acid rain

Ocean geoengineering

October 24, 2024 By EarthWise Leave a Comment

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

A brief bout of bad air in Scotland

July 3, 2024 By EarthWise Leave a Comment

Scotland, and the UK in general, used to suffer from sulfur dioxide pollution. Industrial and domestic emissions, especially from burning coal, contributed heavily to urban air leading to the London smog of the 1950s and the acid rain of the 1980s. But national air pollution agreements and various international measures have been highly successful in reducing sulfur dioxide emissions. Desulfurization of coal-fired powerplants and the introduction of ultralow sulfur fuels among other measures have decreased sulfur dioxide emission by 98% since 1970.

As a result, it came as quite a surprise on May 31st when Edinburgh saw sulfur dioxide levels higher than had been observed in over 30 years. The levels greatly exceeded air quality objectives for 10 hours with concentrations even creeping towards workplace exposure limits.

What happened? For once, it was nothing that people did. Two days earlier, a volcanic fissure eruption took place in the Reykjanes Peninsula in Iceland, some 850 miles from Edinburgh. Because of an unusual meteorological configuration, the prevailing winds sent the plume of volcanic gases southward towards Scotland. Had the eruption taken place 60 miles further north or happened a few hours later, the plume of gases would have missed the UK entirely and would have traveled north to the Arctic region.

Icelandic volcanic eruptions have impacted air travel in Europe on a number of occasions. This non-explosive eruption had little impact outside of its local region, but it turned out to briefly wreak havoc in Scotland. Fortunately, this pollution event was short-lived.

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Atmospheric sulphur dioxide levels reach historic high in Scotland following Icelandic volcano eruption

Photo, posted November 17, 2021, courtesy of Catherine Poh Huay Tan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Adirondack lakes becoming inhospitable for trout

February 15, 2024 By EarthWise Leave a Comment

A combination of the warming climate and the phenomenon of lake browning are making the bottom of most lakes in New York’s Adirondack Mountains unlivable for cold water fish – such as trout, salmon, and whitefish – in the summer.

Lake browning occurs when dissolved organic matter from forests turns the water tea-brown. Browning is the legacy of a century of acid rain and subsequently the fact that forest soils have suffered reduced capacity to absorb weak organic acids, leading to more dissolved plant matter flowing into lakes. Climate change has increased the frequency of extreme precipitation events and the length of growing seasons, leading to more runoff of organic matter.

Browner water traps more of the sun’s heat at the top of the lake and blocks the sun’s rays from reaching deeper. The result of the browning is lakes that are either too warm or too deoxygenated to support trout populations.

A study of 1,467 Adirondack lakes by Cornell University researchers found that only about 5% of them may continue to maintain water that is cold and oxygenated enough to support cold-water fish.

Deeper lakes fare much better because they have so much water that their oxygen is hard to deplete, but only 1% of all Adirondack lakes are deeper than 30 meters. Another 4% are very clear because the influx of cold water outpaces the expansion of low-oxygen zones and limits the effects of browning.

The study urges the protection of as many lakes as possible from species invasions, nutrient and salt pollution, and other forms of environmental degradation.

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Most Adirondack lakes will likely become unsuitable for trout

Photo, posted July 17, 2011, courtesy of Lida via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

What’s The Best Way To Reduce Emissions? | Earth Wise

April 1, 2021 By EarthWise Leave a Comment

A carbon tax is a fee imposed on the burning of carbon-based fuels, like coal, oil, and gas. It’s one way to make the users of carbon fuels pay for the climate damage caused by releasing carbon dioxide into the atmosphere.

According to a new study by researchers at Ohio State University, putting a price on producing carbon is the cheapest and most efficient policy change that legislators can make in order to reduce climate change-causing emissions.

The case study, which was recently published in the journal Current Sustainable/Renewable Energy Reports, looked at the impact that a variety of policy changes would have on reducing carbon dioxide emissions from electricity generation in Texas. The researchers found that assigning a price to carbon, based on the cost of climate change, was most effective.

The study did not look at how policy changes might affect the reliability of the Texas power system, an important consideration after the failure of the state’s power grid following winter storms in February.

But the study did examine other policies and found that they were either more expensive or not as effective, including mandates that a certain amount of energy in a portfolio come from renewable sources. Subsidizing renewable energy sources was also found to be less effective.

According to researchers, market-based solutions have previously proven effective combating environmental issues. For example, a cap-and-trade approach was used to reduce levels of sulfur dioxide, one of the chemicals that causes acid rain.

For the sake of the climate, we should probably tax carbon.

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Want to cut emissions that cause climate change? Tax carbon

What’s a carbon tax?

Photo, posted June 5, 2011, courtesy of John Englart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Lessons From The Forest

July 29, 2016 By WAMC WEB

For more than half a century, scientists have converged on Hubbard Brook Experimental Forest in New Hampshire’s White Mountains to explore how forest ecosystems work. The site was established by the U.S. Forest Service to study the relationship between forests and New England’s water supply. In the 1960s, inquiry was expanded to include ecology, biogeochemistry, and studies of birds and other animals.

Less Sulfur In The Soil

June 9, 2016 By WAMC WEB

Acid rain is rain containing high levels of nitric and sulfuric acids. The main culprit for it is the burning of fossil fuels, particularly coal-burning power plants. The most serious effect of acid rain is the creation of toxicity in lakes, wetlands and other aquatic environments, doing great harm to a wide range of aquatic animals.

Keeping A Pulse On Our Planet

April 6, 2016 By WAMC WEB

The discovery of acid rain in North America was made possible by environmental data collected at a biological field station nestled in the White Mountains of New Hampshire. Hubbard Brook Experimental Forest is just one of the many biological field stations located around the globe that are keeping a pulse on the health of our planet.

Declining Sugar Maples

December 23, 2015 By WAMC WEB

The sugar maple, one of the most economically and ecologically important trees in the eastern United States and Canada, is showing signs of being in decline, according to scientists at SUNY’s College of Environmental Science and Forestry and Harvard Forest.

Wikipedia: Especially Unreliable for Politically Controversial Science Topics

September 24, 2015 By EarthWise

Wikipedia is world’s most popular online encyclopedia, the sixth most visited website in America, and a source most students rely on. But, according to a recent study, Wikipedia entries on politically controversial science topics can be especially unreliable.