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Capturing hot carbon dioxide

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Decarbonizing industries like steel and cement is a difficult challenge.  Both involve emitting large amounts of carbon dioxide both from burning fossil fuels and from intrinsic chemical reactions taking place.  A potential solution is to capture the carbon dioxide emissions and either use them or store them away.  But this sort of carbon capture is not easy and can be quite expensive.

The most common method for capturing carbon dioxide emissions from industrial plants uses chemicals called liquid amines which absorb the gas.  But the chemical reaction by which this occurs only works well at temperatures between 100 and 140 degrees Fahrenheit.  Cement manufacturing and steelmaking plants produce exhaust that exceeds 400 degrees and other industrial processes produce exhaust as hot as 930 degrees.

Costly infrastructure is necessary to cool down these exhaust streams so that amine-based carbon capture technology can work. 

Chemists at the University of California, Berkeley, have developed a porous material – a type of metal-organic framework – that can act like a sponge to capture CO2 at temperatures close to those of many industrial exhaust streams.  The molecular metal hydride structures have demonstrated rapid, reversible, high-capacity capture of carbon dioxide that can be accomplished at high temperatures.

Removing carbon dioxide from industrial and power plant emissions is a key strategy for reducing greenhouse gases that are warming the Earth and altering the global climate.  The captured CO2 can be used to produce value-added chemicals or can be stored underground or chemically-reacted into stable substances.

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Breakthrough in capturing ‘hot’ CO2 from industrial exhaust

Photo, posted March 3, 2010, courtesy of Eli Duke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Limiting global warming

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A pressing question from the recently concluded 29th annual United Nations Climate Change Conference in Azerbaijan is how to transition away from fossil fuels and speed up climate mitigation in line with the 1.5 °C global warming target.

Keeping global average temperatures below 1.5 °C above pre-industrial levels is crucial to avoid the most severe impacts of climate change, including extreme weather, rising seas, biodiversity loss, and disruptions to food and water security. 

According to a new study by researchers from Stockholm University, Chalmers University of Technology, and Uppsala University in Sweden, it is still possible to limit global warming to 1.5 °C.  But the study found that the United States, the European Union, and 16 other countries will have to exceed their own current targets in order to achieve this global goal.  

The study, which was recently published in the journal Nature Communications, introduced an “additional carbon accountability” indicator, which quantifies countries’ responsibility for mitigation and carbon dioxide removal in addition to achieving their own targets.

The study identified 18 countries that should be accountable for increasing their ambitions to stay within their equal per capita share of the global carbon budget for 1.5 °C.  Additional carbon accountability is highest for the United States and China, and highest per capita for the United Arab Emirates, Russia, Saudi Arabia, and the U.S.

Failure to limit global warming risks catastrophic impacts of climate change.

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COP29: Possible to limit climate change to 1.5°C – if EU and 17 other countries go beyond their own targets

Photo, posted December 27, 2015, courtesy of Gerry Machen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric vehicles and health

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Much of the discussion about the benefits of electric vehicles centers about the climate impact of not burning fossil fuels as well as about reduced operating costs.  A new study by the University of Toronto looked at the health benefits of large-scale adoption of electric vehicles.

The Toronto researchers used computer simulations to show that widespread electrification of the U.S. vehicle fleet when coupled with significant use of renewable energy to power the fleet could result in health benefits worth between $84 and $188 billion dollars by 2050.  Expressing these benefits in dollar terms is a way to quantify those benefits, but clearly what is most important is people’s health.

Carbon dioxide coming out of tailpipes is what is most harmful to the climate, but there is much more than CO2 vehicle exhaust.  There are many air pollutants that have a significant, quantifiable impact on human health.  These include nitrogen oxides, sulfur oxides, and small particles known as PM2.5. 

The study simulated levels of air pollution across the United States under various scenarios of adoption of EVs and the use of renewable energy.  The simulations clearly showed that the combination of widespread use of electric vehicles and the greening of the power grid would result in huge cumulative public health benefits.  But these benefits will take time to accrue.  The internal combustion vehicles being sold today will still be on the roads for many years and will continue to spread pollution everywhere there are roads.

