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Geothermal Energy Storage | Earth Wise

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About 12% of the energy consumed by humanity is used to heat and cool homes and businesses.  A study by researchers at Lawrence Berkeley National Laboratory and Princeton University looked at a novel approach to making use of underground water to maintain comfortable temperatures and reduce consumption of natural gas and electricity.

The idea is to use aquifer thermal energy storage (known as ATES) to provide both heat in the winter and cooling in the summer.  The concept leverages the heat-absorbing property of water and natural geological features.  The idea is to pump up water from existing underground reservoirs and heat it at the surface using environmental heat or even excess energy from solar or wind generation.  Then the warm water is pumped back down. It stays warm for a long time – even months – because the earth is a good insulator.  When the water is pumped back up in the winter, it is much hotter than the ambient air and can be used to supply heat to buildings.

Alternately, water can be pumped up and cooled in the winter and then put back down underground and stored until cooling is needed in the summer months.

This technology has not been used much in the US, but it is gaining recognition internationally, particularly in the Netherlands.  It can perform very well in areas with large seasonal fluctuations.

The research study used modeling and various simulations to estimate how much energy ATES could save on the US grid.  The results showed that adding ATES to the grid could reduce consumption of petroleum products for heating and  cooling by up to 40%.  The system could also help prevent blackouts by reducing high power demand during extreme weather events.

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Underground Water Could be the Solution to Green Heating and Cooling

Photo, posted February 19, 2012, courtesy of Sanjay via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Salt Marshes And Climate Change | Earth Wise

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Salt marshes are coastal wetlands that are flooded and drained by salt water brought in and out by the tides. These low-lying wetlands are also sometimes called tidal marshes because they occur in the zone between low and high tides. These wetlands are some of the most biologically productive ecosystems on Earth.

Cape Cod’s beautiful salt marshes are as important as they are iconic.  They act as carbon sinks, protect coastal development from storm surge, play an outsized role in nitrogen cycling, and provide critical habitats for many fish, shellfish, and coastal birds.

According to scientists from the Marine Biological Laboratory in Woods Hole, Massachusetts, more than 90% of salt marshes around the world are likely to be underwater by the end of the century. 

Since 1971, scientists from the Marine Biological Laboratory have mapped vegetative cover in Great Sippewissett Marsh in Falmouth, Massachusetts, to examine whether increased nitrogen in the environment would impact species of marsh grass.  Because of the length of the study, the researchers were also able to investigate the impacts of climate change on the ecosystem, especially those driven by accelerating sea level rise. 

The research team found that increased nitrogen favored higher levels of vegetation and accretion of the marsh surface.  However, the researchers found that salt marshes will not be able to outpace the submergence from global sea level rise – no matter how much nitrogen is applied.

Sea level rise is the biggest threat to salt marshes around the world.  Mitigating some of these projected losses is critical in order for salt marshes to continue to provide their important ecosystem services for people and the planet.  

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Most of the World’s Salt Marshes Could Succumb to Sea Level Rise by Turn of Century

Photo, posted September 27, 2011, courtesy of Chris M Morris via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Counting Trees | Earth Wise

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Scientists estimate that there are about 3 trillion trees on the earth.  A huge number but probably half as many as there were before people entered the picture.  And we’re losing about 10 billion trees a year to toilet paper, timber, farmland expansion, and other human activity.  Trees play a crucial role in taking carbon dioxide out of the atmosphere and storing it away.  For this reason, trees have become an integral part of the effort to mitigate climate change.

There are major initiatives underway around the world to plant more trees.  Part of this is driven by the increasing use of carbon credits by companies trying to offset their carbon emissions.   These credits are earned by either planting new trees or paying farmers or other landowners not to cut down existing trees.  But how many trees are actually planted and how many survive over time?

Whether these efforts are really resulting in more trees and more carbon storage is not easy to determine.  Current international inventories of global tree-sequestered carbon are subject to great uncertainty.

Researchers from the University of Copenhagen and NASA have developed a method for mapping large numbers of trees and determining their carbon content.  Using artificial intelligence techniques to analyze ultra-high-resolution satellite images, they can count trees, determine their individual species, and measure their carbon content.

A study of images from Africa’s Sahel region found that it is home to nearly 10 billion trees that are currently storing 840 million tons of carbon.

