reserves

Megadroughts

February 24, 2025 By EarthWise Leave a Comment

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

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

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

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

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

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The Megadroughts Are upon Us

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

Earth Wise is a production of WAMC Northeast Public Radio

Polar bears and the changing climate

March 7, 2024 By EarthWise Leave a Comment

The changing climate poses a major threat to polar bear survival. Polar bears, whose native range lies largely within the Arctic Circle, depend on sea ice for nearly all of their lifecycle functions. Rising global temperatures are causing this sea ice to disappear.

With less sea ice, polar bears are forced to stay longer on land. However, according to a new study led by researchers from Washington State University, more time stranded on land leads to a greater risk of polar bear starvation.

During three summer weeks in Manitoba, Canada, 20 polar bears observed by researchers tried different strategies to maintain energy reserves. But the research team found that nearly all of them lost weight – losing about 2.2 pounds per day on average.

Some scientists have speculated that polar bears might be able to adapt to the changing climate by acting more like grizzly bears by either resting or eating terrestrial food. But the polar bears tried versions of both strategies – with little success.

Polar bears can weigh nearly twice as much as grizzly bears. To maintain this size, polar bears rely on the energy-rich fat of seals, which they best catch on ice.

In the study, which was recently published in Nature Communications, the researchers found that some polar bears laid down to conserve energy, while others searched on land for food. But neither the activity nor the lack thereof paid off. In fact, only one bear out of the 20 gained weight after stumbling across a dead marine mammal on land.

Polar bears across the Arctic are at risk of starvation as the ice-free period continues to grow.

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Polar bears unlikely to adapt to longer summers

Photo, posted November 16, 2015, courtesy of Anita Ritenour via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Lithium Mining And Andes Ecosystems | Earth Wise

October 28, 2022 By EarthWise Leave a Comment

A remote region in the high Andes straddling the borders between Argentina, Bolivia, and Chile has become known as the Lithium Triangle. The area has become the focus of a global rush for lithium to make batteries for electric cars. The global demand for lithium is expected to quadruple by 2030 to 2.6 million tons a year.

According to the U.S. Geological Survey, more than half of the world’s lithium reserves are dissolved in ancient underground water within the Lithium Triangle. The cheapest way to extract the lithium is to pump the underground water to the surface and evaporate it in the sun to concentrate the lithium carbonate contained in it.

Every ton of lithium carbonate extracted using this cheap, low-tech method dissipates into the air about half a million gallons of water that is vital to the arid high Andes. The process lowers water tables and has the potential to dry up lakes, wetlands, springs, and rivers. Hydrologists and conservationists say the lithium rush in Argentina is likely to turn the region’s delicate ecosystems to deserts.

The global drive for green vehicles to fight climate change has the potential to be an ecological disaster in this remote region of South America and for the indigenous people who live there.

The environmental impacts are not an inevitable price for the transition to electric vehicles. First of all, there are alternatives to lithium. Both zinc and nickel are potential substitutes in rechargeable batteries. But, there are also ways of obtaining lithium that are less destructive than evaporating the metal from saline ecosystems. It is up to battery manufacturers, automakers, and financiers to start demanding lithium from sources that are less environmentally destructive.

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Why the Rush to Mine Lithium Could Dry Up the High Andes

Photo, posted September 25, 2015, courtesy of Nuno Luciano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Coping With Climate Change | Earth Wise

October 11, 2022 By EarthWise Leave a Comment

Extreme weather events including prolonged drought and heavy rainfall are becoming more common and more severe as global temperatures rise. As the climate continues to change in the coming decades, how will animals respond?

Researchers from the University of Southern Denmark have examined how different mammals react to climate change. They analyzed data on population fluctuations from 157 mammal species around the world. They compared these fluctuations with weather and climate data from the same time period. The research team had 10 or more years of data for each species studied.

The researchers found that mammals that live for a long time and/or produce less offspring – like llamas, elephants, bears, and bison – are more climate resilient than small mammals with short lives — like mice, possums, lemmings, and rare marsupials.

