Does atmospheric ppm of CO2 lead temperature rise or lag it, there appears to be a difference of opinion?
It does both. It is part of the feedback cycle that has created major climate change in the past. When the oceans warmed naturally due to minor changes in insolation (amount of sunlight), the warming oceans threw off more CO2 which enhanced the greenhouse effect which in turn created more warming. This feedback cycle takes centuries but eventually has lead to the coming and going of ice ages. CO2 is the most important long term factor on the amount of heat that the atmosphere retains.
There are those who believe in magic CO2. These uneducated and rather thoughtless believers of magic try to claim the current rise in atmospheric CO2 is following rather than leading the warming. But they cannot explain where the carbon in the CO2 comes from. They claim that warming air magically creates carbon. We know that the CO2 is not coming from the oceans as it has during past natural warming because carbon is increasing in the oceans at the same time, and because it is the wrong kind of carbon (the carbon in the atmosphere that is most increasing is the isotope that comes from plants and animals). These people also believe that the CO2 produced by combustion magically disappears rather than enter the atmosphere. Yes, what you call a "difference of opinion" is a belief that by some that CO2 created by combustion magically disappears and meanwhile other CO2 with the same isotopes as fossil fuels is magically entering both the atmosphere and the oceans. To any thinking person, this is silly. And it is silliness that you call a "difference of opinion".
To scientists or persons with basic critical thinking abilities, the CO2 allows testing of whether or not the warming is natural. Were the warming natural, then CO2 would be coming from the oceans, carbon in the oceans would be decreasing, and the ratio of C12/C13 would not be increasing in atmospheric CO2. In both this critical tests, the "natural" hypothesis fails, and the increased CO2 is proved to be totally or predominantly from human activities.
I for one do not believe in magic.
The most honest short answer is "Yes."
Increased atmospheric CO2 (and increases of any other greenhouse gas, including methane) can drive warming. However, if warming is triggered by some other source, such as a change in solar input, then the increase in temperature from that will release CO2 from the oceans, which will lead to warming, which will release more CO2, and so on. It's called a positive feedback. Also, if warming is caused by large quantities of methane, the methane will eventually become CO2, leading to an increase in CO2 that lags behind the temperature increase.
What all this boils down to is, all else being equal, if temperatures rise, atmospheric CO2 will also rise, and if atmospheric CO2 rises, temperatures will also rise.
And, to forestall the next obvious question, the reasons this doesn't just keep cycling temperatures upward indefinitely are negative feedbacks and diminishing returns. Positive feedbacks will make a change bigger, while negative feedbacks will make that change smaller. The simplest negative feedback for the Earth's temperature is that the hotter the Earth is, the more energy it will radiate back into space.
And, well, the more CO2 you put in the air, the less effect each addition has. Theoretically, the effect can become saturated, but practically speaking, even if the center of the absorption spectrum is saturated, the "shoulder" effects continue to increase with increasing CO2.
Much of that effect's actually down to location. Skimming the answers here already I don't see it mentioned, but there was a paper published last year, Shakun et al 2012, that had chronologies of the most recent glacial-interglacial transition for various latitudes - it seems that in the southern latitudes CO2 lagged temperature (we see this in the ice cores for instance), and in the northern hemisphere it led temperatures. Globally the result was a slight CO2 lead.
http://www.nature.com/nature/journal/v48...
I'm not really sure of a mechanism by which CO2 would lag globally anyway, or rather what would cause global temperatures to rise if not by an increasing global greenhouse effect. The only major external forcings on our climate are the Sun, volcanoes, and Milankovitch cycles - neither of the first two have such periodicity as can cause our glacial/interglacial cycle, whereas Milankovitch cycles match extremely well; on the same token, we don't actually absorb more energy as a planet as a whole just from changes in eccentricity/axial tilt/precession.
So, global warming or global cooling doesn't make much sense; regional warming/cooling that leads to global feedbacks would make sense, and that's the mechanism that Shakun et al. describe. But that global feedback is CO2; CO2 increases to cause warming around the rest of the planet, but where the Milankovitch cycles caused regional warming, it will be seen as lagging.
I think that one of the best analogies I've heard regarding the lead/lag question came from Richard Alley's 2009 AGU presentation, in which he likened the climate to a credit card - if you go out and spend a lot on your card before the interest payments catch up, you get into debt before you start accruing interest. However, that doesn't mean that the interest payments don't contribute to your debt, you can't just ignore them.
The concept of something lagging a cause, and helping to perpetuate or exasperate that cause, isn't really without precedent in other situations, and I've thought for a long time that the lag/lead issue isn't really that important.
Both can happen. Rising CO2 levels produce a greenhouse effect that will warm the climate. It is also true that other factors, such as a change in the tilt of Earth on its axis, can cause a warming that begins to release CO2 into the atmosphere. Even now, with the rising CO2 levels causing the climate to warm then the climate could warm to the point that begins to release methane into the atmosphere. Methane has a short life span in the atmosphere, but it begins to break down into CO2 adding to the CO2 levels that are already there.
That was the big (huge) Al Gore lie. his graph of Co2/temp rise was impressive, but he failed to mention Co2 actually lagged behind the temperature rise by up to 800yrs.