Now that the groundwork for this new methodology is complete, it is ready to be deployed by public agencies, NGOs, and other interested in monitoring the numbers of trees and their carbon content.

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The counting of nine billion trees could help manage climate credits and nature restoration

Photo, posted October 27, 2018, courtesy of Ian Dick via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Humanity Weighs On The World | Earth Wise

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There are countless ways in which humankind has had disproportionate effects on our planet and most of those effects have been negative.  A recent study led by the Weizmann Institute of Science in Israel looked at the total combined weight of various groups of mammals on Earth.  The results are that human beings and our domesticated mammals are the overwhelming majority of the total mass of mammals.

We think of large land mammals – elephants, bears, bison, wildebeests, and so on – as adding up to a massive amount of animal matter.  The study determined that all wild land mammals put together add up to about 22 million metric tons. Wild marine mammals – such as dolphins and whales – add up to about 40 million tons in total.  These sound like pretty big numbers until we look at the human and human-created side of the equation.

The study found that humans weigh about 390 million metric tons, while domesticated mammals – like sheep, cows, and pigs as well as dogs and cats – weigh about 630 million metric tons combined.

All told, wild mammals account for only 6% of all mammals by weight.   People and their domesticated animals make up the other 94%.  This enormous imbalance is an indication of how profoundly humans have reshaped life on Earth.  House cats total twice the weight of African elephants and pigs add up to twice the weight of all wild land animals combined.

The conclusion to draw from the big picture here is that wild animals on Earth are not doing very well.  We already knew this from many other perspectives, but this census by weight presents a stark picture of the extent to which we have taken over the planet and its ecosystems.

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Total Weight of Wild Land Mammals Less Than One-Tenth Weight of All Humans

Photo, posted December 27, 2006, courtesy of Nigel Hoult via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protected Areas Are Not Protecting Insects | Earth Wise

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Insects can be found in every environment on Earth and play crucial roles in the planet’s ecosystems.  In fact, Biologist E. O. Wilson once said that “if all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago.  If insects were to vanish, the environment would collapse into chaos.”

While his statement may sound extreme, it’s really not an exaggeration.  Insects are critical to most ecosystems.  They pollinate more than 80% of plants – both those we eat and those that provide food and habitat for other species.  Insects are also a food source themselves, eaten by other insects, birds, fish, and mammals. Without insects, we wouldn’t have the rich biodiversity that supports life on earth today. 

But insect populations are collapsing around the globe, and they continue to be overlooked by conservation efforts.  Protected areas, like national parks, refuges, and sanctuaries, can safeguard threatened species, but only if those threatened species actually live within the protected areas. 

According to a new study recently published in the journal One Earth, 76% of insect species are not adequately covered by protected areas, including several critically endangered insects such as the dinosaur ant, crimson Hawaiian damselfly, and harnessed tiger moth. Alarmingly, the populations of 1,876 species do not overlap with protected areas at all.

Insects have been historically overlooked by conservation programs and need to be included in future conservation assessments. 

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Protected areas fail to safeguard more than 75% of global insect species

Photo, posted August 21, 2014, courtesy of Andy Reago & Chrissy McClarren via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic From Sunlight | Earth Wise

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Photosynthesis is the process that plants use to turn water, carbon dioxide, and energy from sunlight into plant biomass.  It provides humans and much of animal life with food.  Photosynthesis is also nature’s way of reducing the amount of carbon dioxide in the atmosphere.  The CO2 is not directly stored in plants but rather is combined into organic compounds.

Researchers across the globe are trying to find effective ways to mimic photosynthesis.  One version of artificial photosynthesis seeks to take carbon dioxide and combine it into organic compounds that can be used as raw materials for various kinds of manufacturing. 

A research team in Japan has found a way to synthesize fumaric acid from carbon dioxide using sunlight to power the process.  Fumaric acid is a chemical typically synthesized from petroleum and is used as a raw material for making biodegradable plastics such as polybutylene succinate. 

Much of artificial photosynthesis research is aimed at using solar energy to convert carbon dioxide directly into a fuel rather than a raw material.  Such solar fuels can be produced by a variety of means including thermochemical (using the sun’s heat to drive chemical reactions), photochemical (using the sun’s light to drive chemical reactions), and electrochemical (using solar-generated electricity to drive chemical reactions.)   These approaches generally involve the use of specialized catalysts to drive the desired chemical reactions. 

