The proliferation of voluntary carbon offset programs seems like a great way for individuals to help fight climate change. But do carbon offset programs really work? That's the question for Bill Stanley, Science Lead for Carbon Strategies, Climate Change Team at The Nature Conservancy.

Lawrence Hamilton, of Charlotte, VT, asks:

"Are carbon offset programs and forest protection efforts providing real solutions for reducing global carbon emissions? And how do these programs help reduce pollution from mercury, arsenic and other "baddies" that often accompany carbon emissions?"

Bill Stanley, Science Lead for Carbon Strategies, Climate Change Team, replies:

To answer the first question, yes — well-designed carbon offset programs can have a meaningful impact on reducing the carbon emissions that cause climate change.

Deforestation and land-use changes contribute approximately 20 percent of global carbon emissions. Rigorously-designed, forest-based offset programs can make a real dent in that number.

To be effective, any offset program needs to meet high standards. These standards include:

  1. Permanence. The most desirable carbon sequestration projects are those where the restored forests are likely to remain intact indefinitely.
  2. Additionality. The project should only include activities that wouldn't have taken place normally, therefore keeping more carbon dioxide from reaching the atmosphere.
  3. Leakage. When sequestration at a site leads to land clearing elsewhere, it is referred to as "leakage." Offset programs should account for and minimize leakage.
  4. Measurement and monitoring. Periodic field measurements of forest growth and associated capture and storage of carbon are essential.
  5. Standards of verification. Throughout the life of a project, standards should be maintained and measured to ensure the project meets its intended carbon sequestration goals.

Remember Acid Rain?

While sequestration projects do not significantly impact pollution from mercury and arsenic, they can indirectly help cut down on these pollutants when implemented as part of an effective cap-and-trade system. What we need now is a new cap-and-trade system that focuses on carbon emissions, reducing those gases that are causing global warming.

Under such a system, industries are given a hard emissions cap. Companies that come in below that cap are given credits that they can trade with those who are not able to meet this cap. A cap-and-trade system is widely credited with drastically reducing factory emissions of the sulfur and nitrogen oxides that cause acid rain. The same kind of program will work to reduce carbon emissions.

Support a Cap-and-Trade System

The Nature Conservancy strongly believes that credits from forest carbon projects and activities in the United States and in developing countries should be included in a cap-and-trade system.

Including incentives for land conservation and restoration in a cap-and-trade program can help lower the overall compliance costs of such a system, increase support for the program and allow for more aggressive emission reduction goals.

The Conservancy recently began its own voluntary carbon offset program that will help reduce the impacts of climate change and restore critical wildlife habitat.