Earth Wise

A look at our changing environment.

You are here: Home / Archives for heatwaves

heatwaves

Deadly Heatwaves On The Rise | Earth Wise

By Leave a Comment

The European heatwave in the summer of 2003 resulted in at least 30,000 deaths with more than 14,000 in France alone. At the time, such a heatwave was considered to be a once-in-a-hundred-year event. But the warming climate is dramatically changing the odds for deadly heatwaves.

A new study by the ETH Institute in Zurich has found that the risk of fatal heatwaves has risen sharply over the past 20 years, and in the future, such extreme weather will become more frequent and heat-related excess mortality will increase, particularly in Europe.  According to a paper published in Nature Medicine, more than 61,000 deaths in Europe could be blamed on the heat during the summer of 2022, which was the hottest summer on record for the continent.  When the readings from this summer are analyzed, that record is likely to be surpassed.

Heatwaves lead to excess deaths due to dehydration, heat stroke, and cardiovascular collapse.  They are particularly deadly for the elderly, the sick, and the poor.  The ETH researchers analyzed comprehensive data from 748 cities and communities in 47 countries.   They determined the relationship between increased temperature and excess mortality.  Their models look at how excess mortality would develop with an average global temperature increase of 0.7 degrees Celsius (the value in 2000), 1.2 degrees (the value in 2020), and both 1.5 degrees (the limit sought by the Paris Agreement) and 2 degrees.

Even with the current global temperature, heatwaves that were a once-in-a-century event are now expected to occur every 10 years.  With 2 degrees of warming, such heatwaves could happen every 2 to 5 years.

**********

Web Links

Heatwaves are becoming more frequent and more deadly

Photo, posted July 22, 2009, courtesy of Matt McGee via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Why Was the Summer So Hot? | Earth Wise

By Leave a Comment

Many places around the world have experienced extraordinary heat waves this summer.  The 31 days of high temperatures 110 degrees or more in Phoenix is a prime example but many other places suffered from extreme and relentless heat.  Why did this happen?

The overarching reason is climate change, which has warmed the Earth by 2.2 degrees Fahrenheit since the preindustrial era.  This change on a global level is enough to make heatwaves far more likely.  For example, the concurrent heatwaves in Europe and North America were 1000 times more likely to have occurred because of climate change.

But there hasn’t been a sudden increase in global temperature that would make this summer so much hotter.  Instead, what really has happened is three other factors all came into play at the same time.

The first is the 2022 eruption of Hunga Tonga-Hunga Ha-apai, which is an underwater volcano in the South Pacific.  That eruption did not produce much in the way of planet-cooling aerosols in the atmosphere.  Instead, it vaporized huge amounts of seawater, sending water vapor into the atmosphere, which helps trap heat.

The second is a change in the amount of energy radiating from the sun.  That actually rises and falls a small amount every 11 years.  Currently, it is in the upswing and will reach its next peak in 2025.

Finally, there is the arrival of the El Niño in the Pacific, whose balmy ocean waters radiate heat into the air.

The combination of all these factors when added to the already warming climate is a recipe for temperatures to soar to uncharted highs.  We can expect more heat waves, forest fires, flash floods, and other sorts of extreme weather.

**********

Web Links

It’s Not Just Climate Change: Three Other Factors Driving This Summer’s Extreme Heat

Photo, posted February 27, 2017, courtesy of Giuseppe Milo via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The World’s Hottest Day | Earth Wise

By Leave a Comment

Early in July – for four days in a row – the average global temperature was the highest ever recorded.  As many places around the world endured dangerous heatwaves, the average global temperature on the fourth of July reached 62.92 degrees Fahrenheit, the highest ever recorded by human-made instruments.  On July 6th, the global temperature climbed even further to 63.01 degrees.

The average global temperature on an annual basis was about 56.7 degrees from the 1880s through the 1910s.  Temperatures rose a bit after that but ended up about 57.2 degrees until the 1980s.  After that, temperatures have risen fairly steadily as heat-trapping gases have accumulated in the atmosphere driving the current average above 58 degrees.

