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Deep Learning And Dirty Air | Earth Wise

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Poor air quality is a major global problem.  According to the World Health Organization, exposure to air pollution is linked to the premature deaths of an estimated seven million people every year.  In fact, 9 out of 10 people breathe air that contains more pollutants than what the WHO considers safe.  Air pollution is the fourth largest threat to human health, trailing only high blood pressure, dietary risks, and smoking.

But predicting pollution levels at a given place and time remains challenging.  According to a new study recently published in the journal Science of the Total Environment, scientists are turning to deep learning to improve air quality estimates. 

According to researchers, satellite observations and ground observations both measure air pollution, but both have major limitations.  For example, satellites may collect data at the same time and at the same location each day, but they miss how emissions may vary throughout the day.  Ground-based observations from weather stations do continuously collect data, but they only do so in a limited number of locations.    

As a result, scientists have turned to deep learning – a type of machine learning – to analyze the relationship between satellite and ground-based observations of nitrogen dioxide around Los Angeles.  Nitrogen dioxide is associated with emissions from traffic and power plants.  The researchers were able to rely on the learned relationship to take daily satellite observations and create hourly estimates of atmospheric nitrogen dioxide levels in approximately three mile grids.     

According to the research team, this study could be repeated for other greenhouse gases, and applied to different cities and regions – or even whole continents. 

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Scientists turn to deep learning to improve air quality forecasts

Air Pollution

Photo, posted November 4, 2019, courtesy of Ninara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Potential For Solar Canals In California | Earth Wise

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California’s network of almost 4,000 miles of aqueducts is the world’s largest water conveyance system.  It serves the state’s Central Valley which produces a quarter of America’s food.  About 20% of the nation’s groundwater demand is pumped from Central Valley aquifers.

A recent study by the University of California Santa Cruz and UC Merced has determined that covering these aqueducts with solar panels could be an economically feasible way to advance both renewable energy and water conservation.  California’s aqueducts might more properly be called canals because they are located at ground level.  

The concept of solar canals has been gaining increasing interest around the world as the changing climate leads to more droughts in many regions.  Placing solar panels above the canals can shade them to help prevent water loss through evaporation.  In addition, some types of solar panels can work better situated over canals because the cooler environment improves their operation.  In addition to the increased solar panel output and the water evaporation savings, shade from solar panels could help control the growth of aquatic weeds, which are a costly canal maintenance issue.

Spanning canals with solar panels can be accomplished either by using steel trusses or suspension cables, either of which is more expensive to build than ordinary ground-mounted solar panel supports.  But the research study showed how the benefits of solar canals combine to outweigh the added costs for cable-supported installations.

Apart from the economic benefits of a solar canal system, producing solar energy in the canal system could eliminate the use of 15-20 diesel-powered irrigation pumps, helping to reduce air pollution in a region with some of the nation’s worst air quality.

Solar canals could be a real winner.

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New analysis shows potential for ‘solar canals’ in California

Photo, posted July 23, 2015, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Silent Killer | Earth Wise

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Air pollution is deadly.  Studies have found that particles from air pollution can enter our lungs and bloodstream, contributing to major health conditions including heart disease, stroke, cancer, and kidney disease.  Globally, air pollution is responsible for the premature deaths of millions of people every year. 

The first line of defense against air pollution is ambient air quality standards.  But according to researchers from McGill University, more than half of the world’s population lives without the protection of adequate air quality standards.

The research team focused on a specific type of air pollution called particulate matter 2.5 (more commonly called PM2.5).  PM2.5 refers to tiny particles or droplets in the air that are two and one half microns or less in width.  These tiny particles are responsible for an estimated 4.2 million premature deaths every year globally, including more than one million deaths in China, nearly 200,000 in Europe, and more than 50,000 in the United States.