One way or another, what techniques for artificial photosynthesis have in common is trying to imitate what plant life on Earth has been doing for millions of years. 

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Artificial photosynthesis uses sunlight to make biodegradable plastic

Photo, posted June 14, 2017, courtesy of Alex Holyake via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Harvesting Fresh Water From Ocean Air | Earth Wise

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Roughly three-quarters of the world population has access to a safely managed water source.  That means that one-in-four people do not have access to safe drinking water.  Even in the wealthy United States, persistent drought in the west is creating problems in places like Phoenix, Arizona.

Water is plentiful on Earth but more than 99% of it is unusable by humans and many other living things because it is saline, frozen, or inaccessible.  Only about 0.3% of our fresh water is found in the surface water of lakes, rivers, and swamps.

There is an almost limitless supply of fresh water in the form of water vapor above the oceans, but this source is untapped.  Researchers at the University of Illinois have been evaluating the feasibility of a hypothetical structure capable of capturing water vapor from above the ocean and condensing it into fresh water.

Existing ways to obtain fresh water like wastewater recycling, cloud seeding, and desalination have met only limited success and present various problems with regard to cost, environmental impact, and scalability.

The researchers have proposed hypothetical large offshore structures measuring 700 feet by 300 feet to capture water vapor that is continually evaporating from the ocean in subtropical regions.   Their modeling concluded that such structures could provide fresh water for large population centers in the subtropics.  Furthermore, climate projections show that the amount of water vapor over the oceans will only increase over time, providing even more fresh water supply.

This is only a theoretical study at this point, but the researchers believe it opens the door for novel infrastructure investments that could address global water scarcity.

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Researchers propose new structures to harvest untapped source of fresh water

Photo, posted June 28, 2009, courtesy of Nicolas Raymond via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

It Really Is Greenhouse Gases | Earth Wise

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The scientific consensus that human-generated carbon dioxide is changing the climate began to form in the 1980s. 

For a long time, the changes to the climate were simply denied.  After a while, as those changes became increasingly hard to ignore, the argument shifted to the changes being real but not caused by anything people are doing.  The multi-trillion-dollar fossil fuel industry was strongly motivated to focus attention away from the association between carbon dioxide and climate change.

The greenhouse gas effect has been known since the 19th century.  It isn’t just real; it is essential to life on earth.  Without sufficient levels of carbon dioxide in the atmosphere to trap some of the sun’s heat, the earth would be an ice planet incapable of supporting much in the way of life.  But there can be too much of a good thing.

Naysayers continue to grasp at alternative explanations for the warming planet rather than the inconvenient truth.  Some people try to claim that it is the release of heat from all our energy-generating activities -power plants, heaters and air conditioners, vehicles, and so on – that is warming the planet.

That issue has been studied in detail.  Human activity does generate a lot of heat and, technically speaking, that heat does help warm the planet.  However, the sun dumps 10,000 times more heat on the earth than all of human energy production added together.  Just the normal fluctuations in solar energy are 10 times larger than everything we do put together.

What is increasingly warming the planet is not the continuing energy striking the earth; it is primarily the fact that growing levels of greenhouse gases in the atmosphere are trapping more and more of that heat and preventing it from escaping into space.

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Integrating anthropogenic heat flux with global climate models

Photo, posted August 25, 2009, courtesy of Gerald Simmons via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Insects In A Changing Climate | Earth Wise

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Insects can be found in every environment on Earth and are critical components of many ecosystems.  They perform countless important functions, including aerating and fertilizing soil as well as pollinating flowers.  In fact, according to the USDA, 75% of the world’s flowering plants and about 35% of the world’s food crops depend on animal pollinators, the majority of which are insects, to reproduce.

According to a study published in the journal Nature earlier this year, the combination of climate change and intensive agriculture is having a profound impact on both the abundance and diversity of insects.  In regions where substantial warming had occurred and where land had been converted for intensive farming, insects were nearly 50% less abundant and more than 25% fewer species were observed.  Tropical regions were among those most at risk for heavy losses.

According to a new study recently published in the journal Global Change Biology, tropical insects will be even more susceptible to climate change than previously thought.  In a five-year study conducted in Peru, researchers from the Florida Museum of Natural History found that insect populations declined 50% following short periods of drought and following short periods of heavy rainfall.  Insect populations decreased after three months of dry weather, but also decreased after three months of exceptionally wet weather.   

