Earth Wise

A look at our changing environment.

You are here: Home / Archives for scientists

scientists

Microplastics in Antarctica

By Leave a Comment

Microplastics are small plastic pieces less than five millimeters long and typically far smaller than that.  They come from a variety of sources, often from larger plastic debris that degrades into smaller and smaller pieces.  There are also microbeads, which are tiny pieces of manufactured polyethylene plastic that are added to various health and beauty products.  Tiny bits of plastic easily pass through filtration systems and end up in the ocean and other bodies of water.

Microplastics are a pervasive problem for which nowhere on Earth is truly untouched.  Despite stringent regulations on materials entering Antarctica, scientists have discovered microplastics in the snow near some of the deep field camps there.

A study by the British Antarctic Survey made use of a new and advanced technique that can detect microplastics as small as 11 microns – about the size of a red blood cell.

The research team found microplastics at concentrations ranging from 73 to 3,099 particles per liter of snow. 

Snow samples from three different sites identified polyamide (used in textiles), polyethylene terephthalate (found in bottles and packaging), polyethylene, and synthetic rubber.  The results suggest that at least the polyamide, which accounted for half the microplastics found, came from local sources.

Additional research is needed to fully understand the sources of microplastic pollution in Antarctica and to understand the broader implications of microplastics in that frozen wilderness. Microplastics have already been detected in several penguin, seal, and fish species.

**********

Web Links

Microplastics discovered in Antarctica

Photo, posted February 3, 2015, courtesy of Christian Stangl via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Engineering plants to consume more carbon dioxide

By Leave a Comment

The most abundant protein on the planet is an enzyme called ribulose-1,5-bisphosphate carboxylase/oxygenase, better known as RuBisCO.  Its critical role in photosynthesis makes life as we know it on earth possible.  What it does is convert carbon dioxide from the atmosphere into the organic matter contained in plants.

Getting plants to take up more carbon dioxide from the atmosphere is a key strategy for mitigating climate change.  Planting lots of trees is one way to do it.  Another is to get individual plants to capture more carbon dioxide.

Scientists at the University of Illinois have focused on getting plants to produce more RuBisCO which allows them to grow faster, consuming more carbon dioxide in the process.

Some plants are better than others at taking advantage of the earth’s rising carbon dioxide levels.  Among these are food crops like corn, sugarcane, and sorghum.  Such plants’ growth is not primarily limited by how much carbon dioxide is in the atmosphere but rather by how much RuBisCO is in their leaves.  The Illinois scientists tweaked genes in corn and sorghum to produce plants containing more RuBisCO.  Laboratory experiments on corn demonstrated faster corn growth.  Recent outdoor field experiments on sorghum demonstrated a 16% boost in its growth rate. 

Improving photosynthesis in this way is not only a potential strategy for increasing plants’ ability to combat climate change.  It is also a way to cope with the world’s increasing demand for food by producing crops that can grow larger and more quickly.

**********

Web Links

Scientists Engineer Crops to Consume More Carbon Dioxide

Photo, posted April 12, 2016, courtesy of K-State Research and Extension via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Approaching critical global temperature thresholds

By Leave a Comment

The Paris Climate Agreement is a global treaty adopted in 2015 to combat climate change by limiting global warming to well below 2°C above pre-industrial levels, while striving to keep it below 1.5°C.  But according to recent research, the planet is quickly approaching these critical thresholds. 

An international research team led by scientists from Colorado State University, Stanford University, and ETH-Zurich in Switzerland combined insights from 10 global climate models, and – with the help of artificial intelligence – found that regional warming thresholds are likely to be reached faster than previously thought.

In fact, the researchers found that most land regions will likely surpass the critical 1.5°C threshold by 2040 or even earlier.  Additionally, several regions are on track to exceed the 3.0°C threshold by 2060.  Regions including Central Europe, the Mediterranean, South Asia, and parts of sub-Saharan Africa are expected to reach these thresholds faster. 

The research team relied on transfer learning, a cutting-edge machine learning technique that leverages pre-trained models to tackle new, related tasks.

The research, which was recently published in the journal Environmental Research Letters, found that 34 regions are likely to exceed 1.5°C of warming by 2040.  Of those 34 regions, 31 of them are expected to reach 2°C of warming by 2040, and 26 of these 34 regions are projected to surpass 3°C of warming by 2060.

