lifecycle

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.