Researchers have known that tropical insects don’t tend to do well when their habitats dry out.  But the researchers were surprised to discover that these insects were equally averse to increased precipitation.  Alarmingly, precipitation is expected to become more frequent and more intense as a consequence of the changing climate. 

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Tropical insects are extremely sensitive to changing climates

Photo, posted June 11, 2016, courtesy of Z. Leng via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The U.S. Ratifies A Climate Treaty | Earth Wise

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In a rare display of bipartisanship, the U.S. Senate voted 69-27 in favor of ratifying a key international climate agreement aimed at curbing global warming.  The Kigali Amendment to the Montreal Protocol, which has been ratified by 137 other countries so far, ends the use of climate-warming hydrofluorocarbons that are 1,000 times more potent than carbon dioxide in warming the atmosphere.   This is the first international climate treaty that the U.S. has joined in 30 years.

The Kigali Agreement was established in Kigali, Rwanda in 2016 to phase out HFCs, which have been the replacements for CFCs (chlorofluorocarbons) in air conditioners and refrigerators.  CFCs were found to be depleting the ozone layers that protects the earth from harmful ultraviolet rays.  HFCs do not deplete the ozone layer, but they have been a significant contributor to global warming.

The U.S. ratification of the treaty is largely symbolic.  The American Innovation and Manufacturing Act, passed by Congress in 2020, gave the EPA authority to regulate HFCs and the agency has already been doing so.  However, the Senate action shows that the U.S. is back on the international climate bandwagon. 

Failure to ratify the Kigali Amendment would have closed segments of the chemical and manufacturing industries to U.S. producers after 2023 because the Montreal Protocol prohibits trade with countries not party to it or its amendments.

Environmental advocates are hopeful that the U.S. can move forward on other climate actions.  A next step would be to focus on methane, the second leading driver of climate change after carbon dioxide.

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Senate Votes to Ratify the Kigali Amendment, Joining 137 Nations in an Effort to Curb Global Warming

Photo, posted June 13, 2017, courtesy of UNIDO via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Miracle Tree | Earth Wise

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The world needs to be fed without destroying the environment.   We need to grow more trees to store more carbon on earth and reduce the amount in the atmosphere.  But meanwhile, we decimate rainforests to produce palm oil and grow soybeans.

A startup company in California called Terviva thinks they have a solution.  It’s called pongamia, which is an ordinary looking tropical tree.  It produces beans packed with protein and oil, much like soybeans.  However, it has the potential to produce much more nutrition per acre than soybeans and it is hardy enough to grow on pretty much any kind of land without the use of pesticides, fertilizers, or irrigation.  In short, it is a miracle crop for a hot and hungry planet that is running out of fertile farmland and fresh water.

Pongamia is not a new or rare tree.  It is common in India but grows all over the world.  It is often planted as an ornamental here in the U.S.

The initial idea for making use of the hardy tree was to use its oil as a biofuel.  The seeds of pongamia are known to have a bitter taste and disagreeable odor, which is why the seeds or oil were never used for human or animal feed.  However, Terviva has developed a way to de-bitter pongamia oil.  Once this is done, it becomes a golden-colored substitute for olive oil. It also has enormous potential as a protein for plant-based milks and meats, since it contains all nine essential amino acids.

Terviva has raised more than $100 million to further develop pongamia and is now partnering with Danone, a $25 billion multinational food company, to develop pongamia as a climate-friendly, climate-resilient, non-GMO alternative to soy and palm oil.

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This super-tree could help feed the world and fight climate change

Photo, posted December 15, 2015, courtesy of Lauren Gutierrez via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Return Of The Fin Whale | Earth Wise

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The fin whale is the second largest whale species and therefore the second largest creature on Earth.  They can grow to more than 80 feet in length.  From 1904 to 1976, there was massive industrial whaling in the Southern Ocean surrounding Antarctica.  During that period, whalers killed about 700,000 fin whales, reducing their population by 99%.  The species was nearly extinct.

In 1982, the International Whaling Commission voted to ban commercial whaling.  Since that time, fin whales started to make a comeback in their historical feeding grounds.

During a nine-week expedition in the waters around the Antarctic Peninsula, researchers encountered the largest gathering of fin whales ever documented.  About 150 fin whales were seen diving and lunging against the water’s surface.  It was a feeding frenzy triggered by large amounts of krill in the water.  The actions of the whales are known as a “whale pump” that drives the krill to the surface.  Not only does it provide huge amounts of food for the whales but also for other animals, including seabirds and seals.