Global temperatures have only been directly measured since the mid-20th century.  There are proxy measurements from sources like tree rings, ice core samples, glacier measurements, and more that indicate that the recent readings may be the warmest days the earth has seen in millennia.

Average global temperature is determined using temperature readings at thousands of locations on both land and sea across the entire planet.  Those readings are compared with average temperatures at those locations for the date and the difference (known as the temperature anomaly) used to calculate a global average.

With the recent arrival of the El Niño in the Pacific Ocean, it is likely that the warming already being driven by greenhouse gas accumulation will intensify further. 

In a summer already marked by extreme heatwaves in many locations, having the entire planet 4 or 5 degrees hotter than normal is a very big deal and most certainly not a record to celebrate.

**********

Web Links

Earth reaches hottest day ever recorded 4 days in a row

Photo, posted October 29, 2008, courtesy of Darek via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An Unwanted Temperature Threshold Is Approaching | Earth Wise

By Leave a Comment

According to the World Meteorological Organization, there is a 66% chance over the next five years that the Earth’s global temperature will exceed 1.5 degrees Celsius above pre-industrial levels for at least one year.

A combination of the continued accumulation of greenhouse gases in the atmosphere along with a looming El Niño condition will contribute to surging temperatures.  The WMO also reports that there is a 98% likelihood that at least one of the next five years will be the warmest on record and that the five-year period as a whole will be the warmest on record.

Reaching or surpassing the 1.5-degree threshold may only be temporary but would be the strongest indication yet of how quickly climate change is accelerating.   The 1.5-degree point is considered by many scientists to be a key tipping point, beyond which the chances of extreme flooding, drought, wildfires, heatwaves, and food shortages could increase dramatically.

The world has already seen about 1.2 degrees of warming as we continue to burn fossil fuels and produce enormous quantities of greenhouse gas emissions.  As recently as 2015, the WMO put the chance of breaching the 1.5-degree threshold as close to zero.

It is important to understand that the 1.5-degree temperature increase is an average for the entire planet.  Many individual locations around the world have been experiencing tremendously greater amounts of warming with record-breaking temperatures.

The 1.5-degree threshold is important, but it is not itself a tipping point.  There is still time to reduce global warming by moving away from fossil fuels and towards clean energy.  But the clock is ticking and so far, the world is not showing any urgency.

**********

Web Links

‘Sounding the alarm’: World on track to breach a critical warming threshold in the next five years

Photo, posted May 20, 2015, courtesy of Kevin Gill via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saving Lives With Air Conditioning | Earth Wise

By Leave a Comment

This summer, extreme heatwaves struck the United States, Europe, and Africa.  Thousands of people died as a result.  In July, the impact of extreme heat in places ill-prepared for it was evident.  In the U.K., where air conditioning is uncommon, public transportation shut down, schools and offices closed, and hospitals cancelled non-emergency procedures.

Air conditioning, which we mostly take for granted in this country, is a life-saving tool during extreme heat waves.  However, only about 8% of the 2.8 billion people living in the hottest – and often poorest – parts of the world have AC in their homes.

A new study at Harvard modeled the future demand for air conditioning as the number of days with extreme heat continues to increase across the globe.  The researchers identified a massive gap between current AC capacity and what will be needed by 2050 to save lives, particularly in low-income and developing countries.

If the rate of greenhouse gas emissions continues on its present course, the study concluded that that at least 70% of the population in several countries will require air conditioning by 2050.  The number will be even higher in equatorial countries like India and Indonesia.  At this point, even if the goals of the Paris Climate Accords are met, an average of 40-50% of the population in many of the world’s warmest countries will still require AC.

The research looked at various scenarios.  One in which emissions continue to increase leads to widespread need for air conditioning even in temperate countries.  In Germany, 92% of the population would need it, and here in the U.S., 96% would need it.

Planning for future power systems must take into account the essential needs of a warming world.