In the study, which was recently published in the Bulletin of the World Health Organization, the researchers found that where there are air quality protections, the standards are often worse than what the WHO considers safe.  Some regions with high air pollution levels, like the Middle East, don’t even measure PM2.5 air pollution.  The researchers found that the weakest air quality standards are often violated, while the strictest standards are often met. 

More than half of the world’s population is in urgent need of adequate air quality standards.   

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Air pollution: The silent killer called PM 2.5

Photo, posted November 17, 2019, courtesy of Kristoffer Trolle via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Allergies | Earth Wise

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According to a new study published in the Proceedings of the National Academy of Sciences, an addition to the many hardships that climate change is causing around the world is the fact that it is making allergy season worse.

Researchers have found that there is a strong link between planetary warming and pollen seasons.  The combination of warming air and higher levels of carbon dioxide in the atmosphere has caused North American pollen seasons since 1990 to start some 20 days earlier, on average, and to have 21% more pollen.

The most pronounced effects were seen in Texas, the Midwest, and the Southeast.  The effects were less obvious in the northern United States, including New England and the Great Lakes states.  The greatest pollen increases came from trees, as opposed to grasses and weeds.

Allergies do not just trigger sniffles and sneezes; they have serious effects on public health in the form of asthma and other respiratory conditions.  Studies have shown that students do less well in school during peak pollen season.  Of special concern at the moment is that high-pollen periods have been associated with greater susceptibility to respiratory viruses.  The U.S. has nearly 25 million people with asthma and 19 million adults reported hay fever in the past 12 months.  Research suggests that the early onset of pollen season correlates with a higher risk of hospitalization for asthma.

There are far fewer pollen monitoring stations than those measuring particle pollutants and air quality.  As the climate warms, we need to pay more attention to pollen as an airborne pollutant.

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Achoo! Climate Change Lengthening Pollen Season in U.S., Study Shows

Photo, posted May 18, 2012, courtesy of Forest Wander via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Increasing Air Pollution | Earth Wise

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According to researchers from the University of Exeter, half of the world’s population is exposed to increasing air pollution despite global efforts to improve air quality.  The study, which was completed in conjunction with the World Health Organization, suggests that air pollution represents a major and growing threat to human health. 

For the study, which was recently published in the journal Climate and Atmospheric Science, the researchers reviewed global air quality trends between 2010 and 2016.  The research team examined those findings against a backdrop of global policies to reduce air pollution.  The researchers used ground monitoring data and satellite data to develop yearly air quality profiles for individual countries and regions. 

The scientists focused on fine particulate matter, which is a mixture of solid particles and liquid droplets found in the air.  Some of the particles, like dust, soot, or smoke, are large enough to be seen by the naked eye.  Others are so small that they can only be seen using a microscope.  Inhaling fine particulate matter can cause all sorts of health issues, including asthma, respiratory inflammation, and even promote cancer. 

For much of the world’s population, the consequences of polluted air are more deadly than war, violence, and many diseases.  According to the World Health Organization, more than four million deaths every year can be attributed to outdoor air pollution.  Some of the major sources of air pollution include coal-fired power plants, agriculture, transportation, and deforestation. 

The study found that low and middle income countries experience the highest burden of air pollution around the world, with the largest concentrations found in central and southeastern Asia.

More long term policies are needed to curb this growing threat to public health. 

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Half of the world’s population exposed to increasing air pollution

Photo, posted August 2, 2019, courtesy of Ron Reiring via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Forest Regrowth In The Amazon | Earth Wise

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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.

Reducing Air Pollution With Plants | Earth Wise

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New research by Ohio State University suggests that adding plants and trees to the landscapes near factories and other pollution sources could reduce air pollution by an average of 27%.  In addition, the study indicates that, in many cases, plants may be a cheaper option for cleaning the air than more technological approaches.

The study looked at public data on air pollution and vegetation on a county-by-county basis across the lower 48 states. It then calculated what adding additional trees and plants might cost.  The calculations included the capacity of current vegetation to mitigate air pollution as well as the effects that restorative planting might have on pollution levels.

