Earth Wise

A look at our changing environment.

You are here: Home / Archives for Canada

Canada

Tracking atmospheric mercury

By Leave a Comment

Atmospheric mercury is a toxic pollutant released into the air from natural sources—such as volcanoes and wildfires—and from human activities like coal burning and gold mining.  Once in the atmosphere, mercury can travel long distances before settling onto land or into water, transforming into toxic forms that threaten ecosystems and human health.

But tracking atmospheric mercury is a costly and challenging endeavor, requiring specialized equipment and trained personnel. Active monitors, which pump air to collect mercury, are expensive and need electricity, while passive samplers, using activated charcoal for remote areas, cost up to $100 each.

Researchers from Cornell University have found a cheap method for tracking toxic atmospheric mercury near gold mining sites throughout the Global South: wild fig trees.  In the study, which was conducted in the Peruvian Amazon and recently published in the journal Frontiers in Environmental Science, the research team found that the rings in wild fig trees can serve as natural archives of atmospheric mercury, capturing and preserving historical pollution levels over time.

The technique itself is not actually new.  Previous studies have used tree rings to track mercury pollution from coal combustion, particularly in Canada. But the research team wanted to test this method in regions of the Global South, where mercury emissions from gold mining are widespread.

According to the research team, wild fig trees might soon serve as an important biomonitoring tool, helping scientists better understand how mercury disperses across landscapes and through time.

**********

Web Links

Tree rings track atmospheric mercury cheaply

Photo, posted November 13, 2012, courtesy of Steve Kessler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic from food waste

By Leave a Comment

Plastic waste management is a complicated business.  Most methods of recycling or breaking down plastic are costly and harmful to the environment.  The most common biodegradable alternatives – like paper straws – are less than ideal replacements.

There are many approaches to creating biodegradable plastics using feedstocks like seaweed, sugarcane, and other plant matter.  However, the resulting plastics often fall short compared with conventional petroleum-based plastics.

One type of bioplastic that is gaining popularity is polyhydroxyalkanoates, or PHA.  PHA is a plastic produced by microorganisms.  It is fully compostable or biodegradable but in other ways but looks, feels, and functions like regular plastic but without the environmental drawbacks.

PHA can be made using bacterial fermentation of a variety of feedstocks such as vegetable oils, sugars, starches, and even methane and wastewater.

Researchers at a startup from the University of Waterloo in Canada called MetaCycler BioInnovations have developed a process for producing PHA based on bacteria that has been engineered to convert waste from milk and cheese production.  This solution upcycles waste from the dairy industry into cost-effective, sustainable bio-based plastics. 

PHAs can be tailored to have a wide range of properties ranging from being rigid and tough to being quite flexible.  Therefore, they can be suitable for many applications including packaging, agricultural films, and consumer goods. 

The Waterloo technology is a way to tackle the problems of both food waste and plastic pollution with one solution.

**********

Web Links

Turning food waste into a new bioplastic

Photo, posted December 10, 2017, courtesy of Leonard J Matthews via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Polar bear population decline

By Leave a Comment

Researchers from the University of Toronto have directly linked the population decline in polar bears living in Canada’s Western Hudson Bay to climate change.  Between 1979 and 2021, the polar bear population in this region has declined by nearly 50%.

The monitoring data over this period shows that the average size of polar bears has declined, the size of cub litters has dropped, and cub survival rates are reduced.

The primary factor is the declining amount and duration of sea ice.  When there is less ice, bears have less feeding time and less energy overall.  The loss of sea ice means that bears spend less time hunting seals and more time fasting on land.  The lack of food leads to reduced reproduction, cub survival, and, ultimately, population decline. 

The average body mass of adult females has dropped by 86 pounds and of cubs by 47 pounds.  With shorter hunting periods and less food, mothers produce less milk.  Not only have cub litter sizes dropped over the monitoring period, but mothers are keeping their cubs longer because they are not strong enough to live on their own.  The bottom line is that the survival of cubs directly impacts the survival of the population.

Western Hudson Bay is considered to be a bellwether for polar bear populations globally.  It is one of the southernmost populations of polar bears and it has been monitored for a long time.  With the Arctic warming at a rate four times faster than the global average, polar bear populations in other Arctic regions are likely to be experiencing similar declines. 