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New research reveals how large-scale adoption of electric vehicles can improve air quality and human health

Photo, posted May 7, 2020, courtesy of Mark Vletter via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing emissions from cement

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Cement production accounts for about 7% of global carbon emissions.  It is one of the most difficult challenges for emissions reduction.  The emissions associated with producing cement come from both the energy used to provide heat for the process and from the chemical reactions that take place in the formation of cement.  Cement is an essential building block of society, and its use is not expected to decline over time.

A German company called Heidelberg Materials is embarking on an ambitious project to reduce carbon emissions from a cement plant in Norway.  They are building a facility to use absorbent chemicals to capture large quantities of carbon dioxide emitted through cement production.  More than half a ton of carbon dioxide arises from every ton of cement produced at the plant.

Once the carbon dioxide is captured it will be chilled to a liquid, loaded onto ships, and carried to a terminal farther up the Norwegian coast.  From there, it will be pumped into undersea rocks located 70 miles offshore and a mile and a half below the bottom of the North Sea.

With all of this complicated process going on, cement from the plant is likely to be quite expensive.  It might even be two or three times the price of ordinary cement.  Heidelberg Materials is counting on customers’ willingness to pay much more for cement that comes with green credentials. 

Can this be economically viable?  Heidelberg estimates that cement accounts for only about 2% of the cost of a large building project but as much as 50% of the emissions.  As a result, using carbon-free cement could be a relatively inexpensive way for builders to reduce emissions.

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Cement Is a Big Polluter. A Plant in Norway Hopes to Clean It Up.

Photo, posted May 7, 2016, courtesy of Phillip Pessar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ocean geoengineering

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As greenhouse gas emissions continue to be dangerously large and the perils of climate change are increasingly apparent, the world is increasingly exploring ways to deliberately intervene in climate systems.  A number of these ideas involve introducing substances into the atmosphere, but there are also ways to tinker with the oceans.

The oceans naturally absorb about a third of the carbon dioxide that humans pump into the atmosphere, mostly by burning coal, gas, and oil.  People are exploring ways to get the ocean to take up even more of the carbon dioxide.  One approach that is gaining traction is known as alkalinity enhancement.  By adding limestone, magnesium oxide, or other alkaline substances to rivers and oceans, it changes their chemistry and makes them soak up more carbon dioxide.

This approach has been around for a while as a way to mitigate acid rain in rivers and has been very successful.  A start-up company in Canada called CarbonRun is building a machine that grinds up limestone and will release the powder it produces into a local river in Nova Scotia.  The limestone in the river will be naturally converted into a stable molecule that will eventually be washed into the seas, where it should remain for thousands of years.

Expanding this approach to oceans faces many challenges including the costs and complexities of obtaining, processing, and transporting vast amounts of limestone to where it is to be released.  There are also potential environmental issues to grapple with.  But CarbonRun and others are moving forward with testing the approach.

In any event, the biggest barrier to ocean alkalinity enhancement is proving that it works.  That effort is underway.

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They’ve Got a Plan to Fight Global Warming. It Could Alter the Oceans.

Photo, posted May 27, 2007, courtesy of John Loo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The impact of climate change on agriculture

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Agriculture is a major part of the climate problem and remains one of the hardest human activities to decarbonize.  Agriculture is responsible for approximately 30% of global greenhouse gas emissions.

On farms around the world, excess fertilizer gets broken down by microbes in the soil, releasing nitrous oxide into the atmosphere.  Nitrous oxide is a greenhouse gas that is 300 times more potent than carbon dioxide.

According to a sweeping global research review recently published in the journal Science, greenhouse gas emissions from agriculture are now 18 times higher than they were in the 1960s. 

The research, which was co-written by professors at the University of Minnesota with more than 20 experts around the world, also reveals the likelihood of an emergent feedback loop between climate and agriculture.  As the changing climate puts more pressure on the global food supply, agriculture will, out of necessity, adopt practices that may exacerbate its environmental impact. Without changes in agriculture, this feedback loop could make it impossible to achieve the Paris Climate Agreement goal of limiting global warming to 1.5 degrees Celsius above pre-industrial levels. 

The research identifies several agricultural practices that could improve efficiency and stabilize our food supply in the decades to come, including precision farming, perennial crop integration, agrivoltaics, nitrogen fixation, and novel genome editing. 

Finding ways to reduce the warming impact of agriculture while maintaining high crop yields are essential to both mitigating climate change and protecting our food supply from its impacts.

