By David Gelles
On a wind-swept Icelandic plateau, an international team of engineers and executives is powering up an innovative machine designed to alter the very composition of Earth’s atmosphere.
If all goes as planned, the enormous vacuum will soon be sucking up vast quantities of air, stripping out carbon dioxide and then locking away those greenhouse gases deep underground in ancient stone — greenhouse gases that would otherwise continue heating up the globe.
Just a few years ago, technologies such as these, which attempt to reengineer the natural environment, were on the scientific fringe. They were too expensive, too impractical, too sci-fi. But with the dangers from climate change worsening, and the world failing to meet its goals of slashing greenhouse gas emissions, they are moving to the mainstream among scientists and investors, despite questions about their effectiveness and safety.
Researchers are studying ways to block some of the sun’s radiation. They are testing whether adding iron to the ocean could carry carbon dioxide to the sea floor. They are hatching plans to build giant parasols in space. And with massive facilities such as the one in Iceland, they are seeking to reduce the concentration of carbon dioxide in the air.
Since the dawn of the industrial age, humans have pumped huge volumes of heat-trapping gases into the atmosphere in pursuit of industry and advancement. It amounted to a remaking of the planet’s balanced atmosphere that today has transformed the world, intensifying heat, worsening droughts and storms, and threatening human progress.
As the risks became clearer, political and corporate leaders pledged to keep global average temperatures to no more than 1.5 degrees Celsius higher than before the Industrial Revolution. But for several months last year, the world briefly passed that threshold.
Global temperatures are expected to rise as much as 4 degrees Celsius by century’s end. That has given new weight to what some people call geoengineering, although its proponents prefer the term “climate interventions.” The hope is that taking steps such as these might buy some time at a moment when energy consumption is on the rise, and the world isn’t quitting fossil fuels fast enough.
Many of the projects are controversial. A plant similar to the one in Iceland is being built in Texas by Occidental Petroleum. Occidental intends to use some of the carbon dioxide it captures to extract more oil, the burning of which is a main cause of the climate crisis.
Some critics say other types of interventions could create new problems by scrambling weather patterns or amplifying human suffering through unintended consequences. In effect, they are asking: Should humans be experimenting with the environment in this way? Do we know enough to understand the risks?
“We need more information so we can make these decisions in the future,” said Alan Robock, a professor of atmospheric science at Rutgers University. “Which is riskier: to do it, or not to do it?”
Others argue that fanciful or costly technologies will waste resources and time, or lull people with the false idea it will be possible to slow global warming without phasing out fossil fuels.
There is the risk of rogue actors barreling ahead with their own efforts to change the climate. Already, Mexico has banned what’s known as solar radiation modification after a startup from California released sulfur dioxide into the atmosphere without permission.
Because these technologies are so new, there is relatively little regulation governing them.
“There are these much bigger questions around who decides how is this is all coordinated over time,” said Marion Hourdequin, a professor of environmental philosophy at Colorado College.
Edda Aradottir trudged through fresh snow to inspect the direct air capture plant in Iceland.
Aradottir is CEO of Carbfix, an Icelandic company working with the Swiss startup that built the plant, Climeworks. Known as Mammoth, the project is powered by clean geothermal energy and capable of capturing up to 36,000 metric tons of carbon dioxide per year and pumping it down into the bedrock.
That is just one one-millionth of annual global emissions. But unlike trees, Climeworks promises to store that carbon dioxide forever.
When Mammoth is turned on in the coming weeks, it will be the largest such facility in the world, even though the amount of carbon it can absorb is still just a drop in the bucket.
The Occidental plant, being built near Odessa, Texas, will be over 10 times more powerful than Mammoth, powered by solar energy, and have the potential to capture and sequester 500,000 metric tons of carbon dioxide per year.
It uses a different process to extract carbon dioxide from the air, although the goal is the same: Most of it will be locked away deep underground.
Even if more companies do decide to start offsetting their emissions, there are cheaper ways to do so, including by preserving forests and paying for renewable energy. For example, it costs between $500 and $1,000 to capture a metric ton of carbon dioxide with direct air capture, compared with $10 to $30 per ton for most carbon credits today.
The business world is bullish. Boston Consulting Group expects more companies to begin buying credits to pay for carbon dioxide removal. In the United States and Europe, governments have started subsidizing construction. By 2040, BCG expects the market for carbon dioxide removal technologies could grow from less than $10 billion today to as much as $135 billion.
The direct air capture market has vociferous detractors in academia, activist circles and beyond.
Some say it is little more than a ploy by oil and gas companies to prolong the very industries that are responsible for creating global warming. They point to the extensive evidence that fossil fuel interests for years worked to play down public awareness of climate change, and the fact that some of the captured carbon will be used for additional oil production.
As people begin to deliberately tinker with the climate in new ways, there are questions. If the current extreme weather and temperature rise came about inadvertently, what might happen when we begin actively trying to control the planet’s atmosphere?
“It’s true that we have been altering the climate through greenhouse gas emissions for centuries now,” said Hourdequin. “But trying to intentionally manage the climate through geoengineering would be a distinctive endeavor, quite different than the kind of haphazard interference that we’ve engaged in thus far.”