lifecycle

Scrubbers to clean up shipping

May 1, 2025 By EarthWise Leave a Comment

Cargo ships are significant sources of global air pollution because of their fuel oil. Most ships burn heavy fuel oil that is loaded with sulfur, so when it is burned it produces noxious gases and fine particles that can harm human health and the environment. The International Maritime Organization enacted a mandatory cap of 0.5% for the sulfur content of marine fuels in 2020. Heavy fuel oil has a sulfur content of 2 to 3 percent.

Shipping companies can comply by burning low-sulfur fossil fuels or biofuels, but these are much more expensive. The most feasible and cost-effective option is to install exhaust gas cleaning systems, known as scrubbers.

A scrubber is a huge metal tank installed in a ship’s exhaust stack. Seawater is sprayed from nozzles to wash the hot exhaust. The seawater reacts with sulfur dioxide and converts it to sulfates, which are environmentally benign natural components in seawater.

A study by the National Technical University of Athens in Greece has performed a lifecycle assessment of the use of scrubbers and has found that burning heavy fuel oil with the use of scrubbers can match or even surpass the benefits of using low-sulfur fuels.

Producing low-sulfur fuel causes additional greenhouse gas and particulate matter emissions in refineries. On the other hand, scrubbers reduce sulfur dioxide emissions by 97% and dramatically reduce other pollutants as well.

The study shows the importance of incorporating lifecycle assessments into evaluation of environmental impact reduction policies.

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Study: Burning heavy fuel oil with scrubbers is the best available option for bulk maritime shipping

Photo, posted August 3, 2015, courtesy of Lotsemann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The largest iceberg runs aground

April 10, 2025 By EarthWise Leave a Comment

The largest iceberg in the world, which has been slowly drifting for nearly 5 years, has finally come to a halt. The iceberg – called the unexciting name A-23A – came into existence in 1986 when it broke off from another iceberg A-23 that had calved or torn off from Antarctica earlier that year. For decades, A-23A sat in the Weddell Sea, east of the Antarctic Peninsula. Then, in 2020, it came loose from the seafloor and began to move. By 2023, it finally left Antarctic Waters.

Late last year, it began spinning in place caught in an ocean current called a Taylor column. Finally, it headed for South Georgia, a British-owned island that is home to a couple dozen people and lots of seals and penguins. A-23A is now stuck on the continental shelf, about 50 miles from the island.

A-23A is around 1,300 square miles in area. By comparison, New York City is 300 square miles.

Four years ago, a large iceberg called A-68A also came to ground in the vicinity of South Georgia. It quickly broke apart and ultimately added 150 billion metric tons of fresh water to the ocean as well as various nutrients. A-23A is also likely to succumb to the warmer waters, winds, and currents it now encounters and will affect the flora and fauna in the area.

The climate is changing and is impacting how ice shelves melt. Calving and the creation of mammoth icebergs are a normal part of the lifecycle of polar ice sheets, but we are likely to see even more events like this in the future.

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World’s Largest Iceberg Runs Aground

Photo, posted January 29, 2011, courtesy of Drew Avery via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The importance of shallow water

March 26, 2025 By EarthWise Leave a Comment

Vacationers love beaches with shallow water. They are great for families with small kids and for less confident swimmers. Such beaches often attract intense coastal development. However, they are also fragile habitats that are disappearing around the world.

A new study led by the University of South Florida highlights the need to protect these marine ecosystems. Shallow coastal waters are known as tidal flats, and they are critical to global seafood supplies, local economies, and overall marine health. Shallow water ecosystems are interlinked with other marine habitats and are vital for the lifecycle of marine species far from shore.

Shallow water ecosystems are at risk not only from coastal development, but from harmful algal blooms triggered by human activity, from marine heatwaves, and from boats operating in sensitive habitats such as seagrass meadows. These habitats contribute millions of dollars to local economies such as those in Florida but there is not much direct habitat managements in place to protect these ecosystems.

The University of South Florida study, published in the journal Fisheries, enumerated ten core strategies that boaters, anglers, wildlife managers, and policymakers can adopt to prioritize and preserve shallow marine ecosystems from humans and from increasingly powerful weather events. Foremost among these efforts are the protection of key fish species, such as tarpon, whose protection would benefit additional species that use the same habitats.

Habitat management and restoration should be essential concerns for coastal communities to provide long-term benefits for both themselves and for the marine life that depends on shallow-water habitats.

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Why shallow water at the beach is more important than you might realize

Photo, posted February 14, 2018, courtesy of Marcelo Campi 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

The Carbon Footprint Of Electric Vehicles | Earth Wise

November 29, 2022 By EarthWise Leave a Comment

Electric vehicles are widely known to be the environmentally friendly alternative to internal combustion-based cars. But there are skeptics who argue that EVs actually have a larger carbon footprint than nonelectric vehicles. The argument is that the manufacturing and disposal of vehicle batteries is very carbon intensive. They also point to the reliance on coal to produce the electricity that powers the cars.

