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Shrinking Alaskan Salmon | Earth Wise

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According to a new study published in the journal Nature Communications, salmon returning to Alaskan rivers have become significantly smaller over the past 60 years.  As a result of climate change and competition from hatchery fish, wild salmon are spending less time at sea and are returning to spawning grounds at younger ages.

The study, by scientists at the University of Alaska at Fairbanks and the University of California Santa Cruz, examined measurements of over 12 million fish collected by the Alaska Department of Fish and Game from 1957 through 2018.  Over that time period, four out of Alaska’s five wild salmon species – Chinook, chum, coho, and sockeye – have shrunk in size.  Chinook salmon is the official state fish of Alaska and they used to stay out at sea for seven years before returning to spawn.  Many are now returning to rivers at just four years old and are on average 8% smaller than they were 30 years ago.

The shrinking size of Alaskan salmon has consequences for people, the economy, and ecosystems in Alaska.   Wild salmon is a staple food for many residents of the state, particularly among indigenous groups.  More generally, Alaska produces nearly all of the wild salmon in the U.S.   Commercial fishing of over 200 million wild salmon in 2019 resulted in $657 million in income.  The fish are also an important food source for bears and other wildlife and the spawning migration of salmon plays an important role in nutrient transportation in Alaskan river ecosystems.


Multiple factors are driving the changes in the salmon population, but the largest effects are the changing climate and the abundance of salmon in the ocean due in part to hatchery production that results in competition for the salmon’s food.

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Alaska’s Salmon Are Significantly Smaller Than They Were 60 Years Ago

Photo, posted September 5, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Greenland Glaciers Past The Point Of No Return | Earth Wise

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Forty years of satellite data from Greenland shows that the glaciers on the island have shrunk so much that even if global warming came to an abrupt halt, the Greenland ice sheet would continue to shrink.

This conclusion was published in the journal Communications Earth and Environment by researchers at Ohio State University.  According to their study, Greenland’s glaciers have passed a tipping point where the snowfall that replenishes the ice sheet each year can no longer keep up with the ice that is flowing into the ocean from the glaciers.

The study analyzed monthly satellite data from more than 200 large glaciers that drain into the ocean around Greenland.  It looked at how much ice breaks off into icebergs or melts from the glaciers into the ocean as well as the amount of snowfall each year that replenishes the glaciers.

Throughout the 1980s and 90s, these two processes were mostly in balance, keeping the ice sheet intact.  But the amount of ice being lost each year started to increase steadily around the year 2000 while there was no increase in snowfall.   Both processes fluctuate from year to year, but the baseline for ice loss has steadily risen.  Before 2000, the Greenland ice sheet had about the same chance of gaining or losing mass each year.  At this point, the ice sheet is likely to gain mass in only one out of every 100 years.

Large glaciers in Greenland have retreated about 2 miles since 1985, so that many of them are sitting in deeper water with more ice in contact with warmer water making it harder for glaciers to grow back.  At this point, even if the climate reverses its trend, the ice sheet will continue to lose mass.

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Warming Greenland ice sheet passes point of no return

Photo, posted August 27, 2015, courtesy of Joxean Koret via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sharks On The Decline | Earth Wise

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During the past 70 years, global shark populations have been on the decline.   Many species have become threatened or endangered.  Conservation efforts have been underway in many places, but shark populations continue to be at risk because of over-fishing and habitat loss.

A comprehensive study by marine biologists at Texas A&M University deployed more than 15,000 baited remote underwater video stations on 371 coral reefs in 58 countries.   The study included 59 different shark species in the Atlantic, Pacific and Indian Oceans.  The researchers were surprised to find that no sharks at all were detected in almost 20% of the locations surveyed and were almost completely absent from coral reefs in several nations. 

Scientists believe that demand for shark products, such as fins and meat, and bycatch (that is, sharks captured in nets by fisherman trapping other kinds of fish) are strong contributors to the widespread declines in shark numbers around the world.

The study shows that if corrective steps are not taken in regions where marine management is still ineffective, continued depletion of shark populations is highly likely. 

Sharks have important roles in marine ecosystems.  When their habitats deteriorate and their populations decrease, ecosystem stability and health is degraded because sharks help regulate prey populations.