**********

Web Links

In a hotter world, air conditioning isn’t a luxury, it’s a lifesaver

Photo, posted July 24, 2021, courtesy of Phyxter Home Services via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heatwaves And Alpine Mountain Climbing | Earth Wise

By Leave a Comment

From June to August, there were persistent heat waves affecting parts of Europe that caused wildfires, evacuations, and heat-related deaths.  Nearly 12,000 people died from heat stroke or other causes associated with the high temperatures.  The highest temperature recorded during this period was 116.6 degrees F in Pinhao, Portugal on July 14th.  The RAF base in Coningsby, Lincolnshire recorded a temperature over 104 degrees on July 19th, the highest ever recorded in the United Kingdom.

Among the effects of the multiple European heatwaves has been the cancellation of climbing tours up some of the most iconic peaks in the Alps, including Mont Blanc and the Matterhorn.  The high temperatures and rapidly melting glaciers have made the climbing routes too dangerous.  Overall, climbing cancellations occurred on about a dozen peaks, including the Jungfrau in Switzerland, which cancelled tours for the first time in a century.

In previous years, during warm summers, some of these climbing routes were closed in August, but the glaciers were already in a condition that usually only happens at the end of summer or even later.

The combination of heat and glacier melt can be treacherous.  In July, 11 people were killed at Italy’s Marmolada glacier by falling ice and rock.

Glacial melt in the Alps is rapidly accelerating.  The Forni Glacier, the largest valley glacier in Italy, has retreated two miles since 1860 and its area has shrunk by half.  Forecasts are that it will retain only 20% of its current volume by 2050 and may disappear entirely by the end of the century.  Half of the 4,000 glaciers in the Alps are expected to disappear by 2050.

**********

Web Links

European Heat Waves Force Closure of Classic Climbing Routes in Alps

Photo, posted September 4, 2020, courtesy of Dmitry Djouce via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Building Resilient Food Systems | Earth Wise

By Leave a Comment

According to the United Nations and The World Bank, global hunger levels in 2021 surpassed the previous record set in 2020.  The organizations also found that acute food insecurity – defined as when a person’s inability to consume adequate food puts their lives or livelihoods in immediate danger – could continue to worsen this year in many countries around the world. 

According to a new study led by researchers from the University of Colorado Boulder, increased demand for water will be the biggest threat to food security during the next 20 years, followed closely by heat waves, droughts, income inequality, and political instability.  

The report, which was recently published in the journal One Earth, calls for increased collaboration to build a more resilient global food supply.  The impacts of conflict and climate change are already measured and studied around the world.  While these pressing threats are not new, the researchers found that better collaboration between these areas of research could fortify and strengthen global food security. 

In 2019, before the COVID-19 pandemic, the researchers surveyed 69 experts in various fields related to food security.  They found that many effects of climate change – such as unpredictable weather changes – could have the greatest negative impacts on food security.  The researchers also found that threats to food security from income inequality, global price shocks, and political instability and migration are highly likely during the next two decades.  More than half of the world’s food insecure populations also live in conflict-prone regions.

According to the research team, food security has never been a problem of production.  It’s a problem of distribution, access, and poverty, and can be exacerbated by conflict.   

**********

Web Links

Amid climate change and conflict, more resilient food systems a must, report shows

Photo, posted July 19, 2009, courtesy of Danumurthi Mahendra via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heatwaves And Bird Populations | Earth Wise

By Leave a Comment

The increased occurrence and intensity of heatwaves around the world is affecting most living things.  Heatwaves can be lethal for warm-blooded animals – including people – but the behavioral and physiological effects of sub-lethal heat have not been extensively studied.  Heat that doesn’t kill animals can still impact their ability to adapt and thrive as the climate changes.

Researchers at the University of Tennessee in Knoxville recently published a new study that examined how heat impacts the behavior and physiology of Zebra finches.  They exposed the birds to a four-hour heat challenge, similar to what wild birds might experience during a hot summer afternoon.   They used Zebra finches because these songbirds experience extreme temperature fluctuations in their native Australia.

