"Ice cores from Antarctica show that at the end of recent ice ages, the concentration of carbon dioxide in the atmosphere usually started to rise only after temperatures had begun to climb. There is uncertainty about the timings, partly because the air trapped in the cores is younger than the ice, but it appears the lags might sometimes have been 800 years or more. This proves that rising CO2 was not the trigger that caused the initial warming at the end of these ice ages – but no climate scientist has ever made this claim. It certainly does not challenge the idea that more CO2 heats the planet."Well, maybe Al Gore isn't a climate scientist, but I must have missed the press release where he was rebuked for making that assertion. And I have to beg to differ with the assertion that this assertion--if true, "does not challenge the idea that more CO2 heats the planet." Sure it does; why did Al Gore use the stat?
If you read the entire attempted "debunking" (I know, it's a pain, but the alarmists are hoping you'll just take their word for it) you see a whole lot weaselly language. Not real worthy of dogmatism, frankly.
5 comments:
Do you have to be a wingnut to be a science denier like you have to be a bible thumper to be an anti-choicer? Why do these dichotomies always seem to fall in lock step? Do you think it has anything to do with ignorance, education, or abject authoritarianism?
The fact is, there is a lot we don't know about what the unprecedented CO2 rise will do. What we do know is that the present CO2 rise 1) is the highest and most abrupt in since humans have evolved (2.5 million yrs ago), and 2) the rate of fossil fuel burning mirrors almost exactly the amount of CO2 rise and carbon flux.
The smoking gun and inconvenient truth is this:
1) These three variables have also coincided with the hottest years ever measured. (Remember that BS argument carried by conservatives about the NASA temperature error? The error related to US temperature, not World temperature) The top ten hottest years measured since global records were kept have all occured since 1989, (and 2007 may end up being the hottest).
2) The cause of CO2 rise can be tracked to fossil fuel burning by the use of carbon isotope ratios (C12, C13, C14). That is discussed in this peer reviewed study by scientists at the University of California in Irvine, California Institute of Technology, University of Colorado and Europe's Laboratory of Climate and Environmental Science at Saclay, France.
The bottom line is that the last time we have evidence of a comparable CO2 rise was 55 million years ago during the Paleocene-Eocene Thermal Maximum (PETM). Volcanic activity may have been a factor and some suggest a massive asteroid or comet impact could have also triggered the domino effects of this episode that upset oceanic and atmospheric circulation, leading to the extinction of a great number of species. Sea surface temperatures rose between 5 and 8°C over a period of a few thousand years, and in the high Arctic, caused sea surface temperatures to rise to a sub-tropical 23°C/73°F.
The global warming projections
by eight climate labs around the world show an even quicker global temp rise than was experienced during the PETM. The 8 models, representing the best science available - all in relative agreement - predict the sea surface temperature will rise between 2 and 3.8°C in the next hundred years. The PETM was said to have been the result of a 5 to 8°C sea surface temperature rise over a few thousand years.
So Ned, what part of this science don't you understand or wish to deny? Maybe you could endeavor to understand this and explain it to your fellow science deniers?
Who was around to measure CO2 levels 2.5 million years ago? I'd love to see their technology and read their reports.
Do you have to be a wingnut to be a science denier like you have to be a bible thumper to be an anti-choicer? Why do these dichotomies always seem to fall in lock step? Do you think it has anything to do with ignorance, education, or abject authoritarianism?
Right back at ya, sport.
Glen,
The link that William provided on the "Debate over. Not." post has got a lot of their data and arguments. But, as I noted in this post, if the data and arguments are read with an open mind they're a little less of a slam-dunk than William and other "believers" let on.
As William has asserted, there's more to this debate than the "science" . . . on both sides.
Glen,
Prehistoric CO2 levels can be measured using fossils and sea floor core sediments.
Here's an excellent article on a Yale/Stanford study that examines the potential parallels between the Paleocene-Eocene Thermal Maximum and today's unprecedented CO2 rise.
From the article:
"The PETM is a stunning example of carbon dioxide-induced global warming and stands in contrast to critics who argue that the Earth’s temperature is insensitive to increases in carbon dioxide," said Pagani. "Not only did the Earth warm by at least 9°F (5°C), but it did so during a time when Earth’s average temperature was already 9°F warmer than today."
"By examining fossils and ancient sediments on the sea floor, we can see that something very unusual happened to Earth’s carbon cycle," Caldeira explained. "At the same time the climate near the North Pole became like Miami. We can tell it didn't take all that much carbon to make this change in climate."
During the PETM, ocean acidification likely caused a mass extinction of phytoplankton by reducing the availability of carbonate ions necessary for marine organisms to build calcium carbonate shells and exoskeletons. Many scientists are concerned that history could repeat itself, especially with current studies showing a steady increase in ocean acidity. In September 2005, a team of scientists writing in Nature warned that by 2100, the amount of carbonate available for marine organisms could drop by 60%. In surface ocean waters, where acidification starts before spreading to the deep sea, there may be too little carbonate for organisms to form shells as soon as 2050. The loss of these small organisms would have a disastrous impact on predators -- including salmon, mackerel, herring, cod -- that rely on them as a food source and could spell trouble for other species.
"Our carbon dioxide emissions are risking biological, chemical, and climate changes of a magnitude that has not been seen for more than 50 million years"
Post a Comment