Some countries, notably the Bahamas, are combating the problem by providing sanctuaries for sharks where fishing and harvesting is prohibited.  Such places support some of the healthiest shark populations in the world.  However, the decline of coral reefs is just another challenge facing shark populations around the world.

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Study Shows Alarming Decline In Shark Numbers Around The World

Photo, posted January 9, 2017, courtesy of Kris-Mikael Krister via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alaska Is Getting Wetter | Earth Wise

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Siberia has been in the news for record-setting heat waves and wildfires, but it is not the only northern region experiencing unusual weather.   Alaska, apart from setting its own warm weather records, is experiencing the rainiest five years in its century-long meteorological record.

Extreme weather in the Arctic is being driven by an aspect of climate change called Arctic amplification, which leads to temperatures rising faster than the global average.  The physical basis of Arctic amplification is well understood, but its effects over time are much less predictable.

The past five years included two summers with average precipitation, one that was a little drier than usual, and two of the wettest summers on record.    Researchers have taken measurements of how far below the surface permafrost has thawed by the end of summer over a wide range of Alaskan environments.

About 85% of Alaska sits upon permafrost and the increasing rainfall over the past five years is leading to a deeper thaw of permafrost across the state.  The wettest summer on record was 2014 and permafrost didn’t freeze back to previous levels even when the next couple of summers were relatively drier.

The study demonstrated how different types of land cover govern relationships between summer rainfall and permafrost thaw.  As Alaska becomes warmer and wetter, the vegetation cover is projected to change, and the increasing occurrence of wildfires will disturb larger areas of the landscape.  These conditions are likely to lead to a feedback loop driving more and more permafrost thawing.

Fundamental changes to Alaskan ecosystems are occurring on an unprecedented timescale – not gradually over decades or lifetimes, but over mere months or years.

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Alaska is getting wetter. That’s bad news for permafrost and the climate.

Photo, posted June 10, 2011, courtesy of Peter Rintels via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Decline Of Pollinators Threatens Food Security | Earth Wise

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Scientists have been sounding the alarm on the global struggle of pollinators for many years.  According to a United Nations-sponsored report, 40% of invertebrate pollinator species, including bees and butterflies, are facing extinction.  Approximately 80% of all flowering plant species, which are responsible for 35% of global food production, depend on pollination. 

According to new research led by Rutgers University, crop yields for apples, blueberries, and cherries in the United States are being reduced by a lack of pollinators.  The study, the most comprehensive of its kind to date, found that crop production would be increased if crop flowers received more pollination.  In the U.S., the production of crops that depend on pollinators generates more than $50 billion a year.    

For the study, which was recently published in the journal Proceedings of the Royal Society B, researchers collected data on insect pollination of crop flowers and yield of apples, highbush blueberries, sweet cherries, tart cherries, almonds, watermelons, and pumpkins at 131 farms across the United States and British Columbia, Canada.  Four of those seven crops – apples, blueberries, sweet cherries, and tart cherries – showed evidence of being limited by pollination, meaning that their yields are lower than they would be with full pollination. 

The researchers observed that honey bees and wild bees provided similar amounts of overall pollination, so managing habitat for native bee species or stocking more honey bees would boost pollination levels and, in turn, crop production.

Bees and other pollinators play a critical role in food production, and their continued decline could have devastating consequences.

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Decline of bees, other pollinators threatens US crop yields

Photo, posted April 22, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And The South Pole | Earth Wise

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According to a study led by researchers at Ohio University, the South Pole has warmed more than three times the global average over the past 30 years.  While the warming was driven by natural tropic climate variability, the researchers argue that rising greenhouse gas emissions likely intensified the warming. 

The climate in the antarctic has some of the largest ranges in temperature during the year.  Some regions, like most of West Antarctica and the Antarctic Peninsula, experienced warming during the late 20th century.  But the South Pole, which is located in the remote and high-altitude interior of the continent, actually cooled until the 1980s.  The South Pole, as the study highlights, has warmed substantially ever since. 

For the study, which was recently published in the journal Nature Climate Change, the researchers analyzed climate models and weather station data at the South Pole.  They found that, between 1989 and 2018, the South Pole had warmed by 1.8 degrees Celsius.  This warming trend of 0.6 degrees Celsius per decade is three times the global average. 

