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Antarctica’s Hot Summer | Earth Wise

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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.

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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.

Clouds And Global Warming | Earth Wise

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Recent climate models from multiple organizations project that the amount of warming that doubling atmospheric carbon dioxide would cause would be much more than previously estimated.  And one of the significant changes to the models relates to the role of clouds.

Clouds have long been a major uncertainty in climate calculations.  Clouds can shade the earth and thereby provide cooling.  But clouds can also trap heat.  Which effect dominates depends on how reflective the clouds are, how high up they are, and whether it is day or night.  The dynamics of clouds are complicated.

If you fly across the ocean, you will see blankets of low clouds extending for hundreds of miles.  These marine stratus and stratocumulus clouds predominantly cool the Earth.  In fact, they shade roughly a fifth of the oceans and reflect 30-60% of the solar radiation that hits them back into space.

Recent studies indicate that as global temperatures rise, these clouds are likely to become thinner or burn off entirely, leaving more clear skies through which the sun may add another degree Celsius or more to global warming.

The concerns about clouds are part of the larger issue about feedbacks in warming the world.  It has long been clear that the greenhouse effect of doubling CO2 levels in the atmosphere would raise global temperature.  But there are amplifying feedback effects.  Melting large areas of snow and ice reduces reflectivity and allows the land and oceans to absorb more heat.  More water vapor entering the atmosphere traps more heat.  And now clouds are another concern.

Overall, these effects are leading to climate models predicting much larger global temperature increases, which is a scary prospect for the world.

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Why Clouds Are the Key to New Troubling Projections on Warming

Photo, posted September 10, 2006, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cooling The Earth With A Warmer Arctic | Climate Change | Earth Wise

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Researchers are considering a wide range of approaches to mitigate the effects of global climate change.  Among these are various strategies of geoengineering, which must be viewed with enormous caution, given the high likelihood of unintended consequences from almost anything we might do.

Researchers at the International Institute for Applied Systems Analysis have investigated potential strategies for cooling the planet in the absence of Arctic sea ice.

The Arctic region is heating up faster than any other place on earth and its sea ice is rapidly disappearing.  Estimates are that summer sea ice in the Arctic Ocean will be largely gone within a generation.  Arctic ice and snow reflect the sun’s energy into space, which helps to keep the planet cool.  What happens if that ice is gone?

The researchers explored the fact that the Arctic Ocean ice actually insulates the Arctic atmosphere from the warmer water under the ice.  Without the ice layer, the surface water would actually increase air temperatures by 20 degrees C during the winter.  That in turn would increase the heat irradiated into space and thereby cool down the planet.

The Arctic sea ice is in part maintained because the upper regions of the Arctic Ocean have lower salinity than the Atlantic Ocean.  This stops Atlantic water from flowing above the cold Arctic waters.  So, if we were to somehow deliberately increase the salinity of the Arctic Ocean surface water, warmer, less salty Atlantic Ocean water would flow in, increase the temperature of the Arctic atmosphere, and release heat trapped in the ocean into space.

It all sounds pretty crazy, but the researchers say that given the seriousness of climate change, all options should be considered when dealing with it.

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Could we cool the Earth with an ice-free Arctic?

Photo, posted August 19, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cleaning Up Mount Everest

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Mount Everest is the highest mountain above sea level with an elevation over 29,000 feet.  As such, it is a prime attraction for mountain climbers seeking that ultimate achievement.  The summit was first reached in 1953 and for a long time, only major expeditions by the best mountaineers sought to repeat the feat.

In recent years, climbing Everest has become much more common.  In fact, since 1953, more than 4,000 people have reached the summit of the world’s highest mountain.  A record 807 accomplished the feat last year alone.  Thousands more visit lower elevations.

But climbing Everest is neither safe nor easy.  Ice and snow, powerful winds, and generally harsh conditions make Everest a treacherous place.  Over the decades, hundreds of climbers have died on its slopes and many of their bodies are still up there.  Apart from human remains, there are decades worth of garbage left behind by hikers and tourists.

