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Explosive Growth Of Electric Vehicles | Earth Wise

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Not long ago, electric cars were a rarity.  Ten years ago, annual global sales of EVs were only a few hundred thousand.  As of today, globally, still less than one percent of all the cars on the road are electric.  But that is changing rapidly.

In fact, electric vehicles are expected to capture nearly 20% of the global market this year.  Global sales of EVs were 3 million in 2020 and 6.6 million in 2021.  Last year, sales of electric vehicles hit 10 million and are expected to reach 14 million this year according to the International Energy Agency.

Analysts at the IEA have had to repeatedly revise their projections for future EV sales as the numbers keep going up faster than predicted.  Last year, they projected that EVs would account for 21% of global sales by 2030.  Now, they expect that EVs will reach 35% of sales by that year.

In the US, the EU, and China, policy efforts are in place to boost EV sales.  In the US, the Inflation Reduction Act both supports the EV industry and subsidizes consumer purchases with tax credits. As a result of such policies, the IEA expects electric vehicles to account for 60% of sales across these three large markets by 2030.

Part of what is driving the boom in EV sales is that prices continue to come down for the vehicles.  When operating and maintenance costs are figured in, the EVs come out considerably cheaper to own.  In addition, there are starting to be price wars in the EV industry as competition heats up in the sector.

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EVs to Capture One-Fifth of Global Market This Year Amid ‘Explosive Growth’

Photo, posted May 7, 2022, courtesy of Sharon Hahn Darlin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rare Earths And The Energy Transition | Earth Wise

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Limiting the rise in global temperature to no more than 1.5 degrees Celsius requires decarbonization.  This means slashing fossil fuel use, switching to renewable energy sources, and electrifying as many sectors of the economy as possible.  Doing these things requires huge numbers of wind turbines, solar panels, electric vehicles, and storage batteries.   All of them use rare earth elements and other critical metals.

The 17 rare earth elements are actually common, but they are called rare because they are seldom found in sufficient quantities to be extracted easily or economically. 

China once supplied 97% of the world’s rare earth elements as a result of government support, cheap labor, lax environmental regulations, and low prices.  Once the world started to realize the dangers of being so dependent on China, many countries began developing their own rare earth element production. (However, today China still produces 60-70% of the world’s rare earth elements).

It is difficult to mine rare earth elements without causing environmental damage.  The prevalent extraction techniques involve toxic chemicals that can leach into the environment and, because rare earths are often found near radioactive elements, mining often brings dangerous radioactive waste into the environment.

Researchers are working on ways to make rare earth mining more sustainable.  Some of these include biomining – which uses microbes to extract rare earths from ores, electrical methods to free rare earths from ores, and so-called agromining, which is growing plants that hyperaccumulate rare earths from the soil into their tissues.

Making rare earth mining more sustainable and less harmful to the environment is an essential part of the world’s future.

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The Energy Transition Will Need More Rare Earth Elements. Can We Secure Them Sustainably?

Photo, posted November 18, 2008, courtesy of the Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Falling Lithium Prices | Earth Wise

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Lithium, the key element in the batteries that power electric cars, as well as smartphones, tablets, and laptop computers, is sometimes called white gold.  Over time, the price of the metal has gone up and up.  But recently, and surprisingly, the price of lithium has actually gone down, helping to make electric vehicles more affordable.

Over the first couple of months of this year, the price of lithium has dropped by nearly 20%.  The price of cobalt, another important component of vehicle batteries, has fallen by more than half.  Even copper, another battery material, has seen its price drop by 18%.

Many analysts predicted that prices of these commodities would stay high or even climb higher.  The reason for the decline, as well as whether it is likely to persist, is the subject of much debate.

Some experts believe that the price drops are a result of demand not being as high as expected, perhaps related to slowing sales growth of EVs in Europe and China after certain subsidies expired.  Other industry experts said that the drop was a result of new mines and processing plants providing additional supply sooner than was thought possible.

Despite the price drops, mining and processing lithium remains an extraordinarily profitable business.  It costs from $5,000 to $8,000 to produce a ton of lithium that sells for ten times that amount.  With such fat profit margins, there is no shortage of banks and investors eager to finance lithium mining and processing projects.  Such profit margins are probably not sustainable and that will likely result in more reasonable prices over time.

