The Human Element: CO2
In pre-industrial times, carbon dioxide made up about 280 parts per million atmospheric molecules. In 2008, it makes up about 385 parts per million—30% more. So what's the big deal about a few hundred parts per million? Not only is the present atmospheric carbon dioxide concentration higher than it has been for at least 800,000 years, the rate of change is accelerating. Previously it never exceeded 30 parts per million per thousand years, but now, carbon dioxide has risen by 30 parts per million in the last 17 years.
Worldwide, burning fossil fuels is the major source of CO2, but CO2 can also come from cutting trees, burning forests or grasslands, agriculture, and interestingly, making cement.
What Do You Think?
Emissions by Country
Question
What country/group do you think had the highest total CO2 emissions in 2007?
The correct answer is b).
According to data from the Netherlands Environmental Assessment Agency, China passed the U.S. in 2006 and is now the largest emitter of CO2. Notice that the combined emissions of the EU-15 group and the large developing countries group are lower than the U.S. emissions.
Question
What country/group do you think had the highest per capita CO2 emissions in 2007?
The correct answer is a).
On a per person basis, the United States, with a population of 0.31 billion people, emits more than twice as much as the citizens of the EU-15 and about 10 times as much as 1.14 billion people in India.