Earth Wise

A look at our changing environment.

You are here: Home / Archives for warming

warming

The cicadas are coming

By Leave a Comment

After hiding underground for the last 17 years, billions of cicadas are taking to the skies this summer.  This batch of insects, known as Brood XIV, will cover more of the U.S. than any other 17-year brood.  New York and at least 13 other states – Georgia, Kentucky, Maryland, Massachusetts, New Jersey, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, West Virginia, and parts of Indiana are being serenaded by the sound of cicadas in May and June.

There are 15 broods of periodical cicadas that emerge every 13 or 17 years.  They come out when soil temperatures reach 64 degrees.  Around the world there are annual cicadas while periodical cicadas can only be found in the eastern United States.

Once the insects emerge, they will issue their noisy, chirping mating calls for just a few weeks before they lay eggs and die.  The offspring from the eggs will burrow underground and remain dormant or in the nymph stage feeding on tree roots for another 17 years.  Surfacing in vast numbers is a way to overwhelm predators and ensure that at least some cicadas survive to reproduce. 

The emergence of these insects provides a bounty of food to squirrels, lizards, birds, and other creatures.  A study found that once cicadas emerge, the population of cuckoos, blue jays, and red-bellied woodpeckers grows.

As the climate changes, the timing of cicada cycles may also change.  Warmer weather will lead to cicadas emerging earlier in the year.  Eventually, even the time they spend underground may shorten.

**********

Web Links

After 17 Years Underground, Massive Cicada Brood to Swarm U.S.

Photo, posted July 16, 2017, courtesy of Renee Grayson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Living in a warming world

By Leave a Comment

As global temperatures rise due to increased greenhouse gas emissions, communities around the world face more frequent and intense heatwaves, droughts, and extreme weather events. These growing climate pressures not only strain infrastructure and natural resources, but also play a critical role in shaping where people live. 

Recent projections from the First Street Foundation, which analyzes climate risks across the United States, highlight just how significant these shifts could be. In Sacramento County, California, rising flood risks, declining air quality, and soaring insurance costs could lead to a population decline of up to 28% by 2055. The risk assessment also projects that Monmouth and Ocean counties in New Jersey could each lose more than 30% of their populations. And Fresno County, California, could see nearly half of its residents relocate due to mounting climate-related pressures.

Urban areas like cities, towns, and suburbs are particularly vulnerable to the impacts of climate change.  Cities become significantly hotter due to the abundance of heat-absorbing surfaces and lack of green spaces, which intensifies heatwaves, worsens conditions for vulnerable populations, and may ultimately force some people to move.

Addressing these challenges requires a combination of climate solutions focused on both mitigation and adaptation. Solutions like expanding green infrastructure with urban parks and green roofs, and promoting sustainable development through energy-efficient buildings and transit-friendly design could all play a vital role in strengthening climate resilience.

As the planet warms, where we live – and how we live there – is rapidly being redefined.

**********

Web Links

The 12th National Risk Assessment

Solar on farmland

Photo, posted May 15, 2013, courtesy of Germán Poo-Caamaño via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Feeding the future

By Leave a Comment

Climate change is already affecting the yields of major staple crops around the world, and researchers warn that the impacts will become more severe over time. Rising temperatures, shifting rainfall patterns, and more frequent extreme weather events are disrupting growing seasons and reducing agricultural productivity.

Addressing these growing threats requires rethinking how we grow, distribute, and consume food.  To kick off Climate Solutions Week, we wanted to examine some solutions that could make food systems more resilient, sustainable, and adaptable to our rapidly changing environment.

One solution is Climate-Smart Agriculture, which blends traditional practices with modern techniques to boost productivity while reducing greenhouse gas emissions. Methods like zero tillage, intercropping, and crop diversification could improve soil health, conserve water, and help farms withstand climate extremes.

Expanding the production of highly nutritious and climate resilient food crops – like millet, sorghum, teff, quinoa, chickpeas, and tepary beans – will also have an important role to play.  At the same time, reducing food waste through better storage, labeling, and surplus food re-use could help meet demand without increasing production pressure.

Agriculture is the largest user of freshwater globally, and climate change is intensifying water shortages.  Farmers will need to transition to water-efficient farming practices, including drip irrigation, rainwater harvesting, and the reuse of treated wastewater. 

