July 2, 2009 at 11:48 pm
· Filed under what is global warming?
So Chris was at work today, and with all the bad weather he had plenty of time to shout at the boss and another co-worker about global warming. It was a good 2-on-1 handicap match, but talking debates are not really my thing since no opportunity exists to check claims, reference sources, show graphs, etc that you could in online/text correspondence, and so basically anything goes. Even totally wrong claims like “Volcanoes spit out more pollution than humans do.”
The boss and the co-worker were very skeptical. I’m not sure how scientific our exchange was– they spent most of the time trying to convince me I should be very cautious in trusting the general scientific community, and I spent most of the time telling them that they should trust physics, but no one budged. They’re intelligent group of folk (one trained in biology) but not really familiar with the climate science literature, so I tried to avoid ideas like “radiative forcings,” “water vapor feedback,” “stratospheric cooling,” and other concepts. So we didn’t really discuss “how CO2 affects climate” or even radiative feedbacks, and it probably was worthwhile as a philosophy of science talk if anything.
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June 27, 2009 at 8:53 pm
· Filed under curiosity
Many readers who keep up with the blogs will be aware of the recent post at RealClimate concerning a recent review by Alan Carlin and John Davidson on the EPA Endangerment Finding. A certain blog, by one Thomas Fuller, discusses why the EPA should have listened to Carlin. Apparently the science in Carlin and Davison’s report is considered by Fuller and commenters to be “new evidence” that needs to be considered. Chris, feeling argumentive, decided to have a shot at the comments to see how this was so… I learned many new things in my visit, and I plan to document it in the best of scientific sources, a cutting edge research-database…
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June 23, 2009 at 12:10 am
· Filed under Policy, scientific basis
A fundamental issue with changes in atmospheric chemistry is that there may be multiple, and potentially competing effects in terms of problems caused to ecosystems or human welfare. For instance, aerosol declines in developed nations since the middle of the century result in less health and pollution issues, but also lead to global brightening which makes the more of the greenhouse gas influence show up.
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June 22, 2009 at 8:25 pm
· Filed under Policy, scientific basis
First off, I apologize for my lack of posts recently… I’ve been busy and haven’t had much interesting to talk about. A hot topic this week has been the release of the Synthesis report from the discussions at the Copenhagen conference earlier this year. This report, in part, is to take off where the IPCC AR4 left off in discussing key developments that occurred after the deadline for AR4 references.
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May 6, 2009 at 2:02 am
· Filed under Uncategorized
This post has nothing particular to do with climate change, but I thought it might be worth pointing out a recent study analyzing the evolutionary history of Africans and African Americans.
Africa is the source of all modern humans, originating there a few hundred thousand years ago and spreading across the globe within the last 100,000 years. The authors analyze DNA from 113 populations of Africans from across the continent and find that they descend from 14 ancestral groups (with the highest within-population diversity worldwide) and find significant associations between genetic and geographic (as well as linguistic) distance in all regions of Africa. These groups later interact with each other to create the distinct populations that exist today. The study of African genetic diversity will be important for reconstructing African and African American population histories, as well as the genetic basis of diseases prevalent in Africa.
As another sidenote, there is a new blog called Darwinaia which will have focus on paleontology, history of science (particularly evolutionary related stuff), so if you’re into that, check it out.
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April 21, 2009 at 11:03 pm
· Filed under Policy
The EPA has recently announced a “Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Clean Air Act.” It is summarized here for instance,
The Administrator signed a proposal with two distinct findings regarding greenhouse gases under section 202(a) of the Clean Air Act:
The Administrator is proposing to find that the current and projected concentrations of the mix of six key greenhouse gases—carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)—in the atmosphere threaten the public health and welfare of current and future generations. This is referred to as the endangerment finding. The Administrator is further proposing to find that the combined emissions of CO2, CH4, N2O, and HFCs from new motor vehicles and motor vehicle engines contribute to the atmospheric concentrations of these key greenhouse gases and hence to the threat of climate change. This is referred to as the cause or contribute finding.
This proposed action, as well as any final action in the future, would not itself impose any requirements on industry or other entities. An endangerment finding under one provision of the Clean Air Act would not by itself automatically trigger regulation under the entire Act.
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April 7, 2009 at 12:27 am
· Filed under scientific basis
Most people spending much time on the blogosphere are well aware of claims that “Global Warming stopped in 1998″ or similar-style remarks. Even though the 1998-2008 period contains most of the warmest years on the instrumental record (something that is very unusual), and all the years are well above the traditional 1951-1980 (or 1961-90) climatologies, a key focus for skeptics has been the lack of upward slope in a linear regression over the 1998-2008 period.
It has also been emphasized by many that a traditionally defined climatology involves roughly 30 years of data, and so at least a few decades are needed to say much about the underlying trends in climate. However, there is not much in the peer-reviewed literature regarding the probability (or significance) of decadal flatlines, or coolings, when the climate regime is superimposed on a long-term warming trend due to radiative forcing. This is the subject of an upcoming paper in Geophysical Research Letters by David Easterling and Michael Wehner in Is the Climate Warming or Cooling? (subscription required, abstract not available since the paper has not been formally published yet). Their conclusion is that these kind of decadal time-frames can yield slopes of either warming or cooling in a warming world, even in the later 21st century, and nothing is odd about the 1998-2008 trend.
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March 31, 2009 at 3:58 pm
· Filed under scientific basis
Update- Some changes over the last few hours
Update2- Anthony Watts has contacted Lindzen for clarification
Update 3 on bottom
Science is an evolving process. Data, models, and methods all evolve in time, correcting errors along the way, and building more questions or robust conclusions in the process. It is necessary for people with expertise in a particular area to keep up with the data and any changes that may be made to it, as well as the underlying problems that may exist within the data. In some unfortunate cases, people lose objectivity and will use only a particular dataset (or version of that dataset) that re-inforced some point they are trying to make. In presenting information, not telling people outside of their field what the possible caveats are in a dataset, or explaining revisions that were made to data they show is not generally taken well in academic setting. So it is with a recent example. Read the rest of this entry »
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March 14, 2009 at 3:23 am
· Filed under paleoclimate
It is well recognized that warming from a cold glacial period to a warmer interglacial is accompanied by increases in Carbon Dioxide concentrations, which at least amplified Milankovitch-induced forcing over millennial timescales. Atmospheric CO2 concentrations were around 100 ppmv lower than pre-industrial values during deep glacial climates. A key question in paleoclimate studies that is still not sufficiently addressed is how changes in solar insulation could have forced the feedbacks in atmospheric chemistry observed in proxy records.
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March 5, 2009 at 4:04 pm
· Filed under Uncategorized
I don’t like to comment about the information stemming from “Watts up with That” because no one in their right mind gets information from such a source, and by doing so I’m only allowing nonsense to set the tone in the climate debate, but Anthony Watts has a recent post about the water vapor feedback which I felt compelled to elaborate on.
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