freezing

Cold spells and global warming

February 10, 2025 By EarthWise Leave a Comment

January saw some major bouts of subfreezing temperatures across much of North America and significant snowfall in places like Pensacola, Florida and New Orleans. This spate of frigid weather undoubtedly prompted many people to question whether global warming is really happening. But such cold spells quite likely are not happening in spite of global warming, but actually as a result of it.

The polar jet stream is a slim band of westerly winds that circles the Arctic. It is formed where cold air from the north meets warmer air to the south. As the planet warms, the Arctic has been heating up nearly four times faster than the rest of the planet, which narrows the difference in temperature between the northern air and southern air. The result is that the jet stream is weaker and more meandering, which allows frigid air to reach further south.

The polar vortex is a whirling mass of cold air that extends across the Arctic. It is stronger in the winter when the Northern Hemisphere leans away from the sun. The polar jet stream normally holds on to the vortex and keeps it far to the north. But when the jet stream gets wobbly, this mass of cold air can break out and travel south, even to places like Florida, Louisiana, and Texas.

The planet as a whole is warming, and the Arctic is warming even faster. But there will still be plenty of ice, snow, and frigid air in the Arctic winter for decades to come. As the behavior of the polar jet stream gets increasingly erratic, there may well be more frequent episodes of plunging temperatures in areas unaccustomed to them.

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Severe Cold Spells May Persist Because of Warming, Not in Spite of It

Photo, posted January 5, 2025, courtesy of Dermot O’Halloran via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Neighborhood geothermal energy

December 30, 2024 By EarthWise Leave a Comment

Residential geothermal energy makes use of the constant, year-round temperature of the earth below the surface to efficiently provide both heating and cooling for a home. In the summer, the cool earth beneath a house sits at about 55 degrees and can be tapped into with a heat pump to provide cooling. In the winter, that 55-degree underground expanse provides a much warmer source of air to heat instead of the often freezing-cold air outside. Geothermal systems are appealing because they use far less energy than other sources of heating and cooling.

Using geothermal energy to heat and cool buildings is nothing new. But after years of planning and months of drilling into the ground, the first neighborhood-scale geothermal heating and cooling project has come online in Framingham, Massachusetts.

The project ties together 31 residential and five commercial buildings that share the underground infrastructure needed to heat and cool them. This sort of shared geothermal system has previously been used on college campuses and similar places, but never before across a neighborhood in the United States.

The $14 million project, built by Eversource, broke ground in June 2023, and comprises 90 boreholes or wells drilled 600-700 feet underground. Approximately 135 customers are connected to the system, including low- and moderate-income customers, apartment buildings, a gas station, and a kitchen cabinet showroom.

A total of 13 states, including Massachusetts and New York, are considering pilot projects or advancing legislation that would allow gas utilities to develop networked geothermal heating and cooling.

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First-in-the-Nation Geothermal Heating and Cooling System Comes to Massachusetts

Photo, posted September 30, 2019, courtesy of Stephen D. Strowes via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Self-heating concrete

April 24, 2024 By EarthWise Leave a Comment

States in the colder parts of the country spend an estimated $2.3 billion a year on snow and ice removal as well as untold millions on repairing roadways damaged by winter weather. Researchers at Drexel University have been researching a way to extend the service life of concrete surfaces like roadways and to help them maintain a surface temperature above freezing during the winter.

Preventing freezing and thawing as temperatures go up and down and reducing the amount of plowing and salting is a desirable goal. The Drexel team has developed a cold-weather-resilient concrete mix that is capable of melting snow on its own using only the thermal energy in the environment and not requiring salt, shoveling, or heating systems.

The system uses low-temperature liquid paraffin that turns from its room-temperature liquid state into a solid when temperatures go down. Incorporating the liquid paraffin into concrete triggers heating when temperatures drop due to the energy released by the phase change.

Tests on slabs of the concrete on the Drexel campus over the past two years recorded 32 freeze-thaw events. The special slabs maintained a surface temperature between 42 and 55 degrees for up to 10 hours when air temperatures dipped below freezing.