**********

Web Links

Polar bear population decline the direct result of extended ‘energy deficit’ due to lack of food

Photo, posted October 23, 2015, courtesy of Anita Ritenour via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

La Niña has arrived

By Leave a Comment

After seven months of waiting following the end of the recent El Niño condition, La Niña finally showed up in the eastern Pacific Ocean in early December.

El Niño and La Niña are climate patterns in the Pacific Ocean that can affect weather worldwide.  Normally, trade winds in the Pacific blow west along the equator, taking warm water from South America towards Asia.  To replace the warm water, cold water rises from the depths.  During El Niño, trade winds weaken and warm water is pushed back east, toward the west coast of the Americas.  As a result, areas in the northern U.S. and Canada are dryer and warmer than usual.

During La Niña, trade winds are stronger than usual, pushing more warm water toward Asia.  This results in more upwelling of cooler water from the depths.  This tends to lead to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest and Canada.  During a La Niña year, winter temperatures are warmer than normal in the South and cooler than normal in the North.

According to the report published in January by NOAA, the La Niña that has arrived is not a particularly strong one.  Sea surface temperatures are only about 1.3 degrees Fahrenheit below average in the tropical Pacific.  The report also suggests that the La Niña condition may not stick around very long.

The El Niño-Southern Oscillation phenomenon adds a natural source of year-to-year variability in global temperatures.  The presence of La Niña for at least part of this year may temporarily keep the lid on rapidly climbing global temperatures.

**********

Web Links

La Niña Is Here

Photo, posted November 23, 2011, courtesy of NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Thawing permafrost in the Arctic

By Leave a Comment

Permafrost covers about a quarter of the landmass in the Northern Hemisphere.  It stores vast quantities of organic carbon in the form of dead plant matter.  As long as it stays frozen, it is no threat to the climate.  But as permafrost thaws, microorganisms start breaking down that plant matter and large amounts of carbon are released into the atmosphere in the form of carbon dioxide and methane.

Scientists estimate that there could be two and a half times as much carbon trapped in Arctic permafrost as there is in the atmosphere today.

Thawing permafrost poses various risks to the Arctic environment and the livelihoods of its people.  According to a new study led by researchers from the University of Vienna in Austria, Umeå University in Sweden, and the Technical University of Denmark, thawing permafrost threatens the way of life of up to three million people.

To identify these risks, the research team studied four Arctic regions in Norway, Greenland, Canada, and Russia between 2017 and 2023.  The research, which was recently published in the journal Communications Earth and Environment, identified five key hazards posed by the thawing permafrost: infrastructure failure, disruption of mobility and supply, decreased water quality, challenges for food security, and exposure to diseases and contaminants.

These are present developments – not future dangers.  Global scientific cooperation, policy interventions, and investment in research are critical to mitigate the impact of thawing permafrost and address the broader consequences it brings.

**********

Web Links

A transdisciplinary, comparative analysis reveals key risks from Arctic permafrost thaw

Thawing permafrost threatens up to three million people in Arctic regions

Photo, posted February 9, 2017, courtesy of Benjamin Jones / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Drying rivers and hydropower

By Leave a Comment

A decade ago, Ecuador began a major transition to using hydroelectric power.  Like in many other South American countries, the presence of abundant rivers could supply large amounts of energy and drive economic expansion and lead to a new era of prosperity.

This ambitious plan has run into the impacts of climate change.  An extraordinary drought has engulfed much of South America, drying rivers and reservoirs, and has put Ecuador’s power grid on the brink of collapse. 

Since September, daily energy cuts in Ecuador have lasted as long as 14 hours.  An industry group says that the nation is losing $12 million in productivity and sales for every hour the power is out.  Just a few years ago, Ecuador was making great strides in reducing poverty.  Now, as the energy crisis has increased its grip on the country, much of what was achieved is being lost.

Ecuador’s situation is not unique.  In recent years, abnormally dry weather in multiple places has resulted in extreme low water levels in rivers, reducing hydropower resources in Norway, Canada, Turkey, and even rainforest-rich Costa Rica.

Overall, more than one billion people live in countries where more than half of their energy comes from hydroelectric plants.  With a warming climate and increasing incidence of extreme weather events like drought, it is likely that hydropower will become a less reliable energy source.  More than a quarter of all hydroelectric dams are in places with a medium to high risk of water scarcity by 2050. 

