[QUOTE]The American Physical Society, an organization representing nearly 50,000 physicists, has reversed its stance on climate change and is now proclaiming that many of its members disbelieve in human-induced global warming.

 

After reading the actual APS statement, I have to say that the news article misrepresents what it actually says.

There are three possible positions here: (1) humans are the primary cause of global warming; (2) humans are not the primary cause of global warming; (3) we don't actually know enough to tell what the primary cause of global warming is.

Scientists tend to be skeptical, and like to see proof of things. Thus, they'll typically start out in position (3) - undecided - and only move to (1) or (2) when presented with enough evidence. Physicists in particular are in a pretty hard science and tend to want to see really clear proof.

The IPCC is taking position (1) - humans cause global warming. All the APS statement says is that they don't all agree with the IPCC. This doesn't mean they're taking position (2); it just means many of them are still in position (3) - undecided.

Should we wait until there's incontrovertible proof before acting, or might that be too late? Personally, I suspect it's already too late. Of the signatories of the Kyoto protocol, only one of them managed to stay within their CO2 limits; I don't think it's realistic to expect a broader treaty to be any more effective. If it's not human caused, there's even less we can do about it, other than selling off any coastal real estate we own.

 

[QUOTE=APS Web Site (as of this time and date)]
APS Climate Change Statement

APS Position Remains Unchanged

The American Physical Society reaffirms the following position on climate change, adopted by its governing body, the APS Council, on November 18, 2007:

"Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate."

An article at odds with this statement recently appeared in an online newsletter of the APS Forum on Physics and Society, one of 39 units of APS.

 

Too late for what?

 

There was a big news story in the main-stream media a month ago that the polar ice cap would melt this year. First time in 10,000 years, so they said. That sounded like a huge story to me. I thought I'd hear follow up stories on that for weeks and regular updates. But I didn't. Do any of you in the science community have an update?

I ask because I really want to know.

 

Either you are confused or the reporter was confused, or both.

The polar ice caps always melt every year. They also grow every year. Like a glacier, what is of primary interest is the net change -- did it grow more than it melted, or vice versa?

 

Reports on three channels were the same. The report was about the north pole.

 

Quick google came up with this.

http://www.treehugger.com/files/2008/06/no...this-summer.php

 

If the Arctic sea ice melts completely this year -- as it came close to last year -- it won't happen until August or September. The folks monitoring this (and they use satellites, so they're on top of it) will make a bit too-doo about it, you can be sure. HPH

 

Too late to avoid major problematic effects from global warming, in particular major sea level changes. Too late for any possible policy changes to have any significant effect on upcoming climate change in this century.

I think melt through of the north polar ice cap is likely to happen, if not this year, then some year soon. I think it's likely that will change the polar albedo enough that substantial additional melting will start happening each year. For example, greenland could melt through, which would result in a noticeable sea level change.

I know, on the ozone hole, once the threat was clear, everyone got together and banned essentially all use of CFCs overnight, fixing the problem. Somehow I don't think a sudden ban on all fossil fuel consumption will go down quite as easily.

Note that I don't think we should just give up - spreading out the changes over more years will probably make them easier to adjust to. Also, it may not yet be too late to prevent a complete change back to the situation the earth was in before all those fuels were fossilized - you know, the situation where the climate was warm enough for reptiles to have the advantage over mammals, rather than vice versa.