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Turning Dead Trees Into Biomass Energy | Earth Wise

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California has suffered from numerous large wildfires in recent years.  The two largest in the past century took place in 2017 and 2018, and just these two alone burned nearly 750,000 acres, destroyed over 1,200 structures, and killed 24 people.

Apart from the fires, drought, the warming climate, and bark-beetle infestations have killed 147 million California trees since 2013, most of them along the spine of the Sierra mountains.  These dead trees represent a significant danger in forthcoming fire seasons as they threaten to burn with enormous intensity.

There are now biomass projects in California that thin trees in overcrowded forests and remove dead and diseased trees and turn them into wood chips to supply community biomass facilities that burn them to produce heat and electricity.

Proponents say these projects help rebuild rural communities by creating jobs, while at the same time reducing fire risk. 

There are critics of these programs who claim that they are damaging and destroying ecosystems.    They also point out that burning forest fuels emits 50% more carbon than burning coal and three times as much as burning natural gas.  This is true of biomass in general but is mitigated by the fact that it in principle the carbon can be recaptured by new forest growth.

However, the dominant argument about emissions is that wildfires emit far more carbon dioxide than biomass plants, or much of anything else, for that matter.  In 2018 alone, California wildfires released 50% more carbon dioxide than California’s entire industrial sector.  So, reducing the extent of wildfires is a big deal for many reasons.

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In California, A Push Grows to Turn Dead Trees into Biomass Energy

Photo, posted August 24, 2016, courtesy of the USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Dam Failures Likely | Earth Wise

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Two dams in Central Michigan were breached by rain-swollen floodwaters in May and forced the evacuation of tens of thousands of residents and prompted officials to warn of life-threatening danger from a flooded chemical complex and a toxic waste cleanup site.  Engineers say that most dams in the U.S. were designed many decades ago – in some cases, a century ago – and are not suited to a warming world with ever stronger storms.

The dams in Michigan gave way for the same reason behind most dam failures:  they were overwhelmed by water, in this case by five inches of rain falling over two days after earlier storms had saturated the ground and swollen rivers.

It can’t be proven whether this specific set of events was triggered by climate change, but global warming is definitely causing some regions to become wetter and is increasing the frequency of extreme storms.  And these trends are expected to continue as the world continues to warm.

All of this puts more of the 91,500 dams in the U.S. at greater risk of failing.  The American Society of Civil Engineers, in its latest report card on infrastructure issued in 2017, gave the nation’s dams a “D” grade.

Historically, dams have been designed based on past weather history to predict the magnitude of the maximum potential flood that a dam would have to withstand.  There was no expectation that future weather patterns might be very different.  Infrastructure designers will clearly need to change their practices.

For existing dams, operational changes might be called for, such as reducing water levels in anticipation of more extreme storms.  Upgrades might include changing spillway designs to accommodate larger water volumes over a longer time period.

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‘Expect More’: Climate Change Raises Risk of Dam Failures

Photo courtesy of Eye in the Sky/Youtube.

Earth Wise is a production of WAMC Northeast Public Radio.

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 Danger Of Relying On Future Technology | Earth Wise

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The need to mitigate the effects of climate change has been a global focus for about 40 years and has seen ever-changing views on what actions are needed.  The historical record has been defined by over-reliance on promises of new technology to solve climate change.  Looking to future technology to save the environment has been an excuse to postpone necessary action and avoid inconvenient changes in how we do things.

A study at Lancaster University in the UK published in Nature Climate Change exposes how such promises have raised expectations of more effective policy options becoming available in the future and have enabled the continued politics of inadequate action and skirting around the truth.

Even after four decades, rather than acting forcefully to reduce emissions, we are hoping that nuclear fusion power, giant carbon sucking machines, ice-restoration using vast numbers of wind-powered pumps, and spraying particulates into the atmosphere can address the climate crisis rather than dramatic changes in fossil fuel use.

The researchers mapped the history of climate targets in five phases.  Early on, the focus was on improved energy efficiency, large-scale enhancement of carbon sinks, and nuclear power.  Next, the focus was on cutting emissions with efficiency, fuel switching, and carbon capture and storage.  After that, bioenergy was the major focus.  Then, global carbon budgeting and potential negative emission technologies.  Currently, the focus is on temperature outcomes rather than emission targets.

Each novel promise competes with existing ideas and downplays any sense of urgency.   The researchers conclude that putting our hopes on yet more new technologies is unwise.  The time to act is now.