According to the study, the robust warming of the Antarctic interior has been mainly driven by the tropics.  Warm ocean temperatures in the western tropical Pacific Ocean have altered the winds in the South Atlantic, increasing the delivery of warm air to the South Pole.  These atmospheric changes are an important part of what’s driving the climate anomalies in the region.

But the researchers argue that the warming trends are unlikely a result of natural climate change alone.  The effects of anthropogenic – or human-caused – climate change in addition to the natural changes have combined to make this one of the strongest warming trends globally.    

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Extreme warming of the South Pole

Photo, posted February 7, 2011, courtesy of Eli Duke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Problem For New York Apples | Earth Wise

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New York is the second largest apple-producing state in the country, trailing only Washington state.  New York averages nearly 30 million bushels of apples annually from approximately 600 commercial growers.  The apple industry supports 10,000 direct agricultural jobs as well as 7,500 indirect jobs involved with fruit handling, distribution, marketing and exporting.

Thus, there is considerable concern about the recent discovery by Cornell plant pathologists of a new fungal pathogen that causes bitter rot disease in apples.  They also found a second related fungus that is known to cause rot disease in other fruits but has now been found for the first time in apples.  The study was published in early July in the journal Scientific Reports.

Both of these pathogens belong to the genus Colletotichrum, which contains 189 species of fungi that cause devastating rot diseases in multiple fruit crops, including bananas, strawberries, citrus, avocados, papayas, mangoes and apples.

Unless protective measures are taken in a timely manner, apple losses from bitter rot in New York state can average up to 25% per year.  Some organic farms have lost essentially all of their crop at times.  Bitter rot also can destroy up to 5% of marketable fruit in post-harvest storage.

The Cornell study of samples from eight New York counties found both the Colletotrichum chrysophilum fungus, that had not been found in apples before, and a newly-discovered fungus that they named Colletotrichum noveboracense, after the Latin name for New York State.

The researchers plan to work with other plant pathologists and apple breeders to identify possible genes that confer natural resistance to Colletotrichum fungi that can be bred into apple cultivars.

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Scientists identify new pathogen in NY apples

Photo, posted October 12, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The United States And Ticks | Earth Wise

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Tiny ticks are a big problem.  Measuring only three to five millimeters in size, ticks are widely distributed around the world.  They are external parasites, feasting on the blood of birds, reptiles, amphibians, and mammals – including humans.

According to estimates from the Centers for Disease Control and Prevention, ticks infect more than 300,000 people with Lyme disease in the United States every year, and the numbers continue to rise.  Other common tick-borne diseases include anaplasmosis, babesiosis, Rocky Mountain Spotted Fever, and powassan encephalitis.

But while the prevalence of tick-borne illnesses has steadily increased in the United States over the past two decades, a new study on tick surveillance and control “has revealed an inconsistent and often under-supported patchwork of programs across the country.”

The study, by university researchers at the CDC’s five Vector-Borne Disease Regional Centers of Excellence, is the first-ever examination of tick management programs in the United States.  The researchers found clear gaps in our public health infrastructure. 

According to the study, which was recently published in the Journal of Medical Entomology, less than 50% of public health and vector-control agencies conduct tick surveillance.  Only 25% test ticks for disease-causing germs.  And only 12% conduct or support tick-control efforts.  Researchers also discovered that the capacity for public tick-control efforts is low, as is the capacity for information and data sharing between agencies on ticks.    

The findings highlight the degree to which tick surveillance and control is lagging in the United States.  According to the research team, greater support for tick-management programs is critical, and they hope their findings will serve as a baseline from which to measure future improvements.  

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Tick surveillance and control lagging in US

Photo, posted May 4, 2009, courtesy of Jerry Kirkhart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Side Effects Of Geoengineering | Earth Wise

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As the world struggles to reduce the greenhouse gas emissions that are warming the global climate, some researchers are exploring proposals to deliberately engineer climate changes to counteract the warming trend.  One of the most widely discussed approaches is to shade the Earth from a portion of the sun’s heat by injecting the stratosphere with reflective aerosol particles.  Proponents of this idea point out that volcanoes do essentially the same thing, although generally for only a limited amount of time.  Particularly large eruptions, such as the Krakatowa eruption of 1883, wreaked havoc with weather around the world for an entire year.

Schemes to launch reflective aerosols – using planes, balloons, and even blimps – appear to be quite feasible from the standpoint of physically accomplishing them. But this says nothing about the political, ethical, and societal issues involved.  The point is that such an approach could indeed lower global temperatures and thereby potentially offset the warming effects of greenhouse gases.