**********

Web Links

AI predicts that most of the world will see temperatures rise to 3C much faster than previously expected

Photo, posted February 23, 2011, courtesy of 2011 CIAT / Neil Palmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Weather extremes for most people

By Leave a Comment

Scientists from the CICERO Center for International Climate Research in Norway along with researchers at the University of Reading in the UK have analyzed how global warming can combine with normal variations in the weather to produce decades-long periods of very rapid changes involving both extreme temperatures and extreme amounts of rainfall.

Many parts of the world have already been experiencing record temperatures and extreme rainfall events.  Previously, most analyses of the changing climate have focused on the global mean and not on the impact of extreme weather on specific countries.

The study made use of large climate model simulations to show that if global emissions continue on the path they have been on, large parts of the tropics and subtropics – which are home to 70% of the world’s population – are expected to experience strong rates of change in temperature and precipitation extremes over the next 20 years.  But even if there is strong emissions mitigation – meaning that emissions are reduced enough to reach the goals of the Paris Climate Agreement – the expectation is that 20% of the world’s population will face extreme weather risks. 

These extreme events currently account for a disproportionate share of the realized impacts of climate change.  Heatwaves cause heat stress and excess mortality of both people and livestock.  Extreme precipitation leads to flooding, damage to settlements, infrastructure, crops, and ecosystems, as well as to reduced water quality. 

Society will be increasingly vulnerable to these extreme events, especially when multiple hazards occur at the same time.

**********

Web Links

Extreme weather to strengthen rapidly over next two decades

Photo, posted May 20, 2024, courtesy of Dale Cruse via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Svalbard is melting

By Leave a Comment

Svalbard is a Norwegian archipelago between mainland Norway and the North Pole. It is one of the world’s northernmost inhabited areas and is a popular attraction for tourists.  Svalbard is famous for rugged, remote terrain of glaciers and frozen tundra sheltering polar bears, Svalbard reindeer, and Arctic foxes. The Northern Lights are visible during winter, and its summer features the “midnight sun”—sunlight 24 hours a day.  It is the home of the Svalbard Global Seed Vault, which provides safe, free, and long-term storage of seed duplicates from all gene banks and nations around the world. 

Over half of Svalbard’s land area is covered with ice and accounts for about 6% of the planet’s glaciated area outside of Greenland and Antarctica.  But Svalbard is also one of the fastest-warming places on Earth.

It has suffered extreme episodes of melting this summer, brought on by exceptionally high air temperatures.  In late July and early August, temperatures hovered around 7 degrees Fahrenheit above average for this part of the Arctic Circle, causing snow and ice to rapidly melt.

According to scientists, Svalbard’s ice caps broke their all-time record for daily surface melt on July 23rd, shedding nearly half a foot of water equivalent that day, a rate five times larger than normal. 

On August 11th, the high temperature in Longyearbyen, Svalbard’s capital city, reached 68 degrees, the highest August temperature on record and 4 degrees above the previous monthly record.  Svalbard experienced its warmest summer on record in 2023.

**********

Web Links

Svalbard Melts

Photo, posted September 21, 2016, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Emissions and the Great Salt Lake

By Leave a Comment

The Great Salt Lake in Utah has been described as a puddle of its former self.  The lake’s size fluctuates naturally with seasonal and long-term weather patterns, but the lake has been experiencing decline for decades as Utahans take water out of the rivers and streams that once fed the lake.  Over recent decades, the lake has lost 73% of its water and 60% of its surface area.

For years, scientists and environmental leaders have warned that the Great Salt Lake is headed toward a catastrophic decline.  Recent research has found that the lake’s desiccating shores are becoming a significant source of greenhouse gas emissions.  Scientists have calculated that the dried-out portions of the lakebed released about 4.1 million tons of carbon dioxide and other greenhouse gases in 2020.

The recent study, published in the journal One Earth, suggests that the Great Salt Lake – which is largest saltwater lake in the Western Hemisphere – as well as other shrinking saline lakes around the world could become major contributors of climate-warming emissions.

The shrinking back of the water has exposed a dusty lakebed that is laced with arsenic, mercury, lead, and other toxic substances.  Some are naturally occurring, and others are the residue of mining activity in the region.  These substances threaten to increase rates of respiratory conditions, heart and lung disease, and cancers.