The team measured heat effects on thermoregulatory behavior, how heat alters gene activity in tissues critical to reproduction, and how heat affects the area of the brain that controls singing.  The evidence showed that even sub-lethal heat can change a bird’s ability to reproduce both from the functioning of its reproductive system and its motivational circuits for mating behavior.

The researchers found that some individual birds were better able to minimize the physiological effect of heat, for example by adjusting their behavior to dissipate heat.  Some individuals and even some species are likely to be able to adapt to increasingly extreme temperatures.

Global bird populations have been dramatically declining over the past few decades.  Previous studies have shown that birds sing less during heatwaves. Based on the new study, it appears that increasing heatwaves may be a potential underlying mechanism for the decline in bird populations.

**********

Web Links

New Research Suggests Heat Waves Could Lead to Avian Population Decline

Photo, posted August 22, 2017, courtesy of Dennis Jarvis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Marine Heatwaves And Fish | Earth Wise

By Leave a Comment

Marine heatwaves are periods of abnormally high temperatures in the ocean that can trigger devastating impacts on ecosystems, including coral bleaching, toxic algal blooms, and mass mortality events.  Marine heatwaves can occur in any ocean and in any season.  They are defined based on the differences between actual and expected temperatures for the location and time of year.     

According to several studies, even under moderate climate warming scenarios, oceans will experience more frequent and longer-lasting marine heatwaves in the years to come.

Researchers from the University of British Columbia’s Institute for the Oceans and Fisheries in Canada have found that extremely hot years will wipe out hundreds of thousands of tons of fish globally this century.  These losses are in addition to the projected decreases to fish stocks from long-term climate change. 

Under a worst-case scenario where no action is taken to curb greenhouse gas emissions, the research team’s model predicts a 6% drop in the amount of potential catches per year.  In addition, the biomass (or amount of fish by weight) is projected to decrease in 77% of exploited species due to the extreme temperatures.

As a result of climate change and these extreme heat events, the research team projected that fisheries’ revenues would decrease by an average of 3% globally, and employment would fall by 2% globally – a loss of likely millions of jobs.

The research team says active fisheries management is critical.  Catch quotas, for example, need to be adjusted in years when fish stocks are suffering from marine heat events.  In severe cases, the fisheries may need to be shuttered in order to allow fish stocks to rebuild.  

**********

Web Links

Fevers are plaguing the oceans — and climate change is making them worse

Marine heatwaves could wipe out an extra six per cent of a country’s fish catches, costing millions their jobs

Photo, posted October 11, 2016, courtesy of Kahunapule Michael Johnson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Weather Disasters On The Rise | Earth Wise

By Leave a Comment

It seems like the news is always filled with stories about storms, heatwaves, drought, and forest fires.  This is because these things are happening with unprecedented frequency.

According to a new report from the World Meteorological Organization, weather disasters have become five times more common since 1970, in large part a result of climate change.  Extreme weather, climate, and water events are increasing and are becoming more frequent and severe in many parts of the world.

Between 1970 and 2019, there were more than 11,000 reported disasters attributed to weather, resulting in over 2 million deaths and $3.64 trillion dollars in economic losses.

Storms and floods were the most prevalent disasters.  The five costliest disasters ever are all hurricanes that have struck the United States over the past 20 years.

Droughts accounted for the greatest number of human losses, with severe droughts in Ethiopia, Mozambique, and Sudan responsible for 650,000 deaths.

About the only positive news in the report was that even as disasters have grown more prevalent, deaths have declined, dropping from about 50,000 a year in the 1970s to fewer than 20,000 in the 2010s.  This is a result of better early warning systems.  We have gotten better at saving lives.  But early warning systems are woefully insufficient in much of the developing world, where more than 90% of disaster-related deaths occur.

Of the 77 weather-related disasters that struck between 2015 and 2017, 62 show the influence of human-caused climate change.  With the pace of climate change now accelerating, there are likely to be more frequent catastrophic disasters in the years to come.