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Why relying on new technology won’t save the planet

Photo, posted February 13, 2019, courtesy of Jonathan Cutrer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Geoengineering And Volcanoes

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Solar geoengineering is a theoretical strategy for curbing the effects of climate change by introducing aerosol particles in the upper atmosphere to reflect some of the Sun’s radiation back into space and thereby cool the planet.  It would basically be intentionally tinkering with the climate system on a global scale.

The concept is fraught with the danger of unintended consequences and most experts consider the idea almost unthinkable.  But there are those who see it as a last resort if all our other efforts to mitigate the effects of climate change are unsuccessful.

Proponents of the idea like to describe the technique as being like a human-made volcano.  Major volcanic eruptions spew ash particles into the atmosphere which can linger for as long as a few years.  The result is cooler temperatures, sometimes across much of the globe.  The Krakatoa eruption of 1883 lowered average Northern Hemisphere temperatures by more than 2 degrees and created chaotic weather patterns until about 1888.

Researchers at the Carnegie Institution and two Chinese research institutions used sophisticated modeling techniques to compare the effects on the climate of a volcanic eruption with long-term geoengineering deployment.

They found that the volcanic eruption created a greater temperature difference between the land and sea than the geoengineering and resulted in very different precipitation scenarios.  In both cases, there would be less available water for people on land.

Overall, the study demonstrated that volcanic eruptions are imperfect analogs for geoengineering and that scientists should be very cautious about extrapolating too much from them.  It is important to evaluate geoengineering from an informed position, but the truth is that it represents a great and perilous unknown.

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Geoengineering Versus A Volcano

Photo, posted November 1, 2002, courtesy of the NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bananas In Danger

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For a few years we have been talking about the precarious position of the global banana crop, which is almost entirely based upon a single cloned cultivar known as the Cavendish banana.  The banana you buy in Rome is identical to the one in Rochester.  And therein lies the danger:  if a fungal blight can kill one banana shrub, it can kill them all.

For decades, a fungal disease known as Panama Disease Tropical Race 4 has been wreaking havoc on banana plantations in the Eastern Hemisphere.   Even though it was first identified in Taiwanese soil samples in the early 1990s, the destructive fungus remained confined to Southeast Asia and Australia until it was confirmed in both the Middle East and Africa in 2013.  Experts continued to fear its eventual appearance in Latin America, which is the epicenter of the global banana export industry.

In August, Colombian agricultural authorities announced that laboratory tests have positively identified the presence of Tropical Race 4 in the Caribbean coastal region and declared a national state of emergency.

The infection of the banana plant does not produce bananas that are unsafe for humans.  What happens is that the infected plants eventually stop bearing fruit.

Cavendish bananas are a prime example of the dangers of growing crops with limited genetic diversity – known as monoculture.  It leaves food systems dangerously vulnerable to disease epidemics.

This has happened to the global banana crop before when the predecessor to the Cavendish banana – the Gros Michel – was mostly eradicated by another fungal outbreak.  At the moment, there is no ready replacement banana to bail out the industry, but scientists are desperately trying to breed one.  In the meantime, the world’s supply of bananas is in real danger.

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The banana is one step closer to disappearing

Photo, posted July 9, 2009, courtesy of Dabin Lambert via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fish And Their Sense Of Smell

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We use our sense of smell for all sorts of things, like locating food and habitat, avoiding danger, and so on.  Fish do as well.  But instead of smelling scent molecules in the air like humans do, fish use their nostrils to sense chemicals suspended in water.  

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Genetic Engineering And Conservation

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Genetic engineering, or equivalently synthetic biology, is a multi-billion-dollar enterprise involved in pharmaceuticals, chemicals, biofuels and, of course, agriculture.  In these fields, it is already the source of a great deal of controversy.  But there is increasing interest in using synthetic biology (or synbio) technology as a tool for protecting the natural world, which is a prospect some find tantalizing and others find absolutely terrifying.

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Use-By Labels And Food Waste

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By some estimates, Americans waste as much as 40% of food that is produced.   None of the reasons are anything to be proud of, but one of the most frustrating is the confusing array of food date labels that are supposed to tell us whether the food we purchased should be eaten.

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Trouble For Vultures

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When we think of vultures, we picture big, ugly birds circling over a carcass in the desert.  They are a stereotypical harbinger of death.  But in many parts of the world, vultures are in danger of disappearing.  Our knee-jerk reaction might well be “good riddance”, but as is the case for pretty much all participants in ecosystems, vultures have an important role to play.  And when they aren’t around to play that role, bad things can happen.

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