The heating is enough to melt a couple of inches of snow at a rate of a quarter inch an hour. It’s not enough to melt a heavy snow event before plows are needed, but it can help deice road surfaces and increase transportation safety. And simply preventing the surface from freezing, thawing, and refreezing can go a long way towards preventing deterioration. It is promising research toward reducing an ongoing problem in colder climates.

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Drexel’s Self-Heating Concrete Is One Step Closer to Clearing Sidewalks Without Shoveling or Salting

Photo, posted March 16, 2024, courtesy of Ajay Suresh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Shrinking African glaciers

March 27, 2024 By EarthWise Leave a Comment

We don’t usually associate Africa with glaciers, but the continent has had glaciers on its highest peaks for the past 10,000 to 15,000 years. Africa’s glaciers are found in three regions: the Rwenzori Mountains along the border between Uganda and the Democratic Republic of the Congo, Mount Kilimanjaro, and Mount Kenya. At the turn of the 20th century, there were 43 glaciers scattered across 6 peaks within the Rwenzori Mountains. In the intervening years, things have greatly changed.

Since the early 20th century, Africa’s glaciers have shrunk by 90%. Because all these glaciers are close to the equator, they are especially vulnerable to warming. According to a new study published in the journal Environmental Research: Climate, in the last two decades, Africa’s glaciers have lost roughly half their area.

This rapid decrease is alarming to climate scientists because they represent a clear indicator of the impact of climate change. A major factor in the decline of the glaciers is the reduction in cloud cover over the mountains. Sunshine is melting glaciers and turning ice directly into water vapor even when temperatures are below freezing. Reductions in snowfall at the same time means that the melting glaciers are not being replenished.

Scientists believe that the tropical glaciers of Africa may all but disappear over the next 25 years.

Roughly three-quarters of the Earth’s freshwater is stored in the world’s more than 200,000 glaciers. According to scientists, if the world reaches but maintains 1.5 degrees of warming, half of the world’s glaciers could be gone by the end of this century. If the world continues to warm as it has been without slowing down, more than 80% of the glaciers will disappear.

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Africa’s Tropical Glaciers Have Shrunk by 90 Percent, Research Shows

Photo, posted February 26, 2022, courtesy of Ray in Manila via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cryopreserving Corals | Earth Wise

October 3, 2023 By EarthWise Leave a Comment

Recent climate models estimate that if the effects of climate change are not mitigated soon enough, 95% of the world’s corals could die by the mid 2030s. Given the current rate of greenhouse gas emissions, this is an increasingly likely outcome. Coral reefs are estimated to have a $10 trillion economic value apart from their essential role in marine ecosystems.

Researchers at the University of Hawaii at Manoa have demonstrated a successful technique for cryopreserving entire coral fragments; in other words, preserving coral using cold temperatures and successfully reviving them.

Existing coral cryopreservation techniques rely on freezing sperm and larvae, which can only be collected during spawning events, which occur only a few days each year for coral species. This makes it logistically very challenging for researchers and conservationists.

The Hawaiian researchers focused on a process called isochoric vitrification, which is a method of freezing with liquid nitrogen that prevents the formation of ice crystals. They tested the technique with thumbnail-sized fragments of coral, freezing them in small aluminum chambers which restrict the growth of ice crystals that would otherwise damage delicate polyp tissues. Once the chambers were warmed, the fragments were transferred to seawater and allowed to recover. They found that the revived corals behaved the same as those that were never cooled.

The process holds great promise to conserve the biodiversity and genetic diversity of coral. If the process can be scaled up, it may be possible to preserve as many species of coral as possible by 2030, when it may no longer be viable for them to survive in the warming and acidifying oceans.

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Cryopreservation breakthrough could save coral reefs

Photo, posted June 2, 2023, courtesy of USFWS – Pacific Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A New Method of Refrigeration | Earth Wise

February 10, 2023 By EarthWise Leave a Comment

Salting roads before winter storms is a familiar sight in the Northeast. The purpose is to change the temperature at which ice can form on the road. The underlying concept has formed the basis of a new method of refrigeration that has been dubbed “ionocaloric cooling.”