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Impact of Climate Change on Agriculture Suggests Even Greater Challenges to the Environment, Global Food Supply and Public Health

Photo, posted October 16, 2010, courtesy of Timlewisnm via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Canadian wildfires and global emissions

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The wildfires that burned vast amounts of Canada’s boreal forests in 2023 produced enormous amounts of smoke that found its way into American cities, working its way down the eastern seaboard and even producing unsafe air in Florida.

Researchers at Cal Tech and the Jet Propulsion Laboratory analyzed the carbon emissions associated with these fires last year and found that they were greater than those of all but three countries:  China, the US, and India.

Boreal forests have historically been a natural defense against climate change by storing carbon in trees rather than adding carbon dioxide to the atmosphere.  The fires in Canada, fueled by hot and dry weather, were extraordinary when compared with historical records.  But such fires are likely to be increasingly common as the climate continues to warm.

However, the hot and dry weather that fueled the 2023 fires was exceptional in many ways, involving early snow melt and so-called flash droughts.  This year’s fires in Canada are still bigger than average, but so far have not been as destructive as last year’s. 

Canada has been warming at about twice the global rate.  The extreme temperatures last summer were a major factor in the fueling of the fires, which burned an area almost the size of Florida.

Forests absorb about a quarter of global carbon emissions, but the increasing frequency and intensity of fires are calling into question their ability to continue to do so.  Parts of the Canadian forests are not regrowing after fires as they have in the past, partly because blazes burn trees so frequently and intensely.

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Canada’s Wildfires Were a Top Global Emitter Last Year, Study Says

Photo, posted June 8, 2023, courtesy of the Metropolitan Transportation Authority via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An electric reactor for industry

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The industrial sector accounts for nearly a third of greenhouse gas emissions in the US, which is more than the annual emissions from cars, trucks, and airplanes combined.  These emissions primarily come from burning fossil fuels to produce goods from raw materials as well as from the chemical reactions associated with production.  Many industrial processes require very high temperatures that are not easily achieved other than by burning fossil fuels.

Researchers at Stanford University have developed and demonstrated a new kind of thermochemical reactor that can generate the huge amounts of heat required for many industrial processes that runs on electricity rather than the burning of fossil fuels.  The researchers claim that the design is also smaller, cheaper, and more efficient than the fossil fuel technology it would replace.

Standard industrial thermochemical reactors burn fossil fuel to heat a fluid that is piped into the reactor, much like the way home radiators work, albeit at far higher temperatures.  The new reactor uses magnetic induction, similar to the way that induction cooktops work.  Heat is transferred by inducing a current into materials that heat up as the current flows.

A proof-of-concept demonstration powered a chemical reaction called the reverse water gas shift reaction and resulted in more than 85% efficiency.  The reaction in question converts carbon dioxide into a valuable gas that can be used to create sustainable fuels. 

The Stanford researchers are working to scale up their new reactor technology and expand its potential applications.  They are working on designs for reactors for capturing carbon dioxide and for manufacturing cement. 

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Electric reactor could cut industrial emissions

Photo, posted October 30, 2022, courtesy of Helmut via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Less coal for making steel

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Steel is primarily produced using one of two methods:  blast furnaces or electric arc furnaces.  The first blast furnaces were built in the 14th century.  Making steel in a blast furnace starts by melting the raw materials of iron ore, limestone, and coal at very high temperatures.  The resultant reactions ultimately lead to two products:  iron saturated with carbon and carbon dioxide.  A second furnace reacts the liquid iron with oxygen to remove the carbon and results in steel along with even more carbon dioxide.

Making steel using an electric arc furnace is considerably less emissions-intensive and more sustainable.  So-called circular steel making powered by electric arc furnaces uses electricity to melt scrap and other input materials and turn them into high-quality steel.  Of course, to really minimize the emissions associated with steelmaking, the arc furnaces need to get their power from renewable energy sources. 

The global steel industry is turning away from polluting coal-fired blast furnaces and towards electric arc furnaces, which now account for roughly half of all planned new steelmaking capacity. This represents real progress towards a green steel transition.

By the end of this decade, electric arc furnaces will account for more than a third of steelmaking.  However, there are still plenty of new coal-based steel furnaces being built.  So even as electric arc furnaces account for a greater share of steelmaking, these new coal furnaces will still drive emissions upward.   Environmental advocates argue that what the steel industry needs is to make clean development a true priority and back away from coal-based developments.