There is plenty of lithium in the world.  The huge demand for it is a recent phenomenon and the world is still working out how to meet that demand.

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Falling Lithium Prices Are Making Electric Cars More Affordable

Photo, posted January 9, 2023, courtesy of Phillip Pessar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An Accelerating Rate Of Mountain Forest Loss | Earth Wise

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Mountains contribute disproportionately to the Earth’s diversity of life.  While mountains account for about 25% of the land area on Earth, they are home to more than 85% of the mammal, bird, and amphibian species.  But alarmingly, forested mountain habitats in which these species live are disappearing, and they appear to be disappearing at an accelerating rate.

According to a new study recently published in the journal One Earth, more than 300,000 square miles of mountain forest has been lost globally since 2000, which is an area larger than the state of Texas. 

A research team led by scientists from Leeds University in the United Kingdom and the Southern University of Science and Technology in China tracked changes in mountain forests on an annual basis from 2001 to 2018.  The researchers found logging to be the biggest driver of mountain forest loss, responsible for 42% of the overall decline.  This is followed by wildfires at 29%, so-called “slash-and-burn” cultivation at 15%, and permanent or semi-permanent agriculture at 10%.  Significant losses occurred in Asia, Africa, Europe, Australia, and South America, but not in Oceania or North America.

The research team also found that the rate of mountain forest loss seems to be accelerating: in fact, the annual rate of loss increased 50% from 2010-2018 when compared with 2001-2009.

While developing additional forest protection strategies and interventions is critical, the researchers emphasize the importance of also considering food production, livelihoods, and human wellbeing in any new measures.

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Mountain forests are being lost at an accelerating rate, putting biodiversity at risk

Photo, posted December 6, 2018, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric Cars Getting Cheaper | Earth Wise

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A sticking point for buying electric cars has always been that they are typically more expensive than equivalent gasoline-powered cars.  But increasing competition, government incentives, and falling prices for lithium and other battery materials is changing the equation.  In fact, the tipping point when electric cars are as cheap or even cheaper than internal combustion cars is likely to happen this year for many cars and, in fact, has already happened for some.

Battery production is ramping up for Tesla, General Motors, Ford, and others, creating cost savings from mass production. Companies manufacturing batteries in the United States are receiving government subsidies as part of a drive to establish a domestic supply chain and reduce dependence on China.  Before anyone cries foul, it should be noted that globally, oil companies received a trillion dollars in subsidies last year.  The Inflation Reduction Act is making it cheaper for automakers to build electric cars (provided they do it in the United States using US materials) and cheaper for consumers to buy them because of tax credits.

Multiple companies have lowered the price of their electric vehicles in recent months, including both the Tesla Model 3 and Model Y, which are the best-selling electric cars in the United States. GM’s electric Equinox crossover will start at about $30,000, which is still about $3,400 more than the gas-powered version.  But once the electric vehicle tax credit is figured in, it will actually be cheaper.

Electric cars are already cheaper to own and operate because of the much lower cost of powering with electricity instead of gas as well as the greatly reduced maintenance costs for the vehicles.  Once the purchase price of these cars is less than that of gas-powered cars, the economics becomes a no-brainer.

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Electric Vehicles Could Match Gasoline Cars on Price This Year

Photo, posted May 11, 2021, courtesy of Chris Yarzab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Coastal Land Reclamation | Earth Wise

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People are artificially expanding the coastlines of cities by extending industrial ports and creating luxury residential waterfronts.  Major cities have added 900 square miles to their coastlines just since 2000. 

A recent study published in the journal Earth’s Future made use of satellite imagery to analyze land changes in 135 cities with populations of at least 1 million.  But population growth is not the only driver of coastal land reclamation.  It is popular in places that are eager to enhance their reputation and promote revenue growth.

At present, coastal land reclamation is most common in the Global South, where many economies are growing. In the past, the Global North dominated the use of coastal land construction.

The largest additions to land area occurred in China, Indonesia, and the United Arab Emirates.  Port extension is the most common reason for development.  Shanghai alone has added 135 square miles of land.

New land is typically created by piling sediments in the ocean, building cement sea walls and structures to contain sediments or cement, or sometimes filling in wetlands and other shallow areas of water near the coast.  The ecological impacts of reclamation are immense and, unfortunately, are not always considered.  Projects affect both the local ecosystems as well as those of the places where fill materials are obtained.

