Recently, a group of scientists estimated that the increase in carbon dioxide release rate between 2000 and 2006 was greater than any of the scenarios envisioned by the Intergovernmental Panel on Climate Change (IPCC) in the late 1990s. This brings the total amount of carbon dioxide emissions to higher levels than even the worst-case scenario projected by the IPCC. Also the amount of carbon dioxide in the atmosphere is increasing faster now than earlier.
The “release rate” is the sum total of carbon dioxide produced by people around the world. What determines the release rate?
- How much energy people use. This has gone up because the global economy has improved rapidly since 2000. Also, there are more people using this energy.
- How much of that energy is produced from carbon (hence releasing carbon dioxide). While in the past we have typically been getting more efficient in our carbon use per dollar spent, this is no longer happening, at least temporarily.
People use more energy in the industrialized part of the world than in developing countries. In the developed countries, people frequently drive their own cars and heat or cool their houses. They have enough money to buy televisions, computers, cars, and other items that require energy to make and operate. They often live in large homes that take more energy to heat and cool than small homes. In February, we wrote about how these activities are important enough to affect the climate of cities.
In developing countries, people walk more. They live in smaller homes, often heated or cooled by the wind. When they have to travel longer distances, they take buses or trains. It is not surprising that many of these people would like to lead more comfortable lives like those in the developed world.
The larger-than-expected increases in carbon dioxide production are related to rapidly-developing economies, especially in Asia. Economies in Europe and North America are also growing, but close to the rates expected by the IPCC. This means Asians are working hard to earn the many benefits people have in the developed countries. And, as a consequence, their carbon-dioxide emissions are increasing more than anyone expected.
The second part of the reason for the increase in atmospheric carbon dioxide is that less is being taken up by the world’s oceans. Typically, the oceans take up about 60 per cent of the carbon dioxide produced, while the air gets the other 40 per cent. Now, the ocean’s share is getting smaller – meaning more carbon dioxide left in the atmosphere to trap heat.
Together, these two factors are leading to higher carbon dioxide concentrations in the atmosphere at a faster rate than before.
How can this be helped? Nations and individuals around the world need to find other ways of producing the energy that fuels the earth’s economy. Natural gas burns cleaner and produces less carbon dioxide per unit energy produced. We can obtain energy from other sources, such as the wind, flowing rivers, or the sun. Taking these steps has extra benefits – they produce less air pollution than coal-burning. As individuals, we can be more efficient in our energy use, by walking and taking public transportation, air-drying our clothes, and keeping the temperature in our houses closer to the outside temperature. Can you think of other ways to save energy?
I would like to thank Dr. Scott Ollinger, Science PI of the GLOBE Carbon Project, for bringing this information to my attention. For more about the Carbon Project, click on “Carbon Cycle” under the “Projects” menu at www.globe.gov.
