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Sharks and rays in a warming world

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Sharks and rays belong to a group of cartilaginous fish called elasmobranchs, which have been swimming in the world’s oceans for 450 million years. The resilient species have survived five mass extinction events, and are older than dinosaurs, trees, and Mount Everest. 

But despite their resilience, many species of sharks and rays today are threatened by human activities, including overfishing, habitat loss, and climate change.  In fact, according to a new study led by researchers from the University of Vienna in Austria, more than one third of the shark and ray species known today are severely under threat. 

The study, which was recently published in the journal Biology, found that higher carbon dioxide levels were having a negative effect on sharks and rays, ranging from impacts on the animals’ senses to changes in the skeleton during embryonic development.  An examination of fossil records found that higher CO2 levels had contributed to the extinction of individual shark and ray species in the past. 

But the study also found that global warming could be creating opportunities for sharks and rays.  Rising sea levels and higher temperatures have historically expanded shallow coastal habitats and warm waters, supporting species biodiversity.

But according to the research team, the rapid environmental changes, combined with the impacts from human activities, outpace the ability of sharks and rays to adapt, making it unlikely that they will benefit from global warming.

Protecting sharks and rays is crucial not only for their survival but also for maintaining entire ocean ecosystems. Without top predators, these ecosystems could collapse, impacting both marine life and the people and industries that depend on it.

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Sharks and rays benefit from global warming – but not from CO2 in the Oceans

Myths About Sharks and Rays

Photo, posted November 27, 2007, courtesy of Laszlo Ilyes via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Artificial plants to clean indoor air

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The average American spends about 90% of their time indoors breathing the air in our workplaces, homes, or schools.  The quality of this air affects our overall health and well- being.  Indoor air quality is an issue because many sources can generate toxic materials, including building materials, carpets, and more.  But high levels of carbon dioxide are a health hazard themselves. Indoor CO2 levels can often be 5 to 10 times higher than the already heightened levels in the atmosphere. 

Many of us make use of air purification systems, which can be expensive, cumbersome, and require frequent cleaning and filter replacements.

Researchers at Binghamton University in New York are working to develop artificial plants that consume carbon dioxide, give off oxygen, and, as a bonus, generate a little electricity. These artificial plants make use of the artificial light in the indoor environment to drive photosynthesis.  They achieve a 90% reduction in carbon dioxide levels, which is far more than natural plants can achieve.

The Binghamton researchers had been working on bacteria-powered biobatteries for various applications, but they repurposed the work into a new idea for artificial plants.  The artificial plants have “leaves” containing a biological solar cell and photosynthetic bacteria.  Their first plant had five leaves and demonstrated promising carbon dioxide capture rates and oxygen generation.  It also produced a little electricity.  If its generating capacity can be improved, it might also be useful for charging cell phones or other practical applications.

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Binghamton researchers develop artificial plants that purify indoor air, generate electricity

Photo, posted October 13, 2012, courtesy of F. D. Richards via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Megafires and orchard health

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The frequent and massive megafires in places like Canada and the American west have led to a lot of research on the impact of smoke on humans but there has been less study of the effects of smoke on plant health.  Researchers at the University of California, Davis have found that trees are just as vulnerable as humans are to the harmful effects of long-term exposure to smoke.

The Davis researchers studied almond, pistachio, and walnut trees at 467 orchard sites in California’s Central Valley from 2018 to 2022.  In 2022, so-called megafires burned more than 4.2 million acres in California, pouring ash and smoke into the sky.  The researchers had been studying how trees store carbohydrates to cope with heat and drought. 

With the onset of the fires, they saw an opportunity to study how smoke affects carbohydrate levels.  Trees use stored carbohydrates to sustain them through winter dormancy and spring growth.  Trees produce carbohydrates via photosynthesis and thick smoke blocks the amount of light reaching the trees.  Beyond that, there are other aspects of wildfire smoke, such as particulate matter and ozone that appear to affect photosynthesis.

The team found that the smoke not only reduced the amount of carbohydrates in trees but also caused losses that continued even after the fires were extinguished.  This led to nut yield decreases of 15% up to 50% in some orchards.  The researchers expected to see some impact on the trees during periods when smoke was really dense but were not expecting the smoke to have such a lingering effect and result in a significant drop in yield.