Industrialization and the need for urban space have driven much coastal reclamation.  Some projects, such as the palm-tree-shaped artificial islands of Dubai, are essentially for prestige.  Some cities, including Shanghai, are building new land in consideration of future sea level rise.

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New Land Creation on Waterfronts Increasing, Study Finds

Photo, posted October 15, 2010, courtesy of Werner Bayer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Dangers Of Melting Glaciers | Earth Wise

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Some of most dramatic evidence that the Earth’s climate is warming is the retreat and even disappearance of mountain glaciers around the world.  2022 was the 35th year in a row that glaciers tracked by the World Glacier Monitoring Service lost rather than gained ice.  Glaciers gain mass through snowfall and lose mass through melting and sublimation (water evaporating directly from solid ice.)  Some glaciers that terminate in lakes or the ocean lose mass through iceberg calving.

In the warming climate, glaciers retreat and meltwater collects at the front of the glacier forming a lake.  Such lakes can suddenly burst and create a fast-flowing Glacier Lake Outburst Flood that can spread over a large distance from the original site – in some cases over 70 miles.  These floods can damage property, infrastructure, and agricultural land and can also be deadly.

The number of glacial lakes has grown rapidly since 1990 as a result of climate change.  According to research by an international team of scientists led by Newcastle University in the UK, the number of people living in glacial lake catchments has increased significantly.

According to the study, 15 million people live within 30 miles of a glacial lake.  The highest danger is in High Mountain Asia – which encompasses the Tibetan Plateau.  That area, which spans from Kyrgyzstan to parts of China, has 9.3 million people potentially at risk.  India and Pakistan have around 5 million exposed people.

Detailed analysis shows that it is not the areas with the largest number or most rapidly growing lakes that are most dangerous.  It is the number of people in proximity to the lakes and their ability to cope with potential floods.

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Glacial flooding threatens millions globally

Photo, posted February 12, 2022, courtesy of David Stanley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting Wetlands | Earth Wise

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Wetlands are distinct ecosystems that are flooded or saturated by water, either permanently or seasonally.  They include mangroves, marshes, swamps, forested wetlands, bogs, wet prairies, and vernal pools.   The feature that most wetlands share is soil or substrate that is at least periodically saturated with or covered by water.

Wetlands are some of the most threatened ecosystems in the world.  While wetlands can be affected by a variety of natural stressors, including erosion, droughts, and storms, human activities have been the major driver of wetland decline. 

But according to a new study by researchers from McGill University in Canada, the global loss of wetland areas since 1700 has likely been overestimated.  The research team calculated that the area of wetland ecosystems around the world has declined 21-35% since 1700 as a result of human activities – far less than the 50-87% decline estimated in other studies.  The study’s focus beyond regions with historically high wetland losses and its avoidance of possibly misleading extrapolations likely resulted in the lower estimate.      

According to the study, which was published in the journal Nature, more than 2.1 million square miles of wetlands have been lost during the past 300 years – an area roughly the size of India.  The five countries with the highest wetland losses are the United States, China, India, Russia and Indonesia. 

But discovering that fewer wetlands have been historically lost than previously thought gives researchers a second chance to protect wetlands.  The findings of the study will help researchers prioritize global conservation and restoration actions.

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A second chance to protect wetlands

Photo, posted February 2, 2005, courtesy of Jan Tik via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Self-Deicing Roads | Earth Wise

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Driving on snowy or icy roads can be pretty dangerous.  That is why roads are salted or coated with sand to provide traction in icy weather.  But excessive use of these substances is bad for the environment and sometimes a storm will blow in before the roads can be coated.

In a paper published in the American Chemical Society Journal ACS Omega, researchers in China describe a method of adding microcapsules filled with a chloride-free salt mixture to the asphalt with which roads are paved.  The idea is to provide the road itself with long-term snow melting capabilities.

The researchers prepared a sodium-acetate salt and combined it with a surfactant, silicon dioxide, sodium bicarbonate, and blast furnace slag, which is a waste product from power plants.  The substances were reduced to a fine powder and then coated with a polymer solution to form tiny microcapsules.  The microcapsules were then used to replace some of the standard mineral filler in asphalt.