As the lake shrinks, it is becoming saltier and uninhabitable to native flies and brine shrimp and may increasingly become unable to support the 10 million migratory birds and wildlife that frequent it.

The new research about greenhouse gas emissions just adds to a dire list of environmental consequences brought on by the lake’s steep decline.

**********

Web Links

Shrinking Great Salt Lake Becoming Source of Heat-Trapping Gas

Photo, posted January 20, 2020, courtesy of Matthew Dillon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The most endangered marine mammal

By Leave a Comment

For the better part of a decade, conservationists have been trying to eliminate the use of gill nets by fishermen in the Gulf of California.  Species such as the corvina fish have been decimated by the use of this fishing gear.  The nets also trap other marine creatures, include the rare and elusive vaquita porpoise.

The vaquita is the world’s smallest porpoise, measuring no more than five feet in length.  It is the most endangered marine mammal. They live only in the Gulf of California, which is the site of intense fishing activity. Some of that activity is directed towards a fish called the totoaba, which is an endangered species itself.  The totoaba’s swim bladder is highly prized for Chinese traditional medicine, so there is a booming illegal market for it.  The gill nets used to catch totoaba are especially lethal to vaquitas.

Every year, for a few weeks, an international team of scientists searches the Gulf for vaquitas.  Recent surveys estimated that there are around 10 individuals in the area where they are most likely to be living.  This year’s survey estimated that six to eight vaquitas are in the area.  The ones spotted appeared to be in good health and one yearling was seen.

Officially, fishing with gill nets is banned throughout much of the upper Gulf of California.  In practice, enforcement has been difficult to do.  However, the Mexican government has been making an effort to improve the situation.  The Mexican Navy dropped 193 concrete blocks with giant hooks designed to entangle gill nets to deter fishers and they plan to drop more.

The survival of the vaquita depends on whether the use of gill nets stops.

**********

Web Links

The Most Endangered Marine Mammal Still Exists. Here’s the Latest Count.

Photo, posted July 12, 2011, courtesy of Semarnat via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Declining pollinator populations

By Leave a Comment

Scientists have been sounding the alarm on the global struggle of pollinators for decades.  Many recent studies have highlighted alarming declines in pollinator populations, sparking concern about the potential negative impacts on ecosystems and agriculture.  Habitat loss, invasive species, and climate change are some of the factors linked to the population declines. But most pollinator research has focused on well-studied species in easily-accessible regions.

In a new study recently published in the journal PLOS One, a research team led by Northern Arizona University compiled data on four major families of bees and butterflies to create species distribution models, allowing them to assess changes over time and space across North America.

The researchers confirmed that bee and butterfly populations are declining in major regions of North America due to ongoing environmental changes, and found that significant gaps in pollinator research limit the ability to protect these species. 

The highest species richness was found along North America’s West Coast –  especially in California. But the models showed a decline in species richness over the past century in western North America.  In contrast, the research team found disproportionate increases in eastern North America.

Comparisons with climate data indicate that the pollinator population changes are at least partly due to the impacts of climate change, including prolonged drought and habitat degradation. 

The study identifies regions of declining populations where officials can prioritize conservation efforts, and highlights how improved monitoring methods could address the knowledge gaps on pollinator populations.

**********

Web Links

Bee and butterfly records indicate diversity losses in western and southern North America, but extensive knowledge gaps remain

Bees and butterflies on the decline in western and southern North America

Photo, posted April 3, 2017, courtesy of Tracie Hall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hope for amphibians

By Leave a Comment

There are more than 7,000 known species of amphibians, the group of animals that includes frogs, toads, and salamanders.  Over the past 25 years, more than 90 species are believed to have gone extinct and at least 500 more have declining populations.

There are many factors contributing to the decline of amphibian populations but the most alarming is a fungus called Batrachochytrium dendrobatidis – or Bd – that ravages the skin of frogs and toads and eventually causes heart failure.  The fungus has been devastating amphibians on nearly every continent.

In a recent paper in the journal Current Biology, scientists at the University of California Riverside documented the discovery of a virus that infects Bd and could be engineered to control the fungal disease.

The researchers were studying the population genetics of the Bd fungus with DNA sequencing technology and uncovered the virus inside the fungal genome.  Some strains of the fungus are infected with the virus and others are not.  They are now looking for insights into the ways that the virus operates to see how it gets into the fungal cells.  The goal is to engineer the virus to infect more strains of the fungus and potentially end the global amphibian pandemic.

