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Cleaner Air Could Speed Global Warming
Hugh Pickens writes "Scientists estimate that the US Clean Air Act has cut a major air pollutant, sulfate aerosols, by 30% to 50% since the 1980s, helping greatly reduce cases of asthma and other respiratory problems. But NPR reports that this good news may have a surprising downside: cleaner air might actually intensify global warming. One benefit of sulfates is that they've been helpfully blocking sunlight from striking the Earth for many decades, by brightening clouds and expanding their coverage. Researchers believe greenhouse gases such as CO2 have committed the Earth to an eventual warming of roughly 4 degrees Fahrenheit, a quarter of which the planet has already experienced. But thanks to cooling by aerosols starting in the 1940s, the planet has felt only a portion of that warming. And unlike CO2, which persists in the atmosphere for centuries, aerosols last in the air for a week at most, so cutting them would probably rapidly accelerate global warming. The author of 'Hack the Planet' says: 'As we take away that unexpectedly helpful cooling mask, we're going to be facing more global warming than we expected.'"
It is a little know fact that, given the uncertainties of what is happening in our climate system, the warming seen over the last few decades is entirely attributable to the reduction in aerosols in recent years. This is mentioned in WGI chapter 2 of the IPCC report. Of course, that fact didn't make it into the "Summary for Policy Makers." In fairness I should mention that the chances of the temperature change being entirely attributable to the change in aerosols is actually quite low, but it's still something worth considering.
Qxe4
Dear BonquiquiShiquavius,
The LA Times and NPR aren't part of the scientific community. They reported on a book written by Eli Kintisch who is a journalist who writes about science. Also not really part of the scientific community.
I don't think geoengineering is a viable solution, so I don't care to read Kintisch's book. But in the article he seems to be repeating the well known facts that aerosols cool Earth's surface and have a shorter lifetime in the atmosphere than CO2. This doesn't "wildly contradict previous findings"-- I've been explaining for years that these nuances are described in detail by the IPCC AR4 WG1 report.
Sincerely,
A dumb member of the scientific community
>>However the current ecosystem is in a bit of peril, some say that we're currently living through the 6 great extinction of earth, but iirc the jury is still out on that one.
Yeah. While species are going extinct, it's not the "10,000 species a day going extinct" bullshit I heard every time I went to the San Diego Zoo back in the 1980s. The study for that number was based on insect surveys. They dug up a 10 meter square patch of earth, counted the species, then counted them again the next year. Stag horn beetles moved 30' away? They're extinct!
It's one of those memes that everyone knows, but doesn't know just how badly that number was derived.
The actual number of species going extinct is actually very hard to calculate, but it's nowhere near these humans-are-evil numbers tossed around by tree huggers. Just by way of reference, there's only a million animal species or ten on the planet. If these numbers were true, there'd be negative 90 million species left by today.
There has been extensive reporting that the lack of statisticians in the climate research area is a problem.
Some chap called Wegman did a report for the NAS (National Academy of Sciences) that was rather critical of the lack of statistical expertise, and some of the most consistent complaints about climate research are in the area of statistics.
I'm not an expert and don't have an opinion on this, though!
Rational thought is the only true freedom