Lab experiments showed that the special additive lowered the freezing point of water on the asphalt to -6 degrees Fahrenheit.   The researchers estimated that a 2-inch-thick layer of the anti-icing asphalt would be effective at melting snow for seven or eight years.  A real-world pilot test of the coating on a highway offramp showed that it melted snow that fell on the road whereas an uncoated road required snow removal operations.

According to the researchers, given the cost of materials used for the coating and its potential useful lifetime, it could be a practical and economic enhancement for wintertime snow and ice removal.  Maybe we’ll someday have roads that can fairly often deice themselves. 

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Keeping drivers safe with a road that can melt snow, ice on its own

Photo, posted April 8, 2007, courtesy of the Oregon Department of Transportation via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Sea Level Rise And Global Security | Earth Wise

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Recently, United Nations General Secretary Antonio Guterres addressed the U.N. Security Council on the issue of the security threats created by rising sea levels. In the past, some members of the Security Council – notably Brazil, China, Russia, and at times, India – have argued that the U.N.’s climate program should address such issues and that the Security Council doesn’t have a mandate or the expertise to consider the issue.   The underlying problem is that by addressing the security issues created by rising seas, other sensitive geopolitical issues might come to the forefront.

Guterres’ speech focused on the real possibility that rising seas could disrupt and destabilize global societies unless there is an organized international effort to get ahead of the problem.  Major cities facing serious impacts from rising seas include Cairo, Lagos, Bangkok, Jakarta, Mumbai, Shanghai, Copenhagen, London, Los Angeles, New York, and Buenos Aires, among others.

In all, Guterres said that the danger is most acute for about 900 million people living in low-lying coastal areas.  Some countries, particularly small island developing countries, could disappear entirely.

The world is already facing refugee crises related to politics, warfare, and extreme weather.  The flood of refugees created by rising seas could be biblical in magnitude.

The confluence of climate change and global security is growing steadily.  As the global body primarily responsible for maintaining international peace and security, the U.N. Security Council cannot duck this issue much longer.  It has a critical role to play in building the political will required to address the security challenges looming from rising seas.

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Sea Level Rise Could Drive 1 in 10 People from Their Homes, with Dangerous Implications for International Peace, UN Secretary General Warns

Photo, posted July 19, 2021, courtesy of Face of the World via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Complicated Year For Energy | Earth Wise

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2022 was a complicated year for global energy.  Following its invasion of Ukraine, Russia curtailed natural gas exports to Europe.  This led to large increases in coal burning in many countries, but at the same time led to major new investments in renewable energy.  Projections are that the world will add as much renewable power in the next five years as it did over the previous 20.

In China, severe drought reduced the amount of available hydropower, which drove increased demand for coal in that country.  Between the war in Ukraine and the Chinese drought, coal burning reached an all-time high in 2022, albeit only a 1% uptick for the year.  This increased coal consumption is expected to be only temporary as the accelerating deployment of renewables, energy efficiency, and the use of heat pumps will inexorably reduce coal use.

Globally, governments have earmarked an additional $500 billion for clean energy just since March, bringing the total since the onset of the COVID pandemic to more than $1.2 trillion.  Nearly half of this total investment comes from the U.S. under the Inflation Reduction Act and the Infrastructure Investment and Jobs Act.

In light of these energy policies around the world, the International Energy Agency has revised its projections for renewable energy to substantially larger numbers.   Renewables are expected to surpass coal as the world’s largest source of electricity by early 2025. The global energy crisis triggered by the war in Ukraine has kicked off an extraordinary new phase of rapid renewables growth as countries around the world are seeking to obtain energy security as well as the other benefits of clean energy.

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In 2022, Energy Shocks Spurred Both Unprecedented Coal Burning and Massive Renewable Investments

Photo, posted April 5, 2015, courtesy of Jan Remund via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking Global Forest Changes | Earth Wise

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India is one of the most biodiverse countries in the world.  An estimated 47,000 plant species and 89,000 animal species can be found in India, with more than 10% of each thought to be on the list of threatened species.

India is also one of the 10 most forest-rich countries in the world.  Trees cover approximately 25% of the nation.  But this is still a significant decline from years past.  In fact, between the 1890s and 1990s, a combination of rapid development and resource overexploitation caused India to lose nearly 80% of its native forest area.  Today, as India’s forests continue to disappear, researchers are trying to help preserve what forest remains. 