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Smoke From Megafires Puts Orchard Trees at Risk

Photo, posted October 1, 2008, courtesy of Suzi Rosenberg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Clean energy investment at record levels

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According to a new study by the International Energy Agency, global clean energy investment will be nearly twice that of fossil fuels this year.  The surging funding for clean energy is being driven by a combination of lower costs for renewable energy and by improving supply chains.

In 2024, the world’s investments in energy are expected to surpass $3 trillion dollars for the first time.  About $2 trillion of that will be directed at green technologies that include renewable power sources, grids, and energy storage; electric vehicles; low-emission fuels; nuclear power; and heat pumps and efficiency improvements.  The remaining amount of just over $1 trillion will fund oil, gas, and oil projects.

The record growth in clean energy investments is taking place in spite of challenging economic conditions related to high interest rates, which demonstrates the momentum behind the global energy transition.

The IEA report does caution that there are big imbalances and shortages in energy investment in various places around the world.  For example, there is a low amount of green energy spending in developing and emerging economies outside of China.  Countries like Brazil and India are leading the way for this sector by having investments in excess of $300 billion.

More money is currently going into solar power development than all other electricity generation technologies combined.  In 2024, solar photovoltaic power investment is set to grow to $500 billion as the falling price of solar modules spurs new investments.

The largest renewable investments will come from China at $675 billion, followed by Europe and the U.S. at $370 billion and $315 billion, respectively.

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Global Clean Energy Investment Will Nearly Double That of Fossil Fuels in 2024: IEA Report

Photo, posted October 2, 2015, courtesy of John Englart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Dark chocolate is not so dangerous

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Last year, Consumer Reports published a story stating that a third of chocolate products contain potentially dangerous amounts of heavy metals, in particular lead and cadmium. Since it contains much more cacao, dark chocolate was singled out as the most worrisome product.  Needless to say, chocolate lovers found this report quite alarming.

A new study by Tulane University published in Food Research International employed a larger sample size, expanded the scope of testing to 16 metals, and included a risk assessment of toxic metals as well as accounted for the nutritional contribution of essential minerals.

The conclusions of the study were that dark chocolate poses no adverse risk for adults and contains nutritionally beneficial levels of essential minerals.  Some risks remain for very young children, but only from a very small number of chocolate products and only when large quantities are consumed.

The study sampled 155 dark and milk chocolates from various global brands sold in the United States.  It modeled the risk of eating one ounce of the chocolate per day or two large whole bars a week.

Only one brand exceeded the international limit for cadmium; four had cadmium levels that could pose a risk for a child weighing less than 33 pounds.  Only two bars contained lead levels above California interim standard, but neither posed adverse risks for anyone.

Lead in chocolate comes from post-harvest processing; cadmium comes from the soil.  South American chocolates generally have higher levels of metals than chocolates from Asia and West Africa.  Most dark chocolate in the U.S. is sourced from West Africa.

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A dark side to dark chocolate? New study finds very minimal risk for kids from metals in chocolates

Photo, posted February 19, 2012, courtesy of Bodo 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

Mercury in tuna

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Mercury is found throughout the ocean, and there is at least some of it in any fish one might eat. It is an element found naturally in the environment, but it is also a byproduct of manmade pollution. Generally speaking, bigger fish tend to have higher mercury levels than smaller ones, because they are higher up in the food chain. The more small fish those big fish eat, the more mercury builds up in their bodies.  Tuna aren’t the biggest fish in the ocean, but they are very common in many people’s diets.

Increased mercury levels are a result of human activities like burning coal and mining which release methylmercury into the air.  It then finds its way into the oceans in rainwater.  Methylmercury is a particularly toxic chemical that affects the nervous system.  Environmental protection policies in recent decades have helped to reduce mercury pollution.

However, a recent study by French researchers looked at the mercury levels in tuna over the past 50 years.  They found that the levels have basically not changed since 1971.  As a result, they are calling for more restrictive environmental policies to further lower mercury pollution levels.

