but what about the science?

I wound up responding to a comment on another blog that asked about the science behind global warming. It's true: there's a lot of hype out there, making it hard to find the solid information. So, partly as a public service, partly so I can find these links more easily in the future, and maybe a teensy bit because finals are making me a touch grouchy, here are some useful starting points for solid information.

• "I am totally convinced that there is something unusual happening with Global Climate. . . . What I am not convinced about is the science behind the 'causality'."

The IPCC's Working Group 1 reported on this issue. Their Summary for Policymakers (pdf) targets policymakers (as you might expect) rather than scientists. As a result, it has some technical jargon but not too much and is pretty clearly written.

If you want more details and really want to get in to the nitty-gritty, Working Group 1 has now released most of its full report. The summaries come out first, then the report rolls out, with revisions as they go. The report's pretty large, but it includes citations to the scientific literature. That means if you want the details, you can go through the report, find the citation, then go to the nearest university library and track down the papers in their journals and continue your research from there. In some cases, you can find the papers through Google Scholar, but getting the full text tends to be hit-or-miss. On the other hand, Google Scholar does a pretty good job of showing you which other papers cite the paper you're searching for, so you can see how others have commented on the paper.

• What is that I can do personally that will at least stop the situation from becoming worse if not reverse it?

The IPCC's Working Group 3 is reporting on mitigating greenhouse gas effects. They have released a preliminary version of their Summary for Policymakers (pdf), but neither the final version nor the full report is out, yet. Keep an eye on the IPCC's main web page or the WG3's page to see the updates come out. Eventually, the full report will probably be available at the IPCC's publications page, where you can currently find the 2001 assessment. (Note to self: it might be very interesting to compare the 2001 assessment against the statements in the reports out of the White House Council on Environmental Quality.)

The second half of this question comes in two parts. First, the IPCC report shows most of the greenhouse gas emissions come from the energy sector, which suggests energy conservation is something someone can do personally. Transportation is another area to consider (in other words, think twice before buying the gas guzzler.) Second, the U.S. is entering a presidential election cycle, which means We the People might have a shot at steering the debate or changing policy.

• What do scientists think the impact of global warming will be? What does it mean to me?

The IPCC's Working Group 2 is tackling this question. You can find their Summary for Policymakers here (pdf--everything's pdf, I guess because of the pretty color graphs). This one is probably also still early and will see some revisions. Watch the IPCC front page for the rest of their report to come out.

IPCC report on global warming

The Intergovernmental Panel on Climate Change has released a report on global warming. So far, I've been able to find only the Summary for Policymakers (pdf) available for download. Here are some things that jumped out at me during a quick read-through.

• There's a very high confidence (90%+ probability) that the net effect of human activities has been one of warming, with a net forcing effect of +1.6 W/m^2.
• The combined greenhouse gas effect is likely around +2.3 W/m^2 (with a 90% confidence interval of +2.07 to +2.53).
• Offsetting the warming is a global dimming effect due to aerosols and increased cloud cover of -1.2 W/m^2.
• The balance comes from other warming and cooling effects. The warming due to increased solar radiation is +0.12 W/m^2, about half the decrease of -0.2 W/m^2 due to changes in surface albedo (which I'm guessing means effects like desertification--don't know what happens to that number as ice melts.)
• Measurements show warming trends, increase in water vapor present in the atmosphere, and warming oceans (which have been absorbing 80% of the heat added to the system, causing the water to expand).
• Sea level rise from 1993-2003 is significantly higher than the rise from 1961-1993, driven mostly by thermal expansion and the Greenland and Antarctic ice sheets.
• Observed shifts in weather patterns are consistent with the temperature changes.
• From a paleoclimate point of view, "[t]he observed widespread warming of the atmosphere and ocean, together with ice mass loss, support the conclusion that it is extremely unlikely that global climate change of the past fifty years can be explained without external forcing, and very likely that it is not due to natural forces alone." (emphasis omitted)
• Projected temperature increases for the period from 1990-2005 were between 0.15 and 0.3 deg. C per decade. The observed increase for that period has been 0.2 deg. C per decade, strengthening confidence in the projections.
• Warming tends to reduce the CO2 uptake by the land and oceans, leaving more CO2 in the atmosphere.
• Even at the current CO2 concentration, by the end of the century the best estimate of sea level rise is +0.3-0.9 meters. Other, greater CO2 scenarios show a rise of up to about 6 meters.
• Due to the time it takes natural processes to remove carbon from the atmosphere, both past and future carbon emissions will continue to contribute to warming for a millennium.

due for a paradigm shift?

Dark energy. Branes. Multiple dimensions curled up so small we can't see them. Difficulties unifying quantum mechanics with general relativity.

I wonder if we're due for a paradigm shift. The current environment, at least from an outsider's perspective, looks a lot like we're piling epicycles on top of epicycles, or positing the existence of luminiferous aether: we're extending our theories in multiple directions through the use of phenomena to which we're "almost totally blind" (to quote Sciam's Dark Energy article).

Maybe we're due for another Copernicus, Newton, or Einstein to fundamentally reexplain the world around us.

too much reliability?

I've started tuning into David Brin's blog. I've come across his views from time to time. Sometimes I agree with them, often I don't, but they almost always get me thinking. Case in point, in this entry he discusses the failure of the cell network in New Orleans and advocates an emergency packet relay mode built into cell phones:

How about a simple back-up mode for text messaging? One that could use packet-switching to bypass the cell towers when they are down, and pass messages from phone to phone -- or peer-to-peer -- at least among phones that are of the same type?

It got me thinking. Maybe the problem with the cell networks, and the power grid for that matter, is not that they're not reliable enough. Maybe the problem is that they're too reliable. You see, one of the big problems with a back-up system is that, after you get it in place, you still have to test it to make sure it'll work. You might be religious about backing up the files on your computer, for instance, but how many times have you tried to restore them?

It reminds me of the pattern with preventing forest fires. For years, fire suppression was the goal. That caused dead wood to accumulate. Now, when fires do break out, they're a lot nastier because there's all this dead wood. If we'd had small fires more often, the dead wood never would have had the chance to accumulate.

It also reminds me of Y2K planning. Someone was surveying Y2K preparations in a developing country. They asked where person X got his food. Answer: I go next door and slaughter a goat. Question: what would you do if the power went out and your refrigerator stopped working. Answer: I wouldn't slaughter the goat. In areas where service is less reliable, people not only create their own back-up systems, but they also know how to use them because the unreliable service forces them to "test" the back-ups fairly often.

Obviously, even if decreasing reliability makes the system more rugged, there's going to be a trade-off. Electricity and communication are Good Things. They make the economy work. Make them too unreliable and the economy starts to deteriorate. Perhaps there's a nice mathematical model that could estimate how much reliability is optimal. But in any case, I wonder if designing for "five 9's" reliability (99.999% reliable, or five minutes of outage per year) might actually be counterproductive in the long run.