Forty years after the commercial whaling ban, the number of fin whales has been increasing.  Large groups were observed in a 2013 survey.  Aerial surveys in 2018 and 2019 recorded 100 groups of fin whales, usually composed of a just a handful of individuals.  They did document eight large groups of up to 150 individuals.

Not all species of whales have rebounded so successfully since the whaling ban.  The rebound in fin whale population is not only good for the whales, but for the entire ecosystem in the Southern Ocean.  It is a glimmer of good news in a time of great challenges for global biodiversity and for marine life in particular.

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Once Facing Extinction, Massive Fin Whales Have Returned to Antarctic Waters

Photo, posted November 15, 2007, courtesy of Gregory Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Living in a Carbon Bubble | Earth Wise

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The earth’s atmosphere is a little over 0.04% carbon dioxide, currently about 420 parts per million.  That’s more than it’s been in millions of years and is changing our climate.  But these levels of CO2 are not enough to directly affect people.

However, people are sensitive to the amount of carbon dioxide they are breathing.  It is actually an indoor pollutant.  High concentrations have been shown to reduce our cognitive performance, our health, and our comfort.  For example, a study in 2012 showed that performance in a variety of cognitive function tests was reduced by 12% when CO2 levels reached 1,000 parts per million and by 51% at 2,500 ppm.

How common are high levels of carbon dioxide?  Pretty common.  Offices often have CO2 levels of 600 ppm or higher, but 5% of US offices have average concentration about 1000 ppm and some conference rooms can reach 1900 ppm.  Classrooms often reach average levels above 1000 ppm.  Passenger aircraft have average levels around 1400 ppm during flight, and can peak over 4,000 ppm.  Cars with one occupant with the windows closed and the air recirculating have levels above 4,000 ppm. 

Where does it all come from?  From us.  We exhale CO2 and if we are in enclosed spaces with insufficient air circulation and ventilation, we end up living in a carbon dioxide bubble.  Most of us live with high CO2 levels – all day and every day.  It is a form of indoor pollution that has not gotten enough attention.

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I’m living in a carbon bubble. Literally.

Photo, posted October 24, 2013, courtesy of Cory W. Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Dioxide Levels Higher Again | Earth Wise

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The National Oceanic and Atmospheric Administration reported that carbon dioxide levels measured in May at the Mauna Loa Observatory reached a value of 421 parts per million.  This is 50% greater than pre-industrial levels and is in a range not seen on earth for millions of years.

Before the Industrial Revolution, CO2 levels fairly steadily measured around 280 parts per million, pretty much for all 6,000 years of human civilization.  Since the Industrial Revolution began in the 18th century, humans have generated an estimated 1.5 trillion tons of CO2 pollution, much of which will continue to warm the atmosphere for thousands of years.

The present levels of carbon dioxide are comparable to those of an era known as the Pliocene Climatic Optimum, which took place over 4 million years ago. 

The bulk of the human-generated carbon dioxide comes from burning fossil fuels for transportation and electrical generation, from cement and steel manufacturing, and from the depletion of natural carbon sinks caused by deforestation, agriculture, and other human impacts on the natural environment.

Humans are altering the climate in ways that are dramatically affecting the economy, infrastructure, and ecosystems across the planet.  By trapping heat that would otherwise escape into space, greenhouse gases are causing the atmosphere to warm steadily, leading to increasingly erratic weather episodes ranging from extreme heat, droughts, and wildfires, to heavier precipitation, flooding, and tropical storm activity.

The relentless increase of carbon dioxide measured at Mauna Loa is a sober reminder that we need to take serious steps to try to mitigate the effects of climate change.

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Carbon dioxide now more than 50% higher than pre-industrial levels

Photo, posted December 20, 2016, courtesy of Kevin Casey Fleming via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Americans And Lead Exposure | Earth Wise

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Long-term exposure to lead can cause serious health problems, especially in children.  Children are particularly vulnerable because their early years are characterized by rapid growth and brain development.

Lead is a powerful neurotoxin that can cause damage even at low levels of exposure.  Lead poisoning can be acute, and can cause all sorts of health issues, including stomach pain, brain damage, and even death.  Because lead accumulates in the body over time, lead poisoning can develop slowly. Exposure to lead can also contribute to a lower IQ and behavioral problems that can last a lifetime.

