A new study concludes that fossil fuel emissions are likely contributors to a substantial amount of organic carbon found on glaciers in Alaska.
Fossil fuel emissions, which contain organic carbon, can speed up the rate of glacier melt when deposited on glacier surfaces. In addition, the organic molecules associated with these deposits can be transported in rivers and streams, affecting downstream aquatic ecosystems. Knowledge of the source and age of organic carbon in glaciers allows for a better understanding of these and other impacts.
Prior research suggested that the main sources of organic carbon in Alaska's glaciers were from forests and peatlands overrun by glaciers as far back as ten thousand years ago. While old soil and plant material are still possible sources of glacial organic carbon, new research indicates that human-created, or anthropogenic, sources are also important.
"We knew the organic carbon present in Alaska's glaciers was old, but identifying the sources of this material has been difficult due to the lack of chemical data,"ˇ said U.S. Geological Survey (USGS) scientist George Aiken.
While extensive burning of fossil fuels is, geologically speaking, a relatively modern practice, the fuels themselves and the resulting carbon emissions are ancient. This is because the fuels are formed from plants and microorganisms that lived millions of years ago.
"Now we know that a substantial amount of ancient organic matter associated with these and other glaciers is of anthropogenic origin," said Aiken.
Why Study Carbon Levels?
When organic matter and other materials from the atmosphere are deposited on the surface of a glacier, less sunlight can be reflected and, therefore, more radiation and heat are absorbed. Having these materials on snow and ice surfaces causes them to melt faster.
Another concern is impacts to ecosystems and species habitats. As an example, organic matter exported to coastal areas is a potential nutrient or food source for aquatic bacteria, phytoplankton, and small grazing zooplankton. Climate warming or other factors may change the amount and quality of organic carbon available to these organisms. These aquatic organisms are also the base of the food web for all aquatic communities.
"When trying to understand climate change and decipher the carbon cycle puzzle, we need to make sure that we are using all of the right pieces," said USGS scientist Rob Striegl. "As part of that puzzle, we are studying the source and amount of carbon flowing into the Arctic Ocean. An understanding of the complete picture allows for the most informed decisions to protect our environment."
"The Arctic is of special interest because what happens there, such as extensive glacier melt, has impacts on the rest of the world," said Striegl. "Glacier environments, especially those in the high latitudes of the Arctic, are also among the most sensitive to climate warming."
New Twist to Understanding Carbon in Glaciers
"Our new paper describes, for the first time, the detailed chemical composition of dissolved organic matter associated with glaciers and glacial meltwater in coastal Alaska and in Wyoming," said Aiken.
"This study adds a twist to previous understandings, showing there is another source of organic carbon out there that needs to be considered," said Striegl.
This study, published in the journal Nature Geosciences, was a collaborative effort of many institutions led primarily by the University of Alaska Southeast, Skidaway Institute of Oceanography, Woods Hole Research Center, and the USGS.
The Role of USGS Science
Earlier studies by the USGS, in collaboration with university researchers, found the presence of ancient organic carbon in the Yukon River and traced it back to meltwater from glaciers. For further analyses, USGS scientists continued those collaborations to sample meltwater from Mendenhall Glacier and Herbert Glacier in southeastern Alaska. The samples were then analyzed at USGS and university laboratories to develop the conclusions outlined in this new study.
"This truly is a collaborative effort, taking the expertise of many scientists to put the story together on the source of the carbon,"ˇ said Striegl. "The original work of the USGS in the Yukon basin helped form the questions and lab results contributed to answering the questions; but it took specialized instrumentation and scientific expertise from several other organizations to determine the final answer."
Additional samples used for age dating and for other chemical characterization of the organic carbon of glaciers from other locations came from Gulkana Glacier in Alaska and from Fremont Glacier in Wyoming.
The Big Picture of Aquatic Carbon
The USGS has a long term goal of determining the source and fate of organic and inorganic carbon transported to coastal areas and oceans across the entire Nation. USGS research on the Yukon and other Arctic rivers is particularly focused on climate warming effects on mobilizing ancient carbon from permafrost to coastal regions and the Arctic Ocean. The USGS participates in the Arctic Great Rivers Observatory project, which is an international effort to study the six largest rivers, including the Yukon, which flow into the Arctic Ocean.
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EcoWatch Daily Newsletter
By Alexandra Rowles
Oregano is a fragrant herb that's best known as an ingredient in Italian food.
However, it can also be concentrated into an essential oil that's loaded with antioxidants and powerful compounds that have proven health benefits.
