climate change

how-did-volcanism-trigger-climate-change-before-the-eruptions-started?

How did volcanism trigger climate change before the eruptions started?

climate change, Earth science, geology, Science, sediment cores, volcanism / /
Image of a person in a stream-filled gap between two tall rock faces.

Enlarge / Loads of lava: Kasbohm with a few solidified lava flows of the Columbia River Basalts.

Joshua Murray

As our climate warms beyond its historical range, scientists increasingly need to study climates deeper in the planet’s past to get information about our future. One object of study is a warming event known as the Miocene Climate Optimum (MCO) from about 17 to 15 million years ago. It coincided with floods of basalt lava that covered a large area of the Northwestern US, creating what are called the “Columbia River Basalts.” This timing suggests that volcanic CO2 was the cause of the warming.

Those eruptions were the most recent example of a “Large Igneous Province,” a phenomenon that has repeatedly triggered climate upheavals and mass extinctions throughout Earth’s past. The Miocene version was relatively benign; it saw CO2 levels and global temperatures rise, causing ecosystem changes and significant melting of Antarctic ice, but didn’t trigger a mass extinction.

A paper just published in Geology, led by Jennifer Kasbohm of the Carnegie Science’s Earth and Planets Laboratory, upends the idea that the eruptions triggered the warming while still blaming them for the peak climate warmth.

The study is the result of the world’s first successful application of high-precision radiometric dating on climate records obtained by drilling into ocean sediments, opening the door to improved measurements of past climate changes. As a bonus, it confirms the validity of mathematical models of our orbits around the Solar System over deep time.

A past climate with today’s CO2 levels

“Today, with 420 parts per million [of CO2], we are basically entering the Miocene Climate Optimum,” said Thomas Westerhold of the University of Bremen, who peer-reviewed Kasbohm’s study. While our CO2 levels match, global temperatures have not yet reached the MCO temperatures of up to 8° C above the preindustrial era. “We are moving the Earth System from what we call the Ice House world… in the complete opposite direction,” said Westerhold.

When Kasbohm began looking into the link between the basalts and the MCO’s warming in 2015, she found that the correlation had huge uncertainties. So she applied high-precision radiometric dating, using the radioactive decay of uranium trapped within zircon crystals to determine the age of the basalts. She found that her new ages no longer spanned the MCO warming. “All of these eruptions [are] crammed into just a small part of the Miocene Climate Optimum,” said Kasbohm.

But there were also huge uncertainties in the dates for the MCO, so it was possible that the mismatch was an artifact of those uncertainties. Kasbohm set out to apply the same high-precision dating to the marine sediments that record the MCO.

A new approach to an old problem

“What’s really exciting… is that this is the first time anyone’s applied this technique to sediments in these ocean drill cores,” said Kasbohm.

Normally, dates for ocean sediments drilled from the seabed are determined using a combination of fossil changes, magnetic field reversals, and aligning patterns of sediment layers with orbital wobbles calculated by astronomers. Each of those methods has uncertainties that are compounded by gaps in the sediment caused by the drilling process and by natural pauses in the deposition of material. Those make it tricky to match different records with the precision needed to determine cause and effect.

The uncertainties made the timing of the MCO unclear.

Tiny clocks: Zircon crystals from volcanic ash that fell into the Caribbean Sea during the Miocene.

Enlarge / Tiny clocks: Zircon crystals from volcanic ash that fell into the Caribbean Sea during the Miocene.

Jennifer Kasbohm

Radiometric dating would circumvent those uncertainties. But until about 15 years ago, its dates had such large errors that they were useless for addressing questions like the timing of the MCO. The technique also typically needs kilograms of material to find enough uranium-containing zircon crystals, whereas ocean drill cores yield just grams.

But scientists have significantly reduced those limitations: “Across the board, people have been working to track and quantify and minimize every aspect of uncertainty that goes into the measurements we make. And that’s what allows me to report these ages with such great precision,” Kasbohm said.

How did volcanism trigger climate change before the eruptions started? Read More »

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Americans misunderstand their contribution to deteriorating environment

climate change, Science, syndication / /
Power lines are cast in silhouette as the Creek Fire creeps up on on the Shaver Springs community off of Tollhouse Road on Tuesday, Sept. 8, 2020, in Auberry, California.

Enlarge / Power lines are cast in silhouette as the Creek Fire creeps up on on the Shaver Springs community off of Tollhouse Road on Tuesday, Sept. 8, 2020, in Auberry, California.

This article originally appeared on Inside Climate News, a nonprofit, independent news organization that covers climate, energy and the environment. It is republished with permission. Sign up for their newsletter here. 

Most people are “very” or “extremely” concerned about the state of the natural world, a new global public opinion survey shows.

Roughly 70 percent of 22,000 people polled online earlier this year agreed that human activities were pushing the Earth past “tipping points,” thresholds beyond which nature cannot recover, like loss of the Amazon rainforest or collapse of the Atlantic Ocean’s currents. The same number of respondents said the world needs to reduce carbon emissions within the next decade.

Just under 40 percent of respondents said technological advances can solve environmental challenges.

The Global Commons survey, conducted for two collectives of “economic thinkers” and scientists known as Earth4All and the Global Commons Alliance, polled people across 22 countries, including low-, middle- and high-income nations. The survey’s stated aim was to assess public opinion about “societal transformations” and “planetary stewardship.”

The results, released Thursday, highlight that people living under diverse circumstances seem to share worries about the health of ecosystems and the environmental problems future generations will inherit.

Explore the latest news about what’s at stake for the climate during this election season.

But there were some regional differences. People living in emerging economies, including Kenya and India, perceived themselves to be more exposed to environmental and climate shocks, like drought, flooding, and extreme weather. That group expressed higher levels of concern about the environment, though 59 percent of all respondents said they are “very” or “extremely” worried about “the state of nature today,” and another 29 percent are at least somewhat concerned.