The researchers explained that the lowering of mercury airborne levels to date has not necessarily been ineffective.  They theorized that the static levels in tuna may be caused by the upward mixing of “legacy” mercury from deeper ocean water into the shallower depths where tropical tuna swim and feed.  It could very well take decades to dramatically reduce ocean mercury levels. 

Meanwhile, mercury content in tuna varies considerably by tuna type and source and there are both better and worse choices out there.  Consumers should learn the facts.

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Mercury levels in tuna remain nearly unchanged since 1971, study says

Photo, posted November 7, 2015, courtesy of Mussi Katz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Global groundwater depletion

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Groundwater is found underground in aquifers and it bubbles up naturally into springs, streams, and rivers.  It’s also often pumped out for use by people. 

Researchers from UC Santa Barbara have conducted the largest assessment of groundwater levels across the globe, spanning 170,000 wells and nearly 1,700 aquifers across more than 40 countries. The team compiled and analyzed data, including 300 million water level measurements taken over the past 100 years.

In the study, which was recently published in the journal Nature, the researchers found that groundwater is rapidly declining across the globe, often at accelerating rates.  In fact, they found that groundwater is dropping in 71% of the aquifers studied.  The rates of groundwater decline observed in the 1980s and ’90s sped up from 2000 to the present, highlighting how a bad problem became even worse. 

But there are some reasons to be optimistic.  That’s because in 16% of the aquifers studied, the researchers found that the rate at which groundwater levels are falling in the 21st century had slowed down compared to the 1980s and ‘90s.  The research team highlighted specific success stories in Thailand, Arizona, and New Mexico, where groundwater has begun to recover after interventions to better regulate water use or redirect water to replenish depleted aquifers.

While groundwater depletion isn’t inevitable, the researchers stress that aquifer recovery will require interventions.  They hope this study will help scientists, policy makers, and resource managers better understand the global dynamics of groundwater. 

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Global groundwater depletion is accelerating, but is not inevitable

Photo, posted October 4, 2016, courtesy of Deborah Lee Soltesz / Coconino National Forest via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

How will we know if the world is 1.5 degrees warmer?

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The Paris Climate Agreement has a goal of limiting global warming to less than 1.5 degrees Celsius above pre-industrial levels.  How do we know if we are succeeding and, more importantly, how would we know if we have failed?

This may seem like something fairly obvious, but it isn’t.  Global temperatures are definitely creeping upward.  This past year has been the warmest on record.  In fact, the global average temperature was more than 1.4 degrees above pre-industrial levels.  November was 1.75 degrees above pre-industrial levels.  So, does that mean that our climate goals have already failed?  Not really.

On a monthly scale there have already been individual months where warming has exceeded 1.5 degrees in 2016, 2017, 2019, 2020, and 2023.  Would an entire year above the target constitute failure?  Not necessarily.  There really isn’t an agreed-upon answer and that in itself represents something that could undermine global efforts to tackle climate change.

If we don’t know whether we are succeeding or failing, it is more difficult to pursue success.  The United Nations IPCC says the threshold will be surpassed when average warming exceeds 1.5 degrees for 20 years.  But that seems like a building a mountain highway with no guardrails and hoping to be safe.

Scientists are calling for new approaches to defining a universally agreed-upon measure of global warming that could trigger urgent action to avoid further rises.  What we really don’t need are justifications and excuses for continued inaction.  Clearly the climate is not waiting for us to debate the issue.

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Why We Won’t Know When We’ve Passed the 1.5-Degree Threshold

Photo, posted August 2, 2018, courtesy of J Bartlett Team Rubicon/BLM for USFS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mississippi River Running Dry | Earth Wise

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Water levels in the lower Mississippi River are running very low.  During September, the readings in Memphis, Tennessee were within inches of the all-time low.  The situation is causing real problems for the grain export industry.

The water levels of the lower Mississippi are determined by the amount of rainfall in the upper Midwest.  At the point where the Ohio and Mississippi Rivers come together, about 90% of the water headed for the lower Mississippi has been accumulated.