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By Emily Grubert
Natural gas is a versatile fossil fuel that accounts for about a third of U.S. energy use. Although it produces fewer greenhouse gas emissions and other pollutants than coal or oil, natural gas is a major contributor to climate change, an urgent global problem. Reducing emissions from the natural gas system is especially challenging because natural gas is used roughly equally for electricity, heating, and industrial applications.
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What RNG Is and Why it Matters<p>Most equipment that uses energy can only use a single kind of fuel, but the fuel might come from different resources. For example, you can't charge your computer with gasoline, but it can run on electricity generated from coal, natural gas or solar power.</p><p>Natural gas is almost pure methane, <a href="https://www.eia.gov/energyexplained/natural-gas/" target="_blank">currently sourced</a> from raw, fossil natural gas produced from <a href="https://www.eia.gov/energyexplained/natural-gas/where-our-natural-gas-comes-from.php" target="_blank">deposits deep underground</a>. But methane could come from renewable resources, too.</p><p><span></span>Two main methane sources could be used to make RNG. First is <a href="https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks" target="_blank">biogenic methane</a>, produced by bacteria that digest organic materials in manure, landfills and wastewater. Wastewater treatment plants, landfills and dairy farms have captured and used biogenic methane as an energy resource for <a href="http://emilygrubert.org/wp-content/uploads/2019/02/eia_860_2017_map.html" target="_blank">decades</a>, in a form usually called <a href="https://www.eia.gov/energyexplained/biomass/landfill-gas-and-biogas.php" target="_blank">biogas</a>.</p><p>Some biogenic methane is generated naturally when organic materials break down without oxygen. Burning it for energy can be beneficial for the climate if doing so prevents methane from escaping to the atmosphere.</p>
Renewable Isn’t Always Sustainable<p>If RNG could be a renewable replacement for fossil natural gas, why not move ahead? Consumers have shown that they are <a href="https://www.nrel.gov/analysis/green-power.html" target="_blank">willing to buy renewable electricity</a>, so we might expect similar enthusiasm for RNG.</p><p>The key issue is that methane isn't just a fuel – it's also a <a href="https://www.eia.gov/environment/emissions/ghg_report/ghg_overview.php" target="_blank">potent greenhouse gas</a> that contributes to climate change. Any methane that is manufactured intentionally, whether from biogenic or other sources, will contribute to climate change if it enters the atmosphere.</p><p>And <a href="http://doi.org/10.1126/science.aar7204" target="_blank">releases</a> <a href="https://doi.org/10.1016/j.wasman.2019.07.029" target="_blank">will happen</a>, from newly built production systems and <a href="https://theconversation.com/why-methane-emissions-matter-to-climate-change-5-questions-answered-122684" target="_blank">existing, leaky transportation and user infrastructure</a>. For example, the moment you smell gas before the pilot light on a stove lights the ring? That's methane leakage, and it contributes to climate change.</p><p>To be clear, RNG is almost certainly better for the climate than fossil natural gas because byproducts of burning RNG won't contribute to climate change. But doing somewhat better than existing systems is no longer enough to respond to the <a href="https://doi.org/10.1038/nclimate2923" target="_blank">urgency</a> of climate change. The world's <a href="https://www.ipcc.ch/sr15/chapter/spm/" target="_blank">primary international body on climate change</a> suggests we need to decarbonize by 2030 to mitigate the worst effects of climate change.</p>
Scant Climate Benefits<p><a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab9335/meta" target="_blank">My recent research</a> suggests that for a system large enough to displace a lot of fossil natural gas, RNG is probably not as good for the climate as <a href="https://investor.southerncompany.com/information-for-investors/latest-news/latest-news-releases/press-release-details/2020/Southern-Company-Gas-grows-leadership-team-to-focus-on-climate-action-innovation-and-renewable-natural-gas-strategy/default.aspx" target="_blank">is publicly claimed</a>. Although RNG has lower climate impact than its fossil counterpart, likely high demand and methane leakage mean that it probably will contribute to climate change. In contrast, renewable sources such as wind and solar energy do not <a href="https://www.eia.gov/environment/emissions/carbon/" target="_blank">emit climate pollution directly</a>.</p><p>What's more, creating a large RNG system would require building mostly new production infrastructure, since RNG comes from different sources than fossil natural gas. Such investments are both long-term commitments and opportunity costs. They would devote money, political will and infrastructure investments to RNG instead of alternatives that could achieve a zero greenhouse gas emission goal.</p><p>When climate change first <a href="https://www.nytimes.com/1988/06/24/us/global-warming-has-begun-expert-tells-senate.html" target="_blank">broke into the political conversation</a> in the late 1980s, investing in long-lived systems with low but non-zero greenhouse gas emissions was still compatible with aggressive climate goals. Now, zero greenhouse gas emissions is the target, and my research suggests that large deployments of RNG likely won't meet that goal.</p>
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The U.S. Environmental Protection Agency (EPA) recently issued a list of 431 products that are effective at killing viruses when they are on surfaces. Now, a good year for Lysol manufacturer Reckitt Benckiser just got better when the EPA said that two Lysol products are among the products that can kill the novel coronavirus that causes COVID-19.