Americans are included in the global majority, but a more complex picture emerged in the details of the survey, conducted by Ipsos.

Roughly one in two Americans said they are not very or not at all exposed to environmental and climate change risks. Those perceptions contrast sharply with empirical evidence showing that climate change is having an impact in nearly every corner of the United States. A warming planet has intensified hurricanes battering coasts, droughts striking middle American farms, and wildfires threatening homes and air quality across the country. And climate shocks are driving up prices of some food, like chocolate and olive oil, and consumer goods.

Americans also largely believe they do not bear responsibility for global environmental problems. Only about 15 percent of US respondents said that high- and middle-income Americans share responsibility for climate change and natural destruction. Instead, they attribute the most blame to businesses and governments of wealthy countries.

Those survey responses suggest that at least half of Americans may not feel they have any skin in the game when it comes to addressing global environmental problems, according to Geoff Dabelko, a professor at Ohio University and expert in environmental policy and security.

Translating concern about the environment to actual change requires people to believe they have something at stake, Dabelko said. “It’s troubling that Americans aren’t making that connection.”

While fossil fuel companies have long campaigned to shape public perception in a way that absolves their industry of fault for ecosystem destruction and climate change, individual behavior does play a role. Americans have some of the highest per-capita consumption rates in the world.

The world’s wealthiest 10 percent are responsible for nearly half the world’s carbon emissions, along with ecosystem destruction and related social impacts. For instance, American consumption of gold, tropical hardwoods like mahogany and cedar and other commodities has been linked to the destruction of the Amazon rainforest and attacks on Indigenous people defending their territories from extractive activities.

The United States is one of the world’s wealthiest countries and home to 38 percent of the world’s millionaires (the largest share). But a person doesn’t need to be a millionaire to fit within the cohort of the world’s wealthiest. Americans without children earning more than $60,000 a year after tax, and families of three with an after-tax household income above $130,000, are in the richest 1 percent of the world’s population.

United Nations emissions gap reports have said that to reach global climate goals, the world’s wealthiest people must cut their personal emissions by at least a factor of 30. High-income Americans’ emissions footprint is largely a consequence of lifestyle choices like living in large homes, flying often, opting for personal vehicles over public transportation, and conspicuous consumption of fast fashion and other consumer goods.

Americans misunderstand their contribution to deteriorating environment Read More »

string-of-record-hot-months-came-to-an-end-in-july

String of record hot months came to an end in July

climate change, Earth science, Science, temperature records / /

Hot, but not that hot —

July had the two hottest days recorded but fell 0.04° Celsius short of last year.

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Image of a chart with many dull grey squiggly lines running left to right, with an orange and red line significantly above the rest.

Enlarge / Absolute temperatures show how similar July 2023 and 2024 were.

The past several years have been absolute scorchers, with 2023 being the warmest year ever recorded. And things did not slow down in 2024. As a result, we entered a stretch where every month set a new record as the warmest iteration of that month that we’ve ever recorded. Last month, that pattern stretched out for a full 12 months, as June of 2024 once again became the warmest June ever recorded. But, despite some exceptional temperatures in July, it fell just short of last July’s monthly temperature record, bringing the streak to a close.

Europe’s Copernicus system was first to announce that July of 2024 was ever so slightly cooler than July of 2023, missing out on setting a new record by just 0.04° C. So far, none of the other major climate trackers, such as Berkeley Earth or NASA GISS, have come out with data for July. These each have slightly different approaches to tracking temperatures, and, with a margin that small, it’s possible we’ll see one of them register last month as warmer or statistically indistinguishable.

How exceptional are the temperatures of the last few years? The EU averaged every July from 1991 to 2020—a period well after climate change had warmed the planet significantly—and July of 2024 was still 0.68° C above that average.

While it didn’t set a record, both the EU’s Copernicus climate service and NASA’s GISS found that it contained the warmest day ever recorded. In the EU’s case, they were the two hottest days recorded, as the temperatures on the 21st and 22nd were statistically indistinguishable, with only 0.01° C separating them. Late July and early August tend to be the warmest times of the year for surface air temperatures, so we’re likely past the point where any daily records will be set in 2024.

That’s all in terms of absolute temperatures. If you compare each day of the year only to instances of that day in the past, there have been far more anomalous days in the temperature record.

In terms of anomalies over years past, both 2023 (orange) and 2024 (red) have been exceptionally warm.

Enlarge / In terms of anomalies over years past, both 2023 (orange) and 2024 (red) have been exceptionally warm.

That image also shows how exceptional the past year’s temperatures have been and makes it clear that 2024 is only falling out of record territory because the second half of 2023 was so exceptionally warm. It’s unlikely that 2024 will be quite as extreme, as the El Niño event that helped drive warming appears to have faded after peaking in December of 2023. NOAA’s latest forecast expects that the Pacific will remain in neutral for another month or two before starting to shift into cooler La Niña conditions before the year is out. (This is based on the August 8 ENSO forecast obtained here.)

In terms of anomalies, July also represents the first time in a year that a month had been less than 1.5° C above preindustrial temperatures (with preindustrial defined as the average over 1850–1900). Capping our modern temperatures at 1.5° C above preindustrial levels is recognized as a target that, while difficult to achieve, would help avoid some of the worst impacts we’ll see at 2° C of warming, and a number of countries have committed to that goal.

Listing image by Dmitriy83

String of record hot months came to an end in July Read More »

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Memo to the Supreme Court: Clean Air Act targeted CO2 as climate pollutant, study says

air pollution, climate change, Massachusetts v. EPA, Policy, Science, syndication / /
The exterior of the US Supreme Court building during daytime.

Getty Images | Rudy Sulgan

This article originally appeared on Inside Climate News, a nonprofit, independent news organization that covers climate, energy, and the environment. It is republished with permission. Sign up for its newsletter here. 