It is described in a paper published in the journal Science by researchers at the Lawrence Berkeley National Laboratory. The method takes advantage of how energy in the form of heat is either stored or released when a material changes phase – such as water changing from ice to liquid and vice versa. Melting absorbs heat from the surroundings while freezing releases heat. An ionocaloric refrigerator makes use of this phase and temperature change using an electrical current to add or remove ions provided from a chemical salt.

The potential is to make use of this refrigeration cycle instead of the vapor compression systems in present-day refrigerators, which make use of refrigerant gases that are greenhouse gases, many of which very powerful ones. The goal is to come up with a system that makes things cold, works efficiently, is safe, and doesn’t harm the environment.

There are a number of alternative refrigeration systems under development that make use of a variety of mechanisms including magnetism, pressure, physical stretching, and electric fields. Ionocaloric cooling uses ions to drive solid-to-liquid phase changes.

Apart from some very promising theoretical calculations of the system’s potential, the researchers have also demonstrated the technique experimentally. They have received a provisional patent for the technology and are continuing to work on prototypes to demonstrate its capabilities and amenability to scaling up.

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Berkeley Lab Scientists Develop a Cool New Method of Refrigeration

Photo, posted October 29, 2021, courtesy of Branden Frederick via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Climate Change And Crabs | Earth Wise

November 8, 2022 By EarthWise Leave a Comment

Globally, there are more than 6,000 species of crabs. In Alaska’s waters alone, there are 18 species, including 10 that are commercially fished. The perils of crab fishing in this region, including freezing temperatures, turbulent seas, and raising full pots that can weigh well over a ton, have been highlighted for many years in the reality TV series Deadliest Catch.

One of those commercially-fished species is the Alaska snow crab. Alaska snow crabs are a cold-water species found off the coast of Alaska in the Bering, Beaufort, and Chukchi Seas.

In October, officials in Alaska announced that the upcoming winter snow crab season would be canceled for the first time ever due to a sharp population decline. While the number of juvenile snow crabs was at record highs just a few years ago, approximately 90% of snow crabs mysteriously disappeared ahead of last season. Officials also canceled the Bristol Bay red king crab harvest for similar reasons for the second year in a row.

The closures dealt a severe blow to crab fishers in the region. According to the Alaska Seafood Marketing Institute, Alaska’s crab fishing industry is worth more than $200 million.

The canceled seasons also raise questions about the role of climate change in the snow crab population crash. While the causes of the decline are still being researched, scientists suspect that warmer temperatures are responsible. Temperatures in the Arctic region have warmed four times faster than the rest of the planet.

As the climate continues to change, the warming waters around Alaska may become increasingly inhospitable to snow crabs and other species.

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Alaska’s Bering snow crab, king crab seasons canceled

Alaska cancels snow crab season for first time after population collapses

Photo, posted November 16, 2010, courtesy of David Csepp / NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Antarctic Ice Collapse | Earth Wise

March 2, 2022 By EarthWise Leave a Comment

In Antarctica, a huge chunk of the Larsen B Ice Shelf collapsed suddenly and spectacularly in January.

The Larsen Ice Shelf is located on the northeastern side of the Antarctic Peninsula on the Weddell Sea. It was formed over the course of more than 12,000 years. The Weddell Sea used to be a completely frozen body of water. The famous Ernest Shackleton expedition in 1915 was trapped in its ice. But the Antarctic Peninsula has been steadily warming in recent decades.

The Larsen A Ice shelf collapsed in 1995 and the 1,250-square-mile Larsen B Ice Shelf collapsed in 2002. After that event, a portion of the detached ice shelf refroze in 2011 and was attached to the Scar Inlet Ice Shelf. The refrozen ice was called the Larsen B embayment.

In January, the embayment broke apart, taking with it a portion of the Scar Inlet Ice Shelf. It disintegrated within a matter of days. The combined Larsen Ice Shelves – called A, B, C, and D – once extended along a 1000-mile stretch of the eastern Antarctic Peninsula. Since 1995, it has shrunk from 33,000 square miles to 26,000 square miles.

These ice shelves float on the ocean, so their loss does not actually increase global sea levels. However, the shelves act as dams that hold back glaciers located on the land behind them. The loss of Antarctic ice shelves dramatically increases the rate at which glaciers flow into the sea, and that does increase global sea levels.