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For all its posturing on climate change, the Democratic Party has long been weak on the actual policies we need to save us from extinction. President Barack Obama promised his presidency would mark "the moment when the rise of the oceans began to slow," and then embraced natural gas, a major driver of global temperature rise, as a "bridge fuel." Climate legislation passed in the House in 2009 would have allowed industries to buy credits to pollute, a practice known to concentrate toxic air in black and brown neighborhoods while doing little to cut emissions.
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By Charli Shield
When an elephant dies in the wild, it's not uncommon to later find its bones scattered throughout the surrounding landscape.
Elephant Burial Grounds<p>Highly social creatures that form deep familial bonds, elephants have long been observed gathering at the site where a peer or family member has died — often spending hours, even days, quietly investigating the bodies or the bones of other dead elephants.</p><p>Although the popular idea that dying elephants are instinctively drawn to special communal graves — so-called "elephant graveyards" — is a myth, their tendency to go out of their way to visit the bones and tusks of the deceased isn't unlike human rituals at graveyards, says animal psychologist Karen McComb.</p><p>"They spend a lot of time touching and smelling skulls and ivory, placing the soles of their feet gently on top of them, and also lifting them up with their trunks," McComb, who's been studying African elephants for 25 years in Kenya's Amboseli National Park, told DW.</p><p>The most striking part of watching an elephant experience loss, Poole recalls, is the quietude. She still remembers one of the first elephant deaths she witnessed; a mother who birthed a stillborn calf. That elephant stayed with its baby for two days, trying to lift it and defending it from vultures and hyenas.</p><p>"I was so struck by the expression on her face and her body. She looked so dejected. It was really like, 'Oh God, these animals grieve…'. It was just so different," Poole told DW. </p>
Witnessing Emotions in Animals<p>Not all scientists are comfortable concluding that elephants grieve. Among the more than 30 reports of elephant reactions to death that Wittemyer co-reviewed in <a href="https://link.springer.com/article/10.1007/s10329-019-00766-5" target="_blank">a study published in November 2019</a> were accounts of "enormous variation and nuance" he says. "It can be incredibly involved and intricate for extended periods or can be relatively cursory checks."</p><p>In Wittemyer's own experience, it can be difficult not to attribute some kind of emotional experience to the more involved interactions between elephants and their dead.</p><p>He shares the story of an "extraordinary event" involving the death of a 55 year-old matriarch in Kenya in a protected area that happened to be near his place of work. She was visited by multiple unrelated families while she was dying, including another matriarch that exerted such enormous effort attempting to lift her to her feet that she broke her tusk, which Wittemyer says, is "like breaking a tooth." </p><p><span></span>"It was a remarkable example of this heightened emotional state, it was very clearly a very stressful interaction," he says.</p>
A Different Sensory World<p>One factor that limits our ability to fully grasp the way elephants process and respond to loss is our markedly different sensory experiences of the world.</p><p>An elephant's world is fundamentally olfactory — based on smell. Ours is visual. Previous <a href="https://pubmed.ncbi.nlm.nih.gov/25053675/" target="_blank">research</a> has shown elephants possess the most scent receptors of any mammal, and can <a href="https://pubmed.ncbi.nlm.nih.gov/17949977/" target="_blank">use smell</a> to discern the difference between different human tribes from the same local area.</p><p>That could explain why elephants exhibit such interest in sniffing the bones and tusks of others, as a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1617198/" target="_blank">2005 study</a> from McCombs highlighted. When presented with the skulls and ivory of long-dead elephants and those from other large herbivores, including rhino and buffalo, McCombs and her team found elephants approached and were specifically attracted to the remains of their own species. </p><p>Without access to the smells an elephant picks up on, Wittemyer says "an enormous amount of stuff" could be missed by humans when studying these behaviors.</p>
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