Among the many obstacles to enacting federal limits on climate pollution, none has been more daunting than the Supreme Court. That is where the Obama administration’s efforts to regulate power plant emissions met their demise and where the Biden administration’s attempts will no doubt land.

A forthcoming study seeks to inform how courts consider challenges to these regulations by establishing once and for all that the lawmakers who shaped the Clean Air Act in 1970 knew scientists considered carbon dioxide an air pollutant, and that these elected officials were intent on limiting its emissions.

The research, expected to be published next week in the journal Ecology Law Quarterly, delves deep into congressional archives to uncover what it calls a “wide-ranging and largely forgotten conversation between leading scientists, high-level administrators at federal agencies, members of Congress” and senior staff under Presidents Lyndon Johnson and Richard Nixon. That conversation detailed what had become the widely accepted science showing that carbon dioxide pollution from fossil fuels was accumulating in the atmosphere and would eventually warm the global climate.

The findings could have important implications in light of a legal doctrine the Supreme Court established when it struck down the Obama administration’s power plant rules, said Naomi Oreskes, a history of science professor at Harvard University and the study’s lead author. That so-called “major questions” doctrine asserted that when courts hear challenges to regulations with broad economic and political implications, they ought to consider lawmakers’ original intent and the broader context in which legislation was passed.

“The Supreme Court has implied that there’s no way that the Clean Air Act could really have been intended to apply to carbon dioxide because Congress just didn’t really know about this issue at that time,” Oreskes said. “We think that our evidence shows that that is false.”

The work began in 2013 after Oreskes arrived at Harvard, she said, when a call from a colleague prompted the question of what Congress knew about climate science in the 1960s as it was developing Clean Air Act legislation. She had already co-authored the book Merchants of Doubt, about the efforts of industry-funded scientists to cast doubt about the risks of tobacco and global warming, and was familiar with the work of scientists studying climate change in the 1950s. “What I didn’t know,” she said, “was how much they had communicated that, particularly to Congress.”

Oreskes hired a researcher to start looking, and what they both found surprised her. The evidence they uncovered includes articles cataloged by the staff of the act’s chief architect, proceedings of scientific conferences attended by members of Congress, and correspondence with constituents and scientific advisers to Johnson and Nixon. The material included documents pertaining not only to environmental champions but also to other prominent members of Congress.

“These were people really at the center of power,” Oreskes said.

When Sen. Edmund Muskie, a Maine Democrat, introduced the Clean Air Act of 1970, he warned his colleagues that unchecked air pollution would continue to “threaten irreversible atmospheric and climatic changes.” The new research shows that his staff had collected reports establishing the science behind his statement. He and other senators had attended a 1966 conference featuring discussion of carbon dioxide as a pollutant. At that conference, Wisconsin Sen. Gaylord Nelson warned about carbon dioxide pollution from fossil fuel combustion, which he said “is believed to have drastic effects on climate.”

The paper also cites a 1969 letter to Sen. Henry “Scoop” Jackson of Washington from a constituent who had watched the poet Allen Ginsberg warning of melting polar ice caps and widespread global flooding on the Merv Griffin Show. The constituent was skeptical of the message, called Ginsberg “one of America’s premier kooks” and sought a correction of the record from the senator: “After all, quite a few million people watch this show, people of widely varying degrees of intelligence, and the possibility of this sort of charge—even from an Allen Ginsberg—being accepted even in part, is dangerous.”

Memo to the Supreme Court: Clean Air Act targeted CO2 as climate pollutant, study says Read More »

can-the-solar-industry-keep-the-lights-on?

Can the solar industry keep the lights on?

climate change, Policy, solar panels, syndication / /
Image of solar panels on a green grassy field, with blue sky in the background.

Founded in Dresden in the early 1990s, Germany’s Solarwatt quickly became an emblem of Europe’s renewable energy ambitions and bold plan to build a solar power industry.

Its opening of a new solar panel plant in Dresden in late 2021 was hailed as a small victory in the battle to wrestle market share from the Chinese groups that have historically supplied the bulk of panels used in Europe.

Now, Solarwatt is preparing to halt production at the plant and shift that work to China.

“It is a big pity for our employees, but from an economic point of view we could not do otherwise,” said Peter Bachmann, the company’s chief product officer.

Solarwatt is not alone. A global supply glut has pummelled solar panel prices over the past two years, leaving swaths of Europe’s manufacturers unprofitable, threatening US President Joe Biden’s ambition to turn America into a renewable energy force and even ricocheting back on the Chinese companies that dominate the global market.

“We are in a crisis,” said Johan Lindahl, secretary-general of the European Solar Manufacturing Council, the European industry’s trade body.

Yet as companies in Europe, the US, and China cut jobs, delay projects, and mothball facilities, an abundance of cheap solar panels has delivered one significant upside—consumers and businesses are installing them in ever greater numbers.

Electricity generated from solar power is expected to surpass that of wind and nuclear by 2028, according to the International Energy Agency.

The picture underlines the quandary confronting governments that have pledged to decarbonise their economies, but will find doing so harder unless the historic shift from fossil fuels is both affordable for the public and creates new jobs.

Governments face a “delicate and difficult balancing act,” said Michael Parr, director of trade group Ultra Low Carbon Solar Alliance. They must “maximize renewables deployment and carbon reductions, bolster domestic manufacturing sectors, keep energy prices low, and ensure energy security.”

The industry, which spans wafer, cell, and panel manufacturers, as well as companies that install panels, employed more than 800,000 people in Europe at the end of last year, according to SolarPower Europe. In the US almost 265,000 work in the sector, figures from the Interstate Renewable Energy Council show.

“There is overcapacity in every segment, starting with polysilicon and finishing with the module,” said Yana Hryshko, head of global solar supply chain research at the consultancy Wood Mackenzie.

