
By Sara Peach
Dear Sara,
I live in a city that does not have great transportation options, and I live far enough from my work that I am not able to walk or ride a bike. I have a 15-year-old car that I am looking to replace.
My husband and I are open to buying a hybrid or electric car. We live in Michigan, and the gentleman at the dealership told us that in our climate, we would not get maximum efficiency out of a hybrid due to cold temperatures in the winter. Additionally, I understand that hybrid and electric cars have less of a footprint on the road, but require greater resources to create, thus negating the benefit. Is that true? – Christina in Michigan
Dear Christina,
One of the claims you've heard is true – but it's not the whole picture. And the other is false. As I'll explain, Michigan is an imperfect place to drive hybrid or electric vehicles. But overall, their benefits to the climate outweigh the drawbacks, so these vehicles can make solid choices even in your cold Midwestern state.
Why Hybrids Can Be Better for the Climate
Most cars and trucks run by burning diesel or gasoline in internal combustion engines. They contribute to climate change by releasing heat-trapping carbon dioxide from their tailpipes.
Hybrid vehicles, by contrast, contain both an electric motor and an internal combustion engine. The electric motor assists the gasoline engine and in some cases propels the car on its own, boosting the vehicle's efficiency. Hybrids also take advantage of several fuel-saving features, such as powering off automatically at stoplights to prevent idling. As a result, they typically boast better fuel economy – and therefore a smaller climate impact – than vehicles running on conventional engines alone.
But be sure to compare mileage ratings: A hybrid SUV may get fewer miles to the gallon than a compact car running on a conventional engine alone.
The Climate Benefits of Electric Cars
Fueling and driving an electric vehicle generally produces far less carbon dioxide than a car with a conventional engine. That's because across much of the U.S., generating the electricity to charge the car produces less heat-trapping pollution than burning gasoline or diesel.
That said, the mix of fuels powering the electricity grid makes a big difference to the climate impact. For example, California generates less than half of its electricity from fossil fuels. As a result, the average electric car charged in the Golden State is responsible for the same amount of carbon dioxide as a gasoline car getting 109 miles per gallon, according to a Union of Concerned Scientists analysis. In Michigan's Lower Peninsula – where a larger share of electricity is generated from fossil fuels – an average electric car pollutes as much as a gasoline car getting 49 mpg. That's worse for the climate than an electric car fueled in California, but still better than the average new car with an internal combustion engine.
In fact, most U.S. residents now live in a place where electric cars get at least the equivalent of 46 mpg, and often much higher. You can see the mileage estimate for your region here.
When it comes to climate change, an electric car holds another advantage over vehicles with conventional engines: the opportunity to improve if and when the grid reduces its reliance on fossil fuels.
"If you buy a gasoline car, you know, the efficiency is set," said David Reichmuth, an engineer who studies vehicles at the Union of Concerned Scientists. "If anything, it gets a little less efficient, you know, as the car gets older – whereas the electric car could effectively become cleaner over time, not because it becomes more efficient, but because the electricity going into it will become cleaner over time."
How Does Cold Weather Affect Vehicle Efficiency?
Your dealer was correct to say that cold weather reduces the efficiency of hybrid vehicles. But that's not the whole picture. In fact, cold weather causes efficiency to decline in all three kinds of vehicles – hybrid, electric and internal combustion engine. In icy temperatures, vehicle batteries and engines simply don't perform as well as they do in warmer weather, among other factors that drag down efficiency.
According to FuelEconomy.gov, a gasoline car's mileage is 12 to 22% lower at 20 degrees Fahrenheit than at 77 degrees. For hybrids, fuel economy falls by 31 to 34% in cold weather.
But that need not deter you from purchasing a hybrid vehicle – provided you choose one with a high mileage rating. Top-performing hybrids, such as the 2019 Hyundai Ioniq hybrid (58 mpg) and the 2019 Toyota Prius (56 mpg), will likely contribute less to climate change than vehicles with conventional engines, even accounting for cold-weather efficiency declines.
As for electric vehicles, a 2015 paper by Carnegie Mellon researchers found that the range of the Nissan Leaf can drop by as much as 36% in cold climates. Test drives of several electric vehicle models by AAA and Consumer Reports have also found substantial range losses in cold temperatures. So don't miss these tips from Consumer Reports, which advises those living in cold climates to purchase a car with twice the range they expect to use.
