 parts per million at the start of the industrial revolution. Carbon dioxide is one of several heat-trapping gases that contribute to global warming.
... which doesn't change the fact that the atmosphere was ALREADY WARMING at part of a purely natural trend. The question is relative contribution and what result that contribution has.
Quote:Those skeptical of human-caused climate change often point to past warming periods caused by natural events as evidence that the current warming trend is not a result of human activities. Hoenisch noted that natural causes such as massive volcanism were probably responsible for the PETM.
She said, however, that the rate of warming and acidification was much more gradual then, over the course of five millennia compared with one century.
Finally, a valid response to the question of relative contribution. The RATE of warming within a natural trend would carry an implication of relative contribution. Although the result is still implied rather than specified.
I would also remind anyone considering this line of reasoning that even if all the human contribution to warming were completely eliminated today, and all the past activity erased from history, we would STILL be in a very steep warming spike of purely natural causes. The large scale drivers of the environment are still in control here. We are only nudging it along in the direction it was already going. The truck is already rolling downhill heading for the wall (the peak in the natural cycle). Even if we stop pushing it, it's still going to hit the wall and explode (as the globe returns to its more stable state of glaciation).
I don't know where you get the idea that we would be in a steep warming trend without human action, ros, considering looking at Mann et al's (where the hell do you put the apostrophe in a group like that) look at the proxy evidence, which is out best indicator of recent past temps, the last thousand plus years show no such trend (except for the abrupt rise when the industrial age got underway). And ice cores show temp peaks and CO2 concentrations much like the last thousand years. The trend wasn't upward, we were there already. And the current evidence for the next glaciation is at least 10,000 years away.
Not to mention that we know from aabundant pictorial evidence that the Romans, the classical Chinese, the Maya, the Egyptians all did not wear fur coats, and that takes us back well into BC years. Oop, forgot the Sumerians, 2500 BCE.
In fact, there is abundant historical and archaeological evidence for both global and regional warming and cooling. What climatologists refer to as "the little ice age" was probably local in the north Atlantic, and those who study it believe that it may well have been caused by salinity levels in the ocean. It lasted from about 500 BCE to about 500 CE--and there is historical evidence for it, too. Strabo reports a Massilian (Massilia=Marseilles) merchant who sailed to northern Ireland, and who, sailing further north, found pack ice as far south as Iceland--something which has not been seen since that time. This was followed by what is known as "the little climactic optimum," and which was also probably regional in the north Atlantic, and also may well have been a product of ocean salinity. This lasted until about 1000 to 1100 CE, and there is abundant archaeological evidence as well as the historical evidence of the Short Saga, the Eric the Red Saga, the Thorfinn Karlsefni Saga and the Floamana Saga.
The climate change which succeded it was likely global rather than local, and there is not simply archaeological evidence, but historical evidence as well, beginning after about 1200 CE. It reached a peak by the early 18th century. In 1709, it was so cold in France that rabbits, stoats, badgers and other burrowing animals froze to death in their burrow, birds froze to death and fell from the trees, and wolves hunted right up to the barriers of Paris, even going so far as to attempt to attack people in the streets of the city. Similar records exist in China. Since about 1730 or -40, temperatures have been rising steadily, and the historical evidence from Europe and Asia is that the effect has been global.
Temperatures in Europe two thousand years ago were significantly higher than they are now, even despite the little ice age. One of the reasons climatologists now consider the little ice age to have been regional in the north Atlantic is that no effect of it was seen elsewhere. The Romans grew vinifera graps in what is now England, and middens uncovered and studied by archaeologists show the pollen of plants and the bones of birds whose northern ranges are now found no farther north than southern Spain. The climate was sufficiently different then that the Roman provinces of Africa (roughly Tunisia, eastern Algeria and western Libya) and Numidia (immediately to the west) were part of Rome's North African "granaries," along with Egypt.
The biggest lacuna in climatological data for climate change is the influence of the world's oceans. Salinity and albedo, at least, can be major factors, and no climatologist can say with somplete assurance if carbon dioxide levels are a leading or a folloing indicator of the oceanic effect on climate.
@Setanta,
Quote:Salinity and albedo, at least, can be major factors, and no climatologist can say with somplete assurance if carbon dioxide levels are a leading or a folloing indicator of the oceanic effect on climate.
It's not an either/or question Set.
@parados,
It's a question whether or not the oceanic effect is more important than the level of carbon dioxide in the atmosphere, and climatologists cannot answer that question with assurance.
@Setanta,
You are talking about localized climate vs global climate.
No, i'm not. That's not known, either. Try to inform yourself:
From the Woods Hole Oceanographic Institution
@Setanta,
The ocean is warming BECAUSE of the CO2.
We don't know how the ocean will react or what the ocean's reaction will mean for localized climates. But for you to say one OR the other ignores the science.
@parados,
parados wrote:The ocean is warming BECAUSE of the CO2.
OK . . . quote the science for me. Post a link or links, as i did.