According to BloombergNEF, panel prices have plunged more than 60 percent since July 2022. The scale of the damage inflicted has sparked calls for Brussels to protect European companies from what the industry says are state-subsidized Chinese products.

Europe’s solar panel manufacturing capacity has collapsed by about half to 3 gigawatts since November as companies have failed, mothballed facilities, or shifted production abroad, the European Solar Manufacturing Council estimates. In rough terms, a gigawatt can potentially supply electricity for 1mn homes.

The hollowing out comes as the EU is banking on solar power playing a major role in the bloc meeting its target of generating 45 percent of its energy from renewable sources by 2030. In the US, the Biden administration has set a target of achieving a 100 percent carbon pollution-free electricity grid by 2035.

Climate change is a global challenge, but executives said the solar industry’s predicament exposed how attempts to address it can quickly fracture along national and regional lines.

“There’s trade policy and then there’s climate policy, and they aren’t in sync,” said Andres Gluski, chief executive of AES, one of the world’s biggest developers of clean energy. “That’s a problem.”

Brussels has so far resisted demands to impose tariffs. It first levied them in 2012 but reversed that in 2018, partly in what proved a successful attempt to quicken the uptake of solar. Chinese imports now account for the lion’s share of Europe’s solar panels.

In May, the European Commission introduced the Net Zero Industry Act, legislation aimed at bolstering the bloc’s clean energy industries by cutting red tape and promoting a regional supply chain.

But Gunter Erfurt, chief executive of Switzerland-based Meyer Burger, the country’s largest solar panel maker, is skeptical it will be enough.

“You need to create a level playing field,” he said. Meyer Burger would benefit if the EU imposed tariffs because it has operations in Germany.

Can the solar industry keep the lights on? Read More »

will-burying-biomass-underground-curb-climate-change?

Will burying biomass underground curb climate change?

biomass, climate change, Science, syndication / /

stacking bricks —

Though carbon removal startups may limit global warming, significant questions remain.

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Will burying biomass underground curb climate change?

On April 11, a small company called Graphyte began pumping out beige bricks, somewhat the consistency of particle board, from its new plant in Pine Bluff, Arkansas. The bricks don’t look like much, but they come with a lofty goal: to help stop climate change.

Graphyte, a startup backed by billionaire Bill Gates’ Breakthrough Energy Ventures, will bury its bricks deep underground, trapping carbon there. The company bills it as the largest carbon dioxide removal project in the world.

Scientists have long warned of the dire threat posed by global warming. It’s gotten so bad though that the long-sought mitigation, cutting carbon dioxide emissions from every sector of the economy, might not be enough of a fix. To stave off the worst—including large swaths of the Earth exposed to severe heat waves, water scarcity, and crop failures—some experts say there is a deep need to remove previously emitted carbon, too. And that can be done anywhere on Earth—even in places not known for climate-friendly policies, like Arkansas.

Graphyte aims to store carbon that would otherwise be released from plant material as it burns or decomposes at a competitive sub-$100 per metric ton, and it wants to open new operations as soon as possible, single-handedly removing tens of thousands of tons of carbon annually, said Barclay Rogers, the company’s founder and CEO. Nevertheless, that’s nowhere near the amount of carbon that will have to be removed to register as a blip in global carbon emissions. “I’m worried about our scale of deployment,” he said. “I think we need to get serious fast.”

Hundreds of carbon removal startups have popped up over the past few years, but the fledgling industry has made little progress so far. That leads to the inevitable question: Could Graphyte and companies like it actually play a major role in combating climate change? And will a popular business model among these companies, inviting other companies to voluntarily buy “carbon credits” for those buried bricks, actually work?

Whether carbon emissions are cut to begin with, or pulled out of the atmosphere after they’ve already been let loose, climate scientists stress that there is no time to waste. The clock began ticking years ago, with the arrival of unprecedented fires and floods, superstorms, and intense droughts around the world. But carbon removal, as it’s currently envisioned, also poses additional sociological, economic, and ethical questions. Skeptics, for instance, say it could discourage more pressing efforts on cutting carbon emissions, leaving some experts wondering whether it will even work at all.

Still, the Intergovernmental Panel on Climate Change, the world’s forefront group of climate experts, is counting on carbon removal technology to dramatically scale up. If the industry is to make a difference, experimentation and research and development should be done quickly, within the next few years, said Gregory Nemet, professor of public affairs who studies low-carbon innovation at the University of Wisconsin-Madison. “Then after that is the time to really start going big and scaling up so that it becomes climate-relevant,” he added. “Scale-up is a big challenge.”

Will burying biomass underground curb climate change? Read More »

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In the South, sea level rise accelerates at some of the most extreme rates on Earth

climate change, coastal flooding, Florida, rising sea level, Science, syndication / /

migrating inland —

The surge is startling scientists, amplifying impacts such as hurricane storm surges.

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Older man points to the rising tide while standing on a dock.

Enlarge / Steve Salem is a 50-year boat captain who lives on a tributary of the St. Johns River. The rising tides in Jacksonville are testing his intuition.

This article originally appeared on Inside Climate News, a nonprofit, independent news organization that covers climate, energy, and the environment. It is republished with permission. Sign up for their newsletter here. 

JACKSONVILLE, Fla.—For most of his life, Steve Salem has led an existence closely linked with the rise and fall of the tides.

Salem is a 50-year boat captain who designed and built his 65-foot vessel by hand.

“Me and Noah, we’re related somewhere,” said Salem, 75, whose silver beard evokes Ernest Hemingway.

Salem is familiar with how the sun and moon influence the tides and feels an innate sense for their ebb and flow, although the tides here are beginning to test even his intuition.

He and his wife live in a rust-colored ranch-style house along a tributary of the St. Johns River, Florida’s longest. Before they moved in the house had flooded, in 2017, as Hurricane Irma swirled by. The house flooded again in 2022, when Hurricane Nicole defied his expectations. But Salem believes the house is sturdy and that he can manage the tides, as he always has.

