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By Gero Rueter
Heating with coal, oil and natural gas accounts for around a quarter of global greenhouse gas emissions. But that's something we can change, says Wolfgang Feist, founder of the Passive House Institute in the western German city of Darmstadt.
"Buildings can be powered in a climate-neutral way, and that's possible worldwide with renewable energies," he told DW, adding that a crucial factor is to make buildings more efficient so no energy is wasted.
"With good insulation and ventilation systems, it's possible to achieve energy savings — compared to conventional buildings — of 80-90% in new buildings and 75-80% through energy-efficient renovation in old buildings."
The remaining demand could then be met with a mix of renewable energies. And this combination can vary, depending on the region, says Feist, who is a professor of physics and a pioneer of efficient construction methods.
"I see district heating with renewable energies, and heating with ambient heat and heat pumps as important sources here," he says.
The use of wood or wooden pellets is another way of meeting the heating needs of individual buildings, Feist says, adding however that this is "not a sensible option" for entire cities or industries because it's not sustainable and would create excessive demand for biomass.
Germany's financial capital has big environmental plans.
Frankfurt Strives for Climate Neutrality
The German city of Frankfurt is aiming to become climate neutral by 2050. In order to reach that goal, the financial hub is relying on a range of technologies, says Paul Fay from the city's energy department, who is coordinating the transition. With help from scientists, the city has drawn up a master plan that includes passive houses and energy-efficient refurbishments on older structures.
Solar panels on the roofs of Frankfurt's buildings will generate some of the city's thermal energy. Another share will come from heating pipelines serving the city's districts, where warmth will be created by burning waste and wood, or through waste heat from data centers. Ambient energy from the ground can also be harnessed with the help of heat pumps.
How Does a Heat Pump Work?
In theory, a heat pump works like a refrigerator — within a closed, multistage system, heat is generated in a compressor, while cool air is created in an evaporator.
A liquid coolant extracts heat from the environment to warm buildings or water. The heat pump takes energy from the ground, groundwater or air.
Heat pumps need electricity as their operating energy, and how well they perform depends mainly on the heat source.
"We examined 60 heat pump systems in older buildings in Germany," says Marek Miara, a researcher at the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg.
"Heat pumps in older buildings that use air as a heat source generate an average of around 3 kilowatt-hours of heat from 1 kilowatt of electricity. And heat pumps using groundwater and soil as heat sources generate on average 3.9 times as much heat," Miara told DW, adding that systems in new buildings are generally more efficient.
Growth in Key Technologies
Heat pumps are a core component of plans for climate-neutral energy and heating in the future, and the technology is increasingly replacing fossil fuel-powered heating systems around the world.
"We're seeing a very positive global trend," says Thomas Nowak from the lobby organization the European Heat Pump Association (EHPA). "We're experiencing a golden age for heat pumps, it's becoming a mass market."
According to an EHPA report, 18 million heat pumps were sold worldwide in 2018 — 1.3 million of them in Europe. Global sales are growing by 10% each year, the report said.
Heating With Less CO2
Heat pumps have proven extremely popular in Europe, especially in Scandinavian nations. Electricity in these countries is already generated mainly by climate-friendly wind and hydropower. According to calculations by Fraunhofer ISE, heat pump systems in Sweden generate 90% fewer carbon emissions than heating systems that rely on natural gas.
Many countries in the European Union and other parts of the world still get much of their electricity from coal and gas. But according to calculations by Fraunhofer researchers, heat pumps there would also be a more environmentally friendly option than heating with natural gas. Across the EU, using heat pumps would result in an average CO2 saving of around 60% compared to natural gas. In Germany, the saving would be around 30%, the Fraunhofer researchers say.
If electricity continues to become more climate friendly through the expansion of wind and solar power, as is currently the case in Germany, CO2 savings from heat pump systems will only keep growing. And if the pumps' operating power comes from 100% renewables, then this heating technology becomes climate neutral.
Heating Transformation Needs Policy
Energy and building experts agree that making the switch to climate-neutral heating in all buildings and industries worldwide is certainly possible.
The Swiss city of Schaffhausen is among the growing number of municipalities using heat pump technology.
Experts and environmentalists are calling for a ban on the installation of new polluting heating systems.
"However, there is still a need for more training," says Andreas Nordhoff, a consultant for passive house technology who also trains people in the construction industry. "Craftsmen, architects and building owners often lack knowledge about how everything can be optimally coordinated, and how much energy and money can be saved," he says.
Politics also has an important role to play in establishing a climate-friendly heat supply.
"What we need now is a ban on new oil heating systems. These are particularly harmful to the climate, so new installations should be prohibited from now on," says Nicolas Besser, project manager for energy and climate protection at the German environmental organization Deutsche Umwelthilfe (DUH).
"Natural gas heating systems are more climate friendly compared to oil heating, but they're still harmful. That's why we also need a ban on installing them from 2025," Besser says.
In order to reach climate targets set out in the Paris agreement, DUH is calling for an emergency climate protection program for buildings. They want to see funding put towards renovating structures, expanding municipal heating networks and accelerating the phaseout of oil and gas heating.
Reposted with permission from DW.
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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>At a time of impending global food scarcity, cell-based meats and seafood have been heralded as the future of food.
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One city in New Zealand knows what its priorities are.
Dunedin, the second largest city on New Zealand's South Island, has closed a popular road to protect a mother sea lion and her pup, The Guardian reported.
piyaset / iStock / Getty Images Plus
In an alarming new study, scientists found that climate change is already harming children's diets.
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By Jeff Masters, Ph.D.
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
Figure 3. Departure of sea surface temperature from average in the benchmark Niño 3.4 region of the eastern tropical Pacific (5°N-5°S, 170°W-120°W). Sea surface temperature were approximately one degree Celsius below average over the past month, characteristic of moderate La Niña conditions. Tropical Tidbits
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