Cars Emit More Black Carbon Than Previously Thought 292
First time accepted submitter LilaG writes "Gasoline-burning engines put out twice as much black carbon as was previously measured, according to new field methods tested in Toronto. The tiny particles known as black carbon pack a heavy punch when it comes to climate change, by trapping heat in the atmosphere and by alighting atop, and melting, Arctic ice. With an eye toward controlling these emissions, researchers have tracked black carbon production from fossil fuel combustion in gasoline-burning cars and diesel-burning trucks. Until this study was published [abstract of paywalled article], gas-burning vehicles had been thought to be relatively minor players."
Turn off car when stopped at lights (Score:5, Informative)
Just one more reason I turn my car off instead of idling gas away when I know I'll be stopped for more than 30 seconds--stopped at a red light, waiting for someone, etc. The break even point (idling vs. gas used when re-starting car and offsetting battery drain) is around 10 seconds, I'd previously heard up to 20 seconds.
This makes even more sense in several US cities I've visited, where some red lights last for 1-3 minutes!
If this is too pooh-pooh environmentalist BS for you, then approach it from a selfish point of view--you're wasting gas and therefore money. If you're idling for 5 minutes a day, after a year that's 10 gallons wasted gas a year if you have a small-engine car, or 20 gallons for a V8. Do the math with your area's current gas prices, and sure, $30-$100 over one year isn't THAT much, but it's not pocket change either.
Source [thehcf.org], which also addresses old myths that say why we should idle.
Re:Here it comes. (Score:4, Informative)
Consensus in science is when most of the scientists in a field (except for the crackpots) quite arguing about something because they have nothing to argue about. They all agree on the particulars of a point.
Consensus is also when groupthink happens (Score:5, Informative)
Or when you hit the limits of knowledge at the time. Good example would be Newton's laws as applied to planetary motion. Newton was able to work out a great deal about gravity on a universal scale, and how bodies worked in a two body system. However it broke down when he tried to apply it to the multi-body of the solar system. So he invokes god for the first and only time in the Principia "This most beautiful system of the sun, planets, and comets could only proceed from the counsel and dominion of an intelligent and powerful Being."
This remained the scientific consensus on the matter. Newton was more or less The Guy when it came to physics. In two books (Principia and Opticks) he did more to advance the understanding of physics than more or less anyone before or hence. So this remained what scientists though for many years. You could explain gravity in terms of a two body problem, but the complexity of the heavens? God did it.
Up until Laplace. He worked out a method for figuring it all out. He could explain the stability of the solar system without invoking god. When asked by Napoleon about why he didn't mention god he said "I had no need of that hypothesis." (for a great talk on all this watch Dr. Tyson's "The god of the gaps").
Now the point of all this is that just because there is a general consensus on something, doesn't mean it is right. Doesn't mean it is wrong either, but trying to say something like "only the crackpots would argue with consensus," is silly. There have been things that were the consensus that was believed, until a better theory was proposed and tested.
Feynman also gives a good example of the groupthink type of activity with regards to that Millikan's value for the charge of an electron. To quote:
"It's a little bit off, because he had the incorrect value for the viscosity of air. It's interesting to look at the history of measurements of the charge of the electron, after Millikan. If you plot them as a function of time, you find that one is a little bigger than Millikan's, and the next one's a little bit bigger than
that, and the next one's a little bit bigger than that, until finally they settle down to a number which is higher.
Why didn't they discover that the new number was higher right away? It's a thing that scientists are ashamed of--this history--because it's apparent that people did things like this: When they got a number that was too high above Millikan's, they thought something must be wrong--and they would look for and find a reason why something might be wrong. When they got a number closer to Millikan's value they didn't look so hard. And so they eliminated the numbers that were too far off, and did other things like that."
Right there you can see the effects of a sort of scientific groupthink. "My result is too far off from the accepted value, something must be wrong."
Just keep in mind that science isn't about consensus. That there is a consensus doesn't mean it is right, or wrong. Also be wary when people appeal to consensus, that's what you see in advertisements, not science. When people talk about evolution, they talk about evidence, not consensus.
Re:Here it comes. (Score:4, Informative)
Almost all gas engines use smog pumps these days, including Honda. The pump isn't there to dilute the gases, it's to supply fresh oxygen to the mix to allow remaining unburnt gas to finish combusting so the catalytic converter can deal with it.