Drax Power Station in the north of England
Ian Lamond/ Alamy
You’ve probably seen those cool graphs showing the decline in carbon dioxide levels and temperatures at the end of the century. How should this miracle be achieved? The idea is that we harvest plants, burn them for energy and then capture and store the CO2. Voila, problem solved!
Bypassing bioenergy with carbon capture and storage, or BECCS, as the idea is known, is shaping up to be an ongoing disaster. It is not being implemented on the scale expected, partly because it is ridiculously expensive, if done at this scale it would be devastating to biodiversity and, last but not least, it doesn’t even work. This actually increases CO2 emissions rather than reducing them over time.
As Documented by Leo Hickman at CarbonBriefBECCS was first proposed in 2001 by researchers in Sweden wondering how paper mills there could earn carbon credits. In 2005, some climate modelers seized on this purely theoretical idea as a way to justify scenarios in which global temperatures exceed 1.5 degrees Celsius and then fall back down. In 2014, the fifth report of the Intergovernmental Panel on Climate Change (IPCC) highlighted climate models that assumed large amounts of carbon could be removed with BECCS. A non-existent technology had somehow become the “official solution” that was supposed to save the world.
For a while it looked like it might become a reality. In 2015, Drax Energy Company in the UK announced that a giant coal power plant would be converted to run on wood pellets, and capture and store the CO2.
A decade later, the Drax plant is burning wood pellets but not capturing any carbon. In fact, As politico Reported earlier this monthThe company has now postponed its plans to do so. So the world’s flagship project for bioenergy with carbon capture and storage is now dead – or at least in intensive care. A Drax spokesperson says, “We still see BECCS as a potential option for the site, but it is much more long-term than we initially planned.”
A few other smaller projects are planned around the world, but it is clear that BECCS is not taking off the way it was envisioned a decade or so ago. And there is a reason for this – governments are reluctant to provide the huge subsidies required. “It’s unprecedentedly expensive,” says Tim Searchinger At Princeton University.
It may seem like a bad thing that we’re not implementing technology designed to save us, but it’s actually a good thing, because it doesn’t work – at least not on the time scale we need. “There are probably unrealistic scenarios where you might get some negative emissions. But they’re not that big, and you don’t get any benefits for decades,” Searchinger says.
To help convince policymakers, he and his colleagues Releasing a computer model of the carbon flows involvedSo that people can play with the numbers themselves. The model suggests that BECCS could take 150 years to remove any CO2 from the atmosphere, and for the first few decades it is worse than burning natural gas without any carbon capture. Oh, and it will triple the cost of electricity.
Why? Essentially, BECCS turns CO2 already stored in forests into CO2 that can be stored in other ways – perhaps in geological formations below ground – but a lot of the CO2 is destroyed during the process, and ends up in the atmosphere.
For starters, a lot of forest carbon never reaches power plants – roots are left behind to rot, other vegetation is destroyed during harvesting and so on. All this carbon ends up in the atmosphere.
Burning wood produces twice as much carbon per unit energy as burning gas, while lower temperatures mean less of that energy can be converted to electricity. Furthermore, capturing carbon is energy-intensive. So power plants will need to burn a lot of extra wood to power the carbon-capture process – which is likely to capture only about 85 percent of the CO2 released.
There is another, more subtle problem. Some argue that using wood for purposes such as BECCS is fine as long as the carbon is not removed faster than the forest can produce it. But climate projections assume that many forests will absorb additional carbon due to the CO2 fertilization effect – or, in jargon, land subsidence will continue to increase. So what some see as sustainable harvesting is actually destroying the climate solution we are already relying on.
These arguments apply to slow-growing trees, and are envisioned using fast-growing energy crops such as grasses in many BECCS scenarios. There might be modest benefits if we had lots of extra agricultural land doing nothing, but the global picture is that we are still destroying rainforests to free up more land for farms to grow food. Clearing too much land would be even more devastating to biodiversity.
Without BECCS it may be unclear how we can get CO2 levels back down, but for now the focus should be on preventing them from rising further. “We must accelerate our move to wind and solar energy as much as possible,” says Searchinger.
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