Frogs and toads control bad insects, crop pests, and mosquitos.  If their populations around the world collapse, it could be devastating.  They are already having difficulty coping with warmer temperatures, stronger UV light, and worsening water quality in many places. 

Some amphibian species are already acquiring resistance to Bd.  The UCR researchers are hoping to assist nature in taking its course.

**********

Web Links

Discovery could end global amphibian pandemic

Photo, posted August 25, 2010, courtesy of Kev Chapman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hybrid beef rice

By Leave a Comment

There is growing interest in innovative and more environmentally friendly ways to provide protein in our diets.  We’ve heard a great deal about lab-grown or cultured meats and about protein derived from insects. Whether either of these things achieves mainstream acceptance remains to be seen.

Scientists at Yonsei University in South Korea have developed a method for creating cultured beef rice – truly a hybrid food.  The method, described in the journal Matter, results in a nutritious and flavorful food that could be more affordable and have a smaller carbon footprint than current protein sources.

The researchers took rice grains – which are porous and have organized structures – and seeded them with beef muscle and stem cells and allowed them to culture for 9 to 11 days.  The harvested final product is a cell-cultured beef rice.

The hybrid beef rice was steamed and subjected to various food industry analyses, including nutritional value, odor, and texture.  The hybrid rice has 8% more protein and 7% more fat than regular rice.  It was somewhat firmer and more brittle than ordinary rice.  Hybrid rice with higher muscle content had beef- and almond-related odor compounds, while those with higher fat content had compounds corresponding to cream, butter, and coconut oil.

The hybrid rice has low food safety risks and a relatively easy production process.  If commercialized, the hybrid rice would be far less expensive than beef.  The researchers are optimistic that it can be commercialized.  They are continuing to work on the processing, hoping to further boost the nutritional value.  Like other unconventional foods under development, the biggest question is ultimately whether people will want to eat it.

**********

Web Links

By growing animal cells in rice grains, scientists dish up hybrid food

Photo, posted January 26, 2010, courtesy of CIAT / Neil Palmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Is the Amazon rainforest nearing a tipping point?

By Leave a Comment

The Amazon rainforest is the largest rainforest in the world, covering more than 2.5 million square miles.  More than three million species live in the rainforest, which constitutes approximately 10% of the world’s known biodiversity.  The Amazon rainforest’s biodiversity is so rich that scientists are still discovering new species all the time. 

The Amazon rainforest absorbs huge amounts of carbon dioxide from Earth’s atmosphere, making it a key part of mitigating climate change.  But the amount of carbon dioxide absorbed by the Amazon rainforest today is 30% less than it was in the 1990s. 

Deforestation of the Amazon rainforest remains a major problem. Cattle ranching is the leading cause of deforestation, but industrial activities, such as the mining of oil and gas, copper, iron, and gold, are also to blame.

According to a new study recently published in the journal Nature, global warming may be interacting with regional rainfall and deforestation to accelerate forest loss in the Amazon.  In fact, it may be pushing the rainforest towards a partial or total collapse. 

The study, which was led by researchers from Federal University of Santa Catarina in Brazil and the University of Birmingham in the U.K., has identified the potential thresholds of these stressors, and highlighted how their combined effects could produce a tipping point for the Amazon rainforest. 

The findings are important because the Amazon rainforest plays a vital role in the global climate system.  By identifying the most important stressors on the rainforest environment, the researchers hope they can develop a plan to keep the Amazon rainforest resilient.

********** 

Web Links

Is the Amazon forest approaching a tipping point?

Photo, posted July 2, 2017, courtesy of Anna & Michal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hope for white rhinos

By Leave a Comment

There are only two northern white rhinos left in the world, and both of them are female.  The last male died in 2018. Northern white rhinos live to about 40 and one of the two remaining is 35 and the other 24.  The clock is ticking for the species.

Recently, scientists with the BioRescue consortium successfully used in vitro fertilization to impregnate a southern white rhino.  It was the world’s first IVF rhino pregnancy.

There is now some hope that IVF could be used to produce more northern white rhinos.  For various medical reasons, neither of the remaining two female rhinos can serve as a surrogate mother.  But there is a plan B.

