If you’re an insomniac, this situation will probably be familiar to you. It’s the night before a big exam or job interview. You go to bed with plenty of time to spare, but sleep won’t come. It passes midnight. Then the calculation game starts: “If I fall asleep right now, I’ll still get eight hours.” “If I set my alarm half an hour later and skip breakfast, I can still get a solid six hours of sleep.” “Four hours is all you really need, anyway.” Before you know it, your alarm clock is ringing, and you’ve got to face the world sleeplessly.
This same game of feverish calculation and recalculation is the game we’re playing with the Earth’s climate. The Paris Climate Accord, which is still technically in force across the globe, is a commitment to keep warming to below two degrees Celsius. It doesn’t sound like much, but for the global average temperature, however, two degrees Celsius of warming takes us outside the realms at which human civilizations have existed. Four degrees, which could be the total warming by the end of the century, is the difference between an ice age and the moderate climate we’ve been enjoying. But that level of warming, even during the dramatic emergence from an ice age, usually takes place over thousands of years; we’d do it in a century.
You can find a range of perspectives and definitions for this two-degrees-Celsius climate goal. There are all kinds of complexities, including how to deal with feedbacks in the climate system, how to define “pre-industrial temperatures,” and so on. Essentially, we know warming depends on the total CO2 concentration in the atmosphere: if you want it to stop, you have to cut emissions to zero. But emissions are still rising. Every year we wait for turnaround makes the cuts we have to engage in more and more drastic. Some scenarios argue that, for avoiding 2C of warming to become “likely,” emissions need to be halved in the next 20 years.
Indeed, to hit the 1.5C optimistic Paris goal, researcher Glenn Peters calculates that—even if emissions flatline now—we’ve used up our quota by 2021. Even if they begin to steeply decline, they’d have to be zero by 2026 for a 66 percent chance of 1.5C of warming. Similar calculations suggest, for a good chance at 2C, we need to be at zero net emissions by 2035. These are not realistic scenarios. Zero carbon emissions by 2026 will only happen if a rogue asteroid wipes out all life on Earth. It’s getting a little trickier to see how we’re going to get any sleep tonight.
So, the accounting trick that’s being used by some researchers, including the IPCC (Intergovernmental Panel on Climate Change), is to shift the date forward at which emissions fall to zero by introducing negative emissions technologies. These are effectively the same as pushing our alarm clock further and further forwards, planning to get our sleep at later and later times. Indeed, in the same UN report that went along with Paris, 101 out of 116 scenarios where we successfully avoided 2C of warming required large-scale negative emissions—sucking carbon dioxide out of the atmosphere—to work. We have already discussed that any such negative emissions project is no silver bullet.
You have a choice between large-scale carbon dioxide removal “geoengineering,” attempts to manipulate the natural carbon cycle by liming the oceans, or accelerating the weathering of rocks. Alternatively, you go with direct air capture—factories that pull carbon dioxide from the air—but bear in mind that this is expensive, and it requires energy. If you generate that energy by burning coal, or if the direct air capture is inefficient, then the whole project might not work. Klaus Lackner’s “artificial trees” could offer a potential route to direct air capture, but even at his most optimistic price estimates, it would cost nearly a trillion dollars a year to neutralize our current CO2 emissions.
If these technologies don’t take your fancy, then you can rely on BECCS, where a large portion of our energy comes from biofuels, and the CO2 from burning them is sequestered underground. This is the weapon of choice for the IPCC. Ideally, with BECCS, the net result is to bury some carbon, absorbed by the plants in life, underground.
One advantage it arguably has over other negative emissions technologies is that at least there might be money to be made from the bioenergy part of this equation (unlike sucking CO2 out of the atmosphere and having to bury almost all of it, which hardly has investors licking their lips). Historically, these projects have been bottomless pits of money, which makes it even harder to see where the eye-watering $4 trillion of investment by 2050 the International Energy Authority thinks will be needed to avoid 2C is going to come from.
Yet BECCS comes with its own concerns.
Some of the projections in these scenarios, while they can work in economic models, require far more action than we’re currently seeing from governments. David Mackay points out that in some BECCS scenarios, by 2100, we need to be storing five times as much CO2 by mass as the mass of oil the oil industry currently extracts every year. In the same article, Dr. Oliver Geden notes that if you want to use BECCS to delay the timeline for reducing emissions by 15-20 years (which we’re currently doing), you need to devote an amount of land 1.5 times the size of India to the crops that will fuel BECCS.
In other words, it’s still physically possible (although even these scenarios grow less likely every year we fail to reduce emissions), but is it economically and politically possible?
Given that this could constitute up to a quarter of global agricultural land, given that the biofuels we tend to develop aren’t always the best ones for the climate, given that we’d need to generate as much power with biofuel as all coal-fired plants do today… Some researchers don’t think the technology is even scalable, noting that CCS projects associated with coal plants are often way overdue and over budget. Given that the current US research budget for CCS is $66 million (around a quarter of the budget of Disney flop John Carter) and facing a 75 percent cut, this situation is hardly likely to get any better without a major overhaul. Resetting the alarm is not going to be as easy as we think.
Maybe this has turned you against BECCS, or maybe you’re hoping for a mix of technologies plus some direct air capture to save us (one suspects this is what will happen, if CCS is deployed). The issue remains: with any carbon dioxide removal scheme, your efforts have to be at least comparable in size to the industry you’re trying to neutralize. Burying the CO2 we produce in just two years, in liquid form, would require burying a volume equivalent to the total amount of oil we’ve ever extracted. 1,600 coal-fired power plants are under construction or planned worldwide. Meanwhile, only 21 plants, planned or operational, will use CCS.
So, we’re effectively relying on an industry comparable in size to the energy industry (trillions of dollars a year) to spring up in the next 30 or so years. It uses technology that has not been proven at scale yet, and may not work as intended. It must arise without the major potential for profit as a motivator that the energy industry enjoyed. At $50/ton, widely quoted as a “good” price, neutralizing our current emissions will cost billions of dollars a year. All that, just to clean up.
Perhaps it can be done, but it certainly cannot be done without funding. So we sleepwalk into disaster, allowed to believe that salvation is still within reach—if we just change the world even more radically, some other time. Maybe next year. As David Roberts of Vox puts it: “What is clear is that we are betting our collective future on being able to bury millions of tons of carbon. It’s a huge and existentially risky bet—and maybe one out of a million people even know it’s being made.” And all signs indicate we won’t be ready to make it.
This article has included a great deal of doom and gloom. But it doesn’t have to be this way. The simplest, cheapest, and safest way to handle the climate crisis is to get real. Stop investing in new extraction of fossil fuels we cannot afford to burn; divest from them. Scale up solar and battery R&D and deployment. Stop relying on magical techno-fixes. And, if you insist on relying on them: take them seriously, and give them the funding they need.