In 75% of the counties analyzed, it was cheaper to use plants to mitigate air pollution rather than add technological interventions such as smokestack scrubbers to the sources of pollution.  The results varied according to the pollution source.  For example, technology is cheaper at cleaning the air near industrial boilers than ecosystem approaches.  For the broad manufacturing industry, one approach or the other was favorable, depending on the type of factory.

Adding trees or other plants generally can lower air pollution levels in both urban and rural areas, although success rates depend on a variety of factors including how much land is available to grow new plants and current air quality.

Reducing air pollution is critical to public health.  An estimated 4 in 10 people in the U.S. live in areas with poor air quality, leading to health issues including asthma, lung cancer, and heart disease.  The study shows that nature should be part of the planning process for industry to deal with air pollution.

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Nature might be better than tech at reducing air pollution

Photo courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Air Quality In The U.S.

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Globally, poor air is a serious problem.  According to the World Health Organization, exposure to air pollution is linked to the premature deaths of an estimated 7 million people every year.  In fact, 91% of the people on the planet live in places where air pollution exceeds WHO guideline limits. 

In the United States, air pollution has dramatically improved over the last four decades due in large part to federal regulations put in place under the Clean Air Act of 1970.  Fine particulate matter (known as PM2.5) and other pollution, including ozone, sulphur dioxide, and nitrogen dioxide, have all decreased during this time span. 

But according to recent research, this trend has unfortunately done an about-face.  New data reveals that air pollution has increased nationally since 2016.  An analysis of Environmental Protection Agency data by researchers at Carnegie Mellon University found that, on average, fine particulate pollution increased 5.5% across the country between 2016 and 2018. 

This increase in fine particulate pollution was associated with nearly 10,000 additional premature deaths in the United States during that time period. 

According to researchers, there are several factors likely causing this uptick in unhealthy air, including increases in both driving and the burning of natural gas.  Wildfires out west are also thought to be a major contributor. 

The researchers also suggest that a decrease in enforcement of the Clean Air Act may also be playing a role.  The law put in place strict air pollution standards for vehicles, factories, power plants, and other sources, and is credited with saving hundreds of thousands of lives.

It’s time for clean air to be recognized as a basic human right.

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America’s Air Quality Worsens, Ending Years of Gains, Study Says

Photo, posted April 6, 2007, courtesy of Brett Weinstein via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Buses In Latin America

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Latin America has become increasingly urbanized.  In fact, about 80% of the region’s population lives in cities today and by 2050, that figure could climb to 90%.  Transportation is the largest and fastest-growing source of energy-related emissions in Latin America and accounts for about a third of all of the region’s carbon dioxide emissions. 

Private vehicle ownership is rising in Latin America but at the same time, the region’s rapidly growing cities have increased demand for buses, taxis, and motorcycles.  Currently, an estimated 64,000 people die prematurely every year in Latin America and the Caribbean as a result of air pollution, which is mostly caused by transportation emissions.

Given this situation, major cities across Latin America – from Colombia to Argentina – are starting to adopt electric bus fleets.   Latin America actually has the highest use of buses per person globally.  So, the transition to electric buses is an important step toward meeting climate targets, cutting fuel costs, and improving air quality.

Medellin, Colombia – whose metropolitan area has 3.7 million people – has started to add electric buses to its fleet, the rest of which runs on natural gas.  When new units arrive from China later this year, Medellin will have the second largest electric bus fleet in Latin America, after Santiago, Chile. 

Worldwide, 425,000 electric buses are in operation, 99% in China.  Europe has a couple of thousand while the United States has only 300.  But going forward, and especially in Latin America, electric buses are the wave of the future.  Estimates are that there will be 1.3 million on the roads by 2040.

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An Increasingly Urbanized Latin America Turns to Electric Buses

Photo, posted April 22, 2018, courtesy of Hans Johnson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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