But… there’s only been maybe 0.8C of warming since the pre-industrial era… if you get rid of the last decimal…
The Tribune (Jackson, County, IN) reports:
Now, new research has shown that the upward move may have been too hasty, and there’s a discussion in Stockholm over whether to bring the lower end back down to 1.5 C (2.7 F).
It may seem like a minor detail, but it makes a difference to governments, which want to know how much CO2 emissions need to be cut to prevent temperatures from increasing more than 2 C (3.6 F) compared to before humans started burning fossil fuels. That’s the limit they have agreed to in U.N. climate talks. Temperatures have already gone up about 0.8 C (1.4 F).
Reducing the lower range of climate sensitivity “would mean that we have a better chance of staying below 2 degrees than we thought before,” said Kaisa Kosonen, a Greenpeace climate activist. “But I wouldn’t bet on it because they are not lowering the higher end of the range.”
In leaked comments on a June draft of the IPCC report, the British government called climate sensitivity “a key issue of concern” that helps give policy-makers a sense of how big a threat climate change is.
The United States, Australia and Norway have called for the authors to provide a single value as their best estimate in addition to a range, to give policy-makers better guidance.
Meanwhile, EU climate commissioner Connie Hedegaard is downplaying the discussion.
“You don’t need to have the last decimal to see that the overall number isn’t looking good,” she said in a comment emailed by her spokesman.
Some scientists resist giving a single value because it could give the false impression that there’s more certainty than there really is about how sensitive the climate is to CO2. That doesn’t mean they doubt that CO2 serves as an engine of warming — the question is whether it’s a four-cylinder or a V8.
“We know a great deal of the mechanism by which CO2 causes warming,” said Field, the Carnegie scientist. “There is still uncertainty about how much a range of feedbacks either amplify or suppress that warming.”
Geoff, responding to your query, O2 does contribute to the greenhouse effect via its absorption spectrum (it’s based on what wavelengths the mix of gases absorb, not the mass. Density is a factor since it means more gas that the light is going through, but that’s more or less constant for purposes of this discussion). The thing about oxygen and nitrogen are that they are so concentrated that their greenhouse effect are unchanged due to the logarithmic nature of the absorption.
And to go past 2000 ppm CO2, we have to go to what I call a “burn the world” scenario. It’s not possible to get 10,0000 ppm without apocalyptic destruction of large sections of the planet to release the carbon entrained in rocks and soils.
Howdy ben and deacon
I assume that oxygen is a greenhouse component simply by having mass; all mass tends to insulate. I don’t know how oxygen’s other properties compare to CO2’s other properties in terms of handling radiative heat.
The amount of O2-to-CO2 that would have to convert to either cause oxygen depletion or CO2 toxicity is far, far beyond even a deliberate attempt to do so on a planetary scale. Even Ernst Blofeld couldn’t do that.
Oxygen.
C (anything burnable) + O2 -> CO2.
Now, some stupid people have claimed problems with oxygen depletion, but current changes have been
CO2: 250 ppm – 400 ppm
Oxygen: 21% -> 20.9850% ( approximate, I don’t have the data to that low a precision, so really this is still 21%)
Marque, One point of correction. Gas absorption is logarithmic with respect to concentration at a constant pressure, so (assuming all other processes are consistent in their response over this small range of warming, which is a non-trivial, but not bad and certainly a necessary assumption) each doubling will have the same effect. The issue is that we have natural warming to account for as well, given that we are in the upswing at the end of the little ice age. Going by the raw warming gives a CO2 sensitivty of 2C per doubling, but the warming clarly began before the CO2 rise. Trying to separate out the natural from the human warming isn’t neither trivial, nor really possible. However, we can make some estimates. My crude calculations came up with a 0.75-1C per doubling sensitivty.
I have no idea why the URL is in there 3x sorry about that.
If you have the magic 2 degrees, maybe you don’t need the stinking decimals. These guys have been cavalier with numbers, decimal places, significant figures for a long time. It looks like the disdain for accuracy is showing.
