This whole California thing has been bugging the crap out of me, so I started doing some number crunching today.
I went to the Bureau of Transportation Statistics website and started looking for details into how much pollution comes from cars as opposed to other fossil-fuel burning means (agriculture, power plants, shipping, aviation, etc). They had some fascinating numbers for Carbon Monoxide and an array of other pollutants, but none that were easy to find for "greenhouse gases".
For instance, they show that in 2000, we (US or the world? I'm not sure) pumped 109 million short tons of CO into the atmosphere. Sounds like a horrible number, but while it's above the average for the preceding 10 years, it's below the average for the past 30. Of that 109M, 56.06M comes from transportation. The other 53.29M came from industrial processes. 56.06M is the lowest in the entire range of 30 years, and of that, 48.47M came from "on-road transportation".
Unfortunately, that number isn't further broken down, but the key here is that 86% of transportational CO emissions came from cars & trucks. That's just shy of 50% of the total CO released into the atmosphere for the whole year, and it, too, is the lowest in 30 years. It marks only the 2nd time we've dropped below 50M short tons of CO emissions from cars & trucks, and is 10M below the emissions level of 1990, when we commonly assume the era of eco-friendly vehicles to have started.
So the automotive industry has made some pretty big strides over the last 30 years, and they're getting better all the time.
But now let's analyze the greenhouse gas emissions of today. Wikipedia has a great entry on greenhouse gases, and it states that the number 1 greenhouse gas is water vapor, which is not affected by human activity, except on very small, local scales. Water vapor accounts for as much as 70% of all greenhouse gases (or as little as 35%, depending on the "expert"). Carbon Dioxide is a distant second, running anywhere from 9 to 26%, followed by methane (4 - 9%) and nitrous oxide (?%).
Since our two biggest contributions come in CO2 and methane, they're probably where we as humans can make the greatest impact into the phenomenon we've termed global warming.
CO2 levels have remained fairly consistent over the last 10K years: around 260 - 280ppm. Since industrialization, they've risen to approximately 365ppm: an increase of 31%. However, wikipedia shows a wonderful chart breaking down the sources of pollution by pollutant, and we see that transportation accounts for 19.2% of CO2.
Calculating our man-made contribution to this is fairly simple: multiply the increase (31%) by the contribution factors: 9 to 26%. We show a contribution-factor increase of CO2 somewhere between 1.65 and 4.77%. That's not much, and when we multiply that by the percentage which is attributed to transportation (19.2%), we get a range from 0.32 to 0.92%. All the transportation in the world accounts for less than 1% rise in atmospheric CO2. If we can even begin to assume the numbers for CO to have any relevance to CO2, then we can multiply that finding by 86%, revealing on-road transportation to have contributed anywhere from 0.28 to 0.79% of CO2 increases, and that's before you discount trucking.
The math is even easier for methane: the wikipedia entry shows absolutely no contribution from automobiles. None. So man has pumped that in through other means, principally agricultural.
So let's assume an absolute worst-case scenario: cars account for 0.92% of the increase in greenhouse gases that are supposedly raising the temperature of our world.
(And for the naysayers, the Wiki entry is a pro-global-warming page. They fully support the argument that man is destroying the environment with cars & trucks, but their numbers directly contradict the claim.)
California claims to have spent millions on this research. It took me a few minutes on the Bureau of Transportation Statistics website and a quick trip over to Wikipedia. Maybe Califoria residents should sue their legislators.
Here's another tidbit I just found. The BTS has another page on gas wasted due to congestion. In 2000, 1.188 billion gallons of gas were wasted due to congestion in Los Angeles, CA. The next closest metropolitan area was NY/NJ, at 658M. LA consistently shows over 1 billion gallons of gas wasted due to congestion for all but one year since 1990. By comparison, Richmond, VA wasted 11 million gallons.
1 billion gallons of gas. Per year. In one city. And they're suing the auto makers?
More to come. But in the meantime, consider that the man who brought this suit is running for Treasurer in California this November.