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Bananas and climate change

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Bananas are one of the most widely produced fruits globally, with more than 100 million tons grown every year.  They are a key export crop worth approximately $11 billion annually. Bananas are also a staple food in many tropical countries, playing a vital role in both the economies of these nations and in global food security.

The Cavendish variety of banana dominates commercial exports, accounting for nearly 47% of global production. However, the Cavendish banana is highly susceptible to diseases like Panama disease, prompting ongoing efforts to develop disease-resistant alternatives. The spread of these diseases is exacerbated by climate change, which alters growing conditions and weakens banana plants. Additionally, climate change poses further threats to the banana industry by impacting crop yields and distribution patterns.

In fact, a new study led by researchers from the University of Exeter in the U.K. has found that by 2080, rising temperatures will make growing bananas for export economically unsustainable in many regions of Latin America and the Caribbean.  Colombia and Costa Rica will be among the countries most negatively impacted as they are expected to become too hot for optimal banana cultivation. 

The study, which was recently published in the journal Nature Food, found that 60% of the regions currently producing bananas around the world will struggle to grow the fruit unless there are urgent interventions to tackle climate change.  The researchers propose several adaptation strategies, including expanding irrigation systems, developing heat- and drought-resistant banana varieties, and helping banana producers manage climate-related risks.

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Climate change threatens future of banana export industry

Photo, posted June 26, 2024, courtesy of JJ Musgrove via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Megadroughts

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A new study by Swiss and Austrian scientists has found that persistent multi-year droughts have become increasingly common since 1980 and will continue to proliferate as the climate warms.

There are multiple examples in recent years in places ranging from California to Mongolia to Australia.  Fifteen years of persistent megadrought in Chile have nearly dried out the country’s water reserves and even affected Chile’s vital mining output.  These multi-year droughts have triggered acute water crises in vulnerable regions around the world.

Droughts tend to only be noticed when they damage agriculture or visibly affect forests.  An issue explored by the new study is whether megadroughts can be consistently identified and their impact on ecosystems understood.

The researchers analyzed global meteorological data and modeled droughts over a forty-year period beginning in 1980.  They found that multi-year droughts have become longer, more frequent, and more extreme, covering more land.  Every year since 1980, drought-stricken areas have spread by an additional fifty thousand square kilometers on average, an area the size of Vermont and New Hampshire combined. 

The trend of intensifying megadroughts is clearly leading to drier and browner ecosystems.  Tropical forests can offset the effects of drought as long as they have enough water reserves.  However, the long-term effects on the planet and its ecosystems remain largely unknown.  Ultimately, long-term extreme water shortages will result in trees in tropical and boreal regions dying, causing long-term and possibly irreversible damage to these ecosystems.

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The Megadroughts Are upon Us

Photo, posted January 7, 2018, courtesy of Kathleen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Threats to the Amazon Rainforest

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Brazil has made great progress in reducing deforestation in its Amazon Rainforest.  In 2023, the rate of deforestation in Brazil dropped by 50% over the previous year. This was the result of the efforts by conservation-minded President Luiz da Silva, who replaced Jair Bolsonaro, a big proponent of deforestation.  Da Silva’s government has cracked down on land clearing by farmers and ranchers.

In the first quarter of this year, deforestation decreased by 40% over the previous year’s quarter.   Deforestation levels are the lowest they’ve been in six years, although the amount of forest cleared in the period was still nearly 200 square miles.

Unfortunately, the Amazon Rainforest is facing another growing threat:  climate change.  Because of pervasive drought and increasing temperatures, the number of wildfires in the region have hit a 20-year high.

According to satellite data from the national space agency, from January through June, Brazil recorded 13,489 wildfires in the Amazon.  That is 61% more fires than during the same period last year.  And the wildfire season has yet to reach its peak, which usually is in August or September.

Many of these fires begin in pastures or recently cleared rainforest, but then spread into the surrounding rainforest areas.  Many are huge fires.  Hundreds of square miles of rainforest have been consumed by fire, comparable in size to the areas deforested by farmers and ranchers.