“I’m a water dog to begin with. I’ve always been on the water,” said Salem, who prefers to go by Captain Steve. “I worry about things that I have to do something about. If I can’t do anything about it, then worrying about it is going to do what?”

Across the American South, tides are rising at accelerating rates that are among the most extreme on Earth, constituting a surge that has startled scientists such as Jeff Chanton, professor in the Department of Earth, Ocean and Atmospheric Science at Florida State University.

“It’s pretty shocking,” he said. “You would think it would increase gradually, it would be a gradual thing. But this is like a major shift.”

Worldwide sea levels have climbed since 1900 by some 1.5 millimeters a year, a pace that is unprecedented in at least 3,000 years and generally attributable to melting ice sheets and glaciers and also the expansion of the oceans as their temperatures warm. Since the middle of the 20th century the rate has gained speed, exceeding 3 millimeters a year since 1992.

In the South the pace has quickened further, jumping from about 1.7 millimeters a year at the turn of the 20th century to at least 8.4 millimeters by 2021, according to a 2023 study published in Nature Communications based on tidal gauge records from throughout the region. In Pensacola, a beachy community on the western side of the Florida Panhandle, the rate soared to roughly 11 millimeters a year by the end of 2021.

“I think people just really have no idea what is coming, because we have no way of visualizing that through our own personal experiences, or that of the last 250 years,” said Randall Parkinson, a coastal geologist at Florida International University. “It’s not something where you go, ‘I know what that might look like because I’ve seen that.’ Because we haven’t.

“It’s the same everywhere, from North Carolina all the way down to the Florida Keys and all the way up into Alabama,” he said. “All of these areas are extremely vulnerable.”

The acceleration is poised to amplify impacts such as hurricane storm surges, nuisance flooding and land loss. In recent years the rising tides have coincided with record-breaking hurricane seasons, pushing storm surges higher and farther inland. In 2022 Hurricane Ian, which came ashore in southwest Florida, was the costliest hurricane in state history and third-costliest to date in the United States, after Katrina in 2005 and Harvey in 2017.

“It doesn’t even take a major storm event anymore. You just get these compounding effects,” said Rachel Cleetus, a policy director at the Union for Concerned Scientists, an advocacy group. “All of a sudden you have a much more impactful flooding event, and a lot of the infrastructure, frankly, like the stormwater infrastructure, it’s just not built for this.”

In the South, sea level rise accelerates at some of the most extreme rates on Earth Read More »

to-help-with-climate-change,-carbon-capture-will-have-to-evolve

To help with climate change, carbon capture will have to evolve

carbon capture, climate change, Science, syndication / /

gotta catch more —

The technologies are useful tools but have yet to move us away from fossil fuels.

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Image of a facility filled with green-colored tubes.

Enlarge / Bioreactors that host algae would be one option for carbon sequestration—as long as the carbon is stored somehow.

More than 200 kilometers off Norway’s coast in the North Sea sits the world’s first offshore carbon capture and storage project. Built in 1996, the Sleipner project strips carbon dioxide from natural gas—largely made up of methane—to make it marketable. But instead of releasing the CO2 into the atmosphere, the greenhouse gas is buried.

The effort stores around 1 million metric tons of CO2 per year—and is praised by many as a pioneering success in global attempts to cut greenhouse gas emissions.

Last year, total global CO2 emissions hit an all-time high of around 35.8 billion tons, or gigatons. At these levels, scientists estimate, we have roughly six years left before we emit so much CO2 that global warming will consistently exceed 1.5° Celsius above average preindustrial temperatures, an internationally agreed-upon limit. (Notably, the global average temperature for the past 12 months has exceeded this threshold.)

Phasing out fossil fuels is key to cutting emissions and fighting climate change. But a suite of technologies collectively known as carbon capture, utilization and storage, or CCUS, are among the tools available to help meet global targets to cut CO2 emissions in half by 2030 and to reach net-zero emissions by 2050. These technologies capture, use or store away CO2 emitted by power generation or industrial processes, or suck it directly out of the air. The Intergovernmental Panel on Climate Change (IPCC), the United Nations body charged with assessing climate change science, includes carbon capture and storage among the actions needed to slash emissions and meet temperature targets.

Carbon capture, utilization and storage technologies often capture CO2 from coal or natural gas power generation or industrial processes, such as steel manufacturing. The CO2 is compressed into a liquid under high pressure and transported through pipelines to sites where it may be stored, in porous sedimentary rock formations containing saltwater, for example, or used for other purposes. The captured CO2 can be injected into the ground to extract oil dregs or used to produce cement and other products.

Enlarge / Carbon capture, utilization and storage technologies often capture CO2 from coal or natural gas power generation or industrial processes, such as steel manufacturing. The CO2 is compressed into a liquid under high pressure and transported through pipelines to sites where it may be stored, in porous sedimentary rock formations containing saltwater, for example, or used for other purposes. The captured CO2 can be injected into the ground to extract oil dregs or used to produce cement and other products.

Governments and industry are betting big on such projects. Last year, for example, the British government announced 20 billion pounds (more than $25 billion) in funding for CCUS, often shortened to CCS. The United States allocated more than $5 billion between 2011 and 2023 and committed an additional $8.2 billion from 2022 to 2026. Globally, public funding for CCUS projects rose to $20 billion in 2023, according to the International Energy Agency (IEA), which works with countries around the world to forge energy policy.

Given the urgency of the situation, many people argue that CCUS is necessary to move society toward climate goals. But critics don’t see the technology, in its current form, shifting the world away from oil and gas: In a lot of cases, they point out, the captured CO2 is used to extract more fossil fuels in a process known as enhanced oil recovery. They contend that other existing solutions such as renewable energy offer deeper and quicker CO2 emissions cuts. “It’s better not to emit in the first place,” says Grant Hauber, an energy finance adviser at the Institute for Energy Economics and Financial Analysis, a nonpartisan organization in Lakewood, Ohio.