**********

Web Links

The Rivers Run Dry and the Lights Go Out: A Warming Nation’s Doom Loop

Photo, posted January 15, 2020, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Dangers of distant fires

By Leave a Comment

Smoke from wildfires is well known to exacerbate health problems like heart disease, lung conditions, and asthma.  People living in the vicinity of where fires occur face these dangers.  But a new study at the University of Maryland has found that there are health impacts from wildfires occurring thousands of miles away.

During the summer of 2023, massive Canadian wildfires created a vast plume of smoke that drifted more than 2,000 miles across the country resulting in poor air quality across the entire East Coast of the U.S. 

Baltimore had very dark skies over a six-day period in June 2023, sending many individuals to doctors’ offices complaining of breathing issues.  University of Maryland researchers found that medical visits for heart and lung problems rose by nearly 20% during that period.

Using satellite and EPA data combined with electronic health records, the researchers found increased likelihood of patients going to the doctor for complications related to cardiopulmonary conditions during the days with the most smoke in the air.  They found a 55% increase in the risk for an outpatient visit for heart and lung conditions and these additional patients tended to be older, non-smokers, and more socio-economically affluent than the typical patients who see their doctors for such conditions when the air quality is good.

With more climate-related events likely to occur in the future, doctors may require better tools to help disadvantaged patients on so-called hotspot days when conditions are most dangerous.  Increasingly common wildfires are a particular danger to people even when those fires are far away from where they live.

**********

Web Links

Exposure to Remote Wildfire Smoke Drifting Across the U.S. Linked to Increased Medical Visits for Heart and Lung Problems

Photo, posted June 8, 2023, courtesy of Marc A. Hermann / MTA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Megafires and orchard health

By Leave a Comment

The frequent and massive megafires in places like Canada and the American west have led to a lot of research on the impact of smoke on humans but there has been less study of the effects of smoke on plant health.  Researchers at the University of California, Davis have found that trees are just as vulnerable as humans are to the harmful effects of long-term exposure to smoke.

The Davis researchers studied almond, pistachio, and walnut trees at 467 orchard sites in California’s Central Valley from 2018 to 2022.  In 2022, so-called megafires burned more than 4.2 million acres in California, pouring ash and smoke into the sky.  The researchers had been studying how trees store carbohydrates to cope with heat and drought. 

With the onset of the fires, they saw an opportunity to study how smoke affects carbohydrate levels.  Trees use stored carbohydrates to sustain them through winter dormancy and spring growth.  Trees produce carbohydrates via photosynthesis and thick smoke blocks the amount of light reaching the trees.  Beyond that, there are other aspects of wildfire smoke, such as particulate matter and ozone that appear to affect photosynthesis.

The team found that the smoke not only reduced the amount of carbohydrates in trees but also caused losses that continued even after the fires were extinguished.  This led to nut yield decreases of 15% up to 50% in some orchards.  The researchers expected to see some impact on the trees during periods when smoke was really dense but were not expecting the smoke to have such a lingering effect and result in a significant drop in yield.

**********

Web Links

Smoke From Megafires Puts Orchard Trees at Risk

Photo, posted October 1, 2008, courtesy of Suzi Rosenberg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Canadian wildfires and global emissions

By Leave a Comment

The wildfires that burned vast amounts of Canada’s boreal forests in 2023 produced enormous amounts of smoke that found its way into American cities, working its way down the eastern seaboard and even producing unsafe air in Florida.

Researchers at Cal Tech and the Jet Propulsion Laboratory analyzed the carbon emissions associated with these fires last year and found that they were greater than those of all but three countries:  China, the US, and India.

Boreal forests have historically been a natural defense against climate change by storing carbon in trees rather than adding carbon dioxide to the atmosphere.  The fires in Canada, fueled by hot and dry weather, were extraordinary when compared with historical records.  But such fires are likely to be increasingly common as the climate continues to warm.

However, the hot and dry weather that fueled the 2023 fires was exceptional in many ways, involving early snow melt and so-called flash droughts.  This year’s fires in Canada are still bigger than average, but so far have not been as destructive as last year’s. 