A study by scientists at MIT looked at what other effects such a solar geoengineering project might have on the climate.  Their modeling concluded that it would significantly change storm tracks in the middle and high latitudes.  These tracks give rise to cyclones, hurricanes, and many more ordinary weather phenomena.

According to the study, the northern hemisphere would have weakened storm tracks, leading to less powerful winter storms, but also stagnant conditions in summer and less wind to clear away air pollution.  In the southern hemisphere, there would be more powerful storm tracks.

Aside from turning the world’s weather patterns inside out, solar geoengineering would do nothing to address the serious issue of ocean acidification caused by increasing carbon dioxide levels.

As many have pointed out, playing the geoengineering game would have many unintended consequences.

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Study: Reflecting sunlight to cool the planet will cause other global changes

Photo courtesy of MIT.

Earth Wise is a production of WAMC Northeast Public Radio.

A Second Life For Electric Car Batteries | Earth Wise

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The number of electric cars around the world is growing steadily.  Battery technology continues to improve and the battery packs in the cars can have a long life.  Generally, the batteries are considered to require replacement only when their range has dropped below 80% of its original value.  Many are warranted to last for 8 to 10 years or more than 100,000 miles.  Some seem to do much better than that.

But however long it takes, there will eventually be a wave of used batteries whose performance is no longer deemed sufficient for vehicle use.  A new study, published in the journal Applied Energy, looked at the application of used vehicle batteries as backup storage for grid-scale solar photovoltaic installations where they could perform for more than a decade in this less demanding role.

The study looked at the economics of several scenarios including running a solar farm with no battery back up, running the same farm with brand-new batteries, and running the farm with a battery array made of repurposed vehicle batteries.

They found that the used EV battery array, if managed properly, could be a good, profitable investment provided that the batteries cost less than 60% of their original price.  They looked at the technical issues of screening batteries and combining batteries from different cars to work together.  They also looked at the economics of removing batteries from cars, collecting them, checking them over, and repackaging them.

Overall, they found that reusing vehicle batteries could ultimately meet half the forecasted demand for renewable energy backup storage over the next 10 years and would be both a technical and an economic success story.

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Solar energy farms could offer second life for electric vehicle batteries

Photo, posted June 10, 2011, courtesy of Nick Ares via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Emissions And The Coronavirus Shutdown | Earth Wise

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With so much of industry and personal activity curtailed by coronavirus shutdowns across the globe, it is no surprise that greenhouse gas emissions have declined.  According to new research published in the journal Nature Climate Change, average daily global greenhouse gas emissions declined 17% by early April compared to 2019 levels.

If the reopenings around the world continue and the world actually reaches pre-crisis levels by the middle of June, total CO2 emissions for the year would likely end up lower by about 4%.   If various restrictions continue until the end of the year, total global emissions could decline by 7%.

The study analyzed emissions estimates for three levels of coronavirus shutdowns and across six sectors of the economy.  It looked at trends in 69 countries, all 50 U.S. states, and 30 Chinese provinces, representing in total 86% of the world’s population and 97% of global CO2 emissions.

For the first 4 months of the year, emissions from industry declined 19%, the power sector 7%, and public buildings and commerce 21%, compared to last year.  Unsurprisingly, home energy use actually went up by about 3%.

The findings of this study only represent the effects of a short-lived decline in emissions.  As economies open back up, there is no doubt that greenhouse gas emissions will rise back to pre-Covid-19 levels.

The study also reveals that making real changes in emissions will require more than just behavior changes.  Despite billions of people staying home, companies shut down, planes grounded, and cars off the road, we still managed to pump more than 80% of the usual amount of greenhouse gases into the air for the first quarter of the year.

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Global Emissions Fell 17 Percent Due to Coronavirus Shutdowns

Photo, posted May 7, 2020, courtesy of the MTA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Living In Extreme Heat | Earth Wise

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Global climate change has already left observable effects on the planet.  Glaciers have shrunk, trees are flowering sooner, plant and animal ranges have shifted, and so on. Many effects of climate change that scientists had predicted in the past are now occurring.  The loss of sea ice, intensifying heat waves, and accelerating sea level rise are some examples.

