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Extreme Heat And Humidity | Earth Wise

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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 95o 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 88o, 250 above 91o, and multiple reading above 95o.  Even at lower wet-bulb temperatures around 80o, 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

Photo, posted April 16, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Lockdown Cleans Up Indian Air | Earth Wise

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Our stories often discuss how human activities change the natural environment.  With most of us confined to our homes, the lack of human activities is having profound effects on the environment.  We are talking about some of these this week.

India suffers from some of the worst air pollution in the world.  Of the most polluted cities in the world, 21 out of 30 were in India in 2019.  According to World Health Organization standards, at least 140 million people in India breathe air containing 10 times or more greater levels than the safe limit for pollutants.  Air pollution contributes to the premature death of 2 million Indians every year.

Half of India’s air pollution comes from industry, 27% from vehicles, and 17% from crop burning.  Crop burning is prevalent because it is much cheaper than mechanical tilling after the harvest.

On March 25, the Indian government placed its 1.3 billion citizens under a strict lockdown to reduce the spread of COVID-19.   The country-wide mandate decreased activity at factories and drastically reduced car, bus, truck, and airplane traffic.

Within one week, NASA satellite sensor observed aerosol levels at a 20-year low for this time of year in northern India.  Aerosols are tiny solid and liquid particles suspended in the air that reduce visibility and can damage the human lungs and heart.  Some aerosols have natural sources, such as dust storms, volcanic eruptions, and forest fires.  But many come from human activities such as the burning of fossil fuels and croplands.  Scientists expected to see changes in atmospheric conditions during the Indian lockdown, but the current changes are dramatic.  They also present a unique opportunity to separate how natural and human sources of aerosols affect the atmosphere.

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Airborne Particle Levels Plummet in Northern India

Photo, posted April 29, 2020, 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.

Forecasting A Bad Year For Carbon

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Carbon dioxide levels in the atmosphere are higher than they have been for hundreds of thousands of years, and they continue to grow.  The United Kingdom’s national meteorological service – known as the Met Office – issues annual predictions of global CO2 levels based in part on readings taken at the Mauna Loa observatory in Hawaii.  Their forecast for this year is that there will be one of the largest rises in atmospheric carbon-dioxide concentration in the 62 years of measurements at Mauna Loa.

Since 1958, there has been a 30% increase in the concentration of carbon dioxide in the atmosphere.  This has been caused by emissions from fossil fuels, deforestation and cement production.  The increase would actually have been even larger if it were not for natural carbon sinks in the form of various ecosystems that soak up some of the excess CO2.

Weather patterns linked to year-by-year swings in Pacific Ocean temperatures are known to affect the uptake of carbon dioxide by land ecosystems.  In years with a warmer tropical Pacific – such as El Niño years – many regions become warmer and drier, which limits the ability of plants to grow and to absorb CO2 .  The opposite happens when the Pacific is cool, as was the case last year.

The Met Office predicts that the contribution of natural carbon sinks will be relatively weak, so the impact of human-caused emissions will be larger than last year.  The predicted rise in atmospheric CO2 is 2.75 parts-per-million, which is among the highest rises on record.  The forecast for the average carbon dioxide concentration is 411 ppm, with peak monthly averages reaching almost 415 ppm.  With global emissions not really declining, the numbers just get higher and higher.

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Faster CO₂ rise expected in 2019

Photo, posted March 18, 2006, courtesy of Darin Marshall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Indonesian Deforestation

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Deforestation is defined as the intentional destruction of trees and other vegetation without reforesting or allowing the forest to regenerate itself. 

In Indonesia, industrial agriculture, primarily for the production of palm oil, is a major driver of deforestation.  But, according to researchers at Duke University, its impact has diminished  proportionately in recent years as other natural and human causes have emerged. Their peer-reviewed findings were recently published in the journal Environmental Research Letters.

According to the study’s lead author, large-scale plantations were responsible for more than half of Indonesia’s deforestation in the late 2000s, peaking between 2008-2010 when an average of 1.5 million acres of forest was lost annually.  The expansion of the massive plantations was responsible for 57% of the forest loss. Between 2014-2016, an average of more than 2 million acres of forest was lost annually, but plantation expansion only accounted for 25% of this figure.  While the overall rate of deforestation continued to grow, other factors were responsible for most of it.