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Steelmakers Increasingly Forgoing Coal, Building Electric

Photo, posted July 16, 2018, courtesy of Daniel Steelman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Emissions and the Great Salt Lake

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The Great Salt Lake in Utah has been described as a puddle of its former self.  The lake’s size fluctuates naturally with seasonal and long-term weather patterns, but the lake has been experiencing decline for decades as Utahans take water out of the rivers and streams that once fed the lake.  Over recent decades, the lake has lost 73% of its water and 60% of its surface area.

For years, scientists and environmental leaders have warned that the Great Salt Lake is headed toward a catastrophic decline.  Recent research has found that the lake’s desiccating shores are becoming a significant source of greenhouse gas emissions.  Scientists have calculated that the dried-out portions of the lakebed released about 4.1 million tons of carbon dioxide and other greenhouse gases in 2020.

The recent study, published in the journal One Earth, suggests that the Great Salt Lake – which is largest saltwater lake in the Western Hemisphere – as well as other shrinking saline lakes around the world could become major contributors of climate-warming emissions.

The shrinking back of the water has exposed a dusty lakebed that is laced with arsenic, mercury, lead, and other toxic substances.  Some are naturally occurring, and others are the residue of mining activity in the region.  These substances threaten to increase rates of respiratory conditions, heart and lung disease, and cancers.

As the lake shrinks, it is becoming saltier and uninhabitable to native flies and brine shrimp and may increasingly become unable to support the 10 million migratory birds and wildlife that frequent it.

The new research about greenhouse gas emissions just adds to a dire list of environmental consequences brought on by the lake’s steep decline.

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Shrinking Great Salt Lake Becoming Source of Heat-Trapping Gas

Photo, posted January 20, 2020, courtesy of Matthew Dillon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Nearly everyone wants climate action

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A global survey of 75,000 people revealed that 80% of participants want their governments’ climate action commitments to be stronger.  The poll, conducted by the United Nations Development Program, GeoPoll, and Oxford University, asked 15 questions in telephone calls to residents of 77 countries representing 87% of the global population.

According to the survey, 89% of poorer countries favored increasing efforts to curb global emission, while 76% of wealthy G20 nations supported tougher climate action.

The two biggest greenhouse emitters in the world were less enthusiastic:  Chinese participants were 73% in favor of stronger action and Americans were 66% in favor of greater efforts to combat global warming. 

Other demographic differences included that in the big emitting countries of Canada, France, Germany, Australia, and the U.S., women were 10 to 17% more in support of stronger climate action than men.

Overall, only 7% of those polled globally thought their government should not transition away from fossil fuels at all.  More than half of those polled said that they were more worried about climate change this year than last year.  A worldwide majority of 72% support a fast fossil fuel phaseout, including those in nations that are among the top ten coal, oil, and gas producers.

As is the case across the board with respect to climate issues, the more influential factor continues to be economic as opposed to scientific or humanitarian.  Those who stand to lose the most money from the transition away from fossil fuels continue to hold sway over those who will lose in many other ways.

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Four Out of Five People Want Increased Climate Action, UN Poll Says

Photo, posted July 31, 2020, courtesy of School Strike 4 Climate via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Barley plastic

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The durability, malleability, and low cost of plastics have made them ubiquitous.  Plastics are everywhere:  in packaging, clothing, and an endless variety of products.  As a result, they are everywhere in the environment and they tend to stay there, contaminating land and sea.  They are tough to recycle, and their production emits more carbon dioxide than all air traffic combined.  The search for viable substitutes for plastic is global and intensive.

Most common bioplastics are not an ideal solution.  They don’t break down that easily when tossed into the natural environment.  The process can take years. 

Researchers at the University of Copenhagen have invented a new material made from modified starch that can completely decompose in nature and can do so in only two months.  The material is made using natural plant material from crops and could be used for food packaging as well as many other things.

The new material is a biocomposite composed of several substances that decompose naturally.  The main ingredients are amylose and cellulose, common in many plants.  Amylose is extracted from crops like corn, potatoes, wheat, and barley.

The Danish researchers have developed a barley variety that produces pure amylose in its kernels.  Pure amylose is ideal because it is less likely to turn into a paste when it interacts with water. 