Together, these solutions could help revolutionize the global food system to both feed a growing population and help protect the planet. 

*********

Web Links

Climate-smart agriculture

Water for Prosperity and Peace

A Food For The Future

Photo, posted October 16, 2011, courtesy of Alliance of Bioversity International and CIAT via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The oceans are warming faster

By Leave a Comment

A new study has shown that the rate of ocean warming has more than quadrupled over the past 40 years.  The study, by researchers at the University of Reading in the UK, helps to explain why there have been unprecedented ocean temperatures in 2023 and 2024.

Global ocean temperatures hit record highs for 450 days straight in 2023 and early 2024.  Some of this unusual warmth came from the El Niño that was taking place at the time, but the rest of the increased temperature came from the sea surface warming up more quickly over the past 10 years than in previous decades.  In the late 1980s, ocean temperatures were rising at a rate of 0.06 degrees Celsius per decade.  According to the recent research, they are now increasing at 0.27 degrees per decade.

The acceleration of ocean warming is driven by growth in the Earth’s energy imbalance, meaning that more energy from the sun is being absorbed by the Earth than is escaping back into space.  This energy imbalance has roughly doubled since 2010 as a result of two factors:  increasing greenhouse gas concentrations in the atmosphere and reductions in the Earth’s albedo.

Earth’s albedo, the measure of how much sunlight is reflected back into space, has been declining since the 1970s, primarily due to the decrease in snow and ice cover, especially in the Arctic. 

The overall rate of ocean warming observed over recent decade is likely to only increase.  This underscores the urgency of reducing fossil fuel burning to avoid even more rapid temperature increases in the future.

**********

Web Links

Ocean-surface warming four times faster now than late-1980s

Photo, posted January 18, 2007, courtesy of Alexey Krasavin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Vegetation and climate change

By Leave a Comment

Temperatures have been steadily rising around the world as a result of the increased greenhouse gas emissions from human activities.  This warming trend has led to more frequent and intense heat waves, droughts, and other extreme weather events.  Rising temperatures are also impacting human health, leading to increased risks of heat-related illnesses and a higher number of fatalities during extreme heat events.

One simple but effective way to reduce the health risks from extreme heat is to increase urban vegetation.  According to new research led by scientists from Monash University in Australia, increasing urban vegetation by 30% could save more than one-third of all heat-related deaths.  The study, which was recently published in The Lancet Planetary Health, examined more than 11,000 urban areas and found that increasing greenery could have saved up to 1.16 million lives worldwide between 2000 and 2019.

The impact of increasing urban vegetation on heat-related deaths varies by climate, greenness, socioeconomic, and demographic factors, with the greatest benefits seen in Southern Asia, Eastern Europe, and Eastern Asia. 

Vegetation has a cooling effect on temperature.  Vegetation helps regulate the Earth’s climate by absorbing carbon dioxide during photosynthesis, which helps to reduce greenhouse gases in the atmosphere. Vegetation also cools the environment through shading, moisture release, and evapotranspiration, which reduces temperatures and mitigates heat-related health risks.

Incorporating more vegetation into urban areas is a powerful solution to mitigate the impacts of climate change and protect human health.

**********

Web Links

Increasing urban vegetation could have saved over 1.1m lives in two decades

Photo, posted July 1, 2023, courtesy of Lauri via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The warmer, greener Arctic and greenhouse gas

By Leave a Comment

About 15% of the Northern Hemisphere is covered by permafrost.  Permafrost is soil and sediment that has remained frozen for long periods of time, in some cases as much as 700,000 years.  It contains large amounts of dead biomass that has accumulated over millennia and hasn’t fully decomposed.  Therefore, permafrost is an immense carbon sink.

The Arctic is warming four times faster than the rest of the planet and, as a result, thawing permafrost is becoming a carbon source.  As warming continues, ice is melting, and vegetation is spreading.    A new study, published in Nature Climate Change, looked at the state of the Arctic and boreal north from the period 1990 until 2020.  The study found that although half of the Arctic region has been growing greener, only 12% of those green areas are actually taking up more carbon.  For one thing, the growth of forests means that there is more fuel for wildfires which are increasingly common.

A study of lakes in West Greenland found that thousands of crystal blue lakes have turned brown during record heat spells.  Runoff from melting permafrost made the lakes opaque killing off plankton that absorb carbon dioxide.  Meanwhile, plankton that release carbon dioxide multiplied.  So, these lakes went from being carbon sinks to being carbon sources.

