disappearing

Disappearing Glaciers | Earth Wise

February 20, 2023 By EarthWise Leave a Comment

Glaciers are massive bodies of slowly moving ice. Glaciers form on land, and represent the snows of centuries compressed over time. They move slowly downward under the influence of their own weight and gravity.

Most of the glaciers on the planet are found in the polar regions, including Antarctica, the Canadian Arctic, and Greenland. Glaciers can also be found closer to the equator in mountain ranges, such as the Andes Mountain range in South America. Glaciers are always changing, accumulating snow in the winter and losing ice to melting in the summer. But in recent times, the melting has been outpacing the accumulation.

A new international study led by researchers at Carnegie Mellon University’s College of Engineering has produced new projections of glacier loss through the century under different emissions scenarios. According to the projections, the world could lose as much as 41% of its total glacier mass this century – or as little as 26% – depending on climate change mitigation efforts.

In a future with continued investments in fossil fuels (sometimes referred to as the “business as usual” scenario), more than 40% of the glacial mass will be gone by 2100, and more than 80% of glaciers by number could disappear. Even in a best case scenario where the increase in global mean temperature is limited to 1.5° degrees Celsius relative to pre-industrial levels, more than 25% of glacial mass will be gone, and nearly 50% of glaciers by number will disappear.

Glaciers take a long time to respond to changes in climate. A complete halt to emissions today would take anywhere from 30 to 100 years to be reflected in glacier mass loss rates.

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Team projects two out of three glaciers could be lost by 2100

Ice, Snow, and Glaciers and the Water Cycle

Photo, posted August 13, 2010, courtesy of Kimberly Vardeman via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

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.

Crops Threatened With Extinction | Earth Wise

January 4, 2022 By EarthWise Leave a Comment

Crop variety and diversity are critically important for global food security as well as for the livelihoods of millions of people. This diversity entails both the different species of food crops as well as the so-called farmer varieties of crops that in many cases have been cultivated and safeguarded for millennia.

It is well-known that many of these crops and varieties have been rapidly disappearing, but data has been scarce on just how many have been lost, how many we are losing, and which ones are the most threatened going forward.

A new study utilizes a methodology known as the Varietal Threat Index, which was developed by the Alliance of Bioversity International and CIAT, the International Center for Tropical Agriculture. The study assessed about 600 farmers from seven Indian states, covering five different agroecological areas. The farmers were selected based on their knowledge of crops and varieties across the 17 study sites.

The farmers listed the crops and varieties grown in their households, noted their uses, and indicated their spread and abundance, including information on varieties grown during the previous ten years which were no longer grown.

The results of the study showed that while there is a significant diversity of landraces – which are local varieties of species developed over time – more than 50% are threatened. The trend is that crops and varieties mostly used for consumption are most often under threat, whereas varieties with multiple uses are less likely to be threatened.

Studies of this type can aid the development of targets and indicators to monitor the global status of plant genetic resources for food and agriculture and help inform urgent priority conservation actions.

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More than half of surveyed crop varieties are under threat of extinction, according to study in India

Photo, posted February 21, 2014, courtesy of Atibordee Kongprepan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Disappearing Mountaintop Glacier Ice | Earth Wise

August 30, 2021 By EarthWise Leave a Comment

A newly released study has found that mountaintop glacier ice in the tropics of all four hemispheres has diminished dramatically over the past 50 years. Among the findings of the study, published in the journal Global and Planetary Change, are that a glacier near Puncak Jaya, in Papua New Guinea, lost about 93% of its ice between 1980 and 2018. Between 1986 and 2019, the area covered by glaciers on top of Mt. Kilimanjaro in Africa decreased by nearly 75%.

The study combined NASA satellite imagery with data from ice cores drilled during field expeditions on tropical glaciers around the world. The combination of measurements demonstrated that climate change is causing these glaciers to disappear and that the ice loss has accelerated in recent years.

The study looked at glacier ice in Kilimanjaro in Tanzania, the Andes in Peru and Bolivia, the Tibetan Plateau and the Himalayas, and ice fields in Papua, New Guinea. Collecting ice cores from these places provides information on the climate in these regions over the centuries and millennia. As snow falls on a glacier each year, it is buried and compressed to form layers that preserve the chemistry of snow, pollutants from the atmosphere, and biological material such as plants and pollen.

Glaciers in the tropics respond more quickly to climate change because they exist in the warmest areas of the world and survive only at very high altitudes. For many of these tropical glaciers, it is too late to prevent their demise. It is not too late to attempt the slow down the buildup of greenhouse gases in the atmosphere that is causing the planet to warm, but we don’t have unlimited time to act.

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Mountaintop glacier ice disappearing in tropics around the world

Photo, posted February 12, 2009, courtesy of Christoph Strassler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Disappearing Rainforests | Earth Wise

July 2, 2020 By EarthWise Leave a Comment

Forest loss is a major contributor to climate change, and it is continuing at a rapid pace. The tropics lost about 30 million acres of tree cover in 2019, a third of which was within humid tropical primary forests, which are especially important for biodiversity and carbon storage. To put that loss in a human-scale perspective, it is the equivalent of losing a football field of primary forest every six seconds for the entire year.

The losses last year were 2.8% higher than in the previous year, and these losses have continued over the past 20 years despite worldwide efforts to halt deforestation.

Brazil single-handedly accounted for over a third of all global loss of humid tropical primary forests. Bolivia experienced record-breaking tree cover loss due to fires. The losses in its forests were 80% greater than in any previous year. The fires were often started by people who were trying to clear land for agriculture but had the fires go out of control. Several countries in Africa’s Congo Basin also experienced sustained or worsening forest loss.