Combining the amylose with cellulose forms long, strong molecular chains, resulting in a durable, flexible material that can replace plastic in many applications.  The research team has founded a spinoff company and have applied for a patent for the new material.  It is unclear when the biofriendly barley-based plastic might be commercialized, but its potential is quite good.

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Researchers invent one hundred percent biodegradable “barley plastic”

Photo, posted May 20, 2010, courtesy of Frederick Lang Jr. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Thawing permafrost:  Is it a ticking timebomb?

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Permafrost covers about a quarter of the landmass in the Northern Hemisphere.  It stores vast quantities of organic carbon in the form of dead plant matter.  As long as it stays frozen, it is no threat to the climate.  But as it thaws, microorganisms start breaking down that plant matter and large amounts of carbon are released into the atmosphere in the form of carbon dioxide and methane.

This process has often been described as a ticking timebomb for the climate.  The theory is that once global warming reaches a certain level, the process will become self-amplifying setting off a catastrophic amount of warming.  If that level was reached, it would be a tipping point in the changing climate.

An international research team from the Alfred Wegener Institute in Germany has extensively researched this hypothesis.  Their conclusion is that within the permafrost, there are multiple geological, hydrological, and physical processes that are self-amplifying and, in some cases, irreversible.  However, these processes act only locally or regionally.  There is no evidence that some particular threshold in global warming could affect all permafrost and accelerate its thawing on a global level.

This research does not mean that Arctic permafrost is nothing to worry about.  In fact, there are ways in which it is more worrisome.  Because the permafrost is very heterogenous – meaning it is very different in different places – there will be numerous small, local tipping points that will be exceeded at different times and at different levels of warming.  All of this will proceed in step with global warming, contributing to the overall worsening situation.  There is no warming level below which permafrost thawing is not a problem.

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Thawing permafrost: Not a climate tipping element, but nevertheless far-reaching impacts

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record carbon dioxide levels

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Despite the increasing concern about the warming climate, the period between March of last year and March of this year has set a new record for the largest 12-month gain in atmospheric CO2 concentration ever observed.  The new level, measured at Hawaii’s Mauna Loa Observatory was nearly 5 parts per million higher than last year’s level reaching more than 426 parts per million.

CO2 levels averaged 280 ppm for the past 800,000 years until the Industrial Revolution began and people started burning fossil fuels.  Levels started being measured at Mauna Loa in 1958, when they were 315 ppm.  Between 1958 and 2005, the CO2 level rose to 380 ppm.  Over the past 19 years, the amount of CO2 has continued to rise rapidly and with it, global temperatures.

The record increase in carbon dioxide over this past year is probably associated with the end of an El Niño event.  The previous record increase in 2015-2016 was also associated with El Niño.

But the overall trend is clear and discouraging.  Over the past 66 years, the amount of carbon dioxide in the atmosphere has increased by 35%.  This increase is a result of the burning of coal, oil, and natural gas, as well as the effects of deforestation and livestock agriculture.

Carbon dioxide absorbs heat radiating from the Earth’s surface and re-releases it in all directions, including back toward Earth’s surface.  Without this greenhouse effect, the Earth would actually be frozen.  But people are supercharging the natural greenhouse effect and causing the global temperature to rise.  Global energy demand continues to grow and if we continue to meet that demand mostly with fossil fuels, temperatures will continue to rise.

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Scripps Institution of Oceanography: CO2 levels have largest 12-month gain

Photo, posted March 3, 2014, courtesy of Jon Roig via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Recycling cement

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Concrete is the second-most-used material on the planet.  Only water is used more.  Producing concrete is responsible for 7.5% of human-produced carbon dioxide emissions.  So, finding a cost-effective way to reduce these emissions is a major challenge in the face of ever-growing global demand for concrete.

Researchers at Cambridge University have found that used cement is an effective substitute for lime flux, which is an essential material used in steel recycling that results in a waste product called slag.  When lime is replaced with used cement, the end product instead is recycled cement that can be used to make new concrete.

The process does not add any significant costs to concrete or steel production and significantly reduces the emissions associated with both.

Concrete is made from sand, gravel, water, and cement.  Cement is made by a process called clinkering, in which limestone and other materials are heated to 2,600 degrees Fahrenheit.  The process converts the materials into cement but releases large amounts of CO2 as limestone decarbonates into lime. 

