legacy

The carbon cost of wind farms

July 31, 2024 By EarthWise Leave a Comment

Opponents of electric vehicles and renewable energy often try to make arguments to the effect that the carbon footprint associated with producing electric cars, solar panels, and wind turbines negates their advantages over legacy technologies that involve burning fossil fuels. These arguments have been soundly refuted for the case of electric vehicles but there have been fewer studies related to other green technologies.

A new peer-reviewed study by engineers at the Te Herenga Waka Victoria University in Wellington, New Zealand, has analyzed the carbon emissions associated with wind farm operation.

The main result is that after operating for less than two years, a wind farm can offset the carbon emissions generated across its entire 30-year lifespan. The study takes into account everything from the manufacturing of individual turbine parts, to transporting them and installing them into place, to decommissioning the entire wind farm at its life’s end. The environmental impacts of the installation and transportation phases are important, accounting for about 10% of the overall emissions.

The decommissioning phase is also important. The study recommended the development of a recycling process for end-of-life turbine blades. Currently, such blades are disposed of in landfills, but a recycling process could reduce emissions.

The manufacturing of wind turbines is the primary contributor to the carbon and energy consumption footprints and continues to be the subject of efforts to be improved.

There are other aspects of wind farms that are subject to criticism including physical impacts on the local environment and various social, wildlife and economic impacts. But with respect to carbon emissions, wind farms are a winning strategy.

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Wind Farms can Offset Their Emissions Within Two Years, New Study Shows

Photo, posted April 2, 2017, courtesy of Ian Dick via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mercury in tuna

March 25, 2024 By EarthWise Leave a Comment

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

What’s Killing Orcas? | Earth Wise

January 18, 2021 By EarthWise Leave a Comment

With their characteristic tall dorsal fins and black and white color patterns, orcas are one of the ocean’s most iconic species. Measuring up to 32 feet long and weighing as much as 6 tons, orcas have one of the largest geographic distributions of any species. They live in all latitudes, in all oceans, from the Arctic to Antarctica.

While they are often referred to as killer whales, orcas are actually not whales at all. Orcas are the largest dolphin species and one of the most powerful predators on the planet.

But human interference has made life significantly more difficult for orcas in recent years. According to pathology reports on more than 50 orcas stranded over nearly a decade in the northeast Pacific and around Hawaii, the predators face a myriad of mortal threats. Many of those threats stem from human interactions.

Researchers from the British Columbia Ministry of Agriculture analyzed these orca pathology reports in a new study, which was recently published in the journal PLOS ONE,. Of 52 orcas stranded between 2004 and 2013, causes of death were determined for 42%. For example, one orca died after receiving a halibut hook injury. Two orcas died from the blunt force trauma of vessel strikes. While there was no singular common cause of death, the study found a common theme: human-caused deaths occurred in every age class – from juveniles to adults.

The researchers also note that humans aren’t just indirectly hurting orcas with things like lack of salmon or legacy toxins. Humans are also directly killing killer whales with boat strikes and fishing gear.

These findings will help establish a baseline of information to assess future orca conservation efforts.

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What’s killing killer whales?

Photo, posted July 5, 2009, courtesy of Rennett Stowe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.