But despite Michigan's cold climate, the Carnegie Mellon researchers found that an electric vehicle will still likely pollute less than one with a conventional engine. Taking into account the carbon impact of the regional electricity grid and the diminished performance of electric vehicles in a cold climate, the researchers calculated that a Nissan Leaf driven in Michigan's Lower Peninsula is responsible for roughly 200 grams of carbon dioxide per mile driven. That's about half as much as the average new vehicle, according to this greenhouse gas emissions calculator from the U.S. Department of Energy and the Environmental Protection Agency.
How Manufacturing Affects the Climate Impact of Hybrid and Electric Vehicles
Christina, you've heard that hybrid and electric vehicles consume more resources to manufacture than vehicles with internal combustion engines. It's true that producing hybrid and electric vehicles requires more energy – and associated greenhouse gases – than those with only internal combustion engines. Manufacturing batteries for electric vehicles, in particular, consumes a lot of energy.
However, that does not negate the climate benefits of the vehicles. Calculating the lifetime impact of the vehicles is complex, but various studies suggest that after they hit the road, hybrid and electric vehicles more than make up for their energy-intensive beginnings.
Reichmuth of the Union of Concerned Scientists, an author of one such analysis, said that excess emissions from manufacturing electric vehicles are offset quickly: "As long as the car's driving for more than a couple years, there'd be a net emissions benefit," he said.
The bottom line: Either a hybrid or electric vehicle is likely a better choice for the climate than a vehicle with an internal combustion engine, even in chilly Michigan. But nothing beats avoiding unneeded car trips in the first place, so don't neglect to let your leaders know your thoughts on improving local options for walking, biking and public transit.
– Sara
Top #CleanCars for 2019 and 2020 https://t.co/mQpcdYb6Zg @CoolElectricCar @EV_Research
— EcoWatch (@EcoWatch) May 14, 2019
Wondering how climate change could affect you or your loved ones? Send your questions to sara@yaleclimateconnections.org. Questions may be edited for length and clarity.
Sara Peach is the senior editor of Yale Climate Connections.
Reposted with permission from our media associate Yale Climate Connections.
By Lynne Peeples
Editor's note: This story is part of a nine-month investigation of drinking water contamination across the U.S. The series is supported by funding from the Park Foundation and Water Foundation. Read the launch story, "Thirsting for Solutions," here.
In late September 2020, officials in Wrangell, Alaska, warned residents who were elderly, pregnant or had health problems to avoid drinking the city's tap water — unless they could filter it on their own.
Unintended Consequences
<p>Chemists first discovered disinfection by-products in treated drinking water in the 1970s. The trihalomethanes they found, they determined, had resulted from the reaction of chlorine with natural organic matter. Since then, scientists have identified more than 700 additional disinfection by-products. "And those only represent a portion. We still don't know half of them," says Richardson, whose lab has identified hundreds of disinfection by-products. </p>What’s Regulated and What’s Not?
<p>The U.S. Environmental Protection Agency (EPA) currently regulates 11 disinfection by-products — including a handful of trihalomethanes (THM) and haloacetic acids (HAA). While these represent only a small fraction of all disinfection by-products, EPA aims to use their presence to indicate the presence of other disinfection by-products. "The general idea is if you control THMs and HAAs, you implicitly or by default control everything else as well," says Korshin.</p><p>EPA also requires drinking water facilities to use techniques to reduce the concentration of organic materials before applying disinfectants, and regulates the quantity of disinfectants that systems use. These rules ultimately can help control levels of disinfection by-products in drinking water.</p>Click the image for an interactive version of this chart on the Environmental Working Group website.
