(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Taking into account the logarithmic effect of CO2 on temperature, the 35 percent increase we have already seen in CO2 concentrations represents about three-quarters of the total forcing to be expected from a CO2 doubling. Since we have warmed about 0.7 degrees Celsius so far, we should only expect about 0.3 degrees more for a doubling from pre-industrial levels, so about 1 degree total, not 3 degrees as the scientists predict. Clearly the climate model sensitivity to CO2 is much too high. Answer: Even without addressing the …

It's time for everyone to move past the Kyoto Protocol. For those not familiar with the details, Kyoto imposes specific emission-reduction targets for each industrialized country over a five-year "commitment period" of 2008-2012. Targets were defined for total emissions of CO2 and five other greenhouse gases: the required emission reductions were 8 percent for the European Union and a few other European nations; 7 percent for the United States; 6 percent for Japan and Canada; and zero (i.e. hold emissions at their baseline level) for Russia and Ukraine. If all nations met their targets, the total emission reduction from these …

Congressional Democrats' energy priorities are a mixed bag Not so fast with the celebrating. The soon-to-be head of the House Energy and Commerce Committee, Rep. John Dingell (D), has declared no interest in raising U.S. fuel-efficiency standards -- he's from Michigan, natch -- and he's a nuclear-power booster. The Dems' rise could also lead to more offshore drilling; while dethroned Rep. Richard Pombo (R-Calif.) had refused, as House Resources Committee chair, to accept a compromise bill from the Senate, drilling advocates hope the new regime will pass the bill. Still, there are bright spots: Dingell hopes to close a drilling-lease …

(Part of the How to Talk to a Global Warming Skeptic guide) Objection: According to the latest state-of-the-art satellite measurements from over the Arctic, sea levels are falling! Guess all that ice isn't melting after all. Answer: Yes, a new study using Europe's Space Agency's ERS-2 satellite has determined that over the last 10 years, sea level in the Arctic Ocean has been falling at an average rate of about 2 mm/year. This is very new and very interesting news, though it is preliminary and not published in any peer-reviewed journals yet. But even if these results hold up to …

As the U.N. climate-change conference heats up this week in Nairobi, Kenya, strategies to promote clean energy and slow global warming top the agenda for many nations -- not least of all Germany, which is Europe's biggest economy, a global leader in green technology, and the country set to take over the 12-month presidency of the G8 industrialized nations and the six-month European Union presidency in January. Chancellor Angela Merkel has vowed in recent months to use Germany's upcoming leadership stints to tackle climate change afresh, with bold new policies. Some inside the German government, though, are skeptical that her …

Oh great. The White House needs to recapture some political momentum after its party got shellacked this week. It also needs to make good on its laughable promise to "change the tone" and start working with Democrats to "get things done." So where does it turn? What issue can unite politicians across the fractious partisan divide? You guessed it: ethanol subsidies energy independence! The Bush administration will soon launch a big "energy independence" initiative, likely to include renewed emphasis on biofuels, as part of an attempt to regain the political initiative following the midterm elections. Ugh. The question, as always, …

(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Sure, sea ice is shrinking in the Arctic, but it is growing in the Antarctic. Sounds like natural fluctuations that balance out in the end. Answer: Overall, it is true that sea ice in the Antarctic is increasing. Around the peninsula, where there is a lot of warming [PDF], the ice is retreating. This is the area of the recent and dramatic Larsen B and Ross ice shelf breakups. But the rest of the continent has not shown any clear warming or cooling and sea ice has …

Dear Umbra, I am lucky enough to have a home I really love and food to feed my family and my pets. However, the home has one major energy flaw: it is older and has huge, single-pane window/walls with aluminum frames, in two adjoining rooms. We currently are not able to replace them, and they lose heat rapidly. With this winter being a bit colder, is there anything that you can suggest we do, other than the window upgrades we cannot afford, to keep some warmth in the house? Justine Concord, Calif. Dearest Justine, That sounds very chilly to be …

Australia plagued by historic drought, not-so-responsive leadership Wondering how Australia's doing? It's dry as a dead dingo, thanks for asking. The "Sunburnt Country" is undergoing a severe drought -- the worst in 1,000 years, according to one expert. The lack of precipitation could cut agricultural output by 20 percent, and it's only going to get worse: a government organization has predicted that the eastern part of the country will see 40 percent less rainfall and a temperature rise of more than 12 degrees by 2070. The 91 percent of Australians who say global warming is a problem apparently does not …

(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Sure, some glaciers are melting. But if you look at the studies, most of those for which we have data are growing. Answer: This is simply not true, rumors on "the internets" aside. The National Snow and Ice Data Centre and their State of the Cryosphere division, on their Glacial Balance page, report an overall accelerating rate of glacial mass loss. The World Glacier Monitoring Service has similar findings, the most recent data coming from 2004. While there surely are some growing glaciers, studies like these are …