Among supporters of efforts to lower greenhouse gases is Seattle Mayor Greg Nickels. He just announced that the 1,000th city has signed his climate-protection agreement, a pledge to significantly reduce greenhouse-gas emissions.
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Reducing greenhouse gases now may lower climate change risk
By Moises Velasquez-Manoff | 10.05.09
A new climate analysis by scientists at the Massachusetts Institute of Technology and elsewhere, which focuses on probability outcomes, finds that even moderate reductions in greenhouse gas emissions now will significantly lower the risks of dramatic, future climate change.
The analysis also indicates that, to avoid a temperature increase of more than 2 degrees C (3.6 degrees F.) above preindustrial levels — an oft-discussed goal — these emissions reductions had better come soon. If not, say the researchers, dramatic changes in climate driven by feedback loops will become difficult — and perhaps impossible — to control.
The analysis lays out climate salvation in terms of odds. We still have around a 50-50 chance, it says, of stabilizing climate and avoiding a temperature increase of much more than 2 degrees C. (That’s supposed to be encouraging, by the way.) Generally, scientists think that keeping temperature increases to no more than that will avoid dramatic sea level rise, as well as a disruption of agriculture and natural ecosystems.
Here’s what needs to happen in order to fall on the right side of that 50-50 odds ratio, say the authors:
In the US, we need to cut emissions at least by the amount laid out in the current versions of the climate bills before Congress. (The House bill aims to cut emissions by 17 percent by 2020; the Senate version by 20 percent in the same period.
Other rich nations need to follow suit. And then China and other large, developing countries need to jump on the bandwagon within a decade or two.
The scientists explain their “risk assessment” approach:
“The nature of the problem is one of minimizing risk,” explains Mort Webster, assistant professor of engineering systems, who was the lead author of the new report. That’s why looking at the probabilities of various outcomes, rather than focusing on the average outcome in a given climate model, “is both more scientifically correct, and a more useful way to think about it.”
Too often, he says, the public discussion over climate change policies gets framed as a debate between the most extreme views on each side, as “the world is ending tomorrow, versus it’s all a myth,” he says. “Neither of those is scientifically correct or socially useful.”
“It’s a tradeoff between risks,” he says. “There’s the risk of extreme climate change but there’s also a risk of higher costs. As scientists, we don’t choose what’s the right level of risk for society, but we show what the risks are either way.”
The scientists use a computer model called the MIT Integrated Global Systems Model. This model is unique in that it couples a climate model with a model of human economic activity and associated energy use.
In May, the same team of scientists released a study saying that “climate change odds” were “much worse than previously thought.” Using their probabilistic approach, they found that, without major action, the median probability for warming by 2100 was 5.2 degrees C. That’s significantly higher than the “best estimate” in the 2007 report by Intergovernmental Panel on Climate Change: a 4 degree C. increase by century’s end if no carbon-curbing action is taken.
Editor’s note: For more articles about the environment, see the Monitor’s main environment page, which offers information on many environment topics. Also, check out our Bright Green blog archive and our RSS feed.
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2. editorial | 10.05.09
Matt, That was an editing error, not the writer’s fault at all. We had just corrected it.
3. Mike Biggs | 10.06.09
We can make gasoline from carbon dioxide in the air for $5 per gallon, by all estimates far cheaper than unsubsidized gas from oil.
We can also use boiler ships to evaporate lots of water near the poles to increase snowfall & recap the poles with their reflective icy sheen.. From this we can learn how to make it rain within a specified region most places around the world. That would reverse drought & desertification, putting an end to world hunger.
4. Doug Brockman | 10.06.09
The only option is to destroy the environment by erecting birdkilling habitat destroying windmills which will ruin millions of acres of pristine, prairie and desert. Lower irretrievable desert water tables with solar generating equipment and pave over acres and acres of the environment with road systems, fabricating tons of copper wires to run into the wilderness.
Which begs the questions of why do the environmentalists wish to destroy the environment???
5. Blogger 99 | 10.06.09
Check out a new study which links rising ocean levels to the amount of impervious surface coverage … a possible way to cool the planet is to increase on-site absorption of water.
6. DublD | 10.06.09
More “Christian Science”. In the old Christian view, the Earth was the center of the universe, and everything was bound to it. And in this view these claims made sense.
However, in “Science Science” the Earth is actually a speck even just compared to Jupiter. In the context of the Milky Way, it is an infinitesmal speck. In the whole universe it literally equals zero. So the idea that there are net positive feedback loops in our climate is so incomprehensibly ridiculous that MIT should be shut down for suggesting it. To you lay-idiots “feedback” is a fancy term for energy. Net energy is NEVER POSITIVE in any system where work is done. This is the first law of Thermodynamics AND the Law of Conservation of Energy and neither one has never been disproven. The idea that this planet should be CREATING and KEEPING heat energy while it floats around, infinitely small, and in an infinite universe most of which is at absolute zero (thats -273C), is so idiotic that it needs dressing up with terms like “feedback loop”. You know, better to say something nobody understands, then give it to them straight and have them KNOW you are lying.
Another full crock of “Christian Science”. This REAL scientist is quite amused, disappointed and nothing else…
7. freejung | 10.07.09
“So the idea that there are net positive feedback loops in our climate is so incomprehensibly ridiculous that MIT should be shut down for suggesting it. To you lay-idiots “feedback” is a fancy term for energy. Net energy is NEVER POSITIVE in any system where work is done. This is the first law of Thermodynamics AND the Law of Conservation of Energy”
This is a complete misunderstanding of the science. The energy that causes global warming comes from the sun. It is trapped on Earth by greenhouse gases. The positive feedbacks involve systems that, when warmed, cause more of the sun’s heat to be trapped on earth.
A good example of this is when sea ice melts — ice reflects more sunlight than ocean, so when the ice melts, the total amount of the sun’s energy absorbed by the earth increases.
Global warming definitely does not contradict the laws of Thermodynamics (”And in this house, young lady, we obey the laws of Thermodynamics” — Homer Simpson). No real scientist would ever accept a theory that breaks the laws of Thermodynamics, and the vast majority of the worlds leading scientists and all of the major scientific institutions accept the theory of human-caused global warming.
Any real scientist would know that, of course.
8. Another Inconvenient Truth | 10.10.09
Actually, any real scientist would understand that, without the ability to perform control experiments on the planet, there is no means to scientifically verify human causation in the warming of the globe. Human-induced climate change is a BELIEF (albeit one which many scientists hold), and global climate science is and always will be “cargo cult” science.
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1. Matt Yau | 10.05.09
you have errors in your math:
2 degrees centigrade does not equal 36 degrees F…
Since centigrade and Fahrenheit are on different absolute scales, you need only multiple by 9/5 to obtain the degrees F.