Carbon credits, or offsets, have become such a familiar feature of the climate change response landscape that they’ve even earned a euphemism, “nature-based solutions.” The desire to speak of “solutions” rather than the unfashionable “offsets” betrays some of the controversy and criticism surrounding the practice. Indeed, the carbon credit concept has become a staple of climate action in three big areas: corporate responsibility/marketing, institutional emissions frameworks, and personal carbon footprint conscience-easing.
In the corporate world, declaring a low carbon footprint is a common public relations strategy aimed at environmentally-minded customers, but the most common way companies are achieving “100% renewable” is through the purchase of offsets. After all, for a factory or a ski resort connected to the local power grid–running offices, large machinery, and other amenities–it would hardly be realistic to disconnect and quit drawing from the coal or natural gas plant that is yet to be retired. Companies count on consumers not thinking so critically, and pervasive advertising about their renewable power “use” may leave people with the impression, especially in the United States, that we don’t need to do more in investing in our renewable energy infrastructure than we really have. Many corporations certainly do have a climate consciousness in their leadership, and many invest in climate mitigation under theories that climate change affects their bottom line, too, but whether their particular credit scheme offers a true one-to-one tradeoff within the greenhouse effect warrants greater scrutiny.
In institutions like state and local governments–and even national governments and bodies of the UN–carbon credits are similarly an integral means of achieving “net zero” emissions targets on optimistic timelines. In this context and in the regulatory sphere, it is important to distinguish between carbon credits in an offset scheme and carbon credits in an industry regulated by a cap-and-trade scheme. For specific industries, like power plants, carbon dioxide emissions can be relatively easily quantified, and a reduction in emissions at one plant can be accurately equated to an identical increase in another. Carbon credits as offsets, however, are often much less certain, as in when a municipality plants trees in another part of the world in the hopes of compensating for its net transportation emissions month-to-month.
And personal carbon credit purchases also entered into vogue in the past decade or so. A guilt-ridden google search will lead fossil-fuel hungry folks to a smorgasbord of offerings from different marketers. Some more critical research can also lead one to a variety of outlets cautioning that these products may not be what they seem. The only truly sure-fire way to make up for a transatlantic flight’s worth of fuel would be for the couple-hundred passengers to buy up the seats but keep the plane on the ground.
With all the popularity of these conservation-oriented and ostensibly emissions-cutting models, there are reasons to be skeptical. This summer, for example, the UN Environment Programme noted the need for stronger real emissions reduction commitments and stressed that offsets are not a “get-out-of-jail-free card.” When it comes to substantially mitigating climate change, there is no substitute for actually cutting our own emissions, physically, today. The following five criticisms provide a decent summary of the caution with which we should consider claims about the benefits of carbon credit trading. The sixth and final point below, however, explains why we should do it anyway, just with a hefty dose of humility and equal or greater action at home.
(1) Nature can’t keep up. Anthropogenic fossil fuel emissions are simply entering the atmosphere at a much faster rate than natural carbon sinks can store them in the biosphere (and eventually lithosphere). As the UNEP notes, some 50 percent of the greenhouse gases we’ve sent into the atmosphere in our industrial history have arrived there only since 1990. And even with nature’s carbon sequestration mechanisms operating at full speed, our emissions still need to be cut by about 45 percent by 2030 to maintain a fighting chance of staying within globally-agreed warming targets.
(2) Verification varies. Not all carbon offset programs are created equal, and the process for determining the climate effect of the credit purchased is something to consider. There is a robust ecosystem of carbon credit verification programs, but these will vary in their criteria, thoroughness, and reach. Governments like California are exploring verification systems, and intergovernmental organisms like the UNFCCC are developing rigid accounting mechanisms. In a world chock-full of offset-based claims and disparate accountability schemes, however, it’s safe to say that we probably aren’t verifiably achieving all the carbon goodness everyone claims to be.
(3) Carbon sequestration projections are uncertain. Nature’s end of the greenhouse gas mitigation bargain simply isn’t as knowable as we might like to think. Scientific research can reasonably help a person estimate how much CO2 she sends into the atmosphere when she drives her truck 4000 miles. And for many ecosystems, science has a decent grasp of understanding how they grow and the rate at which biomass removes carbon dioxide from the atmosphere. But combining these two ideas compounds the uncertainty. The point of the offset purchase in the first instance is that there is no doubt that the truck is going to be driven 4000 miles. It’s already on the road, and those greenhouse gas molecules are as good as in the sky. Equivalent molecules being taken up by the driver’s offset program of choice, however, hinges on ecological systems far less straightforward than gasoline combustion. Assumptions must be made about precipitation patterns acting predictably, natural disasters staying at bay, growth occurring exactly as present science says it might, nutrients not becoming limiting, and a range of other factors. Add to this the lengthened timescale at which a natural system sequesters carbon relative to a truck belching it out, and it seems like certain emissions today are being traded for merely probable removal tomorrow.
(4) It’s tough to say what counts. Whether an offset program is used to finance renewable energy developments elsewhere, plant trees, or simply stop an area of forest from being cut down, a looming question is to what extent the offset program funds were the device that truly secured the alleged carbon dioxide reductions. How do we police the claiming of credits for other people’s conservation efforts that might have gone forward even in the absence of the additional funding? Another concern is that many carbon offsets are purchased for the prevention of deforestation; these has an extortionist element: “I was going to turn a blind eye to Chevron trampling an acre of the Amazon, but now that I haven’t, you must tolerate my factory doing equivalent climatic harm.”