As the northern latitudes warm, ice and permafrost are melting, vegetation is spreading, and the region is becoming a source of heat-trapping gas after having been a place where carbon has been locked away for thousands of years.  According to the Nature Climate Change study, roughly 40% of the Arctic is now a source of carbon dioxide.

**********

Web Links

Warmer, Greener Arctic Becoming a Source of Heat-Trapping Gas

Photo, posted October 14, 2024, courtesy of Christoph Strässler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

New highs for carbon dioxide

By Leave a Comment

Last year was the hottest year on record and the ten hottest years on record have in fact been the last ten years.  Ocean heat reached a record high last year and, along with it, global sea levels.  Those are rising twice as fast as they did in the 1990s.

The World Meteorological Organization reports that the global atmospheric concentration of carbon dioxide reached a new observed high in 2023, which is the latest year for which global annual figures are available.  The level was 420 ppm, which is the highest level it has been in 800,000 years. 

The increase in carbon dioxide levels was the fourth largest one-year change since modern measurement began in the 1950s.  The rate of growth is typically higher in El Niño years because of increases from fire emissions and reduced terrestrial carbon sinks.

Concentrations of methane and nitrous oxide – which are two other key greenhouse gases – also reached record high observed levels in 2023.  Levels of both of these gases have also continued to increase in 2024.

The annually averaged global mean near-surface temperature in 2024 was 1.55 degrees Celsius above the 1850-1900 average.  Apart from being the warmest year in the 175 years records have been kept, it is also above the 1.5-degree limit set as the goal of the Paris Climate Agreement.  While a single year above 1.5 degrees of warming does not mean that the efforts to limit global warming have failed, it is a strong warning that the risks to human lives, economies, and the planet are increasing.

**********

Web Links

Carbon Dioxide Levels Highest in 800,000 Years

Photo, posted January 30, 2018, courtesy of Johannes Grim via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The largest iceberg runs aground

By Leave a Comment

The largest iceberg in the world, which has been slowly drifting for nearly 5 years, has finally come to a halt.  The iceberg – called the unexciting name A-23A – came into existence in 1986 when it broke off from another iceberg A-23 that had calved or torn off from Antarctica earlier that year.  For decades, A-23A sat in the Weddell Sea, east of the Antarctic Peninsula.  Then, in 2020, it came loose from the seafloor and began to move.  By 2023, it finally left Antarctic Waters.

Late last year, it began spinning in place caught in an ocean current called a Taylor column.  Finally, it headed for South Georgia, a British-owned island that is home to a couple dozen people and lots of seals and penguins.  A-23A is now stuck on the continental shelf, about 50 miles from the island.

A-23A is around 1,300 square miles in area.  By comparison, New York City is 300 square miles.

Four years ago, a large iceberg called A-68A also came to ground in the vicinity of South Georgia.  It quickly broke apart and ultimately added 150 billion metric tons of fresh water to the ocean as well as various nutrients.  A-23A is also likely to succumb to the warmer waters, winds, and currents it now encounters and will affect the flora and fauna in the area.

The climate is changing and is impacting how ice shelves melt.  Calving and the creation of mammoth icebergs are a normal part of the lifecycle of polar ice sheets, but we are likely to see even more events like this in the future.

**********

Web Links

World’s Largest Iceberg Runs Aground

Photo, posted January 29, 2011, courtesy of Drew Avery via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sea turtles and climate change

By Leave a Comment

Life is a struggle for survival from the moment a sea turtle hatches.  In fact, only one sea turtle out of every 1,000 typically reaches adulthood as a result of natural predators and other challenges.  Those fortunate enough to make it to adulthood face serious threats from humans. For example, sea turtles are hunted for their meat, eggs, and shells in some regions. Their beach habitats get developed. Harmful marine debris and oil spills pollute their waters and beaches.

Now, climate change is exposing sea turtles to even greater threats.  Rising sea levels and stronger storms threaten to erode and destroy their nesting beaches. Warming oceans disrupt currents, potentially exposing sea turtles to new predators, and damaging the coral reefs that some depend on to survive.

