A commonly referenced tool in our arsenal against climate change is “net-zero emissions.” It can be easy to become confused by all the terminology bandied about during discussions of corporate responsibility in the fight against climate change. So, what does “net-zero emissions” actually mean?
“Zero emissions”–without the “net” caveat–means emitting no greenhouse gases.
“Net-zero emissions” has more wiggle room. It’s like balancing a checkbook. The country or company cuts most of its emissions through efficiency and clean energy, then offsets the rest by removing carbon dioxide from the atmosphere or eliminating emissions elsewhere.
For example, trees absorb carbon dioxide from the air, so they’re often considered “negative emissions.” The tiny Himalayan kingdom of Bhutan can claim net-zero emissions because almost all of its electricity comes from hydropower, and its forests sequester about three times more carbon than its vehicles, factories and other human activities emit.
Companies have another way to claim net-zero emissions–they can take advantage of carbon reductions elsewhere by buying carbon credits. For example, a U.S. company might pay to protect forests in South America and then subtract those trees’ negative emissions from its own emissions to say that its operations are “net-zero.” Other carbon credits support sustainable development projects, such as installing wind or solar power in poorer countries.
But counting on carbon credits also draws criticism, because it allows those companies to keep generating greenhouse gases. Other concerns are that some projects would happen anyway, the emissions reductions might not be permanent or even verifiable, or they might get double-counted by more than one entity. Some projects, like tree planting, can take years to pay off in emissions reductions while the companies buying forest offsets continue emitting greenhouse gases.