Canada has been warming at about twice the global rate.  The extreme temperatures last summer were a major factor in the fueling of the fires, which burned an area almost the size of Florida.

Forests absorb about a quarter of global carbon emissions, but the increasing frequency and intensity of fires are calling into question their ability to continue to do so.  Parts of the Canadian forests are not regrowing after fires as they have in the past, partly because blazes burn trees so frequently and intensely.

**********

Web Links

Canada’s Wildfires Were a Top Global Emitter Last Year, Study Says

Photo, posted June 8, 2023, courtesy of the Metropolitan Transportation Authority via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Food, timber, and climate change

By Leave a Comment

The sights of coffee plantations in California and vineyards in Britain are becoming more common as the climate changes. But behind what sounds like a success story is a sobering one: climate change is shifting the regions suitable for growing food all around the world. 

According to a new study by researchers from the University of Cambridge, as crop growing shifts northwards, a squeeze will be put on the land needed to produce timber.  The timber these trees produce is used to make everything from paper and cardboard to furniture and buildings.

According to the study, which was recently published in the journal Nature Climate Change, more than 25% of existing forestry land – an area equivalent in size to India – will become more suitable for agriculture by the end of the century if climate change continues unabated.  Approximately 90% of this current forestry land is located in Canada, China, Russia, and the United States.    

Global timber production is worth more than $1.5 trillion every year.  Recent heat waves and wildfires have caused huge losses of timber forests around the world. 

According to the World Bank, the value of the global food system is estimated to be roughly $8 trillion annually.  Scientists expect climate change to cause some areas to become too hot for growing food, particularly in the tropics and southern Europe. 

With the global demand for food and the global demand for wood both projected to double by 2050, the increasing climate change-driven competition between the two is set to be an emerging issue in the coming decades. 

**********

Web Links

Global timber supply threatened as climate change pushes cropland northwards

Do the costs of the global food system outweigh its monetary value?

Photo, posted October 24, 2018, courtesy of Bill Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Nearly everyone wants climate action

By Leave a Comment

A global survey of 75,000 people revealed that 80% of participants want their governments’ climate action commitments to be stronger.  The poll, conducted by the United Nations Development Program, GeoPoll, and Oxford University, asked 15 questions in telephone calls to residents of 77 countries representing 87% of the global population.

According to the survey, 89% of poorer countries favored increasing efforts to curb global emission, while 76% of wealthy G20 nations supported tougher climate action.

The two biggest greenhouse emitters in the world were less enthusiastic:  Chinese participants were 73% in favor of stronger action and Americans were 66% in favor of greater efforts to combat global warming. 

Other demographic differences included that in the big emitting countries of Canada, France, Germany, Australia, and the U.S., women were 10 to 17% more in support of stronger climate action than men.

Overall, only 7% of those polled globally thought their government should not transition away from fossil fuels at all.  More than half of those polled said that they were more worried about climate change this year than last year.  A worldwide majority of 72% support a fast fossil fuel phaseout, including those in nations that are among the top ten coal, oil, and gas producers.

As is the case across the board with respect to climate issues, the more influential factor continues to be economic as opposed to scientific or humanitarian.  Those who stand to lose the most money from the transition away from fossil fuels continue to hold sway over those who will lose in many other ways.

**********

Web Links

Four Out of Five People Want Increased Climate Action, UN Poll Says

Photo, posted July 31, 2020, courtesy of School Strike 4 Climate via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Another ban on neonics

By Leave a Comment

There have been ominous declines in many insect populations.  Chief among them have been declines in pollinators, which have severe consequences for our food supply.  There are multiple possible causes of these declines and undoubtedly several have been involved simultaneously.

A new study on butterfly populations in the Midwest indicates that agricultural insecticides exerted the biggest impact on the diversity of butterfly populations in the Midwest during the period 1998 to 2014.  The biggest culprits were the widely used insecticides called neonicotinoids that are absorbed into the tissues of plants.

Neonics are meant for targeted pesticide use but are often used more broadly, including for corn crops.

Neonics are already well-known to be especially harmful to bees and are gradually being restricted in various places.  Quebec province passed restrictions on neonic-treated seeds in 2019.  Last December, New York signed into law a phase-out of neonic-treated seeds and a ban on non-agricultural uses of them.

