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Deadly Urban Heat On The Rise | Earth Wise

November 9, 2021 By EarthWise Leave a Comment

According to a new study by the Columbia Climate School, exposure to deadly urban heat has tripled since the 1980s. The increase is the combined result of both rising global temperatures and booming urban population growth.

The study looked at more than 13,000 cities worldwide and found that incidents of extreme heat and humidity have increased dramatically. It defined extreme heat as 30 degrees Celsius on the wet-bulb temperature scale that takes into account the effect of high humidity. In 1983, there were 40 billion person-days under such conditions. By 2016, the number was 119 billion. More specifically, in 2016 1.7 billion people were subjected to such conditions on multiple days.

Sheer urban population growth accounted for two-thirds of the increase, while actual warming contributed a third. Over recent decades, hundreds of millions of people have moved from rural areas to cities, which now hold more than half the world’s population. And because of the urban heat island effect, temperatures in cities are generally higher than in the countryside.

In the United States, about 40 sizable cities have seen rapidly growing exposure to extreme heat, mainly clustered in Texas and the Gulf Coast. Globally, nearly a quarter of the world’s population is affected by the increased incidence of extreme temperatures.

A study last year showed that combinations of heat and humidity literally beyond the limits of outdoor human survival have been popping up around the world. A wet-bulb temperature reading of 30 – equivalent to 106 degrees Fahrenheit on the “real feel” heat index – is the point at which even most healthy people find it hard to function outside for long, and the unhealthy might become very ill or even die.

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Exposure to Deadly Urban Heat Worldwide Has Tripled in Recent Decades, Says Study

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Earth Wise is a production of WAMC Northeast Public Radio.

The Silent Killer | Earth Wise

April 26, 2021 By EarthWise Leave a Comment

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.

Increasing Air Pollution | Earth Wise

July 27, 2020 By EarthWise Leave a Comment

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.

Extreme Heat And Humidity | Earth Wise

June 15, 2020 By EarthWise Leave a Comment

On hot, sticky summer days, one often hears the expression “it’s not the heat, it’s the humidity.” That isn’t just an old saw; it is a recognition of what might be the most underestimated direct, local danger of climate change. Extreme humid heat events represent a major health risk.

There is an index called “wet-bulb temperature” that is calculated from a combination of temperature and humidity data. The reading, which is taken from a thermometer covered in a wet cloth, is related to how muggy it feels and indicates how effectively a person sheds heat by sweating. When the wet-bulb temperature surpasses 95^o Fahrenheit, evaporation of sweat is no longer enough for our bodies to regulate their internal temperature. When people are exposed to these conditions for multiple hours, organ failure and death can result.

Climate models project that combinations of heat and humidity could reach deadly thresholds for anyone spending several hours outdoors by the end of this century.

Dangerous extremes only a few degrees below the human tolerance limits – including in parts of the southwestern and southeastern US – have more than doubled in frequency since 1979. Since then, there have been more than 7,000 occurrences of wet-bulb temperatures above 88^o, 250 above 91^o, and multiple reading above 95^o. Even at lower wet-bulb temperatures around 80^o, people with pre-existing health conditions, the elderly, as well as those performing strenuous outdoor labor and athletic activities, are at high risk.

More research is needed on the factors that generate extreme wet-bulb temperatures as well as the potential impacts on energy, food systems, and human security.

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Dangerous Humid Heat Extremes Occurring Decades Before Expected

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Earth Wise is a production of WAMC Northeast Public Radio.

More Extreme Wildfire Seasons | Earth Wise

April 29, 2020 By EarthWise Leave a Comment

According to a new study led by researchers at Stanford University, autumn in California feels more like summer now as a result of climate change, and this hotter and drier weather increases the risk of longer and more dangerous wildfire seasons.

The research team, whose work was recently published in the journal Environmental Research Letters, found that the frequency of extreme fire weather conditions in the fall in California has doubled since the early 1980s. Average temperatures during the season have increased by more than 2 degrees Fahrenheit, and rainfall has fallen by approximately 30%. The most pronounced warming has occurred in the late summer and early fall. That finding means that tinder-dry conditions coincide with the strong “Diablo” and “Santa Ana” winds that are typical in California at this time of year.

In recent years, these conditions have fed large and fast-moving wildfires across California. The state’s two largest wildfires, two most destructive wildfires, and the most deadly wildfire all occurred during 2017 and 2018, resulting in more than 150 deaths and $50 billion in damage.

Because summertime has typically been peak fire season, the recent spate of autumn fires is putting a strain on firefighting resources and funding. The ongoing COVID-19 pandemic could further strain emergency resources. Since fire-prone regions have historically shared wildfire-fighting resources throughout the year, the consequences of California’s extended wildfire season could have a global impact. (For example, California’s recent autumn wildfires have coincided with the beginning of wildfires in Australia).

The researchers highlight some opportunities to manage the intensifying wildfire risk in California, including limiting the trajectory of global warming in keeping with the targets identified in the United Nations’ Paris agreement.

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Researchers forecast longer, more extreme wildfire seasons

Photo, posted September 12, 2019, courtesy of the California National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Predicting Lightning Strikes

November 19, 2019 By EarthWise Leave a Comment

Lightning is one of the most unpredictable phenomena in nature. Approximately 100 lightning bolts strike earth’s surface every second, and each lightning bolt can contain up to one billion volts of electricity. Lightning regularly kills both people and animals and sets homes and forests on fire. It’s also been known to ground airplanes.

