longterm

Megafires and orchard health

November 1, 2024 By EarthWise Leave a Comment

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

Keeping The Keeling Curve Going | Earth Wise

March 21, 2023 By EarthWise Leave a Comment

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

Carbon Capture In Wyoming | Earth Wise

January 25, 2023 By EarthWise Leave a Comment

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

Offsetting Reef Acidification | Earth Wise

August 13, 2021 By EarthWise Leave a Comment

The Great Barrier Reef is the world’s largest coral reef system. It is composed of nearly 3,000 individual reefs and 900 islands covering an area of more than 130,000 square miles. In recent times, it has been under unprecedented stress from ocean warming, tropical cyclones, sediment and nutrient runoff, marine pests, and ocean acidification.

Among these stressors, ocean acidification is one of the most significant threats to the long-term viability of the reef because acidification affects the ability of corals to rebuild and repair their structures and recover from bleaching events.

New research from CSIRO, Australia’s national science agency, studied the impact of artificial ocean alkalinization on the acidity of the waters in the Great Barrier Reef. The idea is to inject a source of alkalinity into the ocean, an accelerated version of a natural process that occurs from the chemical weathering of minerals under the sea.

The results of the study, published in the journal Environmental Research Letters, are that injecting an alkalinizing agent into the ocean along the length of the Reef would make it possible to offset ten years’ worth of ocean acidification based on the present rate of human-generated carbon emissions. Such an effort could use an abundant mineral resource like olivine, which is already mined near the Great Barrier Reef. Releasing 30,000 tons a day of the alkalinizing agent from an existing shipping line from a bulk carrier would reach almost the whole of the Great Barrier Reef.

In response to the declining health of coral reef ecosystems, many different intervention concepts and technologies are under consideration. The goal of these would be to minimize environmental pressures and enhance the resilience of the ecosystems.

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Projected acidification of the Great Barrier Reef could be offset by ten years

Photo, posted August 4, 2019, courtesy of Larry Koester via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Too Many Bison | Earth Wise

May 8, 2020 By EarthWise Leave a Comment

The population of large herbivores in Yellowstone National Park has undergone many dramatic changes over the course of time. The numbers of both the iconic Rocky Mountain elk and bison have gone up and down as a result of human interactions.

Bison, of course, once were a dominant species from east of the Appalachians to west of the Rocky Mountains, with most of an estimated 30 million living on the Great Plains. As the west was settled, bison populations plummeted and by the late 1800s, they were nearly extinct.

When Yellowstone was established, there were exactly 22 bison in the park. By 1925, there were more than 750 in the park and culling of the herd in the park’s Lamar Valley was practiced for the next four decades.

The elimination of predators like grey wolves and cougars in the early 1900s caused both elk and bison populations to mushroom and both underwent culling. When culling was ended in 1968, there were 4,000 elk and 100 bison. Within 20 years, those numbers were 20,000 and 1,000. Reintroducing wolves and cougars reduced the elk population to about 5,000, but bison numbers have continued to grow, now reaching about 4,000.

While the long-term recovery of the Yellowstone bison herd is a major conservation success story, the fact is that bison are powerful ecosystem engineers. Large numbers of them disrupt species distribution across scrub steppe and grasslands because of what they eat, trample, and rub their horns and bodies on. They have a tremendous capacity to limit the structure and composition of ecosystems.

Park administrators have complicated management decisions to make to take into account the often wide range of ecological effects that abundant large herbivores can have on ecosystems.

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Bison in northern Yellowstone proving to be too much of a good thing

Photo, posted August 10, 2016, courtesy of Brian Gratwicke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Forest Regrowth In The Amazon | Earth Wise

January 20, 2020 By EarthWise Leave a Comment

The Amazon is the largest tropical rainforest in the world. It covers an area approximately equal in size to the lower 48 states, and is home to an estimated 10% of the world’s biodiversity and 15% of its freshwater. These so-called “lungs of the planet” provide many important global ecological services, including carbon storage, and regulating air quality and climate.

Deforestation in the Amazon exploded in the 1970s and remains one of its biggest threats today. Since the 1970s, more than 20% of the Amazon rainforest has been cleared. Cattle ranching, soy and palm plantations, logging, and climate change are some of the biggest drivers of deforestation.

Now, according to a new study recently published in the journal Ecology, the regrowth of Amazonian forests following deforestation may happen more slowly than previously thought. These findings could have significant impacts on climate change predictions as the ability of forest regrowth in the Amazon – so-called secondary forests – may have been overestimated. The research, which was conducted in Bragança, Brazil and includes two decades of forest monitoring, reveals that climate change and the wider loss of forests could be hampering regrowth.

After 60 years of regrowth, the research team found that secondary forests only held 40% of the carbon when compared with forests undisturbed by humans. Secondary forests also take less carbon from the atmosphere during periods of drought, and climate change is increasing the number of drought-years in the Amazon. (During their 20 years of monitoring, the researchers also found biodiversity levels in secondary forests were only 56% of those seen in undisturbed forests).

More long-term studies are needed to better understand the impacts of reforestation efforts.

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Amazon forest regrowth much slower than previously thought

Photo, posted September 6, 2009, courtesy of Nao Lizuka via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.