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Wednesday, June 22, 2022

Yellowstone flooding underscores environmental pressures facing US national parks

by Paul McQuiston, University of Southern California

America's national parks are in crisis, and the environmental disaster unfolding at Yellowstone National Park is the latest example of extreme weather driven by climate change battering parkland.

Glacier National Park in Montana is also experiencing severe flooding, in addition to the severe diminishment of the park's 26 named glaciers—some by as much as 80%. THIS PARK IS SHARED CANADA'S WITH WATERTON NATIONAL PARK

The unpredictability caused by climate change adds a further challenge as predictive models become increasingly irrelevant, causing delays in