**********

Web Links

As the Planet Has Warmed, Weather Disasters Have Grown Fivefold, Analysis Shows

Photo, posted September 16, 2021, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wine And Wildfire Smoke | Earth Wise

By Leave a Comment

Rising global temperatures have made droughts and heatwaves more common and intense, leading to larger and more destructive wildfires.   In 2020, wildfires in California blackened more than 4 million acres, the largest wildfire season on record.   With its continuing drought, California has already had 1.5 million acres burned by wildfires this year, and the fires continue.

Wildfires can cause extensive damage throughout the agricultural industry by destroying crops and killing livestock.  But the fires can have a unique effect on the wine industry:  wine grapes can be affected by smoke taint.

Vineyards have demonstrated themselves to be good fire breaks.  They definitely help prevent the movement of wildfires.  But there is no way to stop smoke from the fires from drifting into vineyards.  By far, the damage caused by smoke far outweighs direct losses from fires in vineyards.

Winemakers sometimes add subtle smoky notes to their vintages by aging them in toasted oak barrels.   But wildfire smoke permeating vineyards – even from distant blazes – can end up making wines undrinkable.  Smoke-tainted wines end up having unpleasant aromas that people describe as being like disinfectants or burnt rubber. 

With wildfires an increasingly persistent presence in California, the state’s $43 billion wine industry is facing a major challenge.  An estimated 165,000 to 325,000 tons of California wine grapes went unharvested last year, adding up to more than $600 million in losses from fire and smoke.  The industry will need to figure out ways to detect and manage smoke taint as the problem isn’t going to go away.

**********

Web Links

Wildfire Smoke: An Emerging Threat to West Coast Wines

Photo, posted July 25, 2021, courtesy of Felton Davis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Soaring Heat And Inner-City Neighborhoods | Earth Wise

By Leave a Comment

The record-breaking heatwaves this summer have exposed the special vulnerability inner cities have to the effects of summer heat.  Climate change has exacerbated and supercharged heatwaves, as was seen in Seattle and Portland in late June.

Urban cores can be 10 degrees or more warmer than the surrounding countryside.  The urban heat island effect is a result of how cities are built, with so much pavement, so many buildings, and not enough trees.  On top of this, decades of disinvestment in neighborhoods where people of color live have left them especially vulnerable to heat as their homes are not able to cope with it.

In New York City, some residents of Hunts Point in the Bronx keep lists of neighbors they check on to help keep the most vulnerable alive during heat waves.  The city has subsidized 74,000 air conditioners for low-income, elderly residents, and is spending millions to plant trees.  In Phoenix, the hottest big city in the country, officials are working to develop new models for cooler public housing and cooling for streets and pedestrian corridors.

A study, published in 2020, looked at the linkage between higher heat island temperatures and past practices of redlining, where home loans and insurance were unavailable to people in neighborhoods of color.  In 94 of 108 communities studied, the formerly redlined neighborhoods had higher surface temperatures.

Cities are confronted with two heat problems:  emergencies that require immediate action to save lives, and long-term issues related to combating soaring temperatures in heat islands strengthened by global warming. In many cases, cities are not prepared for either problem.  Dealing with and adapting to heat is essential to the long-term viability and quality of life in our cities.

**********

Web Links

A Triple Whammy Has Left Many Inner-City Neighborhoods Highly Vulnerable to Soaring Temperatures

Photo, posted May 27, 2014, courtesy of Dan DeLuca via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coastlines and Climate Change | Earth Wise

By Leave a Comment

Climate change poses a fundamental threat to life on earth and has already left observable effects on the planet.  For example, glaciers have shrunk, oceans have warmed, heatwaves have become more intense, and plant and animal ranges have shifted. 

As a result of the changing climate, coastal communities around the world are confronting the increasing threats posed by a combination of extreme storms and the predicted acceleration of sea level rise. 

Scientists from the University of Plymouth in England have developed a simple algorithm-based model to predict how coastlines could be affected by climate change.  This model allows coastal communities to identify the actions they need to take in order to adapt to their changing environment.