Vermont has now become the second state to ban the use of neonicotinoids by virtue of its state legislature overriding a veto from Governor Phil Scott.  The law minimizes the use of neonics by requiring potential users to obtain written exemptions. 

Opponents to neonic restrictions claim that slashing their use will greatly reduce crop yields.  The experience in Quebec over the past five years is that the Canadian neonic restrictions have reduced corn and soybean crop yields by about 0.5%.  As a result of this tiny reduction, there has been a strong reduction in the amount of neonics contaminating waterways.

**********

Web Links

Vermont Becomes Second State to Ban Bee-Killing Neonic Pesticides

New ‘Detective Work’ on Butterfly Declines Reveals a Prime Suspect

Photo, posted September 7, 2017, courtesy of Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Eliminating plastic shipping pillows

By Leave a Comment

Anyone who gets packages from Amazon is familiar with the plastic air pillows used to keep products safe in transit.  Amazon uses almost 15 billion of them a year in North America.

Environmentalists have been urging Amazon and other vendors to cut down on the use of plastic packaging. The air-filled plastic pillows are made from plastic film, which is the most common form of plastic litter found in the sea and in seabeds along the shore.  Plastic film can be deadly to wildlife such as sea turtles and sea birds.  Plastic film generally can’t be composted or recycled either.

Recently, Amazon announced that it will replace its plastic pillows with recycled paper filler in all its North American markets – the United States, Canada, and Mexico – which together account for more than 70% of the retailer’s global sales.  It is already making the switch in a big way and is working towards fully removing the plastic materials by the end of the year.

Replacing plastic packaging with paper is a definite improvement.  Paper is recyclable and biodegradable.  It isn’t perfect:  if it ends up in landfills, it can contribute to methane pollution as it biodegrades.  But, on the other hand, paper packaging is more likely to be recycled.

Stemming the tide of plastic waste is an ongoing effort by environmental and consumer groups.  There is pending legislation in New York that aims to reduce the use of plastic packaging by 50% over 12 years by requiring manufacturers to either replace it or pay fees.  The bill cleared the State Senate but has not come up to a vote in the Assembly.  Similar legislation has already been passed in California, Oregon, Maine, and Colorado.

**********

Web Links

Amazon Says It Will Stop Using Puffy Plastic Shipping Pillows

Photo, posted November 20, 2018, courtesy of Todd Van Hoosear via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Deer vs. caribou

By Leave a Comment

The combination of a warming climate and human disruption of traditional habitats has been causing changes in the ranges of many animal species.  Over the past century, white-tailed deer have greatly expanded their range in North America.  Researchers from a group of Canadian institutions have been investigating the expansion of the deer in the boreal forest of Western Canada.  A five-year study used 300 wildlife cameras throughout the region to track the activities of large mammals.

Climate change has created milder winters and habitat alteration from forestry and energy exploration have created new food sources for deer. 

The expansion of deer in the forest has not been a good thing for the woodland caribou. The species was designated as threatened in 2002.  As of 2011, only 34,000 remained in the region.  Deer are ecosystem disruptors, in this case disrupting existing predator-prey dynamics.  Areas with more deer typically have more wolves and wolves are predators of caribou.  Deer can handle high predation rates, but the already threatened caribou cannot.

Understanding the relative roles of climate and human land use is essential in efforts to recover caribou populations.  It is complicated because further north, the climate becomes harsher and human land use decreases.  The debate over the relative effect of climate or habitat change is one of the most pressing issues facing ecologists globally as they pursue efforts for ecosystem restoration.

In any case, winter severity is expected to decline as climate change progresses.  Therefore, deer are expected to keep expanding northward and increasing in abundance, which means increasing risk to caribou.

**********

Web Links

Deer are expanding north, and that’s not good for caribou

Photo, posted January 12, 2016, courtesy of Gerry via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Canadian zombie fires

By Leave a Comment

Canada’s 2023 wildfire season was the most destructive ever recorded.  Over 6,000 fires burned nearly 71,000 square miles of land from the West Coast to the Atlantic provinces.  The burned areas are roughly the size of the entire country of Finland and represent almost triple the amount burned in the previous year, which itself was a lot. Smoke from Canadian fires, particularly those in Quebec, blanketed many cities in the United States and made its way as far south as Florida.