Using satellite-monitoring data, researchers from The Ohio State University have developed a deep learning algorithm that could provide real-time land use and land cover maps for parts of India. 

The land use monitoring system was trained using satellite data from Norway’s International Climate and Forests Initiative.  By combining this data with a global land cover map produced by Tsinghua University in China, the researcher team’s deep learning model was able to acquire a more detailed type of base map of the area.  Using their model, the researchers were able to process 10 monthly maps.  Their research was recently  presented at the annual meeting of the American Geophysical Union.   

Using these maps, the researchers were able to detect seasonal shifts across india.  These include changes to barren land, how crop land was affected by monsoons, and the distribution of forests in mountainous regions. 

Understanding the impact of these seasonal changes will help scientists better predict the effects of climate change on forests.

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Using deep learning to monitor India’s disappearing forest cover

Photo, posted January 20, 2013, courtesy of Frontier Official via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Renewables Will Overtake Coal | Earth Wise

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According to a recent report by the International Energy Agency, worldwide growth in renewable power capacity is set to double in the next five years.  In fact, by 2027, the world will add as much renewable power as it did over the previous 20 years.

Of particular significance is that renewables are going to overtake coal as the largest source of electricity generation by early 2025.

The global energy crisis triggered by the war in Ukraine has had multiple effects on the evolution of the energy system.  While the war has driven a resurgence in fossil fuel consumption in Europe in order to replace gas from Russia, that resurgence is expected to be short-lived.  Instead, the current energy crisis may turn out to be an historic turning point toward a cleaner and more secure energy system.

Soaring fossil-fuel prices triggered by the war have caused many countries to respond by embracing wind turbines, solar panels, nuclear power plants, hydrogen fuels, electric vehicles, and electric heat pumps.  In the US, Congress approved more than $370 billion in spending for clean energy technologies as part of the Inflation Reduction Act.  China, India, South Korea, and Japan have all increased their national targets for renewable power.   However, heating and cooling buildings with renewable power remains a sector needing larger improvement, according to the energy agency.

Overall, the expansion of renewable power over the next five years is now projected to happen much faster than what was projected just one year ago. The new IEA report revised last year’s forecast for renewables growth by 30% as a result of the introduction of new policies by many of the world’s largest greenhouse gas emitters.

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Renewables Will Overtake Coal by Early 2025, Energy Agency Says

Photo, posted March 8, 2021, courtesy of Stanze via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Perennial Rice | Earth Wise

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People have been cultivating rice for more than 9,000 years.  Cultivated rice is an annual crop which is often extended to two crops a year by a process called ratooning, which is cutting back annual rice to obtain a second, weaker harvest.

An extensive project involving multiple institutions in China, the U.S., and Australia has been developing perennial rice.  The researchers developed it through hybridization, crossing a type of Asian domesticated annual rice with a wild perennial rice from Africa.  Using modern genetic tools to identify candidate plants, the team identified a promising hybrid in 2007, planted large-scale field experiments in 2016, and released the first commercial perennial rice variety, called PR23, in 2018.

The researchers spent five years studying the performance of the perennial rice alongside annual rice on farms in China’s Yunnan Province.  For the most part, the yield of the perennial rice was equivalent to that of annual rice over a period of four years. 

Because farmers don’t have to plant rice each season, growing perennial rice requires almost 60% less labor and saves nearly half the costs of seed, fertilizer, and other inputs.

Perennial rice is already changing the lives of more than 55,000 smallholder farmers in southern China and Uganda.  The economic benefits vary by location, but overall profit increases ranged from 17% to 161% over annual rice.

There are already three perennial rice varieties available to farmers, but researchers aren’t done refining the crop.  They plan to use their methodology to enhance traits such as aroma, disease resistance, and drought tolerance to newer versions.

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Farmers in China, Uganda move to high-yielding, cost-saving perennial rice

Photo, posted February 25, 2002, courtesy of Matthieu Lelievre via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Renewable Energy Booming in India | Earth Wise

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India is the country with the second largest population in the world – over 1.4 billion people – second only to China – and will undoubtedly pass China soon based on population trends in the two countries.   India is the third largest emitter of carbon dioxide, after China and the U.S.  With its rapidly growing population and an economy heavily dependent on coal and oil, emissions in India are on a steep upward trajectory.  Currently, fossil fuels account for about 60% of India’s installed energy capacity.  It is essential that actions are taken to curb its rapid increase in greenhouse gas emissions.

