Category: Environment

The realities of climate change are front-page news every day. Temperature records are being smashed. Wildfires are raging. There is no sign of things going back to “normal”. If anything, they will only get worse.

Last year, when the planet was convulsing with the arrival of a pandemic, we pinned our hopes on technology – in the form of an mRNA vaccine – getting us out of our crisis. The vaccine was a technological intervention, injected into the arms of billions of people. Could we (should we?) look to technological solutions to our climate crisis, too?

Related: ‘Fire weather’: dangerous days now far more common in US west, study finds

This is the question posed by Holly Jean Buck in her 2019 book After Geoengineering: Climate Tragedy, Repair, and Restoration. Zooming with me from Buffalo, New York, where she’s a professor of environment at the University of Buffalo, Buck is blunt in her assessment. The pace of climate change, and the insufficiency of humanity’s current response, have effectively already made the choice for us: mankind will have to engage in some kind of “geoengineering” – an umbrella term for various methods of intentional, planetary-scale climate intervention – whether we like it or not.

Geoengineering refers to any number of ways that humans can change our climate through interventions. The two main types of geoengineering are carbon engineering, which aims to suck carbon out of the atmosphere, and solar engineering, which aims to reflect solar energy away from Earth.

“We’re in a climate crisis,” she tells me. “Mitigation isn’t going fast enough. Adaptation needs far more support than it’s getting. It’s clear that we need to remove some amount of carbon from the atmosphere.”

How much? “Hundreds of billions of gigatons,” Buck says. “We have emitted so much, and now we have so much legacy carbon. The challenge isn’t just cutting emissions.” The second challenge is “removing the carbon that’s up there. It’s this massive cleanup operation that we need to undertake this century.”

The idea of deliberately altering the climate can be frightening and distasteful, including to many environmentalists. But Buck argues that climate engineering is coming whether we like it or not. “If people on the environmental left – people who care about climate change – just reject all of these approaches out of hand, then we lose the ability to shape them, which would be a grave mistake,” she says.

The simplest form of geoengineering is the kind of carbon removal many of us learned about in school: planting trees. “Land-based solutions are really important, especially in the next decade or so, because they can be implemented quickly – and we know how to plant forests,” Buck says. She points to other kinds of land-based climate interventions that show promise. Changing agricultural practices can be used to store more carbon in the dirt. Other strategies include storing carbon in wetlands, ocean iron fertilization, or different approaches involving rock weathering.

But land-based solutions, though a helpful beginning, probably won’t be enough, Buck says. To plant enough trees to soak up enough carbon to sufficiently cool our planet, we would have to fundamentally change the way we use land in ways that would make our economy and many of our lives unrecognizable. And there are other risks to relying too heavily on land-based techniques.

“A lot of land-based approaches are vulnerable to climate change itself,” Buck explains. “You don’t want a wildfire to wipe out these removals that you’ve been banking on, right?” Massive reforestation efforts could go up in smoke.

But land-based solutions are not the only option. Carbon removal can also be accomplished with industrial technologies. Buck points to a carbon mitigation strategy called geological carbon capture, which is already widely used to reduce the emissions of heavily polluting industries. “You could outfit, well, scrubbers basically, on a factory, and these collect carbon dioxide. Then you inject [the carbon] underground, into a cavern, and keep it there, under the rock, for a very long time. You keep monitoring it, to make sure it stays where you want it to be.”

There are risks to injecting large amounts of carbon into rock; Buck laments the under-regulated “wild west atmosphere” of fracking, which caused earthquakes in some parts of the US. But scientists have learned from that experience, and technologies exist to keep underground carbon in place. And new techniques may make geological carbon capture safer. “There’s a lot of new research about how to get carbon dioxide to turn into rock quicker once you inject it” underground, Buck says.

This is a carbon mitigation technique that has proved efficient in reducing emissions at an industrial scale, and it has been in use for decades, meaning that the safety and science of the technique are well understood. Buck’s hope is that this technology could advance and be used not just for mitigating carbon emissions, but for removing carbon.

“It becomes carbon removal” – as opposed to mitigation – “if you’re removing the carbon just from the ambient air,” Buck says. There are now machines that can “scrub” carbon out of the air; the carbon can then be transported and stored underground. Without these machines, the technique can also be used to create bioenergy, which involves “producing biomass” – say, a very carbon-dense type of plant – “and combusting it at a power plant, and separating out the carbon and storing it underground again”.

This strategy – using a spectrum of carbon-engineering techniques to inject carbon deep beneath rock – is the most effective and safest, Buck believes. But unless humanity gets its act together soon, we may forced to entertain much riskier climate mitigation strategies. “If we don’t remove carbon, and decarbonize, and reform how we use land, and rework our transportation systems, and change industrial systems fast enough,” Buck says, “then there’s the possibility that people will pitch the idea of solar geoengineering.”

Solar geoengineering is a kind of climate mitigation – thus far theoretical – that involves “blocking a fraction of incoming sunlight and sending it back out into space, which has a cooling effect”. Most solar-engineering techniques involve using special planes to inject gas into the stratosphere. The gas particles would reflect sunlight away, changing both the quantity and the quality of sunlight that reaches earth.

