First open thread of 2012, so perhaps some discussion of the highlights and lowlights of 2011 are in order? Top 5 lists welcome…
Reader Interactions
361 Responses to "Unforced variations: Jan 2012"
flxiblesays
RickBrown @348 – I think this study points at a more “basic” reason that arguing with denialators is useless. Goes a long way toward explaining rebublicat attitudes towards science in general.
Clinker beds, the hard-baked sedimentary layers adjacent to burned-out coal seams, can be seen in North Dakota’s badlands, among other places.
vukcevicsays
If anyone has a link (or a file, email is on the graph’s link below) for the NOAA’s Atlantic Accumulated Cyclone Energy (ACE) index, which would help to evaluate the ‘Atlantic Hurricane probability index’. Currently the ‘probability index’ is only indicative and if evaluation is positive it may be of some value. http://www.vukcevic.talktalk.net/AHpi.htm
In the NASA report the other day they show a .71 degrees rise in temperature since 1880 with some degree of uncertainty in those temps. While listening to the radio I heard one of the deniers claim that it’s not enough to account for the elevated co2 levels.
I’ve been searching this site and Skeptical Science on an article that would explain what the facts really are. Would anyone have a link?
[Response: Not quite sure what you heard, or from who, but the elevated CO2 levels (40% increase over pre-industrial levels) are from anthropogenic burning of fossil fuels combined with mainly-tropical deforestation. They are not elevated because of the global temperature increase. There is long-term carbon cycle feedback to temperature seen in the ice core record but that is on the order of ~10-20 ppm/deg C over hundreds to thousands of years, so can’t possibly account for a 110 ppm rise in 150 years. – gavin]
Gavin, the point he was making was that with those elevated CO2 levels we should be hotter than we are now. He said something to the effect that something was mitigating the affects of the co2 or we don’t have a good understanding of the science.
I had never heard this claim and was wondering if anybody else had.
[Response: Ah.. that’s more standard. But the issue is that climate doesn’t only respond to CO2, and it doesn’t respond instantly. There are multiple drivers of climate change and particularly over the 20th Century, it gets complicated – there are other greenhouse gases (CH4, N2O, CFCs), ozone changes, solar changes and volcanoes. However, the most important in this question is the aerosol forcing which has been a net cooling over the 20th C. This is not as well understood as the greenhouse gases, so the net forcing is a more uncertain, but it is almost certainly true that the net forcing is less than the impact of the main greenhouse gases, and it may be true that net forcing is less than CO2 on it’s own (best guess is that they are comparable). But then you have to take the ocean inertia into account which means that planet takes decades to hundreds of years to reach equilibrium. So if someone claims that the temperature change from CO2 forcing (110ppm extra is around 1.7 W/m2) should have been 3 * 1.7/3.7 = 1.4ºC (estimated from the equilibrium climate sensitivity of 3ºC for a doubling of CO2 = 3.7 W/m2), then they are guilty of ignoring the interia and the additional forcings. – gavin]
Nice to see the response to the WSJ’s previously noted goofiness – too bad that the comments make it clear that in large measure it was preaching to the unconvertible, but it might reach a few. Kudos to the RC contributors.
contains precipitation data. I attempt the same analysis as in Fig 4. of Hansen, i attempt to calculate local precipitation anomaly scaled by local standard deviation.
I get skewed distributions. Is this real or have i erred somewhere ?
sidd
Hunt Janinsays
Re sea level rise:
My coauthor and I are now putting the finishing touches on our introductory survey of sea level rise. I’ve asked this question before but now it seems worthwile for me to ask it once again — one last time before the ms. goes off to the publisher —
If anyone has any NEW thoughts about future black swan events causing sea level rise, I’d like to hear them.
RickBrown @348 – I think this study points at a more “basic” reason that arguing with denialators is useless. Goes a long way toward explaining rebublicat attitudes towards science in general.