To that end, India’s renewables sector is booming.  The country is projected to add 35 to 40 gigawatts of renewable energy each year until 2030.  That’s enough energy to power up 30 million more homes each year.  The country has established a target of producing 50% of its electricity from non-fossil fuel sources by the end of this decade.

 India is expected to reach over 400 gigawatts of renewable energy capacity by 2030

according to the Institute for Energy Economics and Financial Analysis and Climate Energy Finance.  The Indian government’s own projections estimate that the country will reach 500 gigawatts of renewable capacity in that timeframe.

As is the case with China, a country with an enormous population undergoing major economic growth and modernization has vast energy needs.  While it is imperative for the entire world that India puts a cap on its growing greenhouse gas emissions, it is a difficult challenge for an energy-hungry country.

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Renewable energy booms in India

Photo, posted November 14, 2011, courtesy of Amaury Laporte via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Bengal Water Machine | Earth Wise

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Over the past three decades, the owners of 16 million small farms in the Bengal Basin of Bangladesh have been pumping shallow groundwater during dry seasons to irrigate rice paddies.  By lowering groundwater levels in this way during the dry season, the ability of leakage from rivers, lakes, and ponds to replenish the groundwater was greatly enhanced.   Capturing surface water not only improved the recovery of groundwater levels but only helped to reduce flooding during monsoons.

The net result of this enormous collective groundwater pumping by millions of farmers has been the creation of vast natural reservoirs underground that are comparable to what is contained by many of the world’s largest dams.   This system of sustaining irrigation has transformed what was previously a famine-prone country into a food-secure nation.

The details of this remarkable transformation have been laid out in a study by University College London recently published in the journal Science.  According to the study, over the course of 30 years, more than 75 cubic kilometers of fresh water was captured by this process, which is equivalent to the combined reservoirs of China’s Three Gorges Dam and the Hoover Dam in the U.S.

The authors of the study described the water cycling process as “The Bengal Water Machine” and argue that it can be a sustainable alternative to conventional approaches to seasonal river flow storage for irrigation, which typically involve dams and reservoirs.  Such approaches are difficult to implement in densely populated alluvial plains where sand, silt, and clay are laid down by annual floodwaters. 

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Millions of farmers “replumb” world’s largest delta

Photo, posted February 2, 2010, courtesy of Melanie Ko via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Prospects For Floating Solar | Earth Wise

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Countries are trying to figure out how to get enough energy from solar and wind generation to completely decarbonize their economies.  According to some estimates, nations might have to devote between half a percent and five percent of their land area to solar panels to get the job done.  Half a percent is about the amount of the U.S. that is covered by paved roads.  While there is lots of open land in many parts of the country, covering it with solar panels might not be acceptable to farmers, conservationists, or other interested parties.

One way to deploy more solar panels without using up land is the use of floating solar panels.  Floating photovoltaic systems – also known as floatovoltaics – are becoming increasingly common, especially in Asia.  This year, China installed one of the largest floatovoltaic systems in the world on a reservoir near the city of Dezhou.

Floating solar panels stay cooler and run more efficiently than those on land.  The panels also help prevent evaporation from their watery homes and the shading they provide also help to minimize algal blooms.  Solar installations on reservoirs generally puts them near cities, making it easier to feed power into urban grids.

On the other hand, floating solar systems need to be able to withstand water and waves and are generally more expensive to build than land-based systems.

At present, the installed global capacity of floating solar is only about 3 gigawatts, compared with more than 700 gigawatts of land-based systems. However, reservoirs around the world collectively cover an area about the size of France.  Covering just 10 percent of them with floating solar could produce as much power as all the fossil-fuel plants in operation worldwide.

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Solar Takes a Swim

Photo, posted March 7, 2019, courtesy of Hedgerow INC via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Colorful Solar Panels | Earth Wise

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More and more buildings and public spaces are incorporating solar panels and not only just on rooftops.  Some buildings are incorporating power-generating structures all over their facades.