Conversions of forests to grasslands rose sharply in 2015 and 2016 when El Nino caused severe droughts and forest fires. Small-scale farming, often overshadowed by industrial agriculture, was also found to play a bigger role, accounting for 25% of all forest loss. 

Indonesia has experienced some of the highest rates of deforestation.  Its forests absorb and store vast amounts of climate-warming carbon dioxide, help prevent erosion and flooding, and provide habitat to thousands of species.  Understanding the varied causes of Indonesian deforestation should help conservationists and policymakers better address the problem.

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Palm oil not the only driver of forest loss in Indonesia

Photo, posted March 26, 2018, courtesy of Achmad Rabin Taim via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfire Pollution

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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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California’s 2018 Wildfires Have Emitted A Year’s Worth of Power Pollution

Photo, posted October 11, 2017, courtesy of Bob Dass via Flickr. 

Earth Wise is a production of WAMC Northeast Public Radio.

Greenhouses Adapt To Climate Change

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The Telangana region of India has struggled with extreme weather patterns attributed to climate change.  Extended periods of drought, heatwaves, and unpredictable heavy rainfalls have led to crop failures, mounting debt, and a heavy human toll.  More than 3,000 farmers committed suicide in Telangana during a three-year drought.

[Read more…] about Greenhouses Adapt To Climate Change

Saildrones For Science

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Nine years ago, engineer Richard Jenkins broke the world land speed record for a wind-powered vehicle with a sailboat on wheels driving across a dry lakebed at 126 miles per hour.  After years of engineering development, his technology has now taken on the form of a saildrone that can autonomously sail the sea gathering ecologic, oceanic and atmospheric data.

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V2V And Safer Cars

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Automated cars are coming, but they face many challenges in sharing the roads with human drivers.  The on-board sensors in these cars are very effective in many ways, but they cannot see around corners or see through buses or trucks.  They won’t know if six cars ahead, someone has slammed on their breaks leading to a chain-reaction collision.  Of course, human drivers have the same problems.

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How Safe Is Drinking Water?

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Water is life.  It’s a fundamental need for every human being on the planet.  Each person requires more than five gallons of clean and safe water a day for drinking, cooking, and keeping clean.  Dirty water, on the other hand, can be deadly.  An estimated 1.8 million people die every year as a result of diarrheal diseases like cholera.  And tens of millions of people are seriously sickened by water-related maladies. 

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Learning From Fire

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The Tubbs Fire was the huge wildfire that burned parts of Napa, Sonoma and Lake counties in Northern California in October.  Between that fire and several smaller ones going on at the same time, at least 43 people died and over 8,400 homes and buildings were destroyed.  The Tubbs Fire alone burned over 36,000 acres. The even larger December wildfires in Southern California scorched hundreds of thousands of acres in multiple counties.

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Being Ready For Adverse Weather

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Severe weather is a major cause of death and destruction.   Recent hurricanes provided all too many examples.   The catastrophic flooding from Hurricane Harvey led to more than 60 deaths and necessitated thousands of emergency rescues.   And yet, increasingly, weather events like hurricanes don’t occur without warning and accurate weather forecasts are increasingly common.

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Removing Heavy Metals From Water

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Clean and abundant water is the most essential need for all human societies and the supply of it is threatened by increasing populations and volatile climate patterns.   The quality of water is threatened by a host of contaminants, most of our own making.

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The Great Salt Lake Is Shrinking

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Utah’s Great Salt Lake is the largest salt water lake in the Western Hemisphere and is the largest body of water in the United States after the five Great Lakes.  When the pioneers first arrived in the area back in the middle of the 19th century, the lake spread across about 1,600 square miles.   Now, the lake covers an area of only about 1,050 square miles, a reduction of about 35%.

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Wilderness Lost

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Wilderness areas are strongholds for biodiversity.  They buffer and regulate local climates, and they support many of the world’s most politically and economically marginalized communities.  While there is a great deal of attention being paid to the loss of species around the world, there is relatively little focus on the loss of entire ecosystems.  Simply put, wilderness is on the decline, and it has been ever since human civilization began its inexorable expansion.

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Energy Intensity

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Every stage of civilization is characterized by its use of energy.   From burning wood to steam engines to our electrified society, energy is behind everything we do.  Over time, human society has become increasingly energy intensive.  As our standards of living have improved and as we overcome the effects of weather – either cold or warm – it takes more and more energy to live the lives we lead.

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