Thanks for the numbers Steve, it's interesting to see it.
Well, these numbers may look very small, 1% at the scale of the earth is enormous.
And the natural production of greenhouse gaz is absorbed by the plants and oceans, whereas the human CO2 is added to the atmosphere... that is a huge difference.
One should not forget that life is very rare. It only developped on earth because of the delicate and subtle balance found on the earth. It seems that 1% additionnal greenhouse gaz, coupled with deforestation, is enough to disturb this balance. It may not provoked the global warming, but surely accelerated it.
Of course your particular car is not responsible for the global warming.
But like Sartre said, one people can make things change. if you decide to act in an eco-friendly way, you'll induce other people to do so, and gradually it will have an influence. if you buy your car with pollution in mind, and that a lot of people do so, it will make the carmakers hurry up the production of green cars. If you lessen your electricity consumption and buy "green" appareils, it will make the industrials recognize the need for greener goods...
Wikipedia has some graphs figuring the spectacular increase of greenhouse gas since the Industrial Era, but they wouldn't work here, so if you're interested,
Greenhouse gas - Wikipedia, the free encyclopedia
wikipedia says:
Since the beginning of the Industrial Revolution, the concentrations of many of the greenhouse gases have increased. The concentration of CO2 has increased by about 100 ppm (i.e., from 280 ppm to 380 ppm).
The first 50 ppm increase took place in about 200 years, from the start of the Industrial Revolution to around 1973; the next 50 ppm increase took place in about 33 years, from 1973 to 2006.[26]. Many observations are available online in a variety of Atmospheric Chemistry Observational Databases. The greenhouse gases with the largest radiative forcing are:
(Source: IPCC radiative forcing report 1994 updated (to 1998) by IPCC TAR table 6.1 [6][7]).
Also found this, not sure about the source though:
Human CO2 is a tiny % of CO2 emissions The skeptic argument...
As human CO2 emissions are much smaller than natural CO2 emissions, man's impact on climate is minimal.
Manmade CO2 emissions are much smaller than natural emissions. However, the CO2 that nature emits (from the ocean and vegetation) is balanced by natural absorptions (again by the ocean and vegetation). Human CO2 emissions upsets the natural balance.
Consumption of vegetation by animals & microbes accounts for about 220 gigatonnes of CO2 per year. Respiration by vegetation emits around 220 Gt. The ocean releases about 330 Gt. In contrast, human emissions are only around 26.4 Gt per year.
Land plants absorb about 440 Gt of carbon per year and the ocean absorbs about 330 Gt. This keeps atmospheric CO2 levels in rough balance.
How can we know the rising CO2 levels are due to human activity? The carbon atom has several different isotopes (eg - different number of neutrons). Carbon 12 has 6 neutrons, carbon 13 has 7 neutrons. Plants have a lower C13/C12 ratio than in the atmosphere. If rising atmospheric CO2 comes fossil fuels, the C13/C12 should be falling. Indeed this is what is occuring (Ghosh 2003) and the trend correlates with the trend in global emissions.
Figure 2: Annual global CO2 emissions from fossil fuel burning and cement manufacture in GtC yr–1 (black), annual averages of the 13C/12C ratio measured in atmospheric CO2 at Mauna Loa from 1981 to 2002 (red). Image courtesy of Chapter 2 of the IPCC AR4 report.While the ocean absorbs around half of human CO2 emissions, empirical observations reveal the oceans are losing their ability to absorb CO2. A study released in May 2007 found that the Southern Ocean has reached its saturation point, diminishing its ability to absorb more CO2 (Quéré 2007). Similarly, CO2 absorption by the North Atlantic has dropped even more dramatically, halving over the past decade (Schuster 2007). If this trend continues, it potentially leads to a positive feedback where the oceans take up less CO2 leading to CO2 rising faster in the atmosphere leading to increased global warming.
Anyway...it's better to prevent such troubles than to cure them, so even if it's very complex and not as simple as some says, I will try to make some efforts.