<p>Still, some scientists and advocates argue that current regulations do not go far enough to protect the public. Many question whether the government is regulating the right disinfection by-products, and if water systems are doing enough to reduce disinfection by-products. EPA is now seeking public input as it considers potential revisions to regulations, including the possibility of regulating additional by-products. The agency held a <a href="https://www.epa.gov/dwsixyearreview/potential-revisions-microbial-and-disinfection-byproducts-rules" target="_blank">two-day public meeting</a> in October 2020 and plans to hold additional public meetings throughout 2021.</p><p>When EPA set regulations on disinfection by-products between the 1970s and early 2000s, the agency, as well as the scientific community, was primarily focused on by-products of reactions between organics and chlorine — historically the most common drinking water disinfectant. But the science has become increasingly clear that these chlorinated chemicals represent a fraction of the by-product problem.</p><p>For example, bromide or iodide can get caught up in the reaction, too. This is common where seawater penetrates a drinking water source. By itself, bromide is innocuous, says Korshin. "But it is extremely [reactive] with organics," he says. "As bromide levels increase with normal treatment, then concentrations of brominated disinfection by-products will increase quite rapidly."</p><p><a href="https://pubmed.ncbi.nlm.nih.gov/15487777/" target="_blank">Emerging</a> <a href="https://pubs.acs.org/doi/10.1021/acs.est.7b05440" target="_blank" rel="noopener noreferrer">data</a> indicate that brominated and iodinated by-products are potentially more harmful than the regulated by-products.</p><p>Almost half of the U.S. population lives within 50 miles of either the Atlantic or Pacific coasts, where saltwater intrusion can be a problem for drinking water supplies. "In the U.S., the rule of thumb is the closer to the sea, the more bromide you have," says Korshin, noting there are also places where bromide naturally leaches out from the soil. Still, some coastal areas tend to be spared. For example, the city of Seattle's water comes from the mountains, never making contact with seawater and tending to pick up minimal organic matter.</p><p>Hazardous disinfection by-products can also be an issue with desalination for drinking water. "As <a href="https://ensia.com/features/can-saltwater-quench-our-growing-thirst/" target="_blank" rel="noopener noreferrer">desalination</a> practices become more economical, then the issue of controlling bromide becomes quite important," adds Korshin.</p>Other Hot Spots
<p>Coastal areas represent just one type of hot spot for disinfection by-products. Agricultural regions tend to send organic matter — such as fertilizer and animal waste — into waterways. Areas with warmer climates generally have higher levels of natural organic matter. And nearly any urban area can be prone to stormwater runoff or combined sewer overflows, which can contain rainwater as well as untreated human waste, industrial wastewater, hazardous materials and organic debris. These events are especially common along the East Coast, notes Sydney Evans, a science analyst with the nonprofit Environmental Working Group (EWG, a collaborator on <a href="https://ensia.com/ensia-collections/troubled-waters/" target="_blank">this reporting project</a>).</p><p>The only drinking water sources that might be altogether free of disinfection by-products, suggests Richardson, are private wells that are not treated with disinfectants. She used to drink water from her own well. "It was always cold, coming from great depth through clay and granite," she says. "It was fabulous."</p><p>Today, Richardson gets her water from a city system that uses chloramine.</p>Toxic Treadmill
<p>Most community water systems in the U.S. use chlorine for disinfection in their treatment plant. Because disinfectants are needed to prevent bacteria growth as the water travels to the homes at the ends of the distribution lines, sometimes a second round of disinfection is also added in the pipes.</p><p>Here, systems usually opt for either chlorine or chloramine. "Chloramination is more long-lasting and does not form as many disinfection by-products through the system," says Steve Via, director of federal relations at the American Water Works Association. "Some studies show that chloramination may be more protective against organisms that inhabit biofilms such as Legionella."</p>Alternative Approaches