Going forward, worsening wildfires could reverse the gains being made by the government’s deforestation policies.  This could not only threaten forest protection, but also weaken public support for the government’s commitment to protecting the region.

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Brazil Is Seeing a Record Number of Wildfires This Year

Photo, posted January 26, 2018, courtesy of Chris Parker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The global chocolate supply is threatened

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The world is facing the biggest deficit of cocoa in decades. Most cocoa beans are grown in West Africa, where climate change-induced drought has ravaged crops.  Harvests are forecasted to fall short for the third consecutive year. 

The harvest shortfall has triggered a steep rise in cocoa prices.  In fact, cocoa prices have more than doubled in the first four months of this year, and have more than tripled in the past 12 months.

But drought isn’t the only threat:  A rapidly spreading virus is also threatening the future of chocolate.   

Approximately half of the world’s chocolate originates from cacao trees in Ghana and the Ivory Coast.  The Cacao Swollen Shoot Virus Disease is spread by small insects called mealybugs, which eat the leaves, buds, and flowers of cacao trees.  The virus is attacking cacao trees in Ghana, resulting in harvest losses of 15-50%. 

Pesticides don’t work well against mealybugs.  Farmers can vaccinate trees to inoculate them from the virus.  But the vaccines are expensive, and the vaccinated trees produce a smaller harvest of cacao.

According to a new paper recently published in the journal PLOS ONE, an international team of researchers has developed a new strategy to combat these pests: using mathematical data to determine how far apart vaccinated trees need to be planted in order to stop mealybugs from hopping from tree to tree.  The researchers developed two models that allow farmers to create a defensive ring of vaccinated trees around unvaccinated trees

The research team hopes its models will help farmers protect their crops and achieve better harvests in the future. 

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Cacao sustainability: The case of cacao swollen-shoot virus co-infection

Will rising cocoa prices trigger a chocolate crisis?

Photo, posted April 1, 2019, courtesy of Konrad Lembcke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sea Urchins And Climate Change | Earth Wise

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There is a thriving population of black sea urchins in bubbling volcanic vents off the coast of Ishia, a small island in the Gulf of Naples.  The oceanic environment there is very acidic, high in carbon dioxide, and very warm.   The environment represents a proxy for what is gradually happening to oceans around the world.

Researchers from the University of Sydney have determined that the ability of sea urchins to prosper in such an environment means that these animals, which are already abundant in the Mediterranean Sea are likely to spread further afield as oceans continue to warm and become more acidic.  The Mediterranean Sea is warming 20% faster than the global average.

Sea urchins are already an environmental problem in many places around the world.  When their numbers increase disproportionately, they decimate kelp forests and algae, leading to the demise of other species that depend on these things for food or shelter.  The result is something called an urchin barren, which is a rocky, sandy, urchin-filled seafloor devoid of other life.

Urchin barrens are increasingly common in many places, including the east coast of Australia and the coastline in the Americas stretching from Nova Scotia to Chile.

In Australia, for example, sea urchin populations have multiplied, and their range has expanded considerably, overgrazing kelp and damaging abalone and lobster farms.

Tests run by the Sydney researchers found that it is difficult to stress sea urchins.  They appear to tolerate conditions that other creatures simply cannot.   The only real positive is that understanding the urchins’ remarkable survival abilities might offer insights into adaptations that other animals might need in order to survive as the oceans become warmer and more acidic.

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Colonising sea urchins can withstand hot, acidic seas

Photo, posted January 31, 2010, courtesy of Anna Barnett via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Crops Threatened With Extinction | Earth Wise

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Crop variety and diversity are critically important for global food security as well as for the livelihoods of millions of people.  This diversity entails both the different species of food crops as well as the so-called farmer varieties of crops that in many cases have been cultivated and safeguarded for millennia.

It is well-known that many of these crops and varieties have been rapidly disappearing, but data has been scarce on just how many have been lost, how many we are losing, and which ones are the most threatened going forward.