For a number of years, BioRescue has been creating northern white rhino embryos with eggs from the remaining females and sperm that was collected from males before they died.  There are now 30 northern white rhino embryos in cold storage, and they are continuing to produce more.

The recent success with the southern white rhino IVF provides hope that southern white rhino females can act as surrogate mothers with implanted northern white rhino embryos.  The species are similar enough that it should work.

The plan is to select surrogates and implant them.  This should happen this year.  A rhino pregnancy lasts 16 months.  If this is successful, there could be northern white rhino babies in two or three years.  The scientists want the offspring to live with the surviving northern whites for years to learn the social behavior of its kind.

It is possible that these gentle, hulking creatures may get a new lease on life.

**********

Web Links

Just two northern white rhinos are left on Earth. A new breakthrough offers hope

Photo, posted September 16, 2017, courtesy of San Diego Zoo Safari Park via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Natural hydrogen

By Leave a Comment

Hydrogen is considered to be a potential substitute for conventional fossil fuels in applications where electricity cannot easily be used such as in blast furnaces, cement works, industrial heating, long-distance aviation, and shipping.  But most hydrogen is manufactured by separating it from methane, which is energy-intensive and produces carbon dioxide.  So-called green hydrogen is made by splitting water using electricity.  It is a carbon-free process if the electricity is from renewable sources, but it is pretty expensive.

A small community in Mali gets its electricity by burning natural hydrogen, which bubbles up from underground into a village well.  It has long been known that processes in the Earth’s crust can make hydrogen gas from water under certain circumstances.  But conventional wisdom has been that this occurrence is rare and that the hydrogen produced is either inaccessible or seeps away.

An increasing number of geoscientists now are convinced that there is actually an enormous quantity of hydrogen beneath the planet’s surface and that we just haven’t been looking for it in the right places, or at all, for that matter.  Some say that there could be trillions of tons of hydrogen, and more is being generated all the time.

Prospectors have recently been drilling for hydrogen in France, Australia, Morocco, Brazil, and in the United States, in Nebraska, Arizona, and Kansas.  Will extracting natural hydrogen be practical at the scale required and will it be economical?  The jury is still out on all of this, but if it turns out as proponents claim, natural hydrogen could be a very big deal.

**********

Web Links

Natural Hydrogen: A Potential Clean Energy Source Beneath Our Feet

Photo, posted November 4, 2012, courtesy of Heather Paul via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Red mud and steel

By Leave a Comment

Most of us have never heard of red mud.  Otherwise known as bauxite residue, it is an industrial waste product generated by the most common process by which aluminum is made and the world produces 200 million tons of red mud each year.  The stuff is a significant environmental hazard being extremely alkaline and corrosive. Most of it ends up in large landfills and the costs associated with disposing of red mud are substantial.

Red mud is red because it contains large amounts of iron oxide, often as much as 60% of it.  Scientists at the Max-Planck Institute in Germany have developed a method for producing steel from red mud that is much less carbon intensive than traditional steel production and that is economically viable.

The scientists melt the red mud in an electric furnace powered in part by green hydrogen.  Running the furnace this way, even when using electricity from only partially renewable sources, results in far fewer greenhouse gas emissions as well as economic benefits.  In the furnace, liquid iron separates from the other liquid oxides and can be extracted easily.  The resultant iron is so pure that it can processed directly into steel.  The remaining metal oxides are no longer corrosive, and they solidify into a glass-like material that can have practical uses in construction.

There are 4 billion tons of red mud that have accumulated worldwide to date.  According to the researchers, their process could produce over 700 million tons of green steel from it, potentially saving 1.6 billion tons of carbon dioxide emissions. 

**********

Web Links

Green steel from toxic red mud

Photo, posted September 7, 2021, courtesy of Healthy Gulf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Why are bees making less honey?

By Leave a Comment

Scientists have been sounding the alarm on the global struggle of pollinators for a long time.  According to the United Nations, nearly 35% of the invertebrate pollinator species, such as bees and butterflies, are facing extinction. And since 75% of the world’s food crops depend on pollination to some extent, the decline of pollinators poses a major threat to global food security.

Honey bees are among the struggling pollinators.  Honey bee colonies in the United States have experienced annual population declines since 2006.  But in addition to there being fewer bees, the bees that remain are also making less honey.  In fact, honey yields in the United States have been declining since the 1990s. 