It's simple Co2 is dissolved in water (oceans) and the amount that dissolves depends on the temp (cold soda against warm soda pop) cold water can absorb so much more Co2 than warm water, global temp rise equals global Co2 rise, not the other way around.
The simple answer is both!
Which ever one happens first, the other will follow. Each then causes an increase in the other by what is known as a positive feedback loop. This process will continue until equilibrium is restored.
http://en.wikipedia.org/wiki/Climate_cha...
CO2 has lagged in the past; this time it is leading the temperature rise.
Please let me know if you need any more detail.
There is a proven correlation between CO2 rising and subsequently a rise in temperature. This has been documented for over 3 decades. Not sure where you difference of opinion comes from but it is only an opinion and a frequently used question by DA deniers here who have no real scientific climate evidence to support their lame claims.
It depends on what time frame you are talking about. At the end of the last ice age, there were no SUVs. As a consequence, something other than carbon dioxide. The tilt of Earth's axis was stronger than it is now, and ice melted, the oceans released carbon dioxide and bogs in what is now Texas and Alabama released methane. When the warning stopped 6,000 years ago, the methane was oxidized to carbon dioxide. Carbon dioxide is a weaker greenhouse gas than methane, which is why Earth cooled while carbon dioxide continued to increase.
Today, humans are releasing carbon dioxide into the atmosphere. Unlike then, rather than being an effect of the warming, carbon dioxide is the cause.
The temperature of the Earth is determined by something very simple… the difference between the incident radiation (from the sun) and the radiation subsequently re-radiated to space.
The atmosphere contains greenhouse gasses which absorb certain frequencies of light and retain them as heat. CO2 is one of these greenhouse gasses. (sorry for re-stating the obvious, but it needs to be included as a part of the explanation)
If the atmosphere had no CO2 in it, and some were added, then the earth would warm. But only after the CO2 was added. (Note here that this is not how our atmosphere formed).
Adding more CO2 does not increase temperature infinitely. It is in an inverse logarithmic relation. i.e. there is a ceiling beyond which adding more CO2 will not increase absorption. Moreover, CO2 only absorbs in small portions of the spectral frequency range, so again the amount of energy to available be absorbed is finite.
We know that increasing CO2 has no ‘runaway’ effect of the earth’s climate because in the past CO2 concentrations were much, much higher; but the temperature was only modestly higher. It is the algae and plankton in the oceans, which absorbed CO2 out of the atmosphere, that reduced the CO2 content to today’s levels. The planet did not freeze as this occurred.
The oceans absorbed Carbon from the atmosphere at sequestrated it to the sea floor, but the (vast) oceans also contain dissolved CO2. The amount of CO2 that can remain dissolved in sea water is determined by its temperature.
If the oceans warm, they can hold less CO2 than before and must ‘outgas’ some, increasing atmospheric CO2 content. In this case, increased atmospheric CO2 will LAG global temperature rise (if the oceans warm, the earth warms). This is easily seen by examination of the annual change in atmospheric CO2 and annual average ocean temperature.
In the last 100 years or so we have further added CO2 to the atmosphere, which will cause SOME warming… but in inverse logarithmic relation to the quantity released, and there is a ceiling at which adding more CO2 has no effect whatsoever on temperature.
The temperature rise possible from CO2 is finite, and much higher concentrations in the past were not catastrophic for life on earth.
Edit for Big Gryph: "There is a proven correlation between CO2 rising and subsequently a rise in temperature. This has been documented for over 3 decades."
That is just bollocks. Check the data.
Monthly CO2 from Mauna Loa.
ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/c...
Monthly Global Mean temperature, HadCRUt4.
http://www.metoffice.gov.uk/hadobs/hadcr...
In case you won't graph the data for yourself, here's one I made earlier.
http://farm9.staticflickr.com/8091/83914...
The Fossil Fuel Industry wants people to think Climate Change is not the result of human activity
Does CO2 lead temperature rise or lag it?
Does atmospheric ppm of CO2 lead temperature rise or lag it, there appears to be a difference of opinion?
The available evidence shows it lagging behind temperature changes. To say otherwise goes against reality.
There has been a few times where it has been pre-temperature rise according to the data that Al Gore based his movie on. However, the majority of the time the rise in temperature precedes the rise in CO2 level. Al Gore had to admit it under pressure.
However, scientifically, if CO2 were causing a rise in temperature, or being the stimulus, a rise in CO2 would always precede a rise in temperature. The stimulus always precedes the reaction, naturally.
EDIT: Grifter:
Take right now. Earths temperature rose, then for the last decade plus it has reduced. All the while CO2 has risen. End of argument.
EDIT: Then Again. Al Gore and his mega-billion AGW industry wants you to believe that there is AGW. The largest fossil fuel company, Mobil, made $41 billion last year. Obama just ripped off the American public and gave $100 billion, over twice as much, to the UN for global warming. Mobil provided a service to humanity. What is that $100 billion going to do for humanity? Ha! Ha! There is no fool as foolish as a man who gets conned repeatedly.
Both
A rise in temperature precedes CO2 in all proxy datasets as well as ice core data. So the answer is it lags it.
It's a big word. I'll go slowly: B. O. T. H.
It does all three or four or maybe all six.co2 does everything, it is truly evil