The Forecasting Coastal Evolution (or ForCE)  model has the potential to be a game-changer because it allows adaptations in the shoreline to be predicted over timescales of anything from days to decades. As a result, the model is capable of predicting both the short-term impact of extreme storms as well as predicting the longer-term impact of rising seas.   

The ForCE model relies on past and present beach measurements and data showing the physical properties of the coast.  It also considers other key factors like tidal, surge, and global sea-level rise data to assess how beaches might be impacted by climate change.  Beach sediments form the frontline defense against coastal erosion and flooding, and are key in preventing damage to valuable coastal infrastructure.

According to the study, which was recently published in the journal Coastal Evolution, the ForCE model predictions have shown to be more than 80% accurate in current tests in South West England.

**********

Web Links

New model accurately predicts how coasts will be impacted by storms and sea-level rise

Photo, posted April 17, 2016, courtesy of Nicolas Henderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Hottest June | Earth Wise

By Leave a Comment

A series of heatwaves from coast to coast caused June 2021 to be the hottest June on record in the U.S. The average June temperature across the contiguous U.S. was 72.6 degrees Fahrenheit, making it the hottest June in 127 years of record keeping and breaking the previous record set in 2016 by nearly a full degree. Eight states had their hottest June on record and six others marked their second hottest June.

One of the most extreme heatwaves in modern history impacted the Pacific Northwest of the U.S. and western Canada late in the month.  Temperature records were not merely broken in the region; they were smashed over an incredibly hot four-day period from June 26th through June 29th when all-time records over 100 degrees were set at dozens of locations.

Portland, Oregon’s average high temperature over this period was 112 degrees, breaking the previous 3-day record by an amazing 6 degrees.  The high on June 28th was 116 degrees, an all-time record for the city.  Seattle set back-to-back all-time heat records of 104 on June 27th and then 108 on June 28th.  In the previous 126 years, Seattle had only hit 100 degrees three times.  It reached that mark 3 days in a row in June.

Crossing the border, the town of Lytton, British Columbia reached a temperature of 121 degrees on June 29th, the third day in a row in which the town registered a new all-time high temperature ever measured in Canada.  To put this in perspective, this temperature is hotter than has ever been recorded in Las Vegas.

June was a hot month indeed.

**********

Web Links

June 2021 was the hottest June on record for U.S.

Astounding heat obliterates all-time records across the Pacific Northwest and Western Canada in June 2021

Photo, posted July 7, 2021, courtesy of Poyson / GPA Photo Archive via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Global Warming Could Stabilize | Earth Wise

By Leave a Comment

The world has been heading toward climate disaster with the effects of greenhouse gas-induced warming looming larger and larger.  But recent analysis published in Nature Climate Change offers hope that rapidly eliminating emissions could stabilize global temperatures just within a couple of decades.

For quite some time, it has been assumed that further global warming would be locked in for generations regardless of the extent of emissions reductions going forward.  This conclusion was based on having a certain carbon dioxide concentration in the atmosphere which would linger for hundreds of years even if emissions were reduced.

Recent analysis takes into account the dynamism of the Earth’s natural systems which could actually reduce atmospheric CO2 content because of the huge carbon absorption capacity of oceans, wetlands, and forests.  The key requirement is to drastically reduce emissions so that these natural systems can take over.

More than 100 countries have pledged to get to net zero emissions by 2050.  That means they will emit no more carbon dioxide than is removed from the atmosphere by such actions as restoring forests.   The UK, Japan, and the European Union are among the countries that have set this zero target, and the United States is joining the club.

Climate models show that a global temperature rise of 2 degrees Celsius over that of the pre-industrial period would lead to global calamities that include punishing heatwaves, flooding, and mass displacement of people.  The world has already heated up by 1.1 degrees and governments have committed to restrain the rise to less than 1.5 degrees under the Paris Climate Agreement.