A new study by researchers from Penn State University has solved some of the mystery.  Using five decades of data across the United States, the research team analyzed the factors that could be affecting the number of flowers growing in different regions, which, in turn, affects the amount of honey produced by bees. 

In the study, which was recently published in the journal Environmental Research, the scientists found that climate conditions and soil productivity were two of the biggest factors in estimating honey yields.  States in both warm and cool regions produced higher honey yields when they had productive soils.  These two factors set a baseline production level of honey, while herbicide use, weather, and land use changes influenced how much honey was produced in a given year. 

The study’s findings  provide valuable insights that should help beekeepers, growers, and land managers better support honey bees.

**********

Web Links

Why are bees making less honey? Study reveals clues in five decades of data

Photo, posted August 30, 2021, courtesy of Brandon O’Connor / NRCS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Why was 2023 so hot?

By Leave a Comment

Five separate weather-tracking organizations have proclaimed 2023 as the hottest year on record. They all agreed that 2023 beat the previous record-holder – 2016 – by a wide margin.  Organizations that use a pre-industrial baseline of 1850-1900 found that 2023 was 1.45 to 1.48 degrees Celsius above the baseline.  But what caused 2023 – especially the second half of it – to be so hot?

Scientists believe that there were multiple factors that contributed to the record-breaking heat.

First and foremost is the long-term rise in greenhouse gases.  Over 100 years of burning fossil fuels along with major changes in land use (particularly deforestation) have led to a significant rise in the heat-trapping blanket of the gases in the atmosphere.

On top of this long-term trend, the return of the El Niño condition in the Pacific in May helped temperatures rise further.

At the same time, the tropical Pacific was not the only ocean that was hotter than normal.  The global sea surface temperature set new records in 2023 and there were multiple marine heat waves.  Heat trapped by the atmosphere is absorbed by the oceans, raising their temperatures.

Another factor is the quantity of aerosols in the atmosphere.  Many of these aerosols actually cool the atmosphere by reflecting the sun’s light back into space.  Society’s efforts to reduce air pollution and improve air quality have led to decreasing levels of aerosols.

2024 started with some seriously cold weather in some places but predictions are that this year will be roughly as warm as 2023 and possibly warmer given that the dynamics driving last year’s weather are all still in place.

*********

Web Links

Five Factors to Explain the Record Heat in 2023

Photo, posted February 22, 2016, courtesy of Jasmin Toubi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

More mosquitoes in a warming climate

By Leave a Comment

Over millions of years, Earth’s climate has warmed up and cooled down many times. However, today the planet is warming much faster than it ever has over human history.  According to scientists, the warming is primarily the result of increased anthropogenic greenhouse gas emissions.  In fact, human activities are responsible for nearly all of the increase in atmospheric greenhouse gas emissions over the last 150 years. 

According to a new study published in the journal Ecology, the warming climate may soon mean more mosquitoes.  A research team, led by scientists from Virginia Commonwealth University, found that rising temperatures, often linked to climate change, can make predators of mosquito larvae less effective at controlling mosquito populations.  According to researchers, these warmer temperatures accelerate the development time of larvae, which leads to a smaller window of time in which predators like dragonflies could eat them.  As a result, twice as many mosquito larvae could make it to adulthood in the study area. 

Predators help stabilize ecosystems and food webs.  The study looked at predator-prey interactions between dragonfly nymphs and mosquito larvae.  In the study of Belle Isle along the James River in Richmond, Virginia, the research team found that warmer pools had more aquatic rock pool mosquito larvae – even when their predators that naturally control the populations were present.

While this species of mosquito is not an important disease vector, the researchers emphasize that these findings likely apply to other mosquito species that do act as vectors for diseases, such as West Nile or Zika virus.

The changing climate is creating the perfect environment for mosquitoes to thrive. 

**********

Web Links

Hotter weather caused by climate change could mean more mosquitos, according to VCU-led study

Photo, posted June 20, 2014, courtesy of John Tann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

What did the record warmth of 2023 mean?

By Leave a Comment

2023 was the warmest year in the 174 years of global temperature record-keeping.  According to some analyses, it may have been the warmest year in the past 125,000 years.