According to a new study recently published in the journal Proceedings of the National Academy of Sciences, climate change is going to affect humans earlier, harder, and more widely than previously projected.  The research team found that one billion people will be either displaced or endure insufferable heat for every one degree Celsius rise in global temperatures.  

Under a worst case climate scenario, land that one third of the world’s population currently calls home will be as hot as the hottest parts of the Sahara desert within 50 years.  Even under a more optimistic climate outlook, 1.2 billion people will still be exposed to temperatures outside the climate niche in which humans have thrived for at least 6,000 years.

The majority of the human population has always lived in regions where the average annual temperatures were between 43 degrees Fahrenheit and 82 degrees Fahrenheit.  These are ideal temperatures for human health and for food production.  But this temperature range is shrinking and shifting as a result of climate change. 

The study’s authors predict there will be more change in the next 50 years than there has been in the past 6,000 years.  They hope their findings will convince policymakers to accelerate their plans for emissions reductions and other climate mitigation strategies.   

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Future of the human climate niche

One billion people will live in insufferable heat within 50 years – study

Photo, posted November 22, 2008, courtesy of Ronnie Finger via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Recovering Marine Life By 2050 | Earth Wise

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Marine life has faced challenges for a long time.   There have been centuries of overfishing in many places and pollution of various types has been especially harmful in recent decades.   But despite all of this, a new scientific review published in the journal Nature contends that marine life in the world’s oceans could be fully restored in as little as 30 years provided that aggressive conservation policies are adopted.

The research spotlights the strong resiliency of ocean animals and cites the successful recovery of a number of marine species, including humpback whales.

The study indicates that nations around the world must agree to designate 20 to 30 percent of the oceans as marine protected areas, institute sustainable fishing guidelines, and regulate pollution.  These measures would not come cheaply.  The estimated cost would be around $20 billion a year. 

However, the report also estimates that the economic return on this investment would be tenfold and would create millions of new jobs.  Rebuilding fish stocks and maintaining sustainable fishing policies could increase global profits of the seafood industry by over $50 billion a year.  Conserving coastal wetlands could save the insurance industry more than $50 billion a year as well by reducing storm damage.

A major sticking point, however, is climate change.  Climate change is increasing ocean temperatures and driving acidification.  Unless these changes are brought under control, the restoration of marine life is not going to be successful.  We have reached the point where it is within our power to choose between a future with a resilient and vibrant ocean or an irreversibly disrupted ocean.  Whether we embrace that challenge remains to be seen.

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Marine Life Could Recover By 2050 With the Right Policies, Study Finds

Photo, posted April 20, 2012, courtesy of Matthias Hiltner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Benefits Of A Zero-Emissions Boston | Earth Wise

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Many countries, states, and cities around the world have set goals to become carbon neutral, typically by the year 2050.  These goals are based on the desire to mitigate the effects of climate change that are steadily increasing as a result of the buildup of carbon dioxide in the atmosphere.  But reducing emissions is not just a way to combat climate change, it can also be a major contributor to improved public health.

The City of Boston has set a goal to become carbon neutral by 2050.  A new study by the School of Public Health at Boston University published in the journal Environmental Research Letters looked at the consequences of eliminating fossil fuel emissions in the greater Boston area.

According to their modeling, eliminating emissions would save 288 lives a year by reducing fatal and non-fatal cardiovascular and respiratory illnesses.   The resulting decrease in medical costs and lost and reduced work could save $1.7 billion a year in Suffolk County and $2.4 billion a year for the entire 75-square-mile zone modeled in the study.

The study looked at the amounts of two air pollutants known to harm human health:  PM2.5 (particulates with a diameter of less than 2.5 microns) and ozone.  They compared the current levels of these pollutants to what would be present when contributions from motor vehicles, generators, rail, industry, oil- and gas-burning, shipping and boating, and residential wood fires were eliminated.

The study focused on the City of Boston’s climate action plan, but actions taken by Boston will not take place in a vacuum.  Many cities across the region are taking similar actions.  The overall results will come from the collective actions across New England.

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A Zero-Emissions Boston Could Save 288 Lives and $2.4 Billion Annually

Photo, posted August 31, 2019, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Moving Up And Away | Earth Wise

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A new study by the Wildlife Conservation Society, the US Forest Service, and UC Berkeley has shown that mountain-dwelling species trying to escape warming temperatures may also be finding refuge from human pressure.