Almost 400 miles of the Mississippi have experienced water levels at or below critical levels for shipping.  During September, parts of the Mississippi have been closed to ship traffic more than 20 times.  At least 36 vessels were reported to have run aground.

The low water levels on the river have caused shippers of soybean and corn exports to lighten their loads to keep the vessels from running aground.  They have also reduced how many barges they pull at once in order to be able to navigate shipping channels that have narrowed because of the reduced water levels.

Fall is the busiest grain export season for the region.  About 60% of grain exports from the Midwest leave the U.S. through terminals on the Gulf Coast.  The low levels of the Mississippi River threaten gridlock for this vital industry.  It has caused freight costs to be the highest since historic river lows last year caused U.S. grain to be less competitive globally.

Unfortunately, October is not normally a strong precipitation month, but the hope is that the El Niño now underway may lead to increased precipitation in the Southern U.S.

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Mississippi River Nears Historic Lows, Putting Grain Exports at Risk

Photo, posted March 8, 2023, courtesy of Errol Sandler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Greenhouse Gas Emissions Are Still Increasing | Earth Wise

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Recent research has found that the level of greenhouse gases emitted by human activity has reached an all-time high level of nearly 60 billion tons a year.  Despite increasing public attention, policy measures, and adoption of green technologies, the pace at which these changes have been taking place has simply not kept up with the ongoing burning of fossil fuels by increasingly industrialized societies.  The rate at which greenhouse gas emissions has increased over time has indeed slowed, but emissions need to start decreasing and as soon and as much as possible.

Human-induced warming has reached a ten-year average from 2013-2022 of 1.14 degrees Celsius above pre-industrial levels, up from a 1.07 degrees average between 2010-2019. 

Scientists have calculated a carbon budget that describes how much more carbon dioxide can be emitted before global warming exceeds the threshold of 1.5 degrees Celsius that is widely predicted to lead to potentially catastrophic changes to the climate.  In 2020, the Intergovernmental Panel on Climate Change calculated that the remaining carbon budget was about 500 billion tons of carbon dioxide.  Over the past three years, nearly half of that carbon budget has already been exhausted by the continuing onslaught of carbon emissions.

Researchers describe their study as a timely wake-up call that the pace and scale of climate action to date has been insufficient and that we need to change policy and approaches in light of the latest evidence about the state of the climate system.  Time is no longer on our side in trying to stave off the worst effects of climate change.

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Greenhouse gas emissions at ‘an all-time high’, warn scientists

Photo, posted September 18, 2015, courtesy of In Hiatus via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Ocean Oxygen Levels And The Future Of Fish | Earth Wise

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Climate change is creating a cascade of effects in the world’s oceans.  Not only are ocean temperatures on the rise, but oceans are becoming more acidic, and oxygen deprived.  The warming temperatures and acidification have grabbed headlines and prompted academic research. Declining oxygen levels have not garnered as much attention.  But they spell bad news for fish.

Oxygen levels in the world’s oceans have dropped over 2% between 1960 and 2010 and are expected to decline up to 7% over the next century.  There are places in the northeast Pacific that have lost more than 15% of their oxygen.  There are a growing number of “oxygen minimum zones” where big fish cannot survive but jellyfish can.

Oceans are losing oxygen for several reasons.  First, warmer water can hold less dissolved gas than colder water.  (This is why warm soda is flatter than cold soda.)  Deeper in the ocean, oxygen levels are governed by currents that mix oxygen-rich surface water from above.  Melting ice in the warming polar regions add fresh, less-dense water that resists downward mixing in key regions.  Finally, increasing amounts of ocean bacteria in warming waters gobble up oxygen creating dead zones in the ocean.

In many places, fish species that cannot cope with lower oxygen levels are migrating from their usual homes, resulting in a decline in species diversity.  Our future oceans – warmer and oxygen-deprived – will not only hold fewer kinds of fish, but also smaller fish and even more greenhouse-gas producing bacteria.   

Climate change is bad news for fish and for the more than 3 billion people in the world who depend on seafood as a significant source of protein.