Lead is a naturally occurring element found in small amounts in earth’s crust.  But as a result of human activities, lead can be found in all parts of the environment, including the air, soil, and water.

According to a new study recently published in the journal Proceedings of the National Academy of Sciences, approximately half of U.S. adults alive today were exposed to harmful levels of lead as children from the burning of leaded gasoline.  The research team estimates that lead contamination has lowered those Americans’ IQ scores by more than two points on average.

In the study, the researchers used data on childhood blood-lead levels, leaded gasoline use, and population to gauge the lifetime exposure of every American adult in 2015.  They found that more than 170 million Americans had exposure to concerning levels of lead as children.  Those who grew up in the 60s and 70s, when the burning of leaded gasoline was at its peak, had the greatest exposure, losing up to six IQ points on average. 

The legacy of lead exposure remains a persistent problem.

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Half of Americans Exposed to Harmful Levels of Lead as Children

Lead Exposure Remains A Persistent Problem

Photo, posted February 13, 2010, courtesy of Steve Snodgrass via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change On Mount Everest | Earth Wise

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Climate change has shown up in the highest place on Earth.  The highest glacier on Mount Everest is rapidly retreating with rising temperatures.

New research by an international team led by the University of Maine and published in the journal Climate and Atmospheric Science has determined that the South Col Glacier atop Mount Everest has shrunk by half since the 1990s.   Its ice mass has thinned by an estimated 180 feet.

The glacier used to be covered by snow, which reflected the sun’s light and insulated the mass of ice under the snow.  But warmer temperatures, lower humidity, and more severe winds have eliminated the snow cover, fueling the decline of the glacier.

The study of the South Col Glacier highlights the critical balance created by snow-covered surfaces and exposes the potential for loss throughout high mountain glacier systems as snow cover is depleted by warming temperatures.  When even the highest glacier on Mount Everest is impacted, it is clear that no place is safe from the warming climate.

The human significance of this development is substantial.  More than 200 million people in Asia depend on meltwater from glaciers in the high mountains of the continent for their freshwater needs.  But now glaciers in the mountains are melting faster than they can be replenished by snowfall.

As for Mount Everest itself, future expeditions on the mountain will face new challenges as glacier melting causes more avalanches and climbers accustomed to digging into ice and snow will need to scale more exposed bedrock.  Climate predictions for the Himalaya in general all anticipate continued warming and continued loss of glacier mass.

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Climate Change Has Reached the Top of Mount Everest, Thinning Its Highest Glacier

Photo, posted October 27, 2011, courtesy of Goran Hogland via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tree Diversity | Earth Wise

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Scientists have estimated that there are more than 8 million species of plants and animals in existence.  Amazingly, only about 1.2 million of them have been identified and described so far and most of those are actually insects.  Millions of other organisms have yet to be discovered.

One would imagine that most of these unknown species are tiny things that are hard to spot or encounter.  But our ignorance of species even applies to trees, which are pretty easy to spot if you encounter them.

A new study involving more than 100 scientists across the globe has produced an estimate of the number of tree species on the Earth.  The new global estimate is that there are 73,000 tree species, which is about 14% more than previously thought.  Based on a combination of data from two global datasets, the study yielded a total of 64,100 documented tree species worldwide.  The researchers then used novel statistical methods to estimate the total number of unique tree species at biome, continental, and global scales, which includes species yet to be discovered and described by scientists.  Therefore, the estimate predicts that there are likely to be over 9,000 tree species still to be found.

Roughly 40% of the undiscovered tree species are likely to be in South America, which is the continent with the highest number of rare tree species and the highest number of continentally endemic tree species – meaning those found only on that continent.  Hot spots of undiscovered tree species are likely the tropical and subtropical moist forests of the Amazon basin and the Andes-Amazon interface.

Extensive knowledge of tree richness and diversity is key to preserving the stability and functioning of ecosystems.

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Number of Earth’s tree species estimated to be 14% higher than currently known, with some 9,200 species yet to be discovered

Photo, posted November 5, 2017, courtesy of Deensel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Sixth Mass Extinction | Earth Wise

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Extinction is a natural part of life.  Plants and animals disappear all the time.  When one species goes extinct, its place in the ecosystem is typically filled by another.  The so-called normal rate of extinction is thought to be somewhere between 0.1 and 1 species per 10,000 species per 100 years.