A new study utilizes a methodology known as the Varietal Threat Index, which was developed by the Alliance of Bioversity International and CIAT, the International Center for Tropical Agriculture.  The study assessed about 600 farmers from seven Indian states, covering five different agroecological areas.  The farmers were selected based on their knowledge of crops and varieties across the 17 study sites.

The farmers listed the crops and varieties grown in their households, noted their uses, and indicated their spread and abundance, including information on varieties grown during the previous ten years which were no longer grown.

The results of the study showed that while there is a significant diversity of landraces – which are local varieties of species developed over time – more than 50% are threatened.  The trend is that crops and varieties mostly used for consumption are most often under threat, whereas varieties with multiple uses are less likely to be threatened.

Studies of this type can aid the development of targets and indicators to monitor the global status of plant genetic resources for food and agriculture and help inform urgent priority conservation actions.

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More than half of surveyed crop varieties are under threat of extinction, according to study in India

Photo, posted February 21, 2014, courtesy of Atibordee Kongprepan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Reducing COVID-19 Spread With UV Light | Earth Wise

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New research published by the University of Colorado Boulder analyzes the effects of different wavelengths of ultraviolet light on the SARS-CoV-2 virus.   The research found that a specific wavelength of UV light is not only extremely effective at killing the virus that causes COVID-19, but also that this wavelength is safer for use in public spaces.

UV light is naturally emitted by the sun and most forms of it are harmful to living things – including microorganisms and viruses.   The most harmful UV radiation from the sun is filtered out by the atmosphere’s ozone layer.   Human-engineered UV light sources screen out harmful UV rays with a phosphorus coating on the inside of the tube lamps.  Hospitals and some other public spaces already use UV light technology to disinfect surfaces when people are not present.

The new research found that a specific wavelength of far-ultraviolet-C, at 222 nanometers, was particularly effective at killing SARS-CoV-2, but that wavelength is blocked by the very top layers of human skin and eyes.  In other words, that light has essentially no detrimental health effects for people while it is very capable of killing off viruses.

The researchers argue that this safe wavelength of Far UV-C light could serve as a key mitigation measure against the COVID-19 pandemic.  They imagine systems that could cycle on and off in indoor spaces to routinely clean the air and surfaces or perhaps create an ongoing, invisible barrier between teachers and students, customers and service workers, and other places where social distancing is not practical.  Installing these specialized UV lights would be much cheaper than upgrading entire HVAC systems in buildings.

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Specific UV light wavelength could offer low-cost, safe way to curb COVID-19 spread

Photo, posted January 18, 2008, courtesy of Phil Whitehouse via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Spotted Lantern Fly Is A Big Problem | Earth Wise

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The spotted lanternfly is an invasive pest from Asia that arrived in the United States seven years ago.  It is a handsome and colorful insect, but it feeds on the sap of more than 70 plant species, leaving them susceptible to disease and destruction from other natural antagonists.  It destroys fruit crops, trees, and plants by hopping from plant to plant, crop to crop, and tree to tree.

Several states have established quarantines aimed at preventing the spread of the insects.  Pennsylvania, where they were first detected in the U.S., issued an Order of Quarantine and Treatment that imposes fines and even potential criminal penalties on anyone who intentionally moves a spotted lanternfly, at any stage of its life, from one sort of location to another.  The insects hop and fly only short distances, but they can hitch a ride on vehicles, clothing, and other objects that people bring with them.  They have now spread to at least nine states, primarily in the Northeast.

Lanternflies arrived in New York City last year and quickly made it to the Most Wanted List for environmentalists.  The City’s Parks Department says: “If you see a spotted lanternfly, squish it, dispose of it, and report it to us.”  New York’s Department of Agriculture has asked people in the Finger Lakes region, home of numerous vineyards, to collect specimens and provide specifics on where they were found.

Lanternflies are harmless to humans, but they threaten everything from oak, walnut, and poplar trees to grapes, almonds, and fruit orchards.  As the species continues to spread across the country, federal and state officials have a unified message:  if you come across a spotted lanternfly, kill it.