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As Ocean Oxygen Levels Dip, Fish Face an Uncertain Future

Photo, posted January 10, 2022, courtesy of Willy Goldsmith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Two Lost Lakes Return To California | Earth Wise

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The recent siege of powerful storms in California driven by a series of atmospheric rivers has had a significant effect on the severe drought that has plagued most of the state for many years.  Many of the state’s reservoirs are at the highest level they have been for decades.   The snowpack in the Sierras is well over 200% of its historical average.  Many parts of the state are no longer considered to be in drought conditions, and, in fact, flooding has been a serious problem in some areas.  This flooding has had some surprising results.

Two California lakes that drained a century ago have reappeared as a result of floodwaters from the recent storms.

Tulare Lake, in California’s Central Valley used to be fed by rain and snowmelt from the Sierras.  A system of dams and canals constructed in the early 20th century to support regional agriculture diverted water away from the lake.  It used to be the largest freshwater lake in the West but farmers ultimate planted crops in the dried lakebed.

The atmospheric river events in March inundated that farmland and once again there is water in Tulare Lake.

Owens Lake, on the eastern side of the Sierra Nevada, was long fed by mountain streams.  The 1913 construction of the Los Angeles Aqueduct redirected water to that city and desiccated the lake.   Floodwaters in March caused a partial collapse of the aqueduct and when the spill gates on the aqueduct were opened to drain the damaged areas, floodwaters poured in and partially refilled the lake.

California has suffered from drought for many years.  With its massive snowpack, as the weather warms, the state may face even more flooding.

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Two Long-Drained California Lakes Refilled by Floodwaters, Satellite Images Show

Photo, posted November 10, 2014, courtesy of CN via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Keeping The Keeling Curve Going | Earth Wise

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The world’s longest-running record of direct readings of carbon dioxide levels in the atmosphere is the Keeling Curve, measurements taken at the summit of Mauna Loa in Hawaii.  The readings have been going on with almost no interruption since Charles Keeling began taking them in the 1950s.  But the eruption of Mauna Loa last November toppled power lines at the mountaintop observatory and buried a mile of the main road up the mountain in lava.

Scientists have been scrambling to resume measurements and the near-term solution has been to take them, for the first time, on Mauna Kea, the neighboring large volcano about 25 miles away.  The National Oceanic and Atmospheric Administration flew in and installed instruments at the Mauna Kea observatory so that only about a week went by without measurements.   It happened so quickly because months earlier, NOAA had already started looking into installing a backup site on Mauna Kea where there is an observatory run by the University of Hawaii.

NOAA used helicopters to install solar panels and batteries on Mauna Loa to restore power in the short term since it will be months before a new road can be built on the still-cooling lava. The plan is to collect parallel measurements for a year to see if Mauna Kea, which hasn’t erupted for thousands of years, might become a long-term backup for Mauna Loa.

The Hawaiian volcanoes are uniquely suited for the measurements because they are surrounded by thousands of miles of empty ocean and are very high up, away from towns, cars, and forests.  Scientists are now monitoring measurements from the two sites to see how they compare.

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Battling Lava and Snowstorms, 2.5 Miles Above the Pacific

Photo, posted November 2, 2015, courtesy of Neal Simpson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

2022 Temperature Report | Earth Wise

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The average surface temperature for the Earth in 2022 tied with 2015 as the fifth warmest on record.  The warming trend for the planet continued with global temperatures 1.6 degrees Fahrenheit above the average baseline for 1951-1980 that NASA uses for its studies. Compared with the late 19th century average used in setting climate goals, global temperatures are up about 1.1 degrees Celsius, or 2 degrees Fahrenheit.

Overall, the past nine years have been the warmest since modern recordkeeping began in 1880.   The rising temperatures have moved in concert with rising levels of greenhouse gases entering the atmosphere from human activity.  Many factors can affect the average temperature in any given year including El Nino and La Nina conditions in the Pacific.  But the longer-term trend is quite clear.  Global temperatures continue to rise.

Greenhouse gas emissions have reached all-time high levels despite increasing efforts to reduce them.  There was a real drop in levels in 2020 due to reduced activity during COVID-19 lockdowns, but they rebounded soon thereafter. 