As these environmental challenges intensify, sea turtles are beginning to adapt in surprising ways.  According to a new study by researchers from the University of Exeter in England and the Society for the Protection of Turtles in Cyprus, sea turtles are responding to climate change by nesting earlier.  Researchers monitoring nesting green and loggerhead turtles in Cyprus have discovered they are returning to their regular nesting spots earlier each year to compensate for rising temperatures.

Temperature plays a crucial role in determining the biological sex of sea turtles.  Warmer nest temperatures produce more female hatchlings than males.

But at least for now, sea turtles seem to be doing enough to ensure their eggs continue to hatch by nesting earlier in more ideal temperatures.  While this is good news, there’s no guarantee that it will continue. 

**********

Web Links

Turtles change nesting patterns in response to climate change

Photo, posted December 20, 2021, courtesy of Cape Hatteras National Seashore via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Are today’s refrigerants safe?

By Leave a Comment

Refrigeration is based on heat transfer mediums that absorb heat from the area being cooled and transfer it to the outside environment.

The earliest refrigerants were dangerous substances like ammonia.  In the 1930s, chlorofluorocarbons (CFCs) like Freon became the standard refrigerant for use in refrigeration systems and even in aerosol cans.  When these substances were found to be depleting the earth’s ozone layer, the Montreal Protocol dictated their phaseout and by the mid-1990s, CFCs were largely replaced by hydrofluorocarbons (HFCs).

HFCs don’t deplete the ozone layer, but they were eventually determined to be potent greenhouse gases, thousands of times more planet-warming than carbon dioxide.   As a result, the global phaseout of HFCs began in 2016, and have been increasingly replaced by hydrofluoroolefins (HFOs), which are considered a more environmentally-friendly alternative to all their predecessors.

Trying to not be surprised by additional unpleasant discoveries about refrigerants, researchers are studying the potential environmental impacts of HFOs.  Researchers at the University of New South Wales in Australia have found that HFOs can break down in the atmosphere and that some small amounts of the resultant products are in fact fluoroforms, which are the HFC with the greatest global warming potential and can stay in the atmosphere for up to 200 years.

That only a small amount of HFC gets into the atmosphere is good, but nevertheless it reveals that the consequences of replacing widely-used chemicals are not a simple matter to determine.

**********

Web Links

Are our refrigerants safe? The lingering questions about the chemicals keeping us cool

Photo, posted July 19, 2021, courtesy of Vernon Air Conditioning via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sand mining and the environment

By Leave a Comment

Sand mining is the world’s largest mining endeavor.  It is responsible for 85% of all mineral extraction.  It is also the least regulated, possibly the most corrupt, and likely the most environmentally destructive.  Sand is the second-most exploited natural resource in the world after water.  Its global use has tripled in the past two decades.  More than 50 billion tons of sand is extracted from the environment each year.

Sand plays a critical role in much of human development around the world.  It is a key ingredient of concrete, asphalt, glass, and electronics.  It is relatively cheap and relatively easy to extract.  But we use enormous amounts of it.

Sand mining is a major threat to rivers and marine ecosystems.  It is linked to coastal erosion, habitat destruction, the spread of invasive species, and damage to fisheries. 

The harm from sand mining is only beginning to attract widespread attention.  A recent study by an international group of scientists published in the journal One Earth identifies        threats posed by sand mining.  Sand extraction in marine environments remains largely overlooked, despite sand and sediment dredging being the second most widespread human activity in coastal areas after fishing.

Sand is generally seen as an inert, abundant material, but it is an essential resource that shapes coastal and marine ecosystems, protects shorelines, and sustains both ecosystems and coastal communities.  Sand extraction near populated coastlines is particularly problematic as climate change makes coastlines increasingly fragile.

Like all other resources on our planet, even sand cannot be taken for granted.  It must be responsibly managed.

**********

Web Links

The rising tide of sand mining: a growing threat to marine life

Photo, posted February 7, 2013, courtesy of Pamela Spaugy / U.S. Army Corps of Engineers 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

Sharks and rays in a warming world

By Leave a Comment

Sharks and rays belong to a group of cartilaginous fish called elasmobranchs, which have been swimming in the world’s oceans for 450 million years. The resilient species have survived five mass extinction events, and are older than dinosaurs, trees, and Mount Everest. 

But despite their resilience, many species of sharks and rays today are threatened by human activities, including overfishing, habitat loss, and climate change.  In fact, according to a new study led by researchers from the University of Vienna in Austria, more than one third of the shark and ray species known today are severely under threat. 