For example, large, long-lived mammals can invest their energy into one offspring, or simply wait for better times if conditions become challenging. On the other hand, small, short-lived mammals like rodents have more extreme population changes in the short term. In the event of a prolonged drought, large portions of their food base may rapidly disappear, and they are left to starve because they have limited fat reserves.

However, the research team notes that the ability of a species to withstand climate change must not be the only factor when assessing a species’ vulnerability. In fact, in many cases, habitat destruction, poaching, pollution, and invasive species pose a larger threat to animal species than climate change.

While the study only examined 157 species, the findings enable researchers to also predict how animals they know less about will react to climate change.

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Which animals can best withstand climate change?

Photo, posted July 8, 2018, courtesy of Ray via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar Power In Australia | Earth Wise

October 13, 2021 By EarthWise Leave a Comment

Historically, the electricity sector in Australia has been dominated by coal-fired power stations. Even now, coal accounts for about 60% of Australia’s electricity generation. But since 2005, wind power and rooftop solar have led to a fast-growing share of renewable energy in total electricity generation.

Australia is the second-largest exporter of coal in the world and has proven reserves equivalent to over 1,200 times its annual consumption. Australia is home to four of the world’s ten biggest coal mines. But despite this abundant resource, the country is increasing its use of renewable energy.

For just a few minutes on a sunny Sunday afternoon in August, more than half of Australia’s electricity came from solar power. Low demand and sunny skies resulted in the contribution from coal dropping to a record low of 9,315 MW while solar power provided 9,427 MW.

In 2020, 24% of Australia’s electricity came from renewable energy, up from 21% the year before. The increase was driven by a boom in solar installation.

Australia is still a long way from meeting its commitments under the Paris Climate Change agreement. The country ultimately needs 51 GW of new renewable energy generation by 2042 but only 3 GW of new wind and solar projects have been committed to date.

Overall, Australia has promised what has been described as the fastest energy transition in the world. It is all very ambitious, but Australia has a lot of work to do.

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Solar power in Australia outstrips coal-fired electricity for first time

Photo, posted November 30, 2017, courtesy of D. O’Donnell / European Space Agency via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coal Isn’t Even Cheap Anymore

May 15, 2019 By EarthWise Leave a Comment

Coal has historically been very cheap compared with many other energy sources and the reason is that it is so plentiful. The United States has especially abundant quantities of the stuff – perhaps a quarter of the world’s estimated recoverable reserves. Estimates are that at the rate at which we are currently using coal here, the remaining reserves would last about 325 years.

That would be great, of course, if the use of coal was not relentlessly destructive to the environment, hazardous to human health, and a major driver for global warming. Despite all of that, the Trump administration is a big booster of coal.

But coal has little chance of holding on to its current status, much less having some kind of renaissance. According to a new report from renewables analysis firm Energy Innovation, nearly 75% of coal-fired power plants in the United States generate electricity that is more expensive than local wind and solar resources. Wind power, in particular, can at times provide electricity at half the cost of coal.

Wind and solar power are growing by leaps and bounds. The Guardian reported that by 2025, enough wind and solar power will be generated at low enough prices in the U.S. that it could replace 86% of the entire U.S. coal fleet with lower-cost electricity.

It has been known for some time that there are places where the so-called coal crossover has already taken place. But this is actually far more widespread than previously thought. Substantial coal capacity is currently at risk in North Carolina, Florida, Georgia and Texas. By 2025, Indiana, Michigan, Ohio, and Wisconsin will join their ranks.

The biggest threat to coal is not regulators or environmentalists; it is economics.

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Renewables Cheaper Than 75 Percent of U.S. Coal Fleet, Report Finds

Photo, posted May 1, 2011, courtesy of Alan Stark via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Ecotourism And Endangered Species

March 24, 2016 By WAMC WEB

Ecotourism is increasing on a global scale. Ecotourism is generally defined as responsible travel to natural areas that conserves the environment, sustains the well-being of the local people, and involves interpretation and education. Visitor numbers to many protected areas around the world are expanding every year. Ecotourism provides rich experiences for the traveler and often has great benefits to local communities fighting poverty and seeking sustainable development.