Researchers at EPFL – a research institute and university in Switzerland – have developed a novel way to predict where and when lightning will strike. The system relies on a combination of standard data from weather stations and artificial intelligence to predict lightning strikes to the nearest 10 to 30 minutes and within a radius of less than 20 miles. The simple and inexpensive system was outlined in a research paper recently published in Climate and Atmospheric Science, a Nature partner journal.

According to researchers, the current systems for predicting lightning strikes are slow, expensive, and complex, relying on external data acquired by satellite and radar. The new inexpensive system from EPFL uses real time data that can be obtained from any weather station, meaning it can cover remote regions that are out of radar and satellite range and where communication networks are lacking. The quick predictions from the system allow alerts to be issued before a storm has even formed.

The system uses a machine-learning algorithm that’s been trained to recognize conditions that lead to lightning. The researchers took into account atmospheric pressure, air temperature, relative humidity, and wind speed, among other things. After training the algorithm, the system was able to predict lightning strikes accurately nearly 80% of the time.

This system is a simple way to predict a complex phenomenon.

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Using AI to predict where and when lightning will strike

Photo, posted December 14, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Frogs Are In Big Trouble

May 22, 2019 By EarthWise Leave a Comment

Scientists first noticed in the 1970s that some frog populations were declining rapidly. By the 1980s, some species appeared to be extinct. The loss of frog species was mysterious because many were actually living in pristine habitats that did not face pollution or deforestation.

By the late 1990s, researchers had identified that frogs in widely different places around the world were infected with a deadly fungus called Batrachochytrium dendrobatidis – or Bd for short. The fungus originated on the Korean peninsula, but the pathogen spread throughout the world, probably via the international trade in pet amphibians. By 2007, researchers speculated that Bd might be responsible for all known declines of frogs that had no other apparent cause – about 200 species.

Recently, a group of 41 scientists published the first worldwide analysis of the fungal outbreak and the devastation turns out to be far worse than anyone had previously realized. Populations of more than 500 species of amphibians have declined significantly because of the outbreak, including at least 90 species presumed to have gone extinct. These figures are more than twice as large as earlier estimates.

According to biologists, Bd is now considered to be the deadliest pathogen known to science. But the decimation of frogs peaked in the 1980s. Today, although 39% of the species that suffered population declines in the past are still declining, 12% are showing signs of recovery, possibly because natural selection is favoring resistant animals.

There is cautious optimism for the surviving amphibian species, but scientists worry that another strain of Bd or some different species of fungus altogether may prove even deadlier. The best we can do is not participate in moving pathogens around the world.

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The Plague Killing Frogs Everywhere Is Far Worse Than Scientists Thought

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Earth Wise is a production of WAMC Northeast Public Radio.

Reducing Polar Bear Attacks

April 8, 2019 By EarthWise Leave a Comment

The increasing reduction of sea ice in the Arctic is changing the behavior of polar bears. Because they are spending more time on land, they are interacting with people much more frequently, occasionally with deadly results.

A study, published in 2017, looked at 144 years’ worth of polar bear attacks on humans in the Arctic. Between 1960 and 2009, there were a reported 47 attacks by polar bears on people – between 7 and 12 per decade. Between 2010 and 2014, as sea ice reached record lows, there were 15 attacks, a record for a four-year period. Since 2000, 88% of attacks have occurred between July and December, when sea ice is at its lowest level of the year.

Last July, a young male polar bear attacked and killed a man who was berry picking with his children. A month later, a mother polar bear attacked and killed an Inuit hunter and injured two others. This was the first known fatal attack by a mother polar bear.

As a result, Inuit communities in the Nunavut region are asking for higher legal polar bear harvest quotas, arguing that bear populations have increased to a dangerous level.

These recent human fatalities have also provided an impetus for developing new non-lethal conflict-resolution tools than can be used in northern communities before more people as well as bears are killed.

There are now polar bear patrol teams tasked with driving bears away from settlements. There is a bear hotline and electric fencing around sled dog compounds.

The changing face of the Arctic is creating growing stress on the polar bear population and on the people who make their home in that region.

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As Polar Bear Attacks Increase in Warming Arctic, a Search for Solutions

Photo, posted September 28, 2015, courtesy of Anita Ritenour via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfire Pollution

January 24, 2019 By EarthWise Leave a Comment

California’s record-breaking wildfires this past season have been an unmitigated disaster with respect to loss of life, property, impact on human health, and in multiple other ways. And as if all of that was not bad enough, the impact on carbon emissions into the atmosphere was equally catastrophic. The wildfires were deadly and cost billions of dollars but were also terrible for the environment and for the public’s health.

According to estimates from the U.S. Department of the Interior, the California wildfires released emissions equivalent to about 68 million tons of carbon dioxide into the atmosphere. That is equal to the emissions from generating one year’s worth of electricity in the state, or about 15% of the total annual emissions in the state of California.

It is a vicious circle in which the changes to the climate that have lengthened the fire season and shortened the precipitation season are creating additional contributions to the warming of the climate.

Over the past century, California has warmed by about 3 degrees Fahrenheit. That extra-warmed air sucks water out of plants and soils, resulting in trees, shrubs, and rolling grasslands that are dry and primed to burn. That vegetation-drying effect compounds with every additional degree of warming. Plants lose their water more efficiently as temperatures get higher.

The result is that wildfires are increasing in size both in California and across the western United States. Fire experts at Columbia University estimate that since the 1980s, the warming climate has contributed to an extra 10 million acres of burning in western forests – an area about the size of Massachusetts and Connecticut combined.

It’s a bad situation that is getting worse.

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