An alarming aspect of the Canadian fire season is that it didn’t ever really end.  Late in the winter, 149 active wildfires are still burning across Canada.  92 are in British Columbia, 56 in Alberta, and one in New Brunswick.  In these places, the wildfire season is yearlong.

These overwintering fires have come to be known as zombie fires.  They burn slowly below the surface during the winter.  Many areas in the north contain porous peat and moss ground cover and these act as underground fuel for smoldering fires.

Wildfires have become more prevalent in Canada because the changing climate has brought about increases in the hot, dry, and gusty conditions that lead to drought.

Many of the zombie fires don’t pose an increased threat of triggering wildfires in the spring because they are in places that are already so charred that there is nothing left to burn.  But others are in drought areas that are basically tinder boxes ready to burst into flame once spring arrives.

Overall, Canadian government officials are warning that this year’s wildfire season is likely to be even worse than last year’s, particularly in the Western provinces of British Columbia and Alberta.

**********

Web Links

As ‘Zombie Fires’ Smolder, Canada Braces for Another Season of Flames

Photo, posted June 30, 2023, courtesy of P. McCabe / EU via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Small changes can yield big results

By Leave a Comment

Global food production is one of the largest contributors to climate change.  In fact, one-quarter of the world’s greenhouse gas emissions result from food production and agriculture.  Be that as it may, we still have to eat.  But what we choose to eat has a major impact on the environment.

According to a new study by researchers at McGill University in Canada and the London School of Hygiene & Tropical Medicine in the U.K., partially replacing red and processed meat with plant-based proteins can increase lifespan and mitigate climate change. 

In the study, which was recently published in the journal Nature Food, the researchers drew data from a national nutrition survey to analyze Canadians’ dietary records. The study modeled partial replacements (25% and 50%) of either red and processed meat or dairy with plant protein foods like nuts, seeds, legumes, and tofu, on a combination of nutrition, health, and climate outcomes.

In the study, the researchers found that a person’s diet-related carbon footprint plummets by 25% when they replace half of their intake of red and processed meats with plant protein foods. However, dairy substitutions showed smaller reductions of up to just 5%.

Meat and dairy-rich diets are known to increase the risk of heart disease, diabetes, and certain cancers. The researchers also estimated that if half of the red and processed meat in a person’s diet was replaced with plant protein foods, life expectancy would increase nearly nine months on average, due to a reduced risk of chronic disease.

The research team hopes its findings will help people make healthier and more sustainable food choices. 

**********

Web Links

Food production is responsible for one-quarter of the world’s greenhouse gas emissions

Small dietary changes can cut your carbon footprint by 25%

Photo, posted November 24, 2019, courtesy of Theo Crazzolara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Polar bears and the changing climate

By Leave a Comment

The changing climate poses a major threat to polar bear survival.  Polar bears, whose native range lies largely within the Arctic Circle, depend on sea ice for nearly all of their lifecycle functions.  Rising global temperatures are causing this sea ice to disappear.

With less sea ice, polar bears are forced to stay longer on land.  However, according to a new study led by researchers from Washington State University, more time stranded on land leads to a greater risk of polar bear starvation. 

During three summer weeks in Manitoba, Canada, 20 polar bears observed by researchers tried different strategies to maintain energy reserves.  But the research team found that nearly all of them lost weight – losing about 2.2 pounds per day on average.     

Some scientists have speculated that polar bears might be able to adapt to the changing climate by acting more like grizzly bears by either resting or eating terrestrial food.  But the polar bears tried versions of both strategies – with little success.

Polar bears can weigh nearly twice as much as grizzly bears.  To maintain this size, polar bears rely on the energy-rich fat of seals, which they best catch on ice.

In the study, which was recently published in Nature Communications, the researchers found that some polar bears laid down to conserve energy, while others searched on land for food.  But neither the activity nor the lack thereof paid off.  In fact, only one bear out of the 20 gained weight after stumbling across a dead marine mammal on land.

Polar bears across the Arctic are at risk of starvation as the ice-free period continues to grow.

**********

Web Links

Polar bears unlikely to adapt to longer summers

Photo, posted November 16, 2015, courtesy of Anita Ritenour via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting coastal areas with tidal range electricity generation

By Leave a Comment

Tidal range electricity generation uses the water level difference between high and low tides to operate generator turbines.  The method requires the construction of barrages and sluices to capture water during high tides and then release it during generation at low tide.  Tidal range generation is predictable renewable energy driven by the gravitational pull of the moon and sun.

