fall

The Great Salt Lake Is Disappearing | Earth Wise

August 31, 2022 By EarthWise Leave a Comment

Utah’s Great Salt Lake is the largest saltwater lake in the western hemisphere. According to data from the US Geological Survey, the surface water elevation of the Great Salt Lake has fallen to the lowest level since records began in the mid-1800s. The average elevation is now 4,190 feet above sea level. With this drop in water level, the surface area of the lake is little more than half of its historical size. The lower water level has exposed about 700 square miles of previously submerged lakebed.

The lake now contains about a quarter of the volume of water that it did at its high point in 1987. The precipitous drop in water is a result of water usage from the lake coupled with climate change-fueled drought. Increased water demand is due to the rapidly growing population of metropolitan Salt Lake City. Utah’s population is projected to increase by almost 50% by 2060.

The Great Salt Lake goes though seasonal cycles of water loss and replenishment. Rain and snow generally refill its level. However, because of the ongoing megadrought in the West, water evaporation and depletion continue to exceed the amount of water entering the lake. The water levels are expected to further decrease until fall or early winter, when incoming water is expected to equal or exceed evaporation.

The decline of the Great Salt Lake is a serious threat to the economy, ecology, and people of northern Utah. The lake generates snowpack, is a refuge for hundreds of migratory birds and other wildlife and generates millions of dollars in the economy through mineral extraction and tourism.

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Utah’s Great Salt Lake is disappearing

Photo, posted October 6, 2020, courtesy of Julie Girard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mangrove Forests And Climate Change | Earth Wise

August 3, 2022 By EarthWise Leave a Comment

Mangrove forests play a vital role in the health of our planet. These coastal forests are the second most carbon rich ecosystems in the world. A patch of mangrove forest the size of a soccer field can store more than 1,000 tons of carbon. It does this by capturing carbon from the air and storing it in leaves, branches, trunks, and roots.

Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperatures. These forests can be recognized by their dense tangle of prop roots that make the trees look like they are standing on stilts above the water. These roots allow the trees to handle the daily rise and fall of tides. Most mangroves get flooded at least twice a day. The roots also slow the movement of tidal waters, which allows sediments to settle out of the water and build up on the muddy bottom. Mangrove forests stabilize coastlines, reducing erosion from storms, currents, waves, and tides.

A new study by the University of Portsmouth in the UK looked at the effects of climate change on how carbon is stored in mangrove forests. In mangrove ecosystems, a variety of organisms break down fallen wood. These include fungi, beetle larvae, and termites. Closer to the ocean, clams known as shipworms degrade organic material.

Climate change is disrupting these processes in at least two ways. Rising sea levels are changing the way sediments build up and increased ocean acidity is dissolving the shells of marine organisms like shipworms.

Mangrove forests are crucial to mitigating climate change, and changes to the functioning of the carbon cycle of those ecosystems are a threat to their ability to perform that function.

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Study Reveals How Climate Change Can Significantly Impact Carbon-Rich Ecosystem

Photo, posted March 24, 2014, courtesy of Daniel Hartwig via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Record Heat In The Arctic | Earth Wise

January 13, 2021 By EarthWise Leave a Comment

By mid-November, the Arctic stays dark around the clock and twilight does not return until the end of January. But even as winter darkness descended upon the Arctic this year, record-breaking high temperatures in the region continued. In late November, temperatures across the entire Arctic basin were 12 degrees Fahrenheit above normal and some locations saw temperatures as high as 30 degrees above normal.

The entire summer and fall in the Arctic were characterized by exceptionally warm temperatures. In June, the Siberian town of Verkhoyansk – located north of the Arctic Circle – registered a high temperature of 100.4 degrees. The refreezing of the Arctic Ocean was greatly delayed this year. The Northeast Passage along the Siberian Coast remained navigable for a record 112 days before freezing in November, breaking the previous record by more than a month. The extent of sea ice covering the Arctic Ocean in October was the lowest ever recorded for that month.

The strongest warming occurring in the Arctic is during the fall. That is because rapidly disappearing sea ice is enabling the dark waters of the Arctic Ocean to absorb heat in the summer and then radiate it back into the atmosphere until late in the fall. The Arctic region is heating up three times faster than the rest of the planet, which has led to the volume of sea ice decreasing by 2/3 in the past 40 years.

According to researchers, the extreme heat in Siberia this year would have been virtually impossible without human-caused climate change and became 600 times more likely because of human emissions of greenhouse gases.

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Record-shattering Warmth Pushes Arctic Temperatures to 12 Degrees F Above Normal

Photo, posted September 1, 2009, courtesy of the U.S. Geological Survey via Flickr. Photo Credit: Patrick Kelley, U.S. Coast Guard.