There were incredible heatwaves in Arizona and Argentina.  There were relentless wildfires across Canada.  The wintertime ice coverage in the seas surrounding Antarctica was at unprecedented lows

The global temperatures in 2023 did not just beat prior records; they smashed them.  Every month from June through November set all-time monthly temperature records. The US Northeast saw springlike temperatures at the end of the year.  The high temperature in Buffalo, New York on Christmas Day was 58 degrees.

Climate scientists have been predicting the warming trend that has been ongoing over the past several decades.  Indeed, computational models for 2023 called for a warm year.  Various models had a variety of projected temperatures and 2023’s heat was still broadly within the range of what was projected, although certainly at the high end.

The question is whether last year was an indicator that the planet’s warming is accelerating faster than we expect or that it just was a particularly warm year because of cyclical factors such as the El Niño that appeared last spring.

One theory that is being explored is that various types of industrial pollution have previously actually served to cool the atmosphere over time and as those sources are reduced for public health reasons, the warming effects of greenhouse gases have accelerated.

Currently, there is no consensus about why it seems to be getting warmer even faster than many climate models predict.  What there is no doubt about is that it is not a good thing.

**********

Web Links

Earth Was Due for Another Year of Record Warmth. But This Warm?

Photo, posted June 8, 2023, courtesy of Anthony Quintano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

How will we know if the world is 1.5 degrees warmer?

By Leave a Comment

The Paris Climate Agreement has a goal of limiting global warming to less than 1.5 degrees Celsius above pre-industrial levels.  How do we know if we are succeeding and, more importantly, how would we know if we have failed?

This may seem like something fairly obvious, but it isn’t.  Global temperatures are definitely creeping upward.  This past year has been the warmest on record.  In fact, the global average temperature was more than 1.4 degrees above pre-industrial levels.  November was 1.75 degrees above pre-industrial levels.  So, does that mean that our climate goals have already failed?  Not really.

On a monthly scale there have already been individual months where warming has exceeded 1.5 degrees in 2016, 2017, 2019, 2020, and 2023.  Would an entire year above the target constitute failure?  Not necessarily.  There really isn’t an agreed-upon answer and that in itself represents something that could undermine global efforts to tackle climate change.

If we don’t know whether we are succeeding or failing, it is more difficult to pursue success.  The United Nations IPCC says the threshold will be surpassed when average warming exceeds 1.5 degrees for 20 years.  But that seems like a building a mountain highway with no guardrails and hoping to be safe.

Scientists are calling for new approaches to defining a universally agreed-upon measure of global warming that could trigger urgent action to avoid further rises.  What we really don’t need are justifications and excuses for continued inaction.  Clearly the climate is not waiting for us to debate the issue.

**********

Web Links

Why We Won’t Know When We’ve Passed the 1.5-Degree Threshold

Photo, posted August 2, 2018, courtesy of J Bartlett Team Rubicon/BLM for USFS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seabirds rescuing coral reefs

By Leave a Comment

A new study by researchers at Lancaster University in the UK has found that the presence of seabirds on islands adjacent to tropical coral reefs can more than double the coral growth rates on those reefs.

The study found that when coral reefs grow faster, they can bounce back more quickly from bleaching events that occur when the seas become too warm.  The focus of the study was a type of coral called Acropora, which provides complex structures supporting fish populations and reef growth. 

The researchers found that Acropora around islands populated by seabirds recovered from bleaching events about 10 months faster than reefs located away from seabird colonies.  Speeding up coral recovery times could prove the difference between continuing to bounce back from bleaching events and dying off.

The seabirds are helping the coral reefs with their droppings.  The birds feed on fish in the open ocean far from islands and then return to the islands to roost.  They deposit nitrogen- and phosphorus-rich nutrients in the form of guano, some of which is washed off of the islands by rain and into the surrounding seas.  The nutrients fertilize corals and other marine species.

To determine whether the faster growth rates were really due to the bird-supplied nutrients, the researchers studied rat-infested islands that had no bird populations.  The study confirmed that it was the presence of seabirds that provided enhanced nutrients for the coral reefs.  In fact, a primary outcome of the study was to add further weight to the growing body of evidence of the ecological damage across ecosystems on land and sea from invasive rats on tropical islands.

**********

Web Links

Feathered friends can become unlikely helpers for tropical coral reefs facing climate change threat

Photo, posted September 15, 2019, courtesy of Rickard Zerpe via 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...)