Cambridge researchers found that using cement clinker and iron oxide instead of lime works well in steel recycling.  Crushing old concrete and taking out the sand and stone results in a cement that is reactivated by the recycling furnace to produce a material with excellent properties. 

Recent tests by the Materials Processing Institute showed that recycled cement can be produced at scale in an electric arc furnace.  Ultimately, this method could produce zero emission cement if the electricity for the furnace comes from renewable sources.

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Cement recycling method could help solve one of the world’s biggest climate challenges

Photo, posted July 18, 2011, courtesy of Kenta Mabuchi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The largest carbon removal plant

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Direct air capture (DAC) is process that removes carbon dioxide out of the air and stores it away where it can no longer trap heat in the atmosphere.  It is intended to be a way of getting rid of the greenhouse gases that have built up in the atmosphere.  In principle, it’s a great idea.  In practice, it is a huge challenge.

In 2017, a company called Climeworks became the first company to take carbon dioxide out of the air and sell it as a product for use in carbonated drinks and in greenhouses.  In 2021, the company opened a DAC plant called Orca in Iceland that captures CO2 and permanently stores it underground.  Clients like Microsoft pay Climeworks for doing this as a way of offsetting their own emissions.

Recently, Climeworks has started operating a new plant called Mammoth – also in Iceland – that will be able to capture about 10 times more carbon dioxide than Orca.  Iceland is a prime location for DAC technology because its abundant geothermal energy makes powering it cheap and environmentally friendly.

Mammoth, when fully operational, will remove about 36,000 tons of carbon dioxide a year, the largest DAC system in the world.  But there is a long, long way to go.  Microsoft alone emits nearly 13 million tons of carbon dioxide a year.

There are multiple DAC projects in development including several in the United States being funded by the Bipartisan Infrastructure Law.  The four DAC hubs being developed under the program are each supposed to have the capacity to capture at least a million metric tons of CO2 a year.

Whether DAC can make a real difference remains to be seen.

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The world’s largest carbon removal plant is here, and bigger ones are on the way

Photo credit: Climeworks

Earth Wise is a production of WAMC Northeast Public Radio

Marine carbon dioxide removal

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About 30% of the carbon dioxide emitted by human activity is absorbed by the oceans.  As a result, they are getting warmer and more acidic, and the currents that help shape global weather are shifting.  To try to reduce global warming, people want to be able to store even more carbon dioxide in the oceans without the negative effects of doing so.

There are multiple efforts across the globe to achieve effective marine carbon dioxide removal.  Some are based on sinking carbon-rich materials to the bottom of the sea.  This is the marine equivalent of capturing CO2 from the air and storing it underground.  Other efforts involve increasing the alkalinity of the ocean, which increases its ability to chemically react with carbon dioxide as well as lowers its acidity, which is desirable in many ways.

Running Tide, a U.S.-based company, has been dumping thousands of tons of wood-industry waste 190 miles off the coast of Iceland.  The company has also been experimenting with dumping algae and kelp and sinking it deep below the ocean.  Such materials on land either get burned or decay, in both cases releasing CO2 into the atmosphere.  On the deep-sea bottom, the carbon is trapped.

Other efforts involve pumping seawater through electrodialysis filter systems to remove excess acidity or adding alkaline rocks to increase water alkalinity.

All of these efforts are a form of geoengineering, and like proposed ideas to cool the atmosphere, pose potential risks.  There is no silver bullet to solve the climate crisis.  It will take a combination of many solutions to address the issue of excess carbon dioxide in the atmosphere.  Marine carbon dioxide removal is one of the solutions that may play a role.

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Scientists Are Trying to Coax the Ocean to Absorb More CO2

Photo, posted February 22, 2018, courtesy of Bobbie Halchishak/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon dioxide and wildfires

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Climate change is a key factor in the increasing risk and extent of wildfires.  Wildfires require the alignment of several factors, including humidity, temperature, and the lack of moisture in fuels, such as trees, shrubs, and grasses.  All of these factors have strong ties to climate variability and climate change.

While the global surge in wildfires is often attributed to hotter and drier conditions, a new study by researchers from the University of California – Riverside has found that increasing levels of a greenhouse gas may be an even bigger factor. 