These claims have led to multiple studies in the form of life-cycle analyses comparing the amount of greenhouse gases created by the production, use, and disposal of a battery electric vehicle to that associated with a gasoline-powered car of a similar size.

In short, the studies have found that while it is true that the production of a battery electric vehicle results in more emissions than a gasoline-powered one, this difference disappears as the vehicle is driven.

According to a study conducted by the University of Michigan and financed by the Ford Motor Company, the emissions equation evens out in 1.4-1.5 years for sedans, 1.6-1.9 years for S.U.V.s, and about 1.6 years for pickup trucks.

Emissions from driving come from burning gas in the nonelectric vehicles and from the generation of electricity used by the battery-powered cars. In the current average power mix across the U.S., driving an EV results in a 35% reduction in emissions. However, it varies tremendously by location. There are some places with very dirty power and some with very clean power. But of the more than 3,000 counties in the U.S., only 78 end up with higher emissions from electric cars. Of course, as the electric grid gets greener, the advantages of electric cars only become greater.

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E.V.s Start With a Bigger Carbon Footprint. But That Doesn’t Last.

Photo, posted May 21, 2022, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Emissions From Global Computing

October 20, 2021 By EarthWise Leave a Comment

A recent study from Lancaster University in the UK has concluded that global computing is likely to be responsible for a greater share of greenhouse gas emissions than previously thought and that share is continuing to grow.

Previous calculations of the contributions from information and communications technology (or ICT) estimated that globally it accounts for 1.8 to 2.8% of total emissions. According to the new study, these estimates likely fall short of the sector’s real climate impact because they only show a partial picture.

Prior estimates do not account for the full lifecycle and supply chain of ICT products and infrastructure. They do not include the energy expended in manufacturing the products and equipment, the carbon cost associated with all the components in the products, and the operational carbon footprint of the companies producing those components.

The study argues that the true contribution of ICT to global greenhouse gas emissions could be between 2.1 and 3.9%, which is more than the aviation industry. Furthermore, the study warns that new trends in computing and ICT such as the use of big data and artificial intelligence, the so-called Internet of Things, and the use of blockchain and cryptocurrencies, risk driving further substantial growth in ICT’s greenhouse gas footprint.

It has been a commonly held believe that ICT and computing technologies lead to greater efficiencies across many other sectors, leading to savings in net greenhouse gas emissions. According to the new study, the historical evidence indicates the opposite. ICT has driven wide-ranging efficiency and productivity improvements, but the net result in emissions has been that they have been growing steadily.

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Emissions from computing and ICT could be worse than previously thought

Photo, posted March 13, 2018, courtesy of Flickr.

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Busting Electric Vehicle Myths | Earth Wise

September 20, 2021 By EarthWise Leave a Comment

From the early days of hybrid vehicles right on through the current booming market for electric cars, there has been the contention by some people that these cars are responsible for comparable or even greater amounts of greenhouse gas emissions over their product lifetimes. The arguments generally centered around the carbon costs of creating batteries for the cars as well as the emissions associated with generating the electricity used to charge them.

A new study published by the International Council for Clean Transportation reports a life cycle assessment (or LCA) that considers every source of carbon generated from the cradle to the grave of the vehicle.

Included in the assessment are the mining costs of the lithium to make batteries, the transportation of batteries across the world by container ship, the end-of-life burden, the mix of energy generation in various places around the world, and so on.

The results of the analysis are that even in India and China, which are the biggest burners of coal and oil on earth, it still results in lower emissions to drive an EV instead of an internal combustion vehicle.

Lifetime emissions of today’s average medium-size EVs are lower than comparable gasoline cars by 66-69% in Europe, 60-68% in the US, 37-45% in China, and 19-34% in India. As electricity generation continues to further decarbonize, all these numbers will only get better. While it is somewhat more carbon-intensive to manufacture an EV, it doesn’t take very long in the car’s life to come out ahead owning one.

Early skeptics of EVs and hybrids had more legitimate concerns a decade or so ago, but the advantages of these vehicles are now unambiguous.

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One of the Biggest Myths About EVs is Busted in New Study

Photo, posted December 30, 2020, courtesy of Chris Yarzab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Turning Wood Into Plastic | Earth Wise

May 4, 2021 By EarthWise Leave a Comment

Plastic pollution is particularly pernicious because plastics can take hundreds of years to degrade in the environment. For this reason, researchers across the globe search for ways to shift from petrochemical plastics to ones that are biodegradable.

Producing biodegradable plastics is challenging both from the standpoint of the methods needed and from the results obtained. Producing them often requires toxic chemicals and can be very expensive. The materials that emerge often do not have the durability and strength of conventional plastics and can be unstable when exposed to moisture.