The study shows that nearly 60% of the world’s mountainous areas are under intense human pressure.  Most of that pressure occurs at lower elevations and mountain bases, where more people live, grow food, and build roads.  The researchers used climate models to predict how various species would move as the climate changes.   Based upon these predictions, they found that species tend to move to higher elevations, where temperatures are lower.  But those elevations also have more intact land for species because there is less human activity.

Mountains are home to over 85% of the world’s amphibians, birds, and mammals and these species are at risk from human activities such as agriculture, livestock grazing, and development.  These things reduce their habitats, but meanwhile the warming climate pushes them upslope as they struggle to find tolerable temperatures.

The researchers point to their study as new guidance for conservation efforts.  They warn that many conservation efforts don’t take into account the effects of human pressure.   Factoring in human pressure reveals the true extent of mountainous areas for species that are restricted to intact landscapes.  These are often the species that are of greatest concern to conservationists.  This true shape refers to how much land area is potentially available as habitat for a species as it moves up in elevation.  

The results offer a glimmer of hope for mountain-based species under climate change as they move away from the most intense human activity.

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Climate change may push some species to higher elevations — and out of harm’s way

Photo, posted November 22, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Methane-Eating Bacteria And Greenhouse Gas Emissions | Earth Wise

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One of the great concerns about the warming Arctic temperatures is that thawing permafrost will release alarming amounts of methane into the atmosphere.  Organic material in the permafrost begins to decompose when temperatures rise, and methane is released in the process.

Methane is a far more potent greenhouse gas than carbon dioxide.  Methane’s lifetime in the atmosphere is much shorter than carbon dioxide, but it is more efficient at trapping radiation.  Pound for pound, the comparative impact of methane is more than 25 times greater than carbon dioxide.

A new study, published by scientists at Purdue University, has discovered a type of methane-oxidizing bacteria living in upland Arctic soils that could potentially be reducing the amount of methane emitted by decomposing permafrost.

The findings of the research indicate that the net greenhouse gas emissions from the Arctic may be much smaller than previously modeled because of the increased productivity of a type of bacteria known as high affinity methanotrophs, or HAMs.  This group of bacteria uses atmospheric methane as an energy source.  The emissions from wetlands will potentially be very large, but the contribution from the uplands will be mitigated by the bacteria.

Organic-rich soils, including permafrost, comprise only 13% of the Arctic land area and are the major source of methane emissions.  The other 87% of the region is dominated by mineral-rich soils that support HAMs.  Because of this, overall methane emissions continue to be less than climate models have predicted.

While this is good news, the researchers warn that Arctic emissions overall will continue to increase as shown in other studies.

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Methane-Eating Bacteria Could Help Decrease Greenhouse Gas Emissions From Thawing Arctic Tundra

Photo, posted July 12, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Earth Itself Is Quieter | 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.

With about a third of the world’s population sheltering in place, our planet is much quieter these days.  It isn’t just our machines, vehicles, and factories that are making less noise.  The earth itself is quieter.  There has been a reduction in the earth’s seismic vibrations.

According to the journal Nature, various human-powered movements contribute to the persistent vibration of the earth’s crust.  Things like engines firing up in factories, trains pulling into stations, and trucks barreling down highways all make contributions to seismic activity.  Taken individually, such things are insignificant, but taken together, they produce a background of seismic noise that makes it difficult for seismologists to detect natural signals such as volcanic activity and earthquake aftershocks.

With much human activity on pause during the coronavirus outbreak, seismologists across the globe are seeing significant reductions in background seismic noise levels.

This respite in seismic noise, for as long as it lasts, represents an opportunity for scientists to better study the natural activity in the earth’s crust. Researchers studying the impact of ocean waves to predict volcanic activity and those who triangulate the location of earthquake epicenters may be able to make more sensitive measurements than under normal conditions.

There are very few positive things one can say about the coronavirus crisis, but it is providing opportunities to study and observe aspects of the natural world that are ordinarily drowned out by the bustle of humanity.

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Coronavirus lockdowns across the globe are actually causing the Earth to move less

Photo, posted March 9, 2020, courtesy of Jeremy Segrottvia Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Conservation In Vermont | Earth Wise

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In recent times, Vermont and neighboring states have been losing forest land to development at a rate of almost 1,500 acres per year.  With forest fragmentation gaining ground across New England, conserving land for future generations of people, wildlife, and plants has become both increasingly important and increasingly difficult.