Earth Wise is a production of WAMC Northeast Public Radio.

Why Do Trees Change Color? | Earth Wise

December 24, 2020 By EarthWise Leave a Comment

We had a particularly colorful fall in the Northeast this year. Almost everywhere you looked, there were brilliant displays of yellow, orange, and red. The colors of fall are a result of chemistry and environmental events that may have taken place many months in the past.

The color of leaves comes from 4 pigments whose effects are governed by photosynthesis. The one that is actually used in photosynthesis is chlorophyll and it causes leaves to be green. But when a tree begins to prepare for dormancy, it stops producing chlorophyll, the green pigmentation fades, and the other pigments that were already in the leaves become visible.

There are xanthoplylls, which are the yellow pigments that are seen the most in fall trees. They are the same pigments that color egg yolks and sometimes parts of the human eye. They are only produced by plants and appear in humans and animals only through consumption.

There are carotenes, which are the orange pigments found in fruits and vegetables, such as carrots, oranges, some bell peppers and squashes.

And there is anthocyanin, which is the pigment found in blueberries, blackberries, and red or violet roses. Its color depends on the pH level of the plant; higher pH leads to darker color. This is the pigment seen in red maples, black cherry trees, Shumard oaks, and more. Only 10% of trees in temperate climates produce anthocyanin and its red pigmentation and most of those trees are in New England.

All these pigments serve purposes. They help trees absorb light energy, prevent sun damage, and even regulate how much energy chlorophyll produces.

There are complicated chemical and environmental factors at play in fall foliage but when they come together like they did this year, it’s a magnificent spectacle.

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Why Do Trees Change Color?

Photo, posted October 17, 2020, courtesy of John Brighenti via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fall Safety Tips | Earth Wise

November 4, 2020 By EarthWise Leave a Comment

The fall season has its own weather-related hazards, such as raging wildfires across the West and a busy hurricane season in the Atlantic. There might even be snow in some places. The National Weather Service issued a set of four broad safety tips for being prepared for the dangers of fall weather.

With regard to wildfires, it is important for smokers to properly discard cigarettes, for people to avoid activities with open flames or sparks, and to use fire-resistant landscaping around our homes. The Weather Service issues Red Flag Warnings when conditions are ripe for wildfires.

In this busy hurricane season, even people who don’t live in hurricane surge evacuation areas need to know their home’s vulnerability to damage from high winds and inland flooding. People should have a plan that includes an emergency kit and a safe place to shelter should they need to evacuate.

It is important to have a plan in case strong winds pose a threat. When preparing for an extreme wind event, secure objects that can be tossed or rolled, trim trees near homes, and have a plan in case of an extended power failure. Strong winds can even happen on a clear day.

The key advice in case you encounter flood waters is “turn around, don’t drown.” It is never safe to walk or drive into a flooded roadway. It is best to delay travel until roads are clear.

Fall can be the most beautiful season of the year, but it also has its dangers. Following advice such as that provided by the Weather Service is prudent and potentially life-saving.

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Four safety tips for fall hazards: Small actions can have big impacts

Photo, posted October 30, 2014, courtesy of Virginia State Parks via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Extreme Wildfire Seasons | Earth Wise

April 29, 2020 By EarthWise Leave a Comment

According to a new study led by researchers at Stanford University, autumn in California feels more like summer now as a result of climate change, and this hotter and drier weather increases the risk of longer and more dangerous wildfire seasons.

The research team, whose work was recently published in the journal Environmental Research Letters, found that the frequency of extreme fire weather conditions in the fall in California has doubled since the early 1980s. Average temperatures during the season have increased by more than 2 degrees Fahrenheit, and rainfall has fallen by approximately 30%. The most pronounced warming has occurred in the late summer and early fall. That finding means that tinder-dry conditions coincide with the strong “Diablo” and “Santa Ana” winds that are typical in California at this time of year.

In recent years, these conditions have fed large and fast-moving wildfires across California. The state’s two largest wildfires, two most destructive wildfires, and the most deadly wildfire all occurred during 2017 and 2018, resulting in more than 150 deaths and $50 billion in damage.

Because summertime has typically been peak fire season, the recent spate of autumn fires is putting a strain on firefighting resources and funding. The ongoing COVID-19 pandemic could further strain emergency resources. Since fire-prone regions have historically shared wildfire-fighting resources throughout the year, the consequences of California’s extended wildfire season could have a global impact. (For example, California’s recent autumn wildfires have coincided with the beginning of wildfires in Australia).