The government of Nepal has mounted an ambitious project to clean up the refuse on Mount Everest.  In just the first two weeks, volunteers removed more than three tons of trash from the mountain. Among the rubbish removed from Everest are tents, climbing equipment, bottles, cans, empty oxygen containers, and human waste.  They also discovered the bodies of four climbers that had emerged from melting snow and ice.

Helicopters carried a third of the garbage to Kathmandu for recycling.  The rest was taken to a local district for disposal in landfills.  The initial work started at Everest’s base camp.  They are next moving to sites higher on the mountain.  They hope to remove at least 10 tons of trash this year.

Nepal would like to make the world’s tallest mountain clean.

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Volunteers Remove 3 Tons of Trash From Mount Everest in Two Weeks

Photo, posted May 23, 2012, courtesy of Gunther Hagleitner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Weather-Responsive Traffic Signals

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We all spend time sitting at red lights – sometimes it seems like a whole lot of time.  There is a fair amount of science applied in the design of traffic signals that at least has the aim of easing congestion and improving traffic safety.

Signals in modern cities are timed using optimization models that analyze multiple factors including traffic volume and speed with the goal of safely getting as many vehicles as possible through intersections.  It sure doesn’t seem that way in many places, but that is the intent in any case.

But a real problem with these models is that they assume normal conditions including weather conditions.  In places that experience real winter conditions, the assumptions of traffic models fail.  If the road surface is covered with snow and ice and visibility is poor, variables like speed and stopping distances become very different.

Researchers at the University of Waterloo in Canada collected data from real-world intersections and ran computer simulations to determine the effects of adjusting traffic signal behavior in bad weather (as well as in the presence of other conditions such as accidents or construction.)  They found that such adjustments could reduce traffic delays by as much as 20%.   

Cities with computerized signal systems are already equipped to remotely and inexpensively adjust the timing of traffic lights.  To gain the benefits of smarter signals, there would need to be video cameras and a certain amount of artificial intelligence software that would be able to automatically tweak the timing of lights in response to traffic changes caused by weather, accidents or construction. 

It sounds like a great idea.

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Weather-responsive intersections could ease traffic congestion

Photo, posted September 22, 2009, courtesy of Tristan Bowersox via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Glaciers And Water Supply

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The world has roughly 150,000 glaciers covering about 200,000 square miles of the earth’s surface.  Over the last 40 years they’ve lost the equivalent of a layer of ice 70 feet thick.  Most of them are getting shorter as well.  Some have shrunk to nothing; many smaller glaciers in places like the Rockies and the Andes have disappeared entirely.

Glaciers represent the snows of centuries, compressed over time to form flowing rivers of ice.  They always change over time, accumulating snow in winter and losing ice to melting in summer.  But in recent times, the warming climate has allowed the melting to outpace the accumulation.

Much of the discussion about the retreating glaciers relates to sea level rise, catastrophic floods, debris flow, and the effects on rivers and ecosystems.

But in some places, the biggest impact of the loss of glaciers is on the supply of water for people and agriculture.  In Kazakhstan, Almaty, the country’s largest city depends on glacier-fed rivers for drinking water for its 2 million people and for irrigation water for crops.  All across the Tibetan Plateau and the Himalayan and Karakmoram mountain ranges, hundreds of millions of people rely on glacier-fed rivers for their water supplies. 

A melting glacier can at first increase stream flow but eventually reaches a tipping point and meltwater begins to taper.  In the short term, the melting glaciers may provide increased amounts of water coming down from the mountains, but eventually the flow in the rivers will begin to decline and populations will face a crisis.

It will be essential for people in many places to carefully plan for their future water needs in a changing world.

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Glaciers Are Retreating. Millions Rely on Their Water.

Photo, posted September 16, 2011, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

2018 Was A Wet Year

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Recent news reports noted that 2018 was the fourth hottest year on record.  But the changing climate is not just about temperature.  2018 was also the third-wettest year since 1895, when steady record-keeping began.