According to a new study published by researchers at the University of Vermont, the state has already protected a third of the highest priority targeted lands needed to protect and connect valuable wildlife habitats and corridors.  The protected lands amount to 1.3 million acres.

Most of the currently conserved lands are forested.  However, there are high-priority targeted surface water and riparian areas – ponds, rivers, shorelines, and wetlands – and not nearly enough of these have been protected.  (Many animals require zones along waterways in which to travel between the habitats they need to survive).

The state of Vermont and a number of partners have laid out a comprehensive and thoughtful vision that would ensure that Vermont remains a good place for all forms of life in the future.  The new study provides a crucial benchmark of current levels of forest protection to help prioritize future conservation actions. 

Three groups dominate in responsibility for the state’s protected lands:  the federal government, the state government, and private non-profit organizations.  (Each of these account for roughly a third of existing protected lands).

Going forward, Vermont’s nonprofits will play an increasingly important role in land conservation, especially in continuing to protect those areas that are rich with species diversity.  Nonprofits are engaging more and more deeply in restoring wetlands that were previously degraded, planting new forests along river shores, and protecting unique natural communities while also protecting working forests and farmland.

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Vermont Has Conserved One Third of the Land Needed for an Ecologically Functional Future

Photo, posted June 15, 2014, courtesy of Wesley Carr via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Natural Habitats And Strawberry Farms | Earth Wise

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According to a new study led by researchers from the University of California – Davis, conserving natural habitat around strawberry fields can protect farmers’ yields, their bottom line, and the environment.  The study also suggests that conserving natural habitat in this way has no detectable threat to food safety. 

In this study, which was recently published in the journal Ecological Applications, the research team conducted surveys and experiments at 20 strawberry farms along California’s Central Coast.  This region is responsible for 43% of the nation’s strawberry production. 

The researchers found that strawberry farmers were better off with natural habitat, like forests, grasslands, wetlands, and shrubs, around their farms than without it.  According to the study’s models, adding natural habitat can reduce crop damage costs by 23%.  Removing natural habitat can increase costs by as much as 76%. 

Importantly, the strawberry farms with natural habitat surrounding them showed no signs of increased fecal contamination.  While bird feces were regularly encountered on the ground, only 2 of 10,000 strawberries examined show signs of direct fecal contamination.  Those contaminated berries would be discarded during the hand-harvesting process.   

These findings run contradictory to current best practice recommendations that support natural habitat removal around strawberry farms in order to decrease bird fecal contamination and crop damage.  These food safety requirements were a consequence of the deadly outbreak of E. coli in 2006, which was traced back to spinach grown in this region.   

It seems like our agricultural landscapes can both support and benefit from biodiversity. 

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Natural habitat around farms a win for strawberry growers, birds and consumers

Photo, posted June 16, 2011, courtesy of the USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Tropical Forests As Carbon Sinks | Earth Wise

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Tropical forests are an important part of the global carbon cycle because they take up and store large amounts of carbon dioxide.  Because of this, deforestation in the Amazon and other tropical forests is a major contributor to the growing CO2 levels in the atmosphere.

Therefore, climate models need to accurately take into account the ability of tropical forests to sequester carbon.  It turns out that this is not such a simple matter.  A new study by the International Institute for Applied Systems Analysis sought to determine how much detail about tropical forests is needed in order to make valid assumptions about the strength of forest carbon sinks.

They looked at the role of both biotic factors – differences between plant species that are responsible for capturing more or less carbon from the atmosphere – and abiotic factors – local environmental factors like soil properties that also influence carbon sink strength.

It is generally assumed that more diverse forest communities capture available resources more efficiently as a result of complementary characteristics and preferences of certain species to specific conditions.  Factors like soil texture and chemistry are also important.  In general, the results show that abiotic and biotic factors interact with one another to determine how much carbon can be stored by the ecosystem.

Traditional projections of the role of tropical forests in storing carbon mostly rely on remote sensing techniques that integrate over large spatial areas.  The new study shows that there can be large differences in the carbon storing ability of tropical forests and that more detailed models are needed to produce more accurate projections.

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Shedding light on how much carbon tropical forests can absorb

Photo, posted July 17, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)