This kind of geoengineering would certainly cool the planet, at least for a while. But it would not solve the fundamental problem of too much carbon in the atmosphere. “It doesn’t get to the root,” says Buck. “It doesn’t remove emissions. It’s just a blanket of intentional pollution that cools things down.”

And solar geoengineering might create other problems, Buck says. What would a different kind of sunlight do to humankind, or to other living creatures? What would it do to agriculture, and our food supply? We don’t know. Would there be food shortages? Would the sky still be blue? We don’t have those answers, and solar geoengineering remains a risky proposition until we do.

How optimistic is Buck that humanity will attain a livable future without having to resort to solar geoengineering? More than I expected. The vision that she articulates is ambitious. It would require international cooperation and vast overhauls of infrastructure. It would also mean that the United States and other capitalist countries would have to reorient themselves to a more centrally planned economy, devoted less to maximizing growth than to minimizing carbon. It would mean overcoming vast political differences and competing incentives the world over in order to unite in global common cause.

But Buck thinks that the incentives for cooperation in the existential climate intervention project are great enough to ensure at least some success.

“I do think that if people share a common goal, they might disagree about how to reach that goal, but maybe just having the common goal is enough,” she says.

The greatest cleanup operation of history – the cleanup of carbon in our atmosphere – may well happen within our lifetimes. And, if Buck is right, there is no better time to start it than right now.

• Moira Donegan is a Guardian US columnist

Even as ash rained down under a cloud of heavy smoke, the couple wasn’t panicked because they had an early warning to leave their home near Echo Summit, about 10 miles (16 kilometers) south of the lake, and wanted to avoid last-minute pandemonium if the wildfire continued its march toward the tourist destination on the California and Nevada border.

“You don’t want everyone in the basin panicking and scrambling to try and leave at the same time,” McCauley said.

Firefighters were facing changing weather conditions that could push the fire closer to the Tahoe Basin, a home to thousands and recreational playground for millions of tourists who visit the alpine lake in summer, ski at the many resorts in winter and gamble at its casinos year-round.

Winds and temperatures were expected to pick up in coming days while humidity drops, said Daniel Berlant, assistant deputy director of the state firefighting agency.

“That’s what’s closing the window of opportunity we’ve had to make progress and really get hold of the fire,” Berlant said.

Echo Summit, a mountain pass where cliff-hanging U.S. Route 50 begins its descent toward Lake Tahoe, is where firefighters plan to make their stand if the Caldor Fire keeps burning through dense forest in the Sierra Nevada.

“Everything’s holding real good along Highway 50,” said Cal Fire Operations Section Chief Cody Bogan. “The fire has been backing down real slowly … we’ve just been allowing it to do it on its own speed. It’s working in our favor.”

The fire is one of nearly 90 large blazes in the U.S. There were more than a dozen big fires in California, including one that destroyed 18 homes in Southern California, which has so far escaped the scale of wildfires plaguing the north all summer.

A new fire broke out Thursday in the Sierra foothills forcing evacuations near the historic Gold Rush town of Sonora, just dozens of miles from Yosemite National Park.

Fires in California have destroyed around 2,000 structures and forced thousands to evacuate while also blanketing large swaths of the West in unhealthy smoke.

Climate change has made the West warmer and drier in the past 30 years and will continue to make the weather more extreme and wildfires more destructive, according to scientists.

The Caldor Fire has been the nation’s top firefighting priority because of its proximity to Lake Tahoe, where its tourist economy should be in full swing this time of year.

“This is the week before Labor Day weekend — a busy weekend, normally,” South Lake Tahoe City Manager Joe Irvin said. “That is not going to be the case this year.”

The Federal Emergency Management Agency noted in a report on the fire that “social, political, and economic concerns will increase as the fire progresses toward the Lake Tahoe Basin.” The agency did not immediately respond to a request to elaborate beyond that statement.

Visitors are still crowding the highway that loops the massive lake and riding bikes and walking the beaches, but many are wearing masks. The lake, known for its water clarity and the granite peaks that surround it, has been shrouded in dense smoke that has reached hazardous levels.

The Lake Tahoe Visitors Authority reversed its advice from earlier in the week and recommended tourists postpone their travel. Previously the group that promotes tourism on the south side of the lake advised letting visitors decide whether to cancel their trips amid smoke and approaching fire.

Carol Chaplin, the president and CEO, said hotels and lodges were in lockstep with public safety officials.

“They understand that this is not the experience that their guests are used to or look forward to,” she said.

Irvin issued an emergency proclamation Thursday so the city that’s home to Heavenly Ski Resort can be better prepared if evacuation orders come and be reimbursed for related expenses.

The last time the city declared a wildfire emergency was during the 2007 Angora Fire, which destroyed nearly 250 homes in neighboring Meyers and was the last major fire in the basin.

Not far from the neighborhood that was largely wiped out in that fire, residents hurried to clear pine cones and needles from their roofs and gutters to prepare for the possibility of fire.