A mass extinction event is when species disappear at a much faster clip than they can be replaced.  By definition, mass extinction is when about three-quarters of the world’s species are lost in a short amount of time on a geologic scale, which is measured in millions of years.  

There have been five previous mass extinction events throughout the history of life on earth.  Today, many experts warn that a sixth mass extinction event is already underway – the first since dinosaurs were wiped out some 65 million years ago.  While previous mass extinctions were the result of extreme natural phenomena like volcanic eruptions and asteroid strikes, this one is a result of human activities. 

Researchers from the University of Hawai’i at Manoa and the National Museum of Natural History in France recently published a comprehensive assessment of evidence of this ongoing extinction event.  The researchers estimated that since the year 1500, Earth could already have lost between 7.5% and 13% of the two million known species on Earth.  This amounts to a staggering 150,000 to 260,000 species.

While mitigating the effects of climate change and reducing the rates of habitat loss would help, raising awareness of this crisis and its fallout for all life forms – including us – would be most effective in driving change. 

The time we have to avoid dramatic consequences is rapidly running out. 

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Strong evidence shows Sixth Mass Extinction of global biodiversity in progress

Photo, posted September 18, 2015, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

How Quickly Can The Planet Recover? | Earth Wise

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Climate change refers to long-term shifts in temperatures and weather patterns.  Historically, these shifts were natural.  But since the Industrial Revolution, scientists have found that the main driver of climate change has been human activities, primarily by adding significant amounts of greenhouse gases into the atmosphere through the burning of fossil fuels. 

Today, climate change is destabilizing Earth’s temperature equilibrium and is having a widespread impact on humans, animals, and the environment.  Some of the consequences of anthropogenic climate change include warmer air and ocean temperatures, shrinking glaciers, increasing spread of pests and pathogens, declining biodiversity, and more intense and frequent extreme weather events. 

But how quickly can the climate recover from the warming caused by an increase in carbon dioxide in the atmosphere? 

Researchers from Johannes Gutenberg-University Mainz in Germany looked into this question by investigating the significant rise in global temperatures that took place 56 million years ago.  Likely triggered by a volcanic eruption,  the increase of between 5 and 8 degrees Celsius was the fastest natural period of global warming that has impacted the climate. 

Because higher temperatures cause rocks to weather faster, the research team decided to analyze the weathering processes that occurred during the warming event 56 million years ago.  Their findings, which were recently published in the Journal Science Advances, indicate that the climate took between 20,000 and 50,000 years to stabilize following the rise in global temperatures.

Climate change is not some distant problem.  It is happening now and it poses a serious threat to all forms of life.  We need to address the problem with more urgency. 

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How quickly does the climate recover?

Photo, posted August 27, 2017, courtesy of Lt. Zachary West (100th MPAD) / Texas Military Department via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

SuperHot Rock Geothermal Energy | Earth Wise

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The United States in a world leader in geothermal energy.  There are geothermal power plants in 7 states which produce about half a percent of the country’s electricity.  Conventional geothermal energy plants take advantage of natural underground sources of heat such as geysers, superheated underground reservoirs, and such.  Steam from these sources activates generators that produce electricity.  However, there are not many places where these systems can be built.

More recently, there has been growing interest in so-called enhanced geothermal systems (or EGS systems) which generate geothermal electricity without the need for natural convective hydrothermal sources.  There are many places where underground heat is available but no existing water taps into it.  The idea is to tap into the earth’s deep geothermal resources by fracturing rock and pumping water into it to be heated. 

AltaRock Energy, a Seattle-based company that develops EGS technology, has recently announced the results of a comprehensive technical and economic feasibility study demonstrating the potential benefits of an EGS system that could use high-temperature impermeable rock deep below the Newberry Volcano near Bend, Oregon.  The so-called SuperHot rock there is in excess of 750 degrees Fahrenheit.

Based on measurements at the site and modeling, the study determined that an EGS system at the site could cut the levelized cost of electricity in half when compared with a conventional EGS resources at 400-500 degrees. 

The company expects that the study will pave the way for the development of the first SuperHot Rock geothermal resource in the United States.

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AltaRock clears hurdle in quest for ‘next generation’ geothermal resource

Photo, posted June 26, 2018, courtesy of David Fulmer via Flickr.

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