<p>When he moved to the U.S. from Germany, Prasse says he immediately noticed the bad taste of the water. "You can taste the chlorine here. That's not the case in Germany," he says.</p><p>In his home country, water systems use chlorine — if at all — at lower concentrations and at the very end of treatment. In the Netherlands, <a href="https://dwes.copernicus.org/articles/2/1/2009/dwes-2-1-2009.pdf" target="_blank">chlorine isn't used at all</a> as the risks are considered to outweigh the benefits, says Prasse. He notes the challenge in making a convincing connection between exposure to low concentrations of disinfection by-products and health effects, such as cancer, that can occur decades later. In contrast, exposure to a pathogen can make someone sick very quickly.</p><p>But many countries in Europe have not waited for proof and have taken a precautionary approach to reduce potential risk. The emphasis there is on alternative approaches for primary disinfection such as ozone or <a href="https://www.pbs.org/wgbh/nova/article/eco-friendly-way-disinfect-water-using-light/" target="_blank" rel="noopener noreferrer">ultraviolet light</a>. Reverse osmosis is among the "high-end" options, used to remove organic and inorganics from the water. While expensive, says Prasse, the method of forcing water through a semipermeable membrane is growing in popularity for systems that want to reuse wastewater for drinking water purposes.</p><p>Remucal notes that some treatment technologies may be good at removing a particular type of contaminant while being ineffective at removing another. "We need to think about the whole soup when we think about treatment," she says. What's more, Remucal explains, the mixture of contaminants may impact the body differently than any one chemical on its own. </p><p>Richardson's preferred treatment method is filtering the water with granulated activated carbon, followed by a low dose of chlorine.</p><p>Granulated activated carbon is essentially the same stuff that's in a household filter. (EWG recommends that consumers use a <a href="https://www.ewg.org/tapwater/reviewed-disinfection-byproducts.php#:~:text=EWG%20recommends%20using%20a%20home,as%20trihalomethanes%20and%20haloacetic%20acids." target="_blank" rel="noopener noreferrer">countertop carbon filter</a> to reduce levels of disinfection by-products.) While such a filter "would remove disinfection by-products after they're formed, in the plant they remove precursors before they form by-products," explains Richardson. She coauthored a <a href="https://pubs.acs.org/doi/10.1021/acs.est.9b00023" target="_blank" rel="noopener noreferrer">2019 paper</a> that concluded the treatment method is effective in reducing a wide range of regulated and unregulated disinfection by-products.</p><br>Greater Cincinnati Water Works installed a granulated activated carbon system in 1992, and is still one of relatively few full-scale plants that uses the technology. Courtesy of Greater Cincinnati Water Works.
<p>Despite the technology and its benefits being known for decades, relatively few full-scale plants use granulated active carbon. They often cite its high cost, Richardson says. "They say that, but the city of Cincinnati [Ohio] has not gone bankrupt using it," she says. "So, I'm not buying that argument anymore."</p><p>Greater Cincinnati Water Works installed a granulated activated carbon system in 1992. On a video call in December, Jeff Swertfeger, the superintendent of Greater Cincinnati Water Works, poured grains of what looks like black sand out of a glass tube and into his hand. It was actually crushed coal that has been baked in a furnace. Under a microscope, each grain looks like a sponge, said Swertfeger. When water passes over the carbon grains, he explained, open tunnels and pores provide extensive surface area to absorb contaminants.</p><p>While the granulated activated carbon initially was installed to address chemical spills and other industrial contamination concerns in the Ohio River, Cincinnati's main drinking water source, Swertfeger notes that the substance has turned out to "remove a lot of other stuff, too," including <a href="https://ensia.com/features/drinking-water-contamination-pfas-health/" target="_blank" rel="noopener noreferrer">PFAS</a> and disinfection by-product precursors.</p><p>"We use about one-third the amount of chlorine as we did before. It smells and tastes a lot better," he says. "The use of granulated activated carbon has resulted in lower disinfection by-products across the board."</p><p>Richardson is optimistic about being able to reduce risks from disinfection by-products in the future. "If we're smart, we can still kill those pathogens and lower our chemical disinfection by-product exposure at the same time," she says.</p><p><em>Reposted with permission from </em><em><a href="https://ensia.com/features/drinking-water-disinfection-byproducts-pathogens/" target="_blank">Ensia</a>. </em><a href="https://www.ecowatch.com/r/entryeditor/2649953730#/" target="_self"></a></p>EcoWatch Daily Newsletter
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Earth had its second-warmest year on record in 2020, just 0.02 degrees Celsius (0.04°F) behind the record set in 2016, and 0.98 degrees Celsius (1.76°F) above the 20th-century average, NOAA reported January 14.
Figure 1. Departure of temperature from average for 2020, the second-warmest year the globe has seen since record-keeping began in 1880, according to NOAA. Record-high annual temperatures over land and ocean surfaces were measured across parts of Europe, Asia, southern North America, South America, and across parts of the Atlantic, Indian, and Pacific oceans. No land or ocean areas were record cold for the year. NOAA National Centers for Environmental Information
Figure 2. Total ocean heat content (OHC) in the top 2000 meters from 1958-2020. Cheng et al., Upper Ocean Temperatures Hit Record High in 2020, Advances in Atmospheric Sciences
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