The Angora Fire, which was driven by strong winds and took residents by surprise, burned just 3,100 acres, fewer than 5 square miles.

The Caldor Fire has burned over 136,000 acres — or 213 square miles (552 square kilometers) — and was only 12% contained Thursday.

Retired fire district captain Joe McAvoy, who lost his own home in the fire, said wildfires larger than 100,000 acres were once-in-a-lifetime events in his career. Not anymore.

“Now it seems like they’re all 100,000 acres,” McAvoy said. It’s way more extreme. … Now (fires) are 100,000 acres and it’s like, ‘Oh, yeah, big deal.’ You know, it’s every fire.”

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Melley reported from Los Angeles. Associated Press reporter John Antczak contributed from Los Angeles.

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Sam Metz is a corps member for the Associated Press/Report for America Statehouse News Initiative. Report for America is a nonprofit national service program that places journalists in local newsrooms to report on undercovered issues.

Extreme rainfall and flooding left paths of destruction through communities around the world this summer. The latest was in Tennessee, where preliminary data shows a record-shattering 17 inches of rain fell in 24 hours, turning creeks into rivers that flooded hundreds of homes and killed at least 18 people.

A lot of people are asking: Was it climate change? Answering that question isn’t so simple.

There has always been extreme weather, but human-caused global warming can increase extreme weather’s frequency and severity. For example, research shows that human activities such as burning fossil fuels are unequivocally warming the planet, and we know from basic physics that warm air can hold more moisture.

A decade ago, scientists weren’t able to confidently connect any individual weather event to climate change, even though the broader climate change trends were clear. Today, attribution studies can show whether extreme events were affected by climate change and whether they can be explained by natural variability alone. With rapid advances from research and increasing computing power, extreme event attribution has become a burgeoning new branch of climate science.

The latest attribution study, released Aug. 23, 2021, looked at the rainfall from the European storm that killed more than 220 people when floods swept through Germany, Belgium, Luxembourg and the Netherlands in July 2021.

A team of climate scientists with the group World Weather Attribution analyzed the record-breaking storm, dubbed Bernd, focusing on two of the most severely affected areas. Their analysis found that human-induced climate change made a storm of that severity between 1.2 and 9 times more likely than it would have been in a world 1.2 degrees Celsius (2.1 F) cooler. The planet has warmed just over 1 C since the industrial era began.

Similar studies haven’t yet been conducted on the Tennessee storm, but they likely will be.

So, how do scientists figure this out? As an atmospheric scientist, I have been involved in attribution studies. Here’s how the process works:

How do attribution studies work?

Attribution studies usually involve four steps.

The first step is to define the event’s magnitude and frequency based on observational data. For example, the July rainfall in Germany and Belgium broke records by large margins. The scientists determined that in today’s climate, a storm like that would occur on average every 400 years in the wider region.

The second step is to use computers to run climate models and compare those models’ results with observational data. To have confidence in a climate model’s results, the model needs to be able to realistically simulate such extreme events in the past and accurately represent the physical factors that help these events occur.

The third step is to define the baseline environment without climate change – essentially create a virtual world of Earth as it would be if no human activities had warmed the planet. Then run the same climate models again.

The differences between the second and third steps represent the impact of human-caused climate change. The last step is to quantify these differences in the magnitude and frequency of the extreme event, using statistical methods.

For instance, we analyzed how Hurricane Harvey in August 2017 and a unique weather pattern interacted with each other to produce the record-breaking rainstorm in Texas. Two attribution studies found that human-caused climate change increased the probability of such an event by roughly a factor of three, and increased Harvey’s rainfall by 15%.

Another study determined that the western North American extreme heat in late June 2021 would have been virtually impossible without human-caused climate change.

How good are attribution studies?

The accuracy of attribution studies is affected by uncertainties associated with each of the above four steps.

Some types of events lend themselves to attribution studies better than others. For instance, among long-term measurements, temperature data is most reliable. We understand how human-caused climate change affects heat waves better than other extreme events. Climate models are also usually skillful in simulating heat waves.

Even for heat waves, the impact of human-caused climate change on the magnitude and frequency could be quite different, such as the case of the extraordinary heat wave across western Russia in 2010. Climate change was found to have had minimal impact on the magnitude but substantial impact on the frequency.

There can also be legitimate differences in the methods underpinning different attribution studies.

However, people can make decisions for the future without knowing everything with certainty. Even when planning a backyard barbecue, one does not have to have all the weather information.

Read more: The water cycle is intensifying as the climate warms, IPCC report warns – that means more intense storms and flooding

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This article is republished from The Conversation, a nonprofit news site dedicated to sharing ideas from academic experts. It was written by: Xubin Zeng, University of Arizona.

Read more:

• Climate change is relentless: Seemingly small shifts have big consequences
• The water cycle is intensifying as the climate warms, IPCC report warns – that means more intense storms and flooding

Xubin Zeng receives funding from NASA, DOE, NOAA, the US Army Corps of Engineers and the California Department of Water Resources. He is a fellow of both the American Meteorological Society and the American Association for the Advancement of Science, and is a member of the American Geophysical Union.