According to the study, which was recently published in the journal Communications Earth & Environment, carbon dioxide is driving an increase in the severity and frequency of wildfires by fueling the growth of plants that become kindling.

Centuries of burning fossil fuels to produce heat, electricity and to power engines has added alarming amounts of carbon dioxide to the atmosphere.  In fact, atmospheric CO2 levels are measuring more than 420 parts per million, which is a level not seen on earth for 14-16 million years. 

Plants require carbon dioxide, along with sunlight and water, for photosynthesis.  But rising levels of CO2 in the atmosphere are driving an increase in plant photosynthesis – an effect known as the carbon fertilization effect.  This effect can make plants grow bigger and faster. 

Warming and drying are important fire factors.  These are the conditions that make the extra plant mass more flammable.  But the study found that the increase in fires during hotter seasons is driven by the CO2-fueled growth of plants.   

The researchers hope their findings will urge policymakers to focus on reducing carbon dioxide levels in the atmosphere.

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CO2 worsens wildfires by helping plants grow

Current carbon dioxide levels last seen 14 million years ago

Photo, posted January 17, 2024, courtesy of Jennifer Myslivy, BLM Fire/NIFC via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Where not to plant trees

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Planting huge numbers of trees is often proposed as a way to reduce the severity of climate change.  Studies have looked at the potential for Earth‘s ecosystems to support large additional areas of forest and have found that it would be possible to have at least 25% more forested area than we do now.  This in turn could capture large amounts of carbon and substantially reduce the amount in the atmosphere.

A recent study by researchers at Clark University in Massachusetts and The Nature Conservancy mapped the climate impact of tree planting across the globe, identifying where it would be most and also least beneficial.  The study, published in Nature Communications, found that trees planted in arid, desert regions or in snowy places like the Arctic would, on balance, worsen warming rather than reduce it.

Trees take up carbon dioxide from the atmosphere, which helps to keep warming in check.  But trees with dark, green leaves also absorb heat from sunlight.   Snow and desert sand, on the other hand, are light-colored and reflect more sunlight back into space.  For this reason, trees planted in snowy areas or in the desert will absorb more sunlight than their surroundings.  This can negate the climate benefits of soaking up carbon dioxide.

Previous studies only looked at how much carbon dioxide would be removed by planting trees in order to determine how much warming would be prevented.  The new study finds that it matters where the trees are planted.

Fortunately, the new study also shows that tree planting projects that are currently underway or that are in the pipeline are largely concentrated in regions where they will indeed help slow global warming.

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This Map Shows Where Planting Trees Would Make Climate Change Worse

Photo, posted April 5, 2022, courtesy of UC Davis Arboretum and Public Garden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California is the largest emitter of a little-known greenhouse gas

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California is a state known for its aggressive climate policies.  However, and rather ironically, California is also the nation’s greatest emitter of one little-known greenhouse gas: sulfuryl fluoride. 

Sulfuryl fluoride is one of the few treatments to rid buildings of drywood termites, a common regional pest that can be found in wooden structures.  Sulfuryl fluoride is also used at shipping ports to destroy pests before they can hitch a ride to another part of the world. 

But sulfuryl fluoride is also a greenhouse gas that’s several thousand times more effective than carbon dioxide at trapping heat in the atmosphere.    

According to a new study by researchers from Johns Hopkins University, as much as 17% of global emissions of this gas stem from the U.S., and the majority of those emissions can be traced back to just a few counties in Southern California.  In fact, the research team found 60-85% of sulfuryl fluoride emissions in the U.S. come from California, primarily Los Angeles, Orange, and San Diego counties. 

In the paper, which was recently published in the journal Communications Earth & Environment, the researchers attribute approximately 85% of the state’s sulfuryl fluoride emissions to structural fumigation.  Structural fumigation is the practice of sealing an infested structure, pumping this gas into it to kill pests, and then releasing the gas into the atmosphere.  The other 15% of emissions come from agricultural and commodities fumigation.  

Without some form of intervention, the research team warns that sulfuryl fluoride will continue to accumulate in the atmosphere, where it can linger for more than 40 years.

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Web Links

Researcher sheds light on the main source of a rare but destructive greenhouse gas

California leads U.S. emissions of little-known greenhouse gas

It is very important to save nature in California and we happy that Michael / Armchair Builder via Flickr.

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