Indonesia, often the focus of the world’s attention for its deforestation activities, actually saw a 5% reduction in primary forest loss in 2019. It was the third year in a row for lower losses. The now-permanent moratorium on clearing forests for oil palm plantations and logging seems to be working.

Going forward, the coronavirus pandemic poses additional threats to the world’s forests in the near future. There may be a tendency to sacrifice forests in pursuit of economic recovery, which will only lead to future complications for the health and livelihoods of millions of people around the world.

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We Lost a Football Pitch of Primary Rainforest Every 6 Seconds in 2019

Photo, posted February 7, 2011, courtesy of Chad Skeers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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What’s On Nature’s Calendar? | Earth Wise

January 29, 2020 By EarthWise 1 Comment

The Inuit Calendar is based on six seasons defined by weather, ice, animal migration, daylight hours and the night sky. All these variables are in flux according to Harvard Narwhal Biologist Dr. Martin Nweeia. Last August in the high Canadian Arctic, at 72 degrees north latitude, temperatures were at an astounding 70 degrees during the day. In 2018, the same region at the same time of year, experienced one of the coldest August months in 15 years.

Disappearing sea ice in Hudson Bay affects migration patterns of ice-dependent species like narwhal and beluga whales and now allows more shipping traffic which produces more marine noise pollution and the risk of an oil spill. As a natural resource, the Arctic has significant deposits of iron ore, gold, diamonds, phosphate, and bauxite, so cargo shipments are increasing yearly.

The disappearance of caribou herds and altered migrations of other animals have also blurred the seasonal changes. Caribou numbers have decreased by more than half in the last two decades. Narwhal populations are remaining steady but are experiencing migration shifts resulting in their appearance at new locations and their absence from traditional areas. Even the timing of the migration has changed, shifting two weeks later from normal late summer – early fall patterns.

The night sky, which has long had identifiable reference points for Inuit observers, is also changing causing speculation about changes in the magnetic field and a polar shift or flipping of the poles. The earth’s magnetic north has been shifting toward Siberia at an alarming 30 miles each year since 2015. Every million years, it is estimated that the poles flip three times. No one knows if or when it will happen again. That’s a calendar with some unexpected dates.

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–Earth Wise acknowledges script contribution from Dr. Martin Nweeia of Harvard University.

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Migratory Tundra Caribou and Wild Reindeer

Earth’s magnetic field is acting up and geologists don’t know why

Photo, posted June 27, 2014, courtesy of the Bureau of Land Management via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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

January 24, 2020 By EarthWise 1 Comment

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.

Birds Are Disappearing

October 16, 2019 By EarthWise 1 Comment

A new analysis, published in the journal Science, reports that the number of birds in the United States and Canada has fallen by 29% since 1970. There are 2.9 billion fewer birds in the two countries now than there were 50 years ago.

The analysis is the most comprehensive attempt to date to look at the status of avian populations. The results were a shock to researchers and conservation organizations.

It is well-known that some bird species have become vulnerable to extinction, but the new study, which surveyed more than 500 species, uncovered steep losses even among such traditionally abundant birds as robins and sparrows.

There appear to be multiple causes for the steep declines. The largest ones are likely habitat loss and the wider use of pesticides. Rachel Carson’s 1962 book Silent Spring warned of the dangers of pesticides and took its title from a world that has lost its birds.

The survey includes 76% of all bird species in the US and Canada, but actually represents almost the entire population of birds. Grassland species have suffered the biggest declines by far, as a result of modern agriculture and development. Pesticides, such as neonicotinoids, make it harder for birds to put on weight needed for migration, delaying their travel.

There are a few bright spots: bald eagles are thriving, and falcon and waterfowl populations are on the upswing. These are species that have been the subject of conservation measures in recent decades.

Stopping the bird decline will require a great deal of effort to defend habitats, restrict chemicals, and redesign buildings. Without that effort, birds will continue to disappear.

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Birds Are Vanishing From North America

Photo, posted April 1, 2012, courtesy of Barry Skeates via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Rosewood Trade

April 3, 2019 By EarthWise Leave a Comment

Illegal trafficking in endangered flora and fauna is a topic of great interest and concern. We hear a lot about elephant ivory, rhino horn, and even pangolin scales. It turns out that the most trafficked form of flora or fauna in the world is actually rosewood. According to the United Nations Office on Drugs and Crime, rosewood is traded more than ivory, rhino horn, and pangolin scales put together as measured either by volume or economic value. According to Earthsight, a London-based nonprofit that investigates environmental crime, rosewood might account for 40% of overall illegal species trade.

Almost all rosewood is headed to China, where the beautiful wood is used in traditional hongmu furniture. A single bed made from particularly desirable Madagascar rosewood can cost a million dollars.

The illegal rosewood trade has decimated many species of the trees around the world. A tiny village in Madagascar has seen its population grow by 5,000 in recent years because of migrants coming to work as rosewood loggers. The rosewood trade has been banned in Madagascar for decades, but a well-established system of bribes has effectively eliminated that problem. Corruption at all levels allows Madagascar rosewood to find its way onto ships and off to China.

In 2017, the Convention on International Trade in Endangered Species of Wild Fauna and Flora listed all of the world’s rosewood species under its Appendix II, prohibiting all trade except in the rare cases where a local CITES authority issues sustainability permits.

As is the case for other trafficked endangered species, until the demand for the products disappears, people will find a way to make them available. And meanwhile, these beautiful trees are rapidly disappearing.

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