**********

Web Links

Global Warming Could Stabilize Faster than Originally Thought If Nations Achieve Net Zero

Photo, posted September 10, 2017, courtesy of Ron Cogswell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Ocean Currents And Climate Change | Earth Wise

By Leave a Comment

Oceans cover more than 70% of the earth and absorb 94% of incoming solar radiation.  As a result, oceans play a major role in the climate system.  With their massive size and capacity to store heat, oceans help keep temperature fluctuations in check.  But oceans also play a more active role.  Ocean currents are responsible for moving vast amounts of heat around the planet.  

According to a paper recently published in the journal Nature Communications, the world’s strongest ocean currents will experience more intense marine heatwaves than the global average in the coming decades.  These strong ocean currents play key roles in fisheries and ocean ecosystems.  

Sections of the Gulf Stream near the United States, the Kuroshio Current near Japan, the East Australian Current near Australia, and the Antarctic Circumpolar Current will all see more intense marine heatwaves over the next 30 years. 

Scientists from the University of Tasmania and CSIRO in Australia relied on high-resolution ocean modeling to carry out their research.  They confirmed the model’s accuracy by comparing outputs with observations from 1982-2018.  They then used the same model to project how marine heatwaves would alter with climate change out to 2050.

The model projects, for example, that intense marine heatwaves are more likely to form well off the coast of Tasmania, while more intense marine heatwaves along the Gulf Stream start to appear more frequently close to the shore from Virginia to New Brunswick, Canada. 

Marine heatwaves are on the rise globally, but knowing where they will occur and how much hotter they will be will help policymakers, ecologists, and fisheries experts in their regional decision-making. 

**********

Web Links

Where marine heatwaves will intensify fastest: New analysis

Photo, posted April 17, 2016, courtesy of Nicolas Henderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alaska Is Getting Wetter | Earth Wise

By Leave a Comment

Siberia has been in the news for record-setting heat waves and wildfires, but it is not the only northern region experiencing unusual weather.   Alaska, apart from setting its own warm weather records, is experiencing the rainiest five years in its century-long meteorological record.

Extreme weather in the Arctic is being driven by an aspect of climate change called Arctic amplification, which leads to temperatures rising faster than the global average.  The physical basis of Arctic amplification is well understood, but its effects over time are much less predictable.

The past five years included two summers with average precipitation, one that was a little drier than usual, and two of the wettest summers on record.    Researchers have taken measurements of how far below the surface permafrost has thawed by the end of summer over a wide range of Alaskan environments.

About 85% of Alaska sits upon permafrost and the increasing rainfall over the past five years is leading to a deeper thaw of permafrost across the state.  The wettest summer on record was 2014 and permafrost didn’t freeze back to previous levels even when the next couple of summers were relatively drier.

The study demonstrated how different types of land cover govern relationships between summer rainfall and permafrost thaw.  As Alaska becomes warmer and wetter, the vegetation cover is projected to change, and the increasing occurrence of wildfires will disturb larger areas of the landscape.  These conditions are likely to lead to a feedback loop driving more and more permafrost thawing.

Fundamental changes to Alaskan ecosystems are occurring on an unprecedented timescale – not gradually over decades or lifetimes, but over mere months or years.

**********

Web Links

Alaska is getting wetter. That’s bad news for permafrost and the climate.

Photo, posted June 10, 2011, courtesy of Peter Rintels via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Antarctica’s Hot Summer | Earth Wise

By Leave a Comment

The Southern Hemisphere’s recent summer brought drought, heatwaves and bush-fires that ravaged Australia.  At the same time, Antarctica experienced a summer of extreme weather.

In East Antarctica, the Casey research station in the Australian Antarctic Territory had its first heatwave event, recording extreme maximum and minimum temperatures over three consecutive days in January.  Record high temperatures were also reported at bases on the Antarctic Peninsula.

The Casey station recorded a record high maximum temperature of 49 degrees Fahrenheit and a record overnight low of 36 degrees.  In February, Brazilian scientists reported a high temperature of 69 degrees at Marambio, an all-time record for Antarctica.

Ecologists say that the hot summer would most likely lead to long-term disruption of local populations, communities, and the broader ecosystem.  That disruption could be both positive and negative.

