western us

Wildfires and carbon storage

August 14, 2024 By EarthWise Leave a Comment

Forests are known to be a key natural solution to the increasing amounts of carbon dioxide in the atmosphere. For this reason, there are widespread efforts to plant more trees around the world and to prevent increasing deforestation for development and agriculture. But a new study has highlighted the fact that wildfires in the western US are degrading the potential for forests to help curb climate change.

The study has established a baseline for how much carbon is currently stored in Western forests, how that amount is changing, and how fires and droughts are affecting the ability of the forests to mitigate climate change.

The study made use of survey data collected by the US Forest Service to estimate how much carbon is stored in 19 ecoregions across the West. These ecoregions range from hot and dry areas in the Southwest to the wet and cool regions of the Pacific Northwest.

The study reveals that the carbon stored in living trees declined across much of the Western US between 2005 and 2019. Carbon stored in dead trees and woody debris increased. These things do not provide long-term carbon storage. Instead, they release it back into the atmosphere through decomposition or combustion in forest fires.

The increasing frequency and intensity of wildfires, especially since 2020, indicate that the decline in live carbon stored in the forests will become increasingly pronounced. The result, according to the study’s authors, is that we cannot rely on increasing carbon storage in Western US forests. It may be possible to increase the stability of carbon storage in the forests with mechanical thinning and prescribed burning, but the carbon carrying capacity of those forests is not likely to be what is needed.

**********

Web Links

Forest carbon storage has declined across much of the Western US, likely due to drought and fire

Photo, posted July 25, 2021, courtesy of Felton Davis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wind farms and land use

May 20, 2024 By EarthWise Leave a Comment

Wind power has become one of the most affordable ways to generate electricity as well as being renewable and not contributing to global warming. But there has been the perception that wind farms require a lot of land compared with fossil fuel power plants. This issue of land use has made decision-makers reluctant to invest in wind energy in many instances.

A new study by McGill University in Montreal looked at this issue and has found that land use for wind power is far more efficient than previously thought. The study combined data from geographic information systems with machine learning models to assess land usage associated with nearly 16,000 wind turbines in the western U.S.

The study assessed the land use of 320 wind farms. They found that wind power infrastructure (mostly the turbines themselves and the roads that lead to them) typically only uses 5% of the land area of a wind farm. If the wind farm is sited in locations with existing infrastructure, such as on agricultural land, then it can be as much as seven times more land-efficient – meaning the amount energy produced in a given area of land impacted by the infrastructure – than a wind farm that is developed on unused land.

Previous studies of wind farm land usage assumed that all of the land where the wind farm was located was devoted to energy generation. In reality, most of land in question is often used for other purposes, such as agriculture.

The methods developed by the researchers are potentially useable for future assessments of various energy technologies in terms of their environmental sustainability.

**********

Web Links

Clearing the air: wind farms more land efficient than previously thought

Photo, posted September 29, 2009, courtesy of Tim Green via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfires and air quality

January 1, 2024 By EarthWise Leave a Comment

The wildfires last summer in parts of the U.S. and Canada fouled the air over much of the country. Air quality in many places was dangerous for human health. And such fires are becoming more numerous and more intense.

A new study by the University of Iowa has assessed the effects of two decades of wildfires on air quality and human health in the continental U.S.

From 2000 to 2020, air quality in the western U.S. has gotten worse as a result of the numerous fires in that region. More generally, all those fires have undermined the success of federal efforts to improve air quality, primarily through the reductions in automobile emissions.

American air had been getting cleaner and clearer as a result of EPA regulations on vehicle emissions, but the surge in wildfires has limited and, in some cases, erased these air quality gains. Twenty years of efforts by the EPA to make our air cleaner have been lost in fire-prone areas and in many downwind areas.

The Iowa study looked at the concentration of black carbon, a fine-particle air pollutant from fires linked to respiratory and heart disease. In the western U.S., black carbon concentrations have risen 86% on an annual basis.

Fires have also affected the air in the Midwest, although not to the same degree as in the west. The eastern U.S. had no major declines in air quality during the 2000-2020 time period. Given the episodes of smoke from Canadian wildfires experienced by the east coast this past summer – as far south as Florida – even the air in that part of the country is suffering from the spread of wildfires.

**********

Web Links

Wildfires have erased two decades’ worth of air quality gains in western US

Photo, posted June 8, 2023, courtesy of Anthony Quintano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastics In The Air | Earth Wise

October 25, 2023 By EarthWise Leave a Comment

Plastic pollution is a big deal. There are plastics clogging up landfills and waterways and accumulating in the oceans, choking turtles and seabirds. Annual production of plastics has grown from 2 million tons a year in 1950 to more than 450 million tons today.

As if plastic problems weren’t already big enough, it is becoming increasingly clear that there are growing amounts of microplastic particles in the air. Bits of plastic are lofted into the sky from seafoam bubbles and from spinning tires on highways. The particles are so light that they can travel for thousands of miles, far from where they originate.

Studies in recent years documented the presence of plastic particles even in places like the Pyrenees in Europe and in federally protected areas of the US. Other studies have measured the quantity of plastic in the air of various locations and have looked at the origins of the particles.

In the western US, over 80% of microplastics came from roads where vehicles kick up particles from tires and brakes. In remote areas of the Pacific, there is less than a single particle of plastic per cubic meter of air. In cities like London and Beijing, on the other hand, there can be several thousand particles per cubic meter.

Microplastics can act as airborne aerosols, like dust, salt, soot, volcanic ash, and other particles. Aerosols play an important role in the formation of clouds and in temperature regulation on the earth. At low concentrations, such as exist in most places, microplastic aerosols don’t have much of an effect. But there are more in the atmosphere all the time and, at this point, scientists don’t really know what effect they will have.

**********

Web Links

Microplastics Are Filling the Skies. Will They Affect the Climate?

Photo, posted August 28, 2014, courtesy of Alan Levine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Forests And Water | Earth Wise

June 15, 2022 By EarthWise Leave a Comment

We hear a great deal about the environmental services provided by forests. Deforestation is one of the major factors contributing to increasing levels of carbon dioxide in the atmosphere. And, of course, forests – most notably rainforests – are major contributors to biodiversity. A new study by the U.S. Forest Service looked at the role forests play in providing water for Americans.

According to the study, published in the journal Water Resources Research, forested lands across the U.S. provide 83 million Americans with at least half of their water. 125 million people – well over a third of the country – receive at least 10% of their water from forests. Notably, in the drought-stricken western U.S., nearly 40 million people get more than half of their drinking water from forests that are increasingly threatened by wildfires.

The study looked at surface water sources for more than 5,000 public water systems. It provides a critical update to the map of where our water comes from. The study focused on surface waters such as lakes, rivers, and streams because it is too difficult to trace sources of groundwater on a national scale. Included is a new database of inter-basin water transfers, which are how surface water moves from places where it is plentiful to where it is not. Examples are the California Aqueduct and the Central Arizona Project which respectively supply Los Angeles and Phoenix with drinking water.

In Los Angeles, 69% of the water coming in through inter-basin transfers originated in forested lands. In Phoenix, the figure is 82%. There are many urban communities that obtain more than half of their drinking water from inter-basin transfers. Even far from forests, water from forests is essential for millions of Americans.

**********

Web Links

U.S. Forests Provide 83 Million People with Half Their Water

Photo, posted September 26, 2016, courtesy of Don Graham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.