What’s more, fossil fuel companies provide funds to universities and researchers—which some say could shape what is studied and what is not, even if the work of individual scientists is legitimate. For these reasons, some critics say CCUS shouldn’t be pursued at all.

“Carbon capture and storage essentially perpetuates fossil fuel reliance. It’s a distraction and a delay tactic,” says Jennie Stephens, a climate justice researcher at Northeastern University in Boston. She adds that there is little focus on understanding the psychological, social, economic, and political barriers that prevent communities from shifting away from fossil fuels and forging solutions to those obstacles.

According to the Global CCS Institute, an industry-led think tank headquartered in Melbourne, Australia, of the 41 commercial projects operational as of July 2023, most were part of efforts that produce, extract, or burn fossil fuels, such as coal- and gas-fired power plants. That’s true of the Sleipner project, run by the energy company Equinor. It’s the case, too, with the world’s largest CCUS facility, operated by ExxonMobil in Wyoming, in the United States, which also captures CO2 as part of the production of methane.

Granted, not all CCUS efforts further fossil fuel production, and many projects now in the works have the sole goal of capturing and locking up CO2. Still, some critics doubt whether these greener approaches could ever lock away enough CO2 to meaningfully contribute to climate mitigation, and they are concerned about the costs.

Others are more circumspect. Sally Benson, an energy researcher at Stanford University, doesn’t want to see CCUS used as an excuse to carry on with fossil fuels. But she says the technology is essential for capturing some of the CO2 from fossil fuel production and usage, as well as from industrial processes, as society transitions to new energy sources. “If we can get rid of those emissions with carbon capture and sequestration, that sounds like success to me,” says Benson, who codirects an institute that receives funding from fossil fuel companies.

To help with climate change, carbon capture will have to evolve Read More »

climate-wise,-it-was-a-full-year-of-exceptional-months

Climate-wise, it was a full year of exceptional months

climate change, global warming, Science, temperature records / /

Every month is above average —

Last June was the warmest June on record. Every month since has been similar.

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A red and orange background, with a thermometer representing extreme heat in the center.

June 2023 did not seem like an exceptional month at the time. It was the warmest June in the instrumental temperature record, but monthly records haven’t exactly been unusual in a period where the top 10 warmest years on record have all occurred within the last 15 years. And monthly records have often occurred in years that are otherwise unexceptional; at the time, the warmest July on record had occurred in 2019, a year that doesn’t stand out much from the rest of the past decade.

But July 2023 set another monthly record, easily eclipsing 2019’s high temperatures. Then August set yet another monthly record. And so has every single month since, a string of records that propelled 2023 to the warmest year since we started keeping track.

Yesterday, the European Union’s Copernicus Earth-monitoring service announced that we’ve now gone a full year where every single month has been the warmest version of that month since we’ve had enough instruments in place to track global temperatures.

History monthly temperatures show just how extreme the temperatures have been over the last year.

Enlarge / History monthly temperatures show just how extreme the temperatures have been over the last year.

As you can see from this graph, most years feature a mix of temperatures, some higher than average, some lower. Exceptionally high months tend to cluster, but those clusters also tend to be shorter than a full year.

In the Copernicus data, a similar year-long streak of records happened once before (recently, in 2015/2016). NASA, which uses slightly different data and methods, doesn’t show a similar streak in that earlier period. NASA hasn’t released its results for May’s temperatures yet—they’re expected in the next few days. But it’s very likely that NASA will also show a year-long streak of records.

Beyond records, the EU is highlighting the fact that the one-year period ending in May was 1.63° C above the average temperatures of the 1850–1900 period, which are used as a baseline for preindustrial temperatures. That’s notable because many countries have ostensibly pledged to try to keep temperatures from exceeding 1.5° above preindustrial conditions by the end of the century. While it’s likely that temperatures will drop below the target again at some point within the next few years, the new records suggest that we have a very limited amount of time before temperatures persistently exceed it.

For the first time on record, temperatures have held steadily in excess of 1.5º above the preindustrial average.

Enlarge / For the first time on record, temperatures have held steadily in excess of 1.5º above the preindustrial average.

Realistically, those plans involve overshooting the 1.5° C target by midcentury but using carbon capture technology to draw down greenhouse gas levels. Exceeding that target earlier will mean that we have more carbon dioxide to pull out of the atmosphere, using technology that hasn’t been demonstrated anywhere close to the scale that we’ll need. Plus, it’s unclear who will pay for the carbon removal.

The extremity of some of the monthly records—some months have come in a half-degree C above any earlier month—are also causing scientists to look for reasons. But so far, the field hasn’t come to a consensus regarding the sudden surge in temperature extremes.

Because it has been accompanied by significant warming of ocean temperatures, a lot of attention has focused on changes to pollution rules for international shipping, which are meant to reduce sulfur emissions. These went into effect recently and have cut down on the emission of aerosols by cargo vessels, reducing the amount of sunlight that’s reflected back to space.

That’s considered likely to be a partial contributor. A slight contribution may have also come from the Hunga Tonga eruption, which blasted significant amounts of water vapor into the upper atmosphere, though nowhere near enough to explain this warming. Beyond that, there are no obvious explanations for the recent warmth.

Climate-wise, it was a full year of exceptional months Read More »

is-a-colonial-era-drop-in-co₂-tied-to-regrowing-forests?

Is a colonial-era drop in CO₂ tied to regrowing forests?

carbon dioxide, climate change, colonization, Earth science, Ice cores, reforestation, Science / /

More trees, less carbon —

Carbon dioxide dropped after colonial contact wiped out Native Americans.

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Image of a transparent disk against a blue background. The disk has lots of air bubbles embedded in it.