The Arctic region continues to experience the strongest warming trends, as much as four times the global average.  Arctic warming has a major impact on weather at lower latitudes as it changes the behavior of the jet stream as well as affecting ocean currents and water temperatures.

As global temperatures continue to rise, rainfall and tropical storms have become more intense, droughts have become more severe, and ocean storm surges have had increasing impact.  From torrential monsoons in Asia to megadroughts in the U.S. Southwest, extreme weather has become the new normal.

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NASA Says 2022 Fifth Warmest Year on Record, Warming Trend Continues

Photo, posted June 20, 2020, courtesy of Daxis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Growing Threat To Wheat | Earth Wise

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Wheat is one of the most widely-grown crops in the world and plays a major role in human nutrition.  In fact, wheat contributes approximately 20% of the protein and 20% of the calories consumed by humans globally.  It is grown on every continent except Antarctica.  

But wheat is under growing attacks from harmful toxins.  According to a new study by researchers from the University of Bath and the University of Exeter in the U.K., almost half of wheat crops across Europe are impacted by the fungal infection that gives rise to mycotoxins.

Mycotoxins are naturally occurring toxins produced by the fungus that causes Fusarium Head Blight.  Fusarium Head Blight is a disease that affects wheat and other grains growing in the field. Eating products contaminated with mycotoxins can cause sickness in humans and livestock, including vomiting and other gastrointestinal problems.

In the study, the research team examined 10 years of government and agribusiness data, which tracked Fusarium mycotoxins in wheat entering the food and animal supply chains across Europe and the U.K.  Half of the wheat intended for human food in Europe contained the Fusarium mycotoxin.  In the UK, 70% of wheat was contaminated.

Governments set legal limits on mycotoxin contamination levels in wheat that is to be consumed by humans. But with the ubiquitous nature of these mycotoxins, the effect of constant, low-level exposure in the diet over the course of a lifetime is not known. 

With climate change and the war in Ukraine already impacting both wheat yield and price, preventing toxin contamination is critical to help maintain a stable crop price and to protect global good security. 

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Harmful fungal toxins in wheat: a growing threat across Europe

Photo, posted July 11, 2011, courtesy of Maria Keays via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Capture In Wyoming | Earth Wise

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Wyoming produces about 40% of our country’s coal and many towns in the state were built because of and make their living from it.  With coal’s plummeting share in the nation’s electricity, there is a great deal of anxiety among residents of those towns.

As carbon dioxide levels in the atmosphere continue to climb, there is a growing sense that cutting emissions will not happen quickly enough and it will be necessary to pull the greenhouse gas out of the atmosphere.  The current long-term government climate strategy assumes that carbon removal will account for 6 to 8 percent of the nation’s greenhouse gas reductions by 2050.

The Inflation Reduction Act passed in August provides $3.5 billion to help build “direct air capture hubs” around the country, with an emphasis on fossil fuel-dependent communities such as many in Wyoming. 

The town of Rock Springs, Wyoming is home to the Jim Bridger Coal Plant. A company called CarbonCapture, Inc., is launching Project Bison, which will build a direct air capture facility outside of town that is set to begin operations next year.  It will initially capture 10,000 metric tons of CO2 per year but plans to expand that to 5 million tons a year by 2030. 

That would be far more than any current carbon capture plant can do. The largest plant in the world, located in Iceland, pulls in only about 4,000 metric tons a year.

There are many problems associated with carbon capture.  It uses up very large amounts of energy, possibly presents environmental problems, and is very expensive.  In short, the technology has a long way to go before becoming viable.  However, this may ultimately be another example where necessity is the mother of invention.

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Carbon Removal Is Coming to Fossil Fuel Country. Can It Bring Jobs and Climate Action?

Photo, posted July 22, 2012, courtesy of Max Phillips via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Trees Are Growing Bigger | Earth Wise

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The alarming rate of carbon dioxide flowing into the atmosphere is having a real and actually positive effect on plant life. Higher concentrations of carbon dioxide make plants more productive because photosynthesis makes use of the sun’s energy to synthesize sugar out of carbon dioxide and water.  Plants make use of the sugar both as a source of energy and as the basic building block for growth.  When carbon dioxide levels go up, plants can take it up faster, supercharging the rate of photosynthesis.