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Die, Beautiful Spotted Lanternfly, Die

Photo, posted August 30, 2018, courtesy of the USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Kind Of Antibiotic | Earth Wise

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Antimicrobial resistance is a serious and growing problem for public health.  Over time, more and more types of bacteria have become resistant to known antibiotics making it very difficult to treat various kinds of infections. 

A new group of antibiotics with a unique approach to attacking bacteria has been discovered at McMaster University in Canada, representing a promising new clinical approach in the fight against antimicrobial resistance. 

The newly found corbomycin and the lesser-known complestatin have a never-before-seen way to kill bacteria, namely, breaking the function of the bacterial cell wall. Bacteria have a wall around the outside of their cells that gives them shape and is a source of strength.  Antibiotics like penicillin kill bacteria by preventing building of the wall, but the new antibiotics work by doing the opposite – they prevent the wall from being broken down. Breaking down the cell wall is critical for cells to divide. In order for bacteria to grow and spread, they need to expand and divide. By completely blocking the breakdown of the wall, it is as if the bacterium is trapped in a prison and can’t expand or grow. 

The researchers demonstrated in mice that these new antibiotics can block infections caused by the drug resistant Staphylococcus aureus which is a group of bacteria that can cause many serious infections. 

The researchers believe this new approach can be applied to other antibiotics and lead to the discovery of new ones with different mechanisms of action. This study found one completely new antibiotic, but since then, they have found a few others in the same family that have this same new mechanism. 

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Antibiotics discovered that kill bacteria in a new way

Photo, posted March 15, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Engineering Mosquitoes | Earth Wise

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Tropical regions grapple with the spread of diseases – such as dengue, yellow fever, zika, chikungunya, and malaria – by mosquitoes.  A fairly successful strategy has been the Sterile Insect Technique, which is essentially insect birth control. The process involves rearing large quantities of sterilized male mosquitoes in dedicated facilities, and then releasing them to mate with females in the wild. As they do not produce any offspring, the insect population declines over time.

A problem with this approach is that while mosquitoes create health problems for people, they also play important roles in various ecosystems, such as providing food for bats and other animals.  Eliminating mosquito populations on a large scale can trigger major changes in ecosystems.

Recently, an international team of scientists has synthetically engineered mosquitoes that halt the transmission of the dengue virus.  They genetically engineered mosquitoes with an antibody “cargo” that gets expressed in the female mosquitoes that spread the dengue virus.  Once the female mosquito takes in blood, the antibody is activated which hinders the replication of the virus and prevents its dissemination throughout the mosquito, thereby preventing its transmission to humans. Essentially, what the researchers have done is transfer genes from the human immune system to confer immunity to mosquitoes.  The researchers are testing methods to neutralize mosquitoes against other viruses they spread.

This opens up a whole new approach to interrupt mosquito-borne human diseases.  Mosquitoes are among the deadliest killers on the planet because they are the messengers that transmit deadly diseases.  Until now, the only real solution has been to kill the messenger.  The new approach may be a better way to deal with a serious problem.

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Mosquitoes engineered to repel dengue virus

Photo, posted June 20, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Zika Insecticides And Honeybees

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Honeybees, which play a critical role in agriculture by pollinating crops, are not native to the United States.  Beekeepers manage most honeybee colonies and they move the bees around to support farmers.        

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The Spread Of Bark Beetles

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Bark beetles are a global scourge of evergreen forests.  Mountain pine beetles have destroyed pine trees across western North America.  Spruce beetles decimated spruce trees from New Mexico into Colorado and beyond.  Altogether, bark beetles have ravaged 85,000 square miles of forest in the western U.S, an area the size of Utah, since 2000.  They have killed trees across an additional 65,000 square miles of British Columbian forests and have caused millions of dollars of damage to the lumber industry in states like Alabama and Mississippi.

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Ebola And Bats

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Filoviruses have devastating effects on people and primates, as evidenced by the 2014 Ebola outbreak in West Africa. For nearly 40 years, preventing spillovers has been hampered by an inability to pinpoint which wildlife species harbor and spread the viruses.

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