Enlarge / A slice through an ice core showing bubbles of trapped air.

British Antarctic Survey

Did the massive scale of death in the Americas following colonial contact in the 1500s affect atmospheric CO2 levels? That’s a question scientists have debated over the last 30 years, ever since they noticed a sharp drop in CO2 around the year 1610 in air preserved in Antarctic ice.

That drop in atmospheric CO2 levels is the only significant decline in recent millennia, and scientists suggested that it was caused by reforestation in the Americas, which resulted from their depopulation via pandemics unleashed by early European contact. It is so distinct that it was proposed as a candidate for the marker of the beginning of a new geological epoch—the “Anthropocene.”

But the record from that ice core, taken at Law Dome in East Antarctica, shows that CO2 starts declining a bit late to match European contact, and it plummets over just 90 years, which is too drastic for feasible rates of vegetation regrowth. A different ice core, drilled in the West Antarctic, showed a more gradual decline starting earlier, but lacked the fine detail of the Law Dome ice.

Which one was right? Beyond the historical interest, it matters because it is a real-world, continent-scale test of reforestation’s effectiveness at removing CO2 from the atmosphere.

In a recent study, Amy King of the British Antarctic Survey and colleagues set out to test if the Law Dome data is a true reflection of atmospheric CO2 decline, using a new ice core drilled on the “Skytrain Ice Rise” in West Antarctica.

Precious tiny bubbles

In 2018, scientists and engineers from the British Antarctic Survey and the University of Cambridge drilled the ice core, a cylinder of ice 651 meters long by 10 centimeters in diameter (2,136 feet by 4 inches), from the surface down to the bedrock. The ice contains bubbles of air that got trapped as snow fell, forming tiny capsules of past atmospheres.

The project’s main aim was to investigate ice from the time about 125,000 years ago when the climate was about as warm as it is today. But King and colleagues realized that the younger portion of ice could shed light on the 1610 CO2 decline.

“Given the resolution of what we could obtain with Skytrain Ice Rise, we predicted that, if the drop was real in the atmosphere as in Law Dome, we should see the drop in Skytrain, too,” said Thomas Bauska of the British Antarctic Survey, a co-author of the new study.

The ice core was cut into 80-centimeter (31-inch) lengths, put into insulated boxes, and shipped to the UK, all the while held at -20°C (-4°F) to prevent it from melting and releasing its precious cargo of air from millennia ago. “That’s one thing that keeps us up at night, especially as gas people,” said Bauska.

In the UK they took a series of samples across 31 depth intervals spanning the period from 1454 to 1688 CE: “We went in and sliced and diced our ice core as much as we could,” said Bauska. They sent the samples, still refrigerated, off to Oregon State University where the CO2 levels were measured.

The results didn’t show a sharp drop of CO2—instead, they showed a gentler CO2 decline of about 8 ppm over 157 years between 1516 and 1670 CE, matching the other West Antarctic ice core.

“We didn’t see the drop,” said Bauska, “so we had to say, OK, is our understanding of how smooth the records are accurate?”

A tent on the Antarctic ice where the core is cut into segments for shipping.

A tent on the Antarctic ice where the core is cut into segments for shipping.

British Antarctic Survey

To test if the Skytrain ice record is too blurry to show a sharp 1610 drop, they analyzed the levels of methane in the ice. Because methane is much less soluble in water than CO2, they were able to melt continuously along the ice core to liberate the methane and get a more detailed graph of its concentration than was possible for CO2. If the atmospheric signal was blurred in Skytrain, it should have smoothed the methane record. But it didn’t.

“We didn’t see that really smoothed out methane record,” said Bauska, “which then told us the CO2 record couldn’t have been that smoothed.”

In other words, the gentler Skytrain CO2 signal is real, not an artifact.

Does this mean the sharp drop at 1610 in the Law Dome data is an artifact? It looks that way, but Bauska was cautious, saying, “the jury will still be out until we actually get either re-measurements of the Law Dome, or another ice core drilled with a similarly high accumulation.”

Is a colonial-era drop in CO₂ tied to regrowing forests? Read More »

nitrogen-using-bacteria-can-cut-farms’-greenhouse-gas-emissions 

Nitrogen-using bacteria can cut farms’ greenhouse gas emissions 

agriculture, bacteria, Biology, climate change, fertilizer, nitrogen, Science / /

Keeping crops from the greenhouse —

Nitrogen fertilizers get converted to nitrous oxide, a potent greenhouse gas.

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A tractor amidst many rows of small plants, with brown hills in the background.

Fritz Haber: good guy or bad guy? He won the Nobel Prize in Chemistry in 1918 for his part in developing the Haber-Bosch process, a method for generating ammonia using the nitrogen gas in air. The technique freed agriculture from the constraint of needing to source guano or manure for nitrogen fertilizer and is widely credited for saving millions from starvation. About half of the world’s current food supply relies on fertilizers made using it, and about half of the nitrogen atoms in our bodies can be traced back to it.

But it also allowed farmers to use this newly abundant synthetic nitrogen fertilizer with abandon. This has accentuated agriculture’s role as a significant contributor to global warming because the emissions that result from these fertilizers is a greenhouse gas—one that has a warming potential almost 300 times greater than that of carbon dioxide and remains in the atmosphere for 100 years. Microbes in soil convert nitrogen fertilizer into nitrous oxide, and the more nitrogen fertilizer they have to work with, the more nitrous oxide they make.

Agriculture also leaks plenty of the excess nitrogen into waterways in the form of nitrate, generating algal blooms that create low-oxygen ‘dead zones’ where no marine life can live.

One way to reduce nitrogen emissions from farms would be to simply use fertilizer more efficiently. But—as we’ve seen with fossil fuels (and antibiotics and plastics)—when humans have a miraculous substance on our hands, we just can’t seem to use it at levels that minimize its impact. We instead seem compelled to throw around as much of the stuff as we can. But even if we were to start using less fertilizer now, we are past time to choose a single technique to curb greenhouse gas emissions; we need to put them all into action.