It is only a practical scheme in those places that have large tidal ranges.  The largest tidal range in the world is in the Bay of Fundy in Canada.  The second largest is the Severn Estuary, in the UK.  Tidal ranges are large in many places around Britain’s coasts. But they are also vulnerable to flooding and surges from rising seas.

A new study by Lancaster University in the UK has found that the environmental and economic benefits are huge because tidal range barrages can protect coastal areas from flooding and sea level rise. With two-way generation and pumping, the full range of existing tides can be maintained to protect and support low-lying intertidal areas such as saltmarshes and mudflats. High tides can be limited to existing levels simply by closing sluices and running turbines and low tide levels can be maintained by pumping.  The study determined that with modern technology and operating procedures, these so-called estuarine barrages may be the only practical way to protect vital coastal habitats.

Earlier work by the researchers found that tidal range projects under commercial consideration in the UK can produce about 5% of the country’s electricity use and additional projects are feasible for 4 or 5 times as much generation.

**********

Web Links

How tidal range electricity generation can protect coastal areas from flooding

Photo, posted August 17, 2014, courtesy of Andrea via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record high emissions

By Leave a Comment

The world is adding solar and wind power to the grid.   We are driving more and more electric cars.  Countries are pledging to cut back fossil fuel use.  There are highly visible international conferences on the climate crisis.   But despite all of these things, global carbon emissions from fossil fuels have risen once again in 2023, reaching all-time record high levels of more than 40 billion tons, about 1.1% more than the previous year.

In some places, including Europe and the U.S., fossil fuel CO2 emissions are falling, but globally, they are still rising.  Emissions continued to increase in India and China.  Global action to cut fossil fuel use is not happening fast enough to prevent the increasingly dangerous effects of climate change.

Global CO2 emissions include both the contributions of fossil fuel use and the effects of land use change.  Adding the two together, in 2023 the total was about 45 billion tons, basically unchanged from last year. 

Adding insult to injury are the emissions from fires.  The extreme wildfire seasons in Canada, Australia, and other places have contributed CO2 emissions much larger than historical averages.

About half of all the carbon dioxide emitted on Earth is absorbed by carbon sinks on land and the oceans.  The other half remains in the atmosphere, where levels are now averaging 419 parts per million, 51% above pre-industrial levels.

Current efforts are simply not profound enough or widespread enough to put global emissions on a downward trajectory.  Some climate policies in some places are proving effective, but much more needs to be done.

**********

Web Links

Fossil CO2 emissions at record high in 2023

Photo, posted December 18, 2013, courtesy of Steve Nelson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfires and air quality

By Leave a Comment

The wildfires last summer in parts of the U.S. and Canada fouled the air over much of the country.  Air quality in many places was dangerous for human health.  And such fires are becoming more numerous and more intense.

A new study by the University of Iowa has assessed the effects of two decades of wildfires on air quality and human health in the continental U.S.

From 2000 to 2020, air quality in the western U.S. has gotten worse as a result of the numerous fires in that region.  More generally, all those fires have undermined the success of federal efforts to improve air quality, primarily through the reductions in automobile emissions.

American air had been getting cleaner and clearer as a result of EPA regulations on vehicle emissions, but the surge in wildfires has limited and, in some cases, erased these air quality gains.  Twenty years of efforts by the EPA to make our air cleaner have been lost in fire-prone areas and in many downwind areas.

The Iowa study looked at the concentration of black carbon, a fine-particle air pollutant from fires linked to respiratory and heart disease.  In the western U.S., black carbon concentrations have risen 86% on an annual basis.

Fires have also affected the air in the Midwest, although not to the same degree as in the west.  The eastern U.S. had no major declines in air quality during the 2000-2020 time period.  Given the episodes of smoke from Canadian wildfires experienced by the east coast this past summer – as far south as Florida – even the air in that part of the country is suffering from the spread of wildfires.

**********

Web Links

Wildfires have erased two decades’ worth of air quality gains in western US

Photo, posted June 8, 2023, courtesy of Anthony Quintano 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...)