All life on the planet produces CO2. Are we going to see the slogan ” Kill the Planet to Save it”.?
Here is an interesting post from a libertarian blog. The guy Warren is also a skeptic. He came up with a model and assumed a 0.45 degC increase due to CO2 due to the current increased levels. His projection is right on the money and he came up with it 6 years ago. Per his chart there should be cooling until 2030 and then the warming trend will begin again.
http://www.coyoteblog.com/coyote_blog/2013/09/update-on-my-climate-model-spoiler-its-doing-a-lot-better-than-the-pros.html
It is an interesting read, how he, an amateur, came up with a model that is beating all the IPCC models.
http://www.coyoteblog.com/coyote_blog/2013/09/update-on-my-climate-model-spoiler-its-doing-a-lot-better-than-the-pros.html
So I think there is a small influence due to CO2, just not nearly as much as the IPCC would like us to believe
http://www.coyoteblog.com/coyote_blog/2013/09/update-on-my-climate-model-spoiler-its-doing-a-lot-better-than-the-pros.html
…how much a range of feedbacks either amplify or suppress that warming.”
So, the do not even know whether the supposed feedback is either positive or negative. This is beyond error bars; this is ignorance.
If co2 is increasing in the ppm of the atmosphere, what is being removed or replaced?
“the question is whether it’s a four-cylinder or a V8.”
No, the question is whether even a metaphoric V12 would have the horses to melt both icecaps and drown 1/4 of the world while the other 3/4 die in hurricanes, tsunamis, droughts, water shortages, and all the inevitable nasty wars fought over the sudden reduction in resources. The argument has always been that drastic times call for drastic measures. Now that it looks like the times aren’t all that drastic, they’re inexplicably trying to up the ante. They’re desperate to get something; anything implemented so they can point to it and say “See! We stopped global warming.” Before the uninterested masses realize it isn’t happening.
Howdy marque2
I wanted to clarify that human production is essentially lost in the noise. There are a lot of sources of CO2 besides human activity and they are more important to the “carbon budget” than human CO2 production is. As you say, the sensitivity to CO2 is really quite low and it only becomes “catastrophic” by introducing the positive feedbacks that nature displays very rarely indeed.
I wouldn’t say the CO2 is lost in the noise. It is contributing a little bit. I would expect a doubling of CO2 to increase the average temperature by about 1 degC and a second doubling to increase it another 0.5 degC and then due to diminishing returns the increase would be trivial.
What I object to and what any serious sceptic really objects to is the wild positive feedback added into the models of the IPCC where a 1 degree increase gets magically translated to 4, 5 10 degC with no end in sight. If CO2 concentration goes up 10x the increase in temps will be 40x per them and that is just plain silly.
‘by which CO2 causes global warming’ then ‘we’ know nothing as the science is still an unproved theory that violates the 2nd Law of Thermodynamics.
The start of the industrial revolution coincides with the end of the Little Ice Age where their base line begins. We finished climbing out of the Maunder minimum in the late 90’s, then began the current cooling period. Hedegaard is spewing pure cow excrement.
AGW has always used numbers well to the right of the decimal point to claim that catastrophe is imminent. If you have a good math teacher, you learn not to do four-decimal-place math on two-decimal-place data, let alone two-decimal data on +-1 data.
Empirically, we can see that human production of CO2 is waaaay to the right of the decimal place in climate factors, essentially an element lost as noise in the other forcings. We know this because the temperature trends have varied even as human production of CO2 has steadily increased.
Human activity involves real pollution, which “carbon pollution” is not. It involves real choices about land use, resource allocation, good stewardship. If we could provide the energy the world needs without burning, we’d have a good thing. But we can’t now and we can’t foresee when it could be possible, Daryl Hannah’s renewables not withstanding. We have to accept, and I hope to mitigate, some level of pollution and other forms of environmental change or harm. Otherwise we condemn billions to real poverty, billions more to constrained lifestyles, and the few like Gore and Hannah and Gates will live as they do now.
What is the elitist proposition, then?