Most life in Antarctica exists in small ice-free oases and depends on melting snow and ice for a water supply.  Melt water from the warming temperatures will lead to increased growth and reproduction of mosses, lichens, microbes and invertebrates.

However, excessive flooding can dislodge plants and alter the composition of communities of invertebrates and microbial mats. If the ice completely melts early in the season, then ecosystems will suffer drought for the rest of the season.

Extreme events often have impacts for years after the event.  There will be long-term studies of the areas affected by the recent Antarctic heat wave. Such extreme events associated with global climate change are predicted to increase in frequency and impact, and even the most remote areas of the planet are not immune to them.

**********

Web Links

Antarctica’s summer of extreme heat

Photo, posted January 30, 2014, courtesy of Andreas Kambanis via Flickr

Earth Wise is a production of WAMC Northeast Public Radio.

The Hottest Month Ever

By Leave a Comment

European climate researchers announced that July was the hottest July ever recorded and since July is generally the hottest month of the year, it was indeed the hottest month ever recorded.  It just barely beat out the previous record set in July 2016.  There are multiple agencies that track temperatures around the world, and it is possible that some of them may report slightly different results. 

But whatever July’s ultimate ranking is, it is part of a long-term trend.  The past five years have been the hottest on record.   The 10 hottest years ever recorded have all occurred during the past twenty years.

This June was also the warmest on record, and the previous five months were all among the four warmest for their respective months.  All of that puts this year on track to be in the top five warmest years, or perhaps the hottest ever.

The highest above-average conditions were recorded across Alaska, Greenland, and large areas of Siberia.   Large parts of Africa and Australia were warmer than normal, as was much of central Asia.  New temperature records were set in Belgium, the Netherlands, and Germany with temperatures over 104 degrees Fahrenheit.  Great Britain saw an all-time record of 101.7 degrees and Anchorage, Alaska stayed above 79 degrees for a record six days in a row.

Wildfires have raged across the Russian Arctic, India has suffered heatwaves and severe water shortages, and Japan saw more than 5,000 people seek hospital treatment during a heatwave.

While scientists cannot directly link any particular heatwave to climate change, the trend for new heat records is likely to continue and accelerate unless we do something about curbing greenhouse gas emissions.

**********

Web Links

How Hot Was July? Hotter Than Ever, Global Data Shows

Photo, posted May 25, 2019, courtesy of Jakob Montrasio via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Off-The-Charts Heat

By Leave a Comment

There have been some blistering heatwaves this summer – in Europe, in the Middle East, and here in the United States.  A new report by the Union of Concerned Scientists projects that within the next 20 years, millions of people in the United States could be exposed to dangerous “off-the-charts” heat index conditions of 127 degrees Fahrenheit or more.  Within 60 years, over one-third of the population could be exposed to such conditions.

Extreme heat kills hundreds of people every year across the U.S.  Our bodies’ natural cooling process is affected by humidity and the combined heat index measures the impact of high temperature and high humidity.  When the combined heat index reaches 90 degrees, it is considered to be a “dangerous day”, when many groups of people are at serious risk.

Because of the warming climate, the number of dangerous days has been increasing in many parts of the country.  Unless there is success in limiting the effects of climate change, by 2050, even relatively temperate cities like Detroit, Minneapolis, New York, and Chicago will have 50 or more dangerous days a year.  Places like Dallas, Houston, Phoenix and Miami will experience dangerous days for half of the year.

The National Weather Service’s heat index goes up to 127 degrees Fahrenheit.  But in as soon as 20 years, the Southeast, Southern Great Plains, and Midwest will begin to experience days that are so hot that they are “off the charts.”

These extreme conditions could still be avoided with steep, rapid carbon emission reductions.  But however successful we are going forward, the US will still be significantly warmer than today with 85 urban areas exposed to 30 or more days with a heat index above 105 degrees, compared with just three urban areas historically.

**********

Web Links

‘Off-the-charts’ heat to affect millions in U.S. in coming decades

Photo, posted August 8, 2008, courtesy of 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...)