The researchers highlight some opportunities to manage the intensifying wildfire risk in California, including limiting the trajectory of global warming in keeping with the targets identified in the United Nations’ Paris agreement.

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Researchers forecast longer, more extreme wildfire seasons

Photo, posted September 12, 2019, courtesy of the California National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bird Migration And Climate Change | Earth Wise

January 22, 2020 By EarthWise Leave a Comment

A new study of bird migration shows the migration patterns are shifting as a result of climate change. Researchers at Colorado State University, the University of Massachusetts, and the Cornell Lab of Ornithology, looked at the impacts of climate change on a continental scale.

The team looked at the nocturnal migratory behaviors of hundreds of species representing billions of birds using radar and other data. They found that spring migrants are likely to pass certain stops earlier now than they would have 20 years ago. Temperature and migration timing are closely aligned and the greatest changes in migration timing are occurring in regions warming most rapidly. During the fall, shifts in migration were less apparent.

Migratory birds play an important role in ecosystems. They consume insects, disperse seeds, and perform various other significant functions. Birds serve as critical metrics of the health of ecosystems.

Bird migration is a global phenomenon that can provide unique visibility into changes in the climate. The ability to look at it on a global scale has only recently become practical as a result of big data technology and cloud computing. The team was able to crunch the numbers for the study in 48 hours, a task that previously would have taken over a year of continuous computing.

The findings have implications for understanding future patterns of bird migration because birds depend on food and other resources as they travel. As the climate changes, the timing of blooming vegetation or the emergence of insects may end up out of sync with the passage of migratory birds. This could have negative consequences for the health of migratory birds.

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Bird migration timing skewed by climate, new research finds

Photo, posted November 5, 2019, courtesy of Jerry Kirkhart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Another Hot November

January 3, 2020 By EarthWise Leave a Comment

This past fall saw yet more of the high temperatures the world has been experiencing in recent times. Both the season (September through November) and the year to date were the second hottest in recorded history. November itself was the second-hottest November in the 140-year global climate record.

The high temperatures were felt at both ends of the world. Sea ice coverage across both the Arctic and Antarctic oceans fell to near-record lows in November. Arctic sea ice coverage was nearly 13% below the 1981-2010 average, while Antarctic coverage was 6.35% below average.

The average global land and ocean surface temperature for November was 1.66 degrees Fahrenheit above the 20^th century average. The year-to-date global temperature was 1.69 degrees Fahrenheit above the 20^th century average. These numbers correspond to almost a 1-degree Celsius increase, which should be compared with the Paris Climate Accord goal of keeping that increase to no more than 1.5 degrees.

November was the hottest November on record for South America, Africa, and the Hawaiian Islands. The Caribbean had its second-hottest November, and Europe had its seventh hottest on record.

The world’s average sea surface temperature ranked second warmest for the year to date and was only 0.05 degrees cooler than the all-time record.

The National Oceanic and Atmospheric Administration issues monthly global climate reports and for quite some time, these reports seem to all be the same. Another new record for heat or at least another near record. We have to expect that this trend will continue at least until the world starts making progress in dealing with its root cause.

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November 2019 was 2nd hottest on record for the planet

Photo, posted July 20, 2016, courtesy of Salehin Chowdhury via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dangerous Cities For Migrating Birds

May 14, 2019 By EarthWise Leave a Comment

Billions of birds migrate north in the spring and south in the fall. The majority of them fly at night. But as they pass over large cities, the birds can become disoriented by bright artificial light – so-called light pollution, causing them to crash into buildings or windows.

Researchers estimate that 600 million birds die from building collisions in the United States every year. Now, a new paper from researchers at Cornell University reveals which metropolitan areas are most dangerous for birds and why.

The researchers ranked cities where, as a result of geography and exposure to light pollution, birds are at the greatest risk of becoming attracted to and disoriented by lights and crashing into buildings. They combined light pollution levels with bird density data in order to make their calculations. Their paper was recently published in the journal Frontiers in Ecology and the Environment.

Chicago, Houston, and Dallas finished as the three most dangerous cities for migrating birds. While migration routes vary depending on the season, these three cities still topped all others during both the spring and fall migrations due to their size and geographic positioning in the heart of North America’s most trafficked aerial corridors.

Audubon’s Lights Out program is one of several national efforts encouraging cities to reduce light pollution, particularly on heavy migration nights, in order to reduce bird mortality.

But homeowners need to do their part as well since an estimated quarter-million birds die from collisions with residential houses every year. The suggestion to cities and homeowners alike is the same: If you don’t need the lights, turn them off.

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Chicago tops list of most dangerous cities for migrating birds

Photo, posted May 18, 2017, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.