Cigarette butts on the side of the road are an eyesore and bad for the environment, but it’s difficult to keep smokers from flicking them out the window. Imagine that someday, a cigarette company decides to try to reduce the problem. It seems quite likely that it would only approach this in a way that would save it time or money. For instance, it might make longer cigarettes and even advertise its new design as helping to reduce littering. In the end, the chain-smoking driver would toss fewer butts out the window, but they would accumulate on the side of the road.
Those cigarette butts are not so different from carbon dioxide—another form of waste. Burning fossil fuels to obtain energy releases new CO2 that accumulates in the atmosphere. The more CO2 is released, the greater the projected damages from climate change. And the companies responsible for CO2 only want to make the changes that help their bottom line.
This month, delegates from around the world have gathered to take a “first step” (after 21 years of negotiations) to create a nonbinding framework to limit emissions—basically, the fewer-butts approach. However, as long as it continues to be legal to treat the atmosphere like a public dump, attempts to stabilize the climate will fail. The Intergovernmental Panel on Climate Change stated in its fifth assessment report that we need negative emissions in order to stabilize emissions below 450 parts per million (a measure of how much CO2 is in the atmosphere), which is considered “safe.” We are now at 400 ppm and are adding 2 ppm each year.
This gives the world a window of about 20–30 years to try to halt emissions before breaching the 450-ppm mark, which most people consider an important threshold. Staying within this limit, while accounting for population and economic growth, requires reducing the carbon intensity of the global economy by 8 percent each year. However, more realistic scenarios suggest we will fall short of these reductions and will have to make up the difference with negative emissions—basically, create a future waste disposal service. As people globally try to work together to address climate change, there are so many ways to fail: powerful interest groups could block legislation; some countries could continue to emit, even while others decarbonize (that is, remove fossil fuels from their economies); climate-induced catastrophes may distract attention and investment from dealing with the root cause (too much CO2 in the air); the list goes on. Perhaps this is why climate change is considered a “super wicked problem:” Time is running out. Delaying action leaves future generations stuck with dealing with our garbage without the tools to clean up.
So what will make a real difference? Setting global targets for zero waste instead of reduced emissions. Treating carbon dioxide like a waste—like a cigarette butt or fast-food wrapper—obligates emitters to remove all of the waste, while our current approach rewards emitters for emitting less but never considers whether the improvement will actually make it possible to stop dumping CO2 in the atmosphere. You probably know the phrase “reduce, reuse, recycle”—intended to encourage limiting the amount of waste ending up in landfills. It’s time to apply that maxim to CO2, and the best way to apply it is to make clear that the only alternative is safe and permanent disposal.
We know how to reduce our emissions: explore alternative fuels, increase our energy efficiency, or conserve energy. In many places, reducing even pays for itself. These efforts have received the lion’s share of attention as the obvious low-hanging fruits, but it is dangerous to think that reducing emissions alone will stop climate change. We’re stuck with a fossil fuel infrastructure, so reducing alone will never drive emissions to zero, and it certainly cannot create negative emissions.
However, with newly emerging technologies that can capture CO2—either from a flue gas at a power plant or from the air—we can reuse and recycle what is emitted. Eventually, we hope to learn how to remove what’s already in the atmosphere.
Carbon-capture technologies that collect CO2 at big point sources could deliver waste CO2 for reuse rather than letting it escape to the atmosphere. While the long-term goal is to dispose of this CO2 underground, it is possible to repurpose at least some of this CO2 to make cement or other commodities like baking soda; you could feed the waste CO2 to algae to make fuels; or you could inject it underground to extract oil.
Eventually, direct air-capture technologies that remove CO2 from the atmosphere would allow us to recycle CO2 that is already in the air. A number of startup companies already have viable business models for these industries, whether this is in the smallest amounts—like a couple of grams a day—for an aquarium, or at a larger scale, such as using CO2 for indoor agriculture, or eventually to make synthetic fuels. Beverage companies could even directly source CO2 for carbonating drinks.
If we don’t manage to create or scale the technologies that reduce, reuse, and recycle CO2 waste, we will have to rely on biological or technical methods to dispose of it. The most common way is to plant a tree, which will hold onto carbon for about 50 years. Of course, that would be an awful lot of trees—it’s probably not a viable solution for all of the CO2 without taking over arable land needed for feeding the planet. Another option might be to burn the trees in power plants and collect the CO2 waste and permanently store it underground or bind it to certain soils or rocks rich in olivine and form mineral carbonates. Biochar can also sequester some carbon dioxide.
But direct air-capture might be our best option—unlike planting trees, it has the potential to scale limitlessly because it can collect 1,000 times as much CO2 on the same physical footprint as a tree. Combined with permanent storage options like underground storage or mineral carbonate formation, direct air-capture could cancel out any emission. But just like landfilling costs motivate people to reduce, reuse, and recycle waste materials, the cost of air capture and disposal could motivate less CO2 waste generation in the first place.
With a chance to act and make real commitments it is insufficient to only talk about reducing emissions over the next 15 years. The bottom line is that for every ton of carbon dioxide emitted, another ton must be put away safely and permanently.