- Given that the serious impacts of climate change are rapidly escalating, some scientists, backed up increasingly by governments, are looking into extreme measures such as geoengineering to slow the rate of change.
- A new report examines 61 climate mitigation ideas for the Arctic, including geoengineering.
- The report ranked tried and true measures, like restoring peatlands, the highest, but some geoengineering ideas, such as solar geoengineering, also ranked high.
- Researchers say, however, that while geoengineering ideas may be worth studying, the goal right now must be to aggressively cut emissions. Some also fear that geoengineering will become a costly distraction, diverting attention from the need for fossil fuel companies to cut production, and for decarbonization of the economy.
Last year was the hottest on record and possibly the hottest in 125,000 years — long before humans invented agriculture, the internet, the wheel, or beer pong. The planet is toasting.
And flooding: On April 15, Dubai got more rain in 24 hours than it averages all year; a recent study linked this to climate change. Three days later, record flooding hit Kenya, killing more than 180 people and displacing 165,000. Then Brazil in May, with 150 dead and more than 600,000 people displaced.
And burning: Last year’s record fire season seems headed to a second sizzling year, with Canada announcing the fire season start in February, with a dozen major out-of-control blazes covering at least 200,000 hectares (500,000 acres) by mid-May. The Amazon, including Venezuela, has been aflame, and the U.S. West is bracing for another above-normal wildfire year.
And the ocean is seething: Marine heat waves have triggered massive die-offs, as Earth’s oceans have set heat records for 13 months straight. In April, scientists announced the world’s fourth catastrophic coral bleaching event.
And amid all this, world leaders and fossil fuel companies continue resisting decisive climate action.
All said, Earth is in peril, leaving some scientists and policymakers turning attention to a subject that was largely taboo just a few years ago, but made a big splash at the fossil fuel-industry dominated COP28 climate summit in Dubai last December: geoengineering.
Also known as climate engineering, the approach would employ technology writ large to manipulate the climate on a regional or planetwide scale in a bid to mitigate the worst impacts of global warming, including catastrophic tipping points in the Arctic, Amazon and elsewhere. But many worry these approaches could bring dire consequences.
Regardless, in 2020, the U.S. Congress directed the National Oceanic and Atmospheric Administration (NOAA) to begin studying potential climate interventions. NOAA released an extensive report on solar geoengineering last year, calling for more research. The EU is also funding a pair of projects to evaluate geoengineering ideas.
The definition of geoengineering remains fluid, but the Intergovernmental Panel on Climate Change (IPCC) in 2022 stopped using the term when talking about carbon-removal methods or technologies such as direct air capture of carbon or reforestation. This leaves methods to decrease the sun’s radiative heat as the major form of geoengineering. Such schemes include blocking the sun with giant space mirrors, releasing particulates in the stratosphere, or brightening clouds over the ocean to reflect sunlight back into space. Other wilder ideas include trying to stabilize ice sheets or covering glaciers in reflective fabric.
“Folks are realizing we have done too little too late and we will be crossing some critical tipping points in the climate system as we approach 2°C [3.6°F] of global warming,” says Julienne Stroeve, a professor who specializes in remote sensing in the Arctic and Antarctic. Importantly, she says, the focus should stay on transforming our economic system to cut greenhouse gas emissions, and most scientists agree that we shouldn’t let geoengineering ideas distract us from the task at hand: aggressively slashing emissions.
At this point, most geoengineering ideas are simply that and nothing more: ideas.
Some have been analyzed using computer modeling, but very few have been tested in the field. And to date, no one has employed geoengineering at the scale required to make a notable difference (a U.S.-based company, Make Sunsets, has been sending balloons with reflective particles into the atmosphere, and thereby created a minor geopolitical incident when those balloons floated from U.S. into Mexican airspace.
For ideas to become reality, however, more research is urgently need to tease out which of them, if any, are worth carrying to the experimental stage to assess the possibilities for success and potential risk at scale.
But time is running short.
Arctic ideas
The Arctic is heating up faster than anywhere else on the planet. Recent research finds it to be warming nearly four times faster than the Earth average, with highly reflective Arctic sea ice expected to vanish in summer in less than two decades, causing the dark blue-colored Arctic Ocean to absorb even more heat. Glaciers are vanishing, snow cover is shrinking, permafrost is melting, and life for Indigenous peoples and wildlife is being radically transformed. If the Greenland ice sheet goes entirely, that’s a 7-meter (23-foot) rise in sea levels.
Can anything be done? Scientists say we must first stop burning fossil fuels for energy. But even if we stopped that today, and that’s clearly not happening, the world will remain hotter for decades if not centuries. So how can we cool things down?
In hopes of delaying catastrophe, scientists recently developed a report examining 61 climate mitigation ideas for the Arctic, ranking them on everything from technological readiness, to cost, to potential effectiveness. Many fit into the carbon sequestration bucket, but a number recommend various geoengineering approaches.