Researchers at the Yale School of the Environment have developed a process of decomposing the porous matrix of natural wood into a slurry that can be formed into a biodegradable plastic. The material shows high mechanical strength, stability when holding liquids, and is resistant to the effects of ultraviolet light. Along with all these favorable properties, the material can be recycled or safely biodegraded in the natural environment.

The slurry mixture is created by taking wood powder – a processing residue usually discarded in lumber mills – and deconstructing it with a biodegradable and recyclable solvent. The resulting mixture has a high solid content and high viscosity and can be casted and rolled without breaking.

The researchers conducted a comprehensive life cycle assessment to test the environmental impacts of the bioplastic compared with conventional plastics. Sheets of it were buried in soil and observed to fracture after two weeks and completely degrade after three months. The material can also be broken back down into the slurry by mechanical stirring.

The remaining topic to investigate is the potential impact on forests if the manufacturing of this bioplastic is scaled up.

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Turning wood into plastic

Photo, posted October 12, 2016, courtesy of the US Forest Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The U.S. Military And Climate Change

July 9, 2019 By EarthWise Leave a Comment

According to new research by scientists from Durham University and Lancaster University, the United States military is one of the largest climate polluters. The U.S. military consumes more liquid fuels and emits more greenhouse gases than most countries.

The study, published in Transactions of the Institute of British Geographers, finds that if the U.S. military were a country, it would be the 47^th largest emitter of greenhouse gases in the world, falling between Peru and Portugal. And this only takes into account the emissions from its liquid fuel consumption. For this study, the U.S. military’s 2015 consumption was compared with the 2014 World Bank country liquid fuel consumption.

In 2017, the U.S. military purchased more than 269,000 barrels of oil a day, emitting more than 25,000 kt- CO2e by burning those fuels. The Air Force accounted for $4.9 billion worth of this fuel, followed by the Navy at $2.8 billion, the Army at $947 million, and the Marines at $36 million.

The Air Force and the Navy are not only the U.S. military’s largest purchasers of fuel, they also use the most polluting types of fuel. The Air Force is the largest emitter of greenhouse gases at more than 13,000 kt CO2e, nearly double that of the Navy’s 7,800 kt CO2e.

Despite this study’s findings and a general uptick in awareness, it’s unlikely that the U.S. military’s dependence on fossil fuels will change. That’s because the military continues to pursue open-ended operations around the globe, and the lifecycle of its existing military equipment insures dependence on hydrocarbons for many years to come.

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U.S. military consumes more hydrocarbons than most countries — massive hidden impact on climate

Photo, posted July 8, 2016, courtesy of Alan Wilson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hybrid-Electric Aircraft

May 20, 2019 By EarthWise Leave a Comment

The commercial aviation industry is a major source of carbon dioxide emissions and, as other industries try to move towards decarbonization, its share is getting larger. But reducing emissions from aircraft is challenging because powering planes without burning fossil fuel is hard to do.

The biggest problem is that powering aircraft with electric motors instead of fossil fuel motors requires so much energy that the batteries needed to supply it become impractically heavy. While research goes on to develop lighter-weight batteries, an interim concept may pay dividends.

Just as hybrid cars represent a stepping stone towards full electrification, hybrid-electric aircraft may be a way to obtain substantial reductions in aircraft emissions. The idea is to use battery-powered electric motors to power planes, but to greatly reduce the capacity requirements of the batteries by having an on-board fossil-fuel generator to charge the batteries and supply additional needed power.

A study by the University of Illinois looked at the potential emissions reductions for hybrid-electric aircraft taking into account the emissions associated with generating the electricity that charges the batteries in the plane. The requirements in the study were that the plane needs to be able to carry the same number of passengers and travel the same distance as current aircraft.

The results were that a drivetrain that gets 50% of its power from battery charge reduced emissions by about 50% over the full lifecycle of the plane.

As batteries get lighter and the electric grid gets greener, the possibility of making major reductions in aircraft carbon emissions looks increasingly realistic. But there is a long way to go.

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Study Examines Commercial Hybrid-Electric Aircraft, Reduced Carbon Emissions

Photo, posted September 26, 2014, courtesy of Jeff Turner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Emissions From Electric Buses

September 12, 2018 By EarthWise Leave a Comment

Municipalities and transit agencies are gradually replacing conventional diesel buses with cleaner alternatives such as natural-gas-powered, diesel-electric hybrid, or fully electric buses. The goal is to reduce the substantial carbon emissions associated with buses as well as reducing unhealthy air pollution. Diesel buses on average get less than 5 miles per gallon as they transport passengers around, so there is plenty of motivation to find more efficient ways to power them.

Indirect Greenhouse Gas Emissions

February 15, 2018 By EarthWise Leave a Comment

When considering the greenhouse gas emissions associated with any energy source, it is important to look at the total life cycle emissions both from the direct use of the energy source and from the indirect emissions associated with building the system, producing and transporting fuels and other supplies and, ultimately, decommissioning the system. Taking all of this into consideration is necessary in order to have a full accounting of the carbon impact of power sources.