The study, which was recently published in the journal Biology, found that higher carbon dioxide levels were having a negative effect on sharks and rays, ranging from impacts on the animals’ senses to changes in the skeleton during embryonic development.  An examination of fossil records found that higher CO2 levels had contributed to the extinction of individual shark and ray species in the past. 

But the study also found that global warming could be creating opportunities for sharks and rays.  Rising sea levels and higher temperatures have historically expanded shallow coastal habitats and warm waters, supporting species biodiversity.

But according to the research team, the rapid environmental changes, combined with the impacts from human activities, outpace the ability of sharks and rays to adapt, making it unlikely that they will benefit from global warming.

Protecting sharks and rays is crucial not only for their survival but also for maintaining entire ocean ecosystems. Without top predators, these ecosystems could collapse, impacting both marine life and the people and industries that depend on it.

**********

Web Links

Sharks and rays benefit from global warming – but not from CO2 in the Oceans

Myths About Sharks and Rays

Photo, posted November 27, 2007, courtesy of Laszlo Ilyes via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A record warm January

By Leave a Comment

Americans experienced unusually cold and wintery weather in January.  Places like southern Louisiana and Florida saw appreciable amounts of snow.  For those who experienced January’s Arctic blast, it was a cold January.  But despite that, January was the world’s warmest on record, extending a run of extraordinary heat in which 18 out of the last 19 months saw an average global temperature more than 1.5 degrees Celsius above pre-industrial times.  In fact, the global average temperature in January was 1.75 degrees above the pre-industrial average.

The exceptional warmth was surprising to climate researchers.  It happened despite the emergence of La Niña conditions in the Pacific Ocean, which tend to lower global temperatures, at least for a while.

Researchers are investigating whether there is something beyond the effects of greenhouse gas emissions that is boosting temperatures to an unexpected degree.  It is true that emissions, associated with the burning of coal, gas, and oil, reached record levels in both 2023 and 2024.  But January’s warmth was still something of a surprise.

One prevalent theory is that cutting dangerous pollution is playing a role in causing global warming to accelerate.  As regulators have curbed sulfate pollution to protect people’s lungs, the cooling effect of these particles that help form more and brighter clouds has diminished.

January demonstrates that the global climate system is complex and the weather in any particular region does not necessarily reflect what is happening to the planet as a whole.

**********

Web Links

Global Temperatures Shattered Records in January

Photo, posted December 22, 2013, courtesy of SD Anderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Megadroughts

By Leave a Comment

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

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

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

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

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

**********

Web Links

The Megadroughts Are upon Us

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

Earth Wise is a production of WAMC Northeast Public Radio

Soaring coffee prices

By Leave a Comment

Wholesale coffee prices hit record highs in the midst of the Trump administration’s deportation and tariff dispute with Colombia.  But coffee prices have already been trading near 50-year highs for a while as a result of shortages related to extreme weather and increased global demand.

In recent years, repeated droughts and flooding have put pressure on the global supply of coffee.  These climate swings have caused prices to soar, much as they have for other staples like cocoa, olive oil, and orange juice.  All the while, the global demand for coffee has kept rising.

Coffee is one of the world’s most consumed beverages, but it can be grown only under very specific conditions, namely in misty, humid, and tropical climates, and in rich soil free of disease.   The United States imports nearly all of its coffee – there is only a small amount grown in Hawaii.  Otherwise, the US is the world’s largest coffee importer.  With a limited number of sources for the beans, global coffee prices are very susceptible to the effects of extreme weather.

More than half of the world’s coffee production comes from arabica beans, and Brazil is the largest exporter.  A severe drought there this summer devastated the harvest that typically runs from May to September.   In Vietnam, a severe drought followed by heavy rains harmed the world’s largest source of robusta, the second most popular coffee variety.

People tend to think of coffee as a commodity and not so much as an agricultural product, subject to the vagaries of weather and having prices that fluctuate accordingly.  The bottom line is that drinking coffee is likely to become a bigger strain on one’s own bottom line.