> the WSJ op-ed
For Dave Erickson:
“The Rise of the Dedicated Natural Science Think Tank …
Coal seam fires are an ancient phenomenon, about which books have been written: Geology of coal fires: case studies from around the world
Clinker beds, the hard-baked sedimentary layers adjacent to burned-out coal seams, can be seen in North Dakota’s badlands, among other places.
If anyone has a link (or a file, email is on the graph’s link below) for the NOAA’s Atlantic Accumulated Cyclone Energy (ACE) index, which would help to evaluate the ‘Atlantic Hurricane probability index’. Currently the ‘probability index’ is only indicative and if evaluation is positive it may be of some value.
http://www.vukcevic.talktalk.net/AHpi.htm
Was the Little Ice Age triggered by volcanoes? Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea-ice/ocean feedbacks.
Press release.
In the NASA report the other day they show a .71 degrees rise in temperature since 1880 with some degree of uncertainty in those temps. While listening to the radio I heard one of the deniers claim that it’s not enough to account for the elevated co2 levels.
I’ve been searching this site and Skeptical Science on an article that would explain what the facts really are. Would anyone have a link?
[Response: Not quite sure what you heard, or from who, but the elevated CO2 levels (40% increase over pre-industrial levels) are from anthropogenic burning of fossil fuels combined with mainly-tropical deforestation. They are not elevated because of the global temperature increase. There is long-term carbon cycle feedback to temperature seen in the ice core record but that is on the order of ~10-20 ppm/deg C over hundreds to thousands of years, so can’t possibly account for a 110 ppm rise in 150 years. – gavin]
Gavin, the point he was making was that with those elevated CO2 levels we should be hotter than we are now. He said something to the effect that something was mitigating the affects of the co2 or we don’t have a good understanding of the science.
I had never heard this claim and was wondering if anybody else had.
[Response: Ah.. that’s more standard. But the issue is that climate doesn’t only respond to CO2, and it doesn’t respond instantly. There are multiple drivers of climate change and particularly over the 20th Century, it gets complicated – there are other greenhouse gases (CH4, N2O, CFCs), ozone changes, solar changes and volcanoes. However, the most important in this question is the aerosol forcing which has been a net cooling over the 20th C. This is not as well understood as the greenhouse gases, so the net forcing is a more uncertain, but it is almost certainly true that the net forcing is less than the impact of the main greenhouse gases, and it may be true that net forcing is less than CO2 on it’s own (best guess is that they are comparable). But then you have to take the ocean inertia into account which means that planet takes decades to hundreds of years to reach equilibrium. So if someone claims that the temperature change from CO2 forcing (110ppm extra is around 1.7 W/m2) should have been 3 * 1.7/3.7 = 1.4ºC (estimated from the equilibrium climate sensitivity of 3ºC for a doubling of CO2 = 3.7 W/m2), then they are guilty of ignoring the interia and the additional forcings. – gavin]
A good reminder at Azimuth, John Baez’s blog: How to Cut Carbon Emissions and Save Money
27 January, 2012
Nice to see the response to the WSJ’s previously noted goofiness – too bad that the comments make it clear that in large measure it was preaching to the unconvertible, but it might reach a few. Kudos to the RC contributors.
In
http://www.columbia.edu/~jeh1/mailings/2012/20120105_PerceptionsAndDice.pdf
Hansen et al. New Climate dice, Figure 4, exhibit distributions over 60 years of local temperature anomalies scaled by local standard deviation.
the following URL
ftp://precip.gsfc.nasa.gov/pub/gpcp-v2.2/
contains precipitation data. I attempt the same analysis as in Fig 4. of Hansen, i attempt to calculate local precipitation anomaly scaled by local standard deviation.
http://membrane.com/sidd/precip-dist.png
I get skewed distributions. Is this real or have i erred somewhere ?
sidd
Re sea level rise:
My coauthor and I are now putting the finishing touches on our introductory survey of sea level rise. I’ve asked this question before but now it seems worthwile for me to ask it once again — one last time before the ms. goes off to the publisher —
If anyone has any NEW thoughts about future black swan events causing sea level rise, I’d like to hear them.