Albert van Wijngaarden, one of the report’s authors and a Ph.D. student at Cambridge University in the U.K., says the team of Arctic experts wanted first to “clear up some of the misunderstandings and obscurity around projects that might mitigate the effects of climate change in the Arctic.”
He says the team — including researchers from the Arctic Center at the University of Lapland in Finland; the University of the Arctic, a group of universities and other institutions across Arctic nations; and GRID-Arendal, a Norwegian government-funded nonprofit, among others — was keen to examine as many ideas as possible, evaluating schemes ranging from the viable to the wildly improbable.
“Many of these projects had just been suggested once, or were only promoted by a small group of advocates, with very little critical reflection,” van Wijngaarden says. The goal was essentially to separate the wheat from the chaff.
The good …
Not surprisingly, some of the highest-scoring ideas were ones that didn’t involve geoengineering, had a long history of development, and came with major known benefits. Among these were rewilding, reforestation, and managing northern wildfires.
“There are some projects that seem to be generally beneficial and harmless, like peatland restoration and preservation, which seem like straightforwardly good options,” van Wijngaarden says.
But other more challenging and controversial geoengineering ideas also scored relatively well. They include insulating Arctic glaciers with reflective fabrics, or creating artificial glaciers to replace melting ones. Both scored well compared to more radical ideas involving the entire Arctic ice sheet.
When it came to solar engineering methods for shielding the Arctic from heat, polar marine cloud brightening or enhancing snowfall came out near the top. Also among the most popular large-scale geoengineering ideas was injecting aerosols into the Arctic stratosphere, a process known as solar radiation management (SRM), whose effectiveness has modeled well. The method would essentially mimic a volcanic plume in the stratosphere, and many researchers have suggested it as a way to reduce warming worldwide.
Attempting to stabilize ice sheets via seabed curtains, an idea that’s gaining publicity despite the obvious challenges of scale, scored relatively high, especially on arguably the most important criteria: the “potential to make a global difference.”
“Climate change in the Arctic is multifaceted, and there is no silver-bullet solution,” van Wijngaarden cautions. “So, even though we tried to give some clarity as to what the potential merits and downsides of proposals might be, it is very much up to our readers to look at the goals and issues they find important.”
Stroeve reiterates that the focus must always be to decrease greenhouse gas emissions quickly. But of the ideas in the report, she says carbon capture methods that “target the root cause” are better than many others that only “put a BandAid on the problem locally, while still warming up the planet.”
In the geoengineering category, she says, stratospheric aerosol injection is “probably the most promising” but may come with large drawbacks, such as disrupting monsoons vital to global agriculture. Despite the potential, she adds, there have been no large-scale field trials, though NOAA has begun gathering baseline stratosphere data.
And the not-so-good …
Some ideas fell flat when evaluated. Modifying ocean currents, pumping water onto ice sheets to reinforce them, or trying to protect permafrost using various covers and coatings all scored low.
Stroeve says some ideas grossly underestimated the scale of the vast areas involved. For example, how could one conceivably cover 15 million square kilometers (6 million square miles) of sea ice with water? However, she adds that such solutions might be used to strengthen small patches of key species habitat, for polar bears or other animals.
Van Wijngaarden says one of the “big benefits” of the report is to weed out the worst ideas, such as removing sea ice to somehow “increase the amount of outgoing radiation to space” — not something Arctic researchers are keen on, given they’re trying to save reflective sea ice.
Some ideas have gotten more attention, even though there’s little research behind them. Van Wijngaarden points to a popular YouTube video that has 239,000 views showing an animation of an imaginary Arctic submarine manufacturing icebergs — reminiscent, perhaps, of Superman’s construction of his Fortress of Solitude.
“This was proposed by an Indonesian team for a design competition, and has not been developed further,” van Wijngaarden says of the video that appeared four years ago.
A number of proposals have barely been studied. Sometimes, van Wijngaarden says, this was because an idea fell apart quickly, or because it’s recent and researchers haven’t had a chance to dig into it.
Of the more controversial ideas, van Wijngaarden says, “Perhaps several could be considered in combination with sustained global efforts to mitigate emissions and reduce the levels of atmospheric carbon.”
But Stroeve is more skeptical: “We cannot even get governments to agree to reform [economic] systems to reduce greenhouse gas emissions. I’m not sure we will be able to get agreement to manipulate the climate between nations.”
Banner image: Two polar bear siblings play-fighting in the wild on Barter Island, Alaska. A rapidly warming Arctic is changing how animals move and feed. Some may not survive in a future hotter Arctic. Image by cheryl strahl via Flickr (CC BY-NC 2.0).
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Citation:
Rantanen, M., Karpechko, A. Y., Lipponen, A., Nordling, K., Hyvärinen, O., Ruosteenoja, K., … Laaksonen, A. (2022). The Arctic has warmed nearly four times faster than the globe since 1979. Communications Earth & Environment, 3(1). doi:10.1038/s43247-022-00498-3
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