Overall, the U.S. recorded 4.68 inches more precipitation in 2018 than the 20th century average.  But all that rain and snow was nothing like evenly distributed.  The eastern half of the country – especially in places like North Carolina and Virginia – saw record amounts of precipitation, while most of the West remained stuck in drought.

The warming climate leads to precipitation extremes at both ends, meaning that wet places are likely to get wetter and dry places drier.  There has been a marked upward trend in short-duration extreme events.   For example, Cyclone Mekunu dumped almost 13 inches of rain on Salalah, Oman in 36 hours, more than double its annual average rainfall.

In the southeast and eastern U.S., the trend toward stronger storm events is mostly driven by strong warming of the oceans that fringe their shores.  Warm oceans evaporate more water into the air and warm air holds more water than cooler air.  Warmer, moisture-laden air acts like a blanket over the land, keeping heat trapped near the ground.  Many of the states that had their wettest-ever years also set records for high minimum temperatures – their coldest temperatures were less cold than in the past.

Air temperatures are projected to warm up even further in the coming years and, as a result, many scientists are anticipating that extreme precipitation events will only get more extreme.  The pattern of drought in the west and wetness in the east is likely to stay.

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2018 was the U.S.’s third-wettest year on record—here’s why

Photo, posted August 18, 2018, courtesy of Jim Lukach via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cold Weather In A Warming Climate

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The climate is warming.  The average global temperature is going up year after year, bringing about significant changes to weather around the world.  But the fact is that these changes don’t always lead to warmer weather.  And ordinary variations in local weather can also go in either direction.

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Cold And Snow From Global Warming

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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.

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The Ecology Of Dust

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It isn’t something we think about very often, but dust is a connector of ecosystems around the world.  Dust carries various minerals and nutrients to places where such things are in very scarce supply.  This includes the oceans of the world as well as many forests and other ecosystems.  For example, phosphorus-bearing dust carried from the Gobi Desert is essential to the growth of giant redwoods in California’s Sierra Mountains.

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Winter Outlook

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Each year around this time, the National Oceanic and Atmospheric Administration, or NOAA, releases its U.S. Winter Outlook that predicts overall weather trends around the country for the upcoming winter.  They produce these seasonal outlooks to help communities prepare for the weather that is likely to be forthcoming.

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Northeast Temperatures

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A year ago, nearly 200 countries signed an agreement, known as the Paris Accord, to fight climate change by mitigating greenhouse gas emissions.  They each promised to reduce their carbon output as soon as possible, and to do their best to keep global warming well below 2-degrees Celsius (or 3.6 degrees Fahrenheit). 

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Climate Change And Reindeer

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Hundreds of thousands of reindeer roam Russia’s Yamal Peninsula, which is located in northwestern Siberia, and are herded by the indigenous Nenets people, reportedly among the Arctic’s last truly nomadic reindeer herders.  Reindeer provide these indigenous people with transportation, food, clothes, and even tools made from their bones.  Reindeer are well suited for the freezing temperatures and thick snow of this climate.  But they are not well suited for climate change. 

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De-Icing Roadways

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We have been using salt to keep winter roads free of ice and snow since the late 1930s.  In the United States alone, some 20 million tons of salt are applied to roadways each year.  And while its use has real benefits in terms of safety and navigation, there have been cumulative costs to the environment, including degrading freshwater resources and contaminating groundwater. 

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Road Salt

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Snow season is here.  The chances are good you’ll find yourself behind a truck spreading salt on the roads in an attempt to deice them. You may even try a little salt on your own front porch. Annually we spread about 20 million tons of road salt in the U.S., and we’ve been doing it since the late 1930s.

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Snowpack Loss

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A recent study showed that this year the snowpack in California, which is suffering an ongoing drought as well as long-term warming, reached its lowest point in 500 years.   Snowmelt from the Sierra Nevada mountains fills reservoirs that provide a third of all of the drinking water for the state of California, as well as water used to fight fires and generate electricity.

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