Denitrifying bacteria reduces levels of nitrous oxide in soil by converting it to the molecular form of nitrogen found in air. They use it as an oxidizer for respiration under conditions with low or no oxygen. So adding these nitrogen-respiring bacteria to soil could help decrease nitrous oxide emissions.

Modifying the microbiome of soil is just as hard as modifying the microbiome in our bodies. So instead of trying to promote the growth of any denitrifying bacteria that might happen to already be in soil, researchers decided to grow them externally and then add them in. Their source was partially treated sewage, called digestate, that was destined as organic fertilizer anyway. Keeping the digestate in oxygen-free conditions enriched their levels of one strain of nitrogen-respiring bacteria.

The researchers homed in on this particular strain because it has the enzyme needed to break down nitrous oxide, but not the enzymes used to make it from other nitrogen compounds. And although it is not the fastest, most efficient strain at nitrogen respiration, it won because it is the most tenacious: It grows to high concentrations even when oxygen is present, and it works well in soil.

When this digestate was mixed into soil, fertilizer-induced emissions were reduced by 50–95 percent, depending on the pH and organic carbon content of the soils. The effect lasted over the entire growing season. The presence of the added nitrogen-respiring bacteria did not seem to affect the indigenous microbiota already present in the soil, and the added bacteria did not carry genes for antibiotic resistance or pathogenicity, which is obviously essential if they are to be used in farming. What hasn’t been tested yet, however, is whether the presence of these bacteria influence the growth of crops.

Using mathematical modeling of future emissions, the researchers concluded that adding these bacteria to soil could reduce nitrous oxide emissions by 60 percent, and if they are added to all liquid manure systems in Europe, Europe could reduce its anthropogenic nitrous oxide emissions by 3 to 4 percent.

Nature, 2024.  DOI: 10.1038/s41586-024-07464-3

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dinosaurs-needed-to-be-cold-enough-that-being-warm-blooded-mattered

Dinosaurs needed to be cold enough that being warm-blooded mattered

Biology, climate change, dinosaurs, evolution, paleontology, Science, warm blooded / /

Some like it less hot —

Two groups of dinosaurs moved to cooler climes during a period of climate change.

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Image of a feathered dinosaur against a white background.

Enlarge / Later theropods had multiple adaptations to varied temperatures.

Dinosaurs were once assumed to have been ectothermic, or cold-blooded, an idea that makes sense given that they were reptiles. While scientists had previously discovered evidence of dinosaur species that were warm-blooded, though what could have triggered this adaptation remained unknown. A team of researchers now think that dinosaurs that already had some cold tolerance evolved endothermy, or warm-bloodedness, to adapt when they migrated to regions with cooler temperatures. They also think they’ve found a possible reason for the trek.

Using the Mesozoic fossil record, evolutionary trees, climate models, and geography, plus factoring in a drastic climate change event that caused global warming, the team found that theropods (predators and bird ancestors such as velociraptor and T. rex) and ornithischians (such as triceratops and stegosaurus) must have made their way to colder regions during the Early Jurassic. Lower temperatures are thought to have selected for species that were partly adapted to endothermy.

“The early invasion of cool niches… [suggests] an early attainment of homeothermic (possibly endothermic) physiology in [certain species], enabling them to colonize and persist in even extreme latitudes since the Early Jurassic,” the researchers said in a study recently published in Current Biology.

Hot real estate

During the Mesozoic Era, which lasted from 230 to 66 million years ago, proto-dinosaurs known as dinosauromorphs began to diversify in hot and dry climates. Early sauropods, ornithischians, and theropods all tended to stay in these regions.

Sauropods (such as brontosaurus and diplodocus) would become the only dinosaur groups to bask in the heat—the fossil record shows that sauropods tended to stay in warmer areas, even if there was less food. This suggests the need for sunlight and heat associated with ectothermy. They might have been capable of surviving in colder temperatures but not adapted enough to make it for long, according to one hypothesis.

It’s also possible that living in cooler areas meant too much competition with other types of dinosaurs, as the theropods and ornithiscians did end up moving into these cooler areas.

Almost apocalypse

Beyond the ecological opportunities that may have drawn dinosaurs to the cooler territories, it’s possible they were driven away from the warm ones. Around 183 million years ago, there was a perturbation in the carbon cycle, along with extreme volcanism that belched out massive amounts of methane, sulfur dioxide, and mercury. Life on Earth suffered through scorching heat, acid rain, and wildfires. Known as the Early Jurassic Jenkyns Event, the researchers now think that these disruptions pushed theropod and ornithischian dinosaurs to cooler climates because temperatures in warmer zones went above the optimal temperatures for their survival.

The theropods and ornithischians that escaped the effects of the Jenkyns event may have had a key adaptation to cooler climes; many dinosaurs from these groups are now thought to have been feathered. Feathers can be used to both trap and release heat, which would have allowed feathered dinosaurs to regulate their body temperature in more diverse climates. Modern birds use their feathers the same way.

Dinosaur species with feathers or special structures that improved heat management could have been homeothermic, which means they would have been able to maintain their body temperature with metabolic activity or even endothermic.

Beyond the dinosaurs that migrated to high latitudes and adapted to a drop in temperature, endothermy might have led to the rise of new species and lineages of dinosaurs. It could have contributed to the rise of Avialae, the clade that includes birds—the only actual dinosaurs still around—and traces all the way back to their earliest ancestors.

“[Our findings] provide novel insights into the origin of avian endothermy, suggesting that this evolutionary trajectory within theropods… likely started in the latest Early Jurassic,” the researchers said in the same study.

That really is something to think about next time a sparrow flies by.

Current Biology, 2024.  DOI: 10.1016/j.cub.2024.04.051

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