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Post by icefisher on Apr 6, 2009 17:19:22 GMT
glc, you are entitled to your opinion, but those links point to clear negative forcings. In addition, some climate scientists are of the opinion that sulphate aerosols could be used to reverse "global warming" I appreciate that any science contrary to the current paradigms does get little attention. The recent cooling decades and following cooling is entirely consistent with the rise then leveling off & falling of human sulphate aerosol emissions. For the inquiring scientist, it is an area that needs examining. I have no opinion, belief or an "feelings" toward sulphate emissions. I'm just pointing out that others have noted the correlation, and, given the current sate of ignorance on all things climate, we should keep every possible cause in mind. It is a possible explanation. You lose most of the AGW alarmists when you suggest actually controlling the environment. . . .or worse improving it for mankind. I think they believe the planet has been in danger ever since space aliens colonized the planet and started disrupting the "natural" order of things.
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Post by vukcevic on Apr 6, 2009 20:36:40 GMT
Kiwistonewall thanks for your contribution, it sounds convincing, and combined with atmospheric nuclear tests producing effect similar to that of cosmic rays (only recently explained by Svensmark), and dust clouds as suggested by Timo, we may have a plausible explanation.
Glc I value your views but are they supported by any research for the period?
It is a shame that at the time when climatic changes are on of top of the agenda, that there is no single authoritative article on decline in global temperature during this period, which could help in understanding what followed in the next three decades.
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Post by glc on Apr 6, 2009 23:28:03 GMT
Glc I value your views but are they supported by any research for the period? The pattern of mid-20th cooling is not consistent with either the pattern or the timing of aerosol emissions. It's as simple as that. The most plausible explanation is the negative PDO shift which kicked in in the early 1940's.
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Post by kiwistonewall on Apr 7, 2009 2:23:03 GMT
glc,
there are multiple causes for global temperature change.
Sulphate aerosol forcing is just one, and the forcing is known, and can be factored in. Anyone looking for a single cause is simply deluded.
This is not an explanation: "The most plausible explanation is the negative PDO shift which kicked in in the early 1940's."
It still amazed me that people think the state of the PDO, ENSO or any other oscillation index is a "cause". These are simply measurements of a particular state of the Earth's circulation system. That state may correlate with certain weather patterns, but the CAUSE of that state is entirely another matter.
The various indexes (indices for the purists) have great predictive power. We know the probability of particular seasonal weather patterns correlated with the state of the Index.
The index is a placeholder for the true cause (or causes) which are obviously complex. We are not yet able to predict what the PDO or ENSO will do with certainty, though there are models devoted to this task.
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Post by magellan on Apr 7, 2009 2:32:31 GMT
glc, there are multiple causes for global temperature change. Sulphate aerosol forcing is just one, and the forcing is known, and can be factored in. Anyone looking for a single cause is simply deluded. This is not an explanation: "The most plausible explanation is the negative PDO shift which kicked in in the early 1940's." It still amazed me that people think the state of the PDO, ENSO or any other oscillation index is a "cause". These are simply measurements of a particular state of the Earth's circulation system. That state may correlate with certain weather patterns, but the CAUSE of that state is entirely another matter. The various indexes (indices for the purists) have great predictive power. We know the probability of particular seasonal weather patterns correlated with the state of the Index. The index is a placeholder for the true cause (or causes) which are obviously complex. We are not yet able to predict what the PDO or ENSO will do with certainty, though there are models devoted to this task. No comments yet on Hansen's recent curious statements: www.columbia.edu/~jeh1/2009/Copenhagen_20090311.pdf We do not have measurements of aerosols going back to the 1800s – we don’t even have global measurements today. Any measurements that exist incorporate both forcing and feedback. Aerosol effects on clouds are very uncertain.
Even if we accept the IPCC aerosol estimate, which was pretty much pulled out of a hat, it leaves the net forcing almost anywhere between zero and 3 watts. How about the effects of clouds themselves, or even what regulates them? No Wonder Climate Alarmists Refuse to Debate ;D www.americanthinker.com/2009/04/no_wonder_climate_alarmists_re.html
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Post by vukcevic on Apr 10, 2009 11:49:06 GMT
Sulphur emissions may well have been the driver for concerns of global cooling in the 70's Kiwistonewall You are absolutely correct. Since the 1890s, surface temperatures have risen faster in the Arctic than in other regions of the world. In part, these rapid changes could be due to changes in aerosol levels. Clean air regulations passed in the 1970s, for example, have likely accelerated warming by diminishing the cooling effect of sulfates. Credit: Drew Shindell, Goddard Institute for Space Studies.
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Post by eldotda on Apr 10, 2009 19:44:37 GMT
Check out this angle: broadcast.homestead.comThere is a fascinating chart that maps the temperature fluctuations along with changes in broadcast usage.
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Post by icefisher on Apr 11, 2009 3:22:09 GMT
Check out this angle: broadcast.homestead.comThere is a fascinating chart that maps the temperature fluctuations along with changes in broadcast usage. LOL! And the recent downturn to cooler temperatures must be attributable to the failure of leftwing radio. ;D
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Post by eldotda on Apr 11, 2009 16:33:32 GMT
I don't listen to leftwing radio...I don't know about its status.
I have been wondering what impact the recent change from analog to digital over-the-air TV broadcasting might have, though.
Have you looked at that chart that maps temp changes against broadcast changes?
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Post by vukcevic on Apr 11, 2009 18:12:20 GMT
If you use all the junk on world temperatures for last 120 years, chew it up, and spit it out, you see we are where we were in 1940.
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