Now that the sea ice from the Larsen B embayment is gone, it is likely that there will be additional inland ice losses from the newly exposed glaciers.

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Remnant of Antarctica’s Larsen B Ice Shelf Disintegrates

Photo, posted February 13, 2018, courtesy of NASA/Nathan Kurtz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving The Arctic Permafrost | Earth Wise

April 17, 2020 By EarthWise Leave a Comment

Permafrost is frozen ground – a combination of soil, rock, sand, and ice – that remains at or below freezing for at least two consecutive years. Approximately 25% of the land in the Northern Hemisphere meets this criterion, the majority of which can be found in northern Russia, Canada, Alaska, Iceland, and Scandinavia.

But as a result of the changing climate, these permafrost soils in the Arctic are beginning to thaw. As they thaw, large quantities of greenhouse gases could be released, further accelerating climate change.

A new study recently published in the journal Scientific Reports explores an unconventional countermeasure: resettling massive herds of large herbivores. According to researchers from the University of Hamburg in Germany, herds of horses, bison, and reindeer could be used to significantly slow the loss of permafrost soils.

During Arctic winters, the air temperature is often much colder than the permafrost. Thick layers of snow can insulate the ground from the frigid air, keeping the permafrost warm (relatively speaking). But when the snow cover is scattered and compressed by the hooves of grazing animals, the insulating effect is reduced, which intensifies the freezing of the permafrost.

If climate change continues unchecked, the research team expects permafrost temperatures to rise 3.8-degrees Celsius. This would result in half of the world’s permafrost thawing by the year 2100. But in contrast, researchers found that the permafrost would only warm by 2.1 degrees Celsius with the resettled animals. This 44% reduction in permafrost temperature would preserve 80% of the existing permafrost by 2100.

Natural manipulations of ecosystems could have tremendous results.

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How horses can save the permafrost

Photo, posted July 17, 2012, courtesy of Kitty Terwolbeck via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Melting Permafrost | Earth Wise

February 26, 2020 By EarthWise Leave a Comment

The Arctic is warming faster than any region on Earth and mostly we’ve been hearing about the rapid disappearance of Arctic sea ice. But the land in the Arctic is also undergoing major changes, especially to the permafrost that has been there for millennia.

Permafrost occurs in areas where the temperature of the ground remains below freezing for two years or more. About a quarter of the Northern Hemisphere’s landscape meets this criterion. Most of the world’s permafrost is found in northern Russia, Canada, Alaska, Iceland, and Scandinavia.

Permafrost regions previously carpeted in cranberries, blueberries, shrubs, sedges, and lichen are now being transformed into nothing but mud, silt, and peat. So-called regressive thaw slumps – essentially landslides – are creating large craters in the landscape. (The Batagaika Crater in the Yana River Basin of Siberia is a kilometer long and 100 meters deep).

Apart from the violence being done to the Arctic landscape, the greatest concern is that the permafrost has locked in huge stores of greenhouse gases, including methane, carbon dioxide, and nitrous oxide. It is estimated that the permafrost contains twice as much carbon as is currently contained in the atmosphere. As the permafrost thaws, these gases will be released. With them will be pathogens from bygone millennia whose impact cannot be predicted. Climatologists estimate that 40% of the permafrost could be gone by the end of the century.

As the permafrost thaws, the region’s ecosystems are changing, making it increasingly difficult for subsistence indigenous people and Arctic animals to find food. Landslides are causing stream flows to change, lakes to suddenly drain, seashores to collapse, and water chemistry to be altered.

The warming Arctic is about much more than disappearing sea ice.

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How Thawing Permafrost Is Beginning to Transform the Arctic

Photo, posted February 9, 2017, courtesy of the U.S. Geological Survey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cold And Snow From Global Warming

April 4, 2018 By EarthWise Leave a Comment

The Arctic has been experiencing record warm temperatures and record low sea ice levels. During February, there were nine days in a row with temperatures averaging 27 degrees above normal and often above freezing. Over the previous 20 years, there were only two previous readings above freezing in February – once in 2011 and once last year.