In a new study published in the journal Nature Communications, scientists at Ohio State University found that trees are feasting on decades of carbon dioxide emissions and are growing bigger as a result. 

The researchers tracked wood volume in 10 different tree groups from 1997 to 2017 and found that all of them except aspens and birches grew larger.  Over that time period, carbon dioxide levels climbed from 363 parts per million to 405 parts per million.  According to the study, each 1% increase in lifetime CO2 exposure for trees has led to more than a 1% increase in wood volume.

In the big picture, the news isn’t so positive.  The global warming caused by increasing carbon dioxide levels increasingly threatens the forests of the world.  It has led to worsening droughts, insect infestations, and wildfires.  So overall, increasing levels of carbon dioxide are by no means a good thing for the world’s trees.  However, since trees are growing bigger more quickly, it means that planting them is an increasingly cost-effective method for fighting climate change because the same number of trees can sequester more carbon.

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As Carbon Dioxide Grows More Abundant, Trees Are Growing Bigger, Study Finds

Photo, posted September 12, 2015, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfire Smoke And Air Quality | Earth Wise

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According to a new study published by Stanford University, the average number of people in the U.S. exposed to unhealthy levels of airborne particulates at least one day a year has increased 27-fold over the last decade as a result of wildfires.

Millions of Americans are now routinely exposed to plumes of wildfire smoke that sometimes travel thousands of miles across the country.  Accumulations of deeply unhealthy air have emerged mainly in the West, where increasingly intense wildfires have become all too common.  Six of the seven largest wildfires in California recorded history have occurred since 2020.

Wildfire smoke has resulted in school closures, flight postponements, and even cancelled concerts.  Overall, the regression in air quality has undone much of the clean air progress that has taken place since the advent of the Clean Air Act in 1970.

Wildfire smoke has added about 5 micrograms of PM 2.5 particles per cubic meter of air on average in many places in the West.  This is a substantial increase from national levels, which are a total of about 10 micrograms per cubic meter and mostly result from emissions from cars, trucks, and power plants.

A decade ago, fewer than 500,000 Americans were exposed to any days of an air quality index of 100 or more due to smoke, which is a level that is deemed unhealthy.  In 2020, 25 million Americans were in areas with such levels at least one day during the year.

Ordinarily, if people don’t live near a highway or power plant, their air quality is likely to be pretty good.  But incursion from wildfire smoke is changing that, and the trend is likely to increase.

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Number of Americans Exposed to Harmful Wildfire Smoke Has Increased 27-Fold

Photo, posted August 19, 2013, courtesy of Mike Lewelling / National Park Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Bengal Water Machine | Earth Wise

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Over the past three decades, the owners of 16 million small farms in the Bengal Basin of Bangladesh have been pumping shallow groundwater during dry seasons to irrigate rice paddies.  By lowering groundwater levels in this way during the dry season, the ability of leakage from rivers, lakes, and ponds to replenish the groundwater was greatly enhanced.   Capturing surface water not only improved the recovery of groundwater levels but only helped to reduce flooding during monsoons.

The net result of this enormous collective groundwater pumping by millions of farmers has been the creation of vast natural reservoirs underground that are comparable to what is contained by many of the world’s largest dams.   This system of sustaining irrigation has transformed what was previously a famine-prone country into a food-secure nation.

The details of this remarkable transformation have been laid out in a study by University College London recently published in the journal Science.  According to the study, over the course of 30 years, more than 75 cubic kilometers of fresh water was captured by this process, which is equivalent to the combined reservoirs of China’s Three Gorges Dam and the Hoover Dam in the U.S.

The authors of the study described the water cycling process as “The Bengal Water Machine” and argue that it can be a sustainable alternative to conventional approaches to seasonal river flow storage for irrigation, which typically involve dams and reservoirs.  Such approaches are difficult to implement in densely populated alluvial plains where sand, silt, and clay are laid down by annual floodwaters. 

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Millions of farmers “replumb” world’s largest delta

Photo, posted February 2, 2010, courtesy of Melanie Ko via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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