Using solar panels in this way puts some design constraints on buildings because solar panels are typically a deep black color.  This is because solar panels need to absorb light and making them any other color decreases their ability to do so and generate power.  But the problem is that people don’t necessarily want a black building.

One alternative to traditional solar panel design is to use structural sources of color that include microscopic shapes that only reflect specific light frequencies, like the scales on butterfly wings.  But this approach generally leads to iridescence – which might not be what is wanted – and is often quite expensive to implement.

A team of researchers at a university in Shanghai has now demonstrated a way to give solar panels color that is easy and inexpensive to apply and that does not reduce their ability to produce energy efficiently.

The technique involves spraying a thin layer of a material called a photonic glass onto the surface of solar cells.  The photonic glass is made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres.  Even though most light can pass through the photonic glass, certain colors are reflected back, depending on the sizes of the spheres.  By varying that size, the researchers created solar panels that were blue, green, or purple with only a very small drop in solar panel efficiency.

The solar panels made this way maintained their color and performance under durability testing.  With this new technology, there may soon be colorful solar panels on our buildings.

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Colorful solar panels could make the technology more attractive

Photo, posted December 15, 2021, courtesy of Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar-Powered Desalination | Earth Wise

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About two-thirds of humanity is affected by water shortages.  In the developing world, many areas with water shortages also lack dependable sources of electricity.  Given this situation, there is widespread research on using solar heat to desalinate seawater.  To date, many approaches to this face problems with fouling of equipment with salt buildup.  Tackling this issue has proven to add complexity and expense to solar desalination techniques.

A team of researchers from MIT and China has recently developed a solution to the problem of salt accumulation that is more efficient than previous methods and is less expensive as well.

Previous attempts at solar desalination have relied on some sort of wick to draw saline water through the device.  These wicks are vulnerable to salt accumulation and are difficult to clean.  The MIT-Chinese team has developed a wick-free system instead.  It is a layered system with dark material at the top to absorb the sun’s heat, and then a thin layer of water that sits above a perforated layer of plastic material.  That layer sits atop a deep reservoir of salty water such as a tank or pond.  The researchers determined the optimal size for the holes in the perforated plastic.

The 2.5 millimeter holes are large enough to allow for convective circulation between the warmer upper layer of water above the perforated layer and the colder reservoir below.  That circulation naturally draws the salt from the thin layer above down into the much larger body of water below.

The system utilizes low-cost, easy to use materials.  The next step is to scale up the devices into a size that has practical applications.  According to the team, just a one-square-meter system could provide a family’s daily needs for drinking water.

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Solar-powered system offers a route to inexpensive desalination

Photo, posted February 13, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Making Cotton More Sustainable | Earth Wise

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In the United States, cotton is a $7 billion annual crop grown in 17 states.  Cotton plants in the largest producing countries in the world – India, China, and the U.S. – are genetically very similar and, like other crops that lack diversity, can be at risk.

Cultivated cotton around the world has been bred to look and act very similar.  It is high yielding and easy to harvest using machines.  But it is also wildly unprepared to fight disease, drought, or insect-borne pathogens.

Researchers are looking beyond breeding for ways to combat the low genetic diversity of cultivated cotton.  There are new approaches that combine breeding with elements of genetic modification.  Most cotton in the U.S. has already been genetically modified to resist caterpillar pests.  But as new problems emerge, new solutions will be needed that may require complicated changes to the cotton genome.  Getting regulatory approval for a genetically modified crop is a long and expensive process.

However, ordinary genetic modification is not the only possibility.  Modern genetic sequencing technology can allow researchers to examine various wild cotton varieties and identify the genetic markers for desirable traits.  Once valuable genes in wild species have been identified, traditional plant breeding techniques could be used to produce cultivated cotton varieties that are more resistant to disease and drought.

Climate change is raising average global temperatures and some important cotton-producing regions such as the U.S. Southwest are becoming drier.  Researchers are hoping to produce cultivated cotton that can tolerate drought at the seedling stage.  The ultimate goal is to create more sustainable and genetically diverse cotton that can thrive in a changing world.

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Cotton Breeders Are Using Genetic Insights To Make This Global Crop More Sustainable

Photo, posted November 9, 2008, courtesy of BP Takoma via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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