Options to Reduce CO2
Human (also known as anthropogenic
emissions result from
human activities like burning fossil fuel for energy, making cement from limestone, or plowing land for farming. The level
of human CO2
emissions to the atmosphere is rising, and the CO2
concentration in the atmosphere is rising.
Significant fossil fuel use began in the 1850s with the growth of steelmaking and railroads. The fossil fuel portion of human
emissions since the 1750s is shown in the figure below.
emissions are projected to rise from 29.0 billion metric tons in 2006 to 33.1 billion metric tons in 2015
and then grow to 40.4 billion metric tons in 2030—an increase of 39% over the projection period. By midcentury, CO2
emissions are expected to be twice what they are today. Most of the growth in these human CO2
emissions will come from
the rapidly developing economies of China and India.
Many scientists believe that if we can prevent 200 billion tons of human CO2
from entering the atmosphere
over the next 50 years, we can stabilize the amount of CO2
in the atmosphere at the 500-ppm level, which may greatly reduce the
threat of climate change.2
The CO2 wedge
suggests ways in which
we can apply today’s technology to reduce carbon emission in large amounts known as wedges. Each carbon reduction wedge would be
designed to prevent 1 billion tons of carbon from entering the atmosphere by 2050. If we start applying theses actions to create
just eight wedges, we could prevent 200 billion tons of CO2
from entering the atmosphere by midcentury.4
and geologic sequestration
(as part of Carbon Capture and Storage
) play a key role in the CO2
- OECD stands for the Organization for Economic Cooperation and Development and consists of the world’s industrialized democracies, including the United States, the countries of the European Union, Australia, and Japan. The bulk of the projected economic growth and growth in
anthropogenic CO2 emissions is in the non-OECD countries of China and India.
- CO2 levels equal to 0.06% of the atmosphere (six parts in 10,000 parts) and preindustrial levels of
CO2 in the atmosphere are estimated to have been 0.03% (three parts in 10,000 parts).
- Princeton University’s Carbon Mitigation Initiative, www.princeton.edu/wedges (accessed on January 14, 2010).
- Pacala, S., and Sokolow, R., 2004, Stabilization wedges – solving the climate problem for the next 50 years with current technologies: Science, v. 305, p. 968–972.