Carbon offsets are voluntary programs that consumers can buy into to help reduce the buildup of carbon pollution that is causing climate change. When you know how much you are contributing to greenhouse gas emissions (see carbon footprint above), you can opt to buy credits to offset those emissions. The major criticism of carbon offsets is that because carbon dioxide and greenhouse gases are so long-lived in the atmosphere, if you somehow pay for something that will offset your emissions, it must last at least 100 years.
Carbon Offset opportunities include renewable energy projects, forest carbon sequestration projects, projects that donate to efforts to reduce the use of fossil fuels or reduce the rate of deforestation, and the like. Such programs vary greatly in terms of their methodologies and offerings.
The Nature Conservancy (TNC) offers the following list of important considerations that they use for their offset program. TNC’s program is forest-based but the principles include good considerations (http://www.nature.org/ourinitiatives/urgentissues/global-warming-climate-change/help/carbon-offset-program-frequently-asked-questions.xml#1). Any project offered by TNC must address certain issues, including:
- “Permanence, which, simply stated, is the life of the project. It wouldn’t help to reduce climate change much if a tree were planted or saved one year only to be cut the next. The most desirable forest carbon projects are those where the restored and protected forests are likely to remain intact indefinitely.
- Additionality, which refers to the amount of carbon dioxide captured, stored or prevented from reaching the atmosphere compared to what would happen without the project. In other words, is this something that would have happened anyway?
- Leakage, which occurs when emissions avoided within a site are not eliminated, but rather displaced to another location, or when carbon capture and storage at a site leads to land clearing elsewhere.
- Measurement and monitoring, which entails periodic field measurements of forest growth and associated capture and storage of carbon, as well as, in some cases, analysis of satellite imagery and models of forest growth and deforestation.
- Verification, of carbon benefits by an accredited independent third-party, which occurs periodically throughout the life of a project to ensure it meets its intended goals of carbon storage and that all additionality, measurement, leakage and permanence requirements are being met.”
However, it is far better to do everything possible to reduce your emissions than to purchase carbon offsets in the hope that you can mitigate emissions that will persist a hundred years or more.