hypothesis

Making wind turbines safer for birds

September 18, 2024 By EarthWise Leave a Comment

There are people who oppose the installation of wind turbines for a variety of reasons. It is true that wind turbines can be dangerous to birds. Estimates are that about 250,000 birds are killed flying into wind turbines each year in the U.S.

However, this data needs to be looked at in comparison to bird deaths from flying into electrical lines (25 million), vehicles (214 million), and building glass (at least 600 million). And even these figures pale in comparison to the more than 2 billion birds killed by domestic cats each year.

Despite these facts, it would still be great if fewer birds died from flying into wind turbines. Researchers at Oregon State University are part of a team looking at reducing bird collision risks from wind turbines by painting a single blade of the turbine black.

Recent research in Norway found that painting a single turbine blade black reduced the number of bird collisions by nearly 72%. Why should this work? The hypothesis is that the black-painted blades disrupt the visual uniformity of the airspace around the turbines and makes them more noticeable to birds, which prompts avoidance behavior.

The Norwegian data is based on a relatively small sample size and the Oregon State researchers as well as others in Spain, Sweden, and South Africa are working on more rigorous and comprehensive studies.

The hope is that this rather simple strategy could make windfarms safer for birds. Unfortunately, this approach is not likely to be very effective with bats, which rely more on auditory cues rather than visual cues.

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Scientists studying impact of painting wind turbine blade black to reduce bird collisions

Photo, posted May 21, 2024, courtesy of Roy Harryman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Thawing permafrost: Is it a ticking timebomb?

July 8, 2024 By EarthWise Leave a Comment

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

Fish In Small Lakes

March 28, 2018 By EarthWise 1 Comment

There are millions of lakes on our planet. Many are quite large such as the Great Lakes in our country and Lake Victoria in Africa, but one-third of the world’s standing water is contained in lakes and ponds of 25 acres or less. Many of these lakes are found in remote, often mountainous areas with no inflow and outflow. Nevertheless, in most of these lakes there are fish.

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Did People Create The Sahara Desert?

April 25, 2017 By EarthWise

One of the arguments some people make when discussing human causes of climate change is that people can’t cause such massive changes. However, there is a long historical record of human-driven ecological and climatic change in Europe, North America and New Zealand, among other places.