**********

Web Links

Why Coffee Prices Are Soaring (Again)

Photo, posted October 13, 2023, courtesy of Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The warmest year on record

By Leave a Comment

It came as no surprise that 2024 ended up as the warmest year on records. It was the hottest year since record keeping began in 1880.  The global average temperature was 1.28 degrees Celsius (or 2.3 degrees Fahrenheit) above the 20th-century baseline period of 1951-1980.  It was actually 1.47 degrees above the 1850-1900 average.

The Paris Climate Agreement has a goal to keep the global average temperature increase below 1.5 degrees Celsius over the long term.  Long term is specified because for more than half of 2024, average temperatures were more than 1.5 degrees above the baseline.

The temperature of an individual year can be influenced by various natural climate fluctuations, such as the presence of an El Niño or a La Niña condition in the Pacific, or volcanic eruptions.  A strong El Niño began in 2023 and continued throughout much of 2024.  That El Niño has abated, so it is no longer a factor in the global climate condition.

The global temperature is determined using surface air temperature data collected from thousands of meteorological stations as well as sea surface temperature data collected by ships and buoy-based instruments. 

When the climate changes, it is observed first in the global mean temperature.  Then there are changes seen on a continental scale and then at the regional scale.  Finally, changes are observable at the local level.  These changes are becoming more and more common as people’s everyday weather experiences become different from any they had encountered before.

**********

Web Links

2024 Was the Warmest Year on Record

Photo, posted August 26, 2015, courtesy of Saskia Madlener / NASA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cold spells and global warming

By 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.

**********

Web Links

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

Unexplained heat wave hotspots

By Leave a Comment

2023 and 2024 have been the hottest years since records have been kept.  But above and beyond the upward march of average temperatures around the globe, there has been the phenomenon of distinct regions across the globe experiencing repeated heatwaves that are so extreme that they cannot be accounted for in any models of global warming.

A new study by Columbia University’s Climate School has provided the first worldwide map of such regions, which have emerged on every continent except Antarctica.  Heatwaves in these regions have killed thousands of people, withered crops and forests, and triggered devastating wildfires.

These recent regional-scale record-breaking temperature extremes have raised questions about whether current climate models can provide adequate estimates of the relationship between global mean temperature changes and regional climate risks.

Some of these regional events in recent years include a nine-day heatwave in the U.S. Pacific Northwest and southwestern Canada in June 2021 that broke daily records in some places by 54 degrees Fahrenheit.  Across Germany, France, the UK, the Netherlands, and other countries, the hottest days of the year are warming twice as fast as the summer mean temperatures. 

There is yet little understanding of the phenomenon.  Some theories related to destabilization of the jet stream don’t really explain all the temperature extremes observed.  But regardless of the underlying causes, the health impacts of these heat waves are severe, as are the effects on agriculture, vegetation, and infrastructure.  Society is not built to quickly adapt to them.

**********

Web Links

Unexplained Heat Wave ‘Hotspots’ Are Popping Up Across the Globe

Photo, posted August 16, 2022, courtesy of Alisdare Hickson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Corals and climate change

By Leave a Comment

Climate change is a major threat to coral reefs around the world.  Ocean warming triggers coral bleaching – a stress response where corals expel the symbiotic algae essential for their survival.  If coral bleaching is severe, it can lead to coral death.

A new study led by scientists from Newcastle University in England suggests that corals are unlikely to adapt to ocean warming quickly enough to keep pace with global warming, unless there are rapid reductions in global greenhouse gas emissions.

The study, which was recently published in the journal Science, found that coral heat tolerance adaptation via natural selection could keep pace with ocean warming, but only if the climate goals of the Paris Agreement are realized.  In the Paris Agreement, countries agreed to limit global warming by the end of the century to two degrees Celsius above pre-industrial levels.  

However, current climate policies around the world have the globe on track to warm by three degrees Celsius.  According to the research team, this could lead to significant reductions in reef health, elevated risks of local coral extinctions, and considerable uncertainty in the so-called “evolvability” of corals. 

Coral reefs are among the most biologically diverse ecosystems on Earth.  They are often referred to as the “rainforests of the sea” because they support an incredible variety of marine life.  They provide essential ecosystem services, such as protecting coastlines from erosion and storm surges, supporting fisheries, and serving as a source of income through tourism. Coral reef health is vital for the health of the planet.

**********

Web Links

Coral adaptation unlikely to keep pace with global warming

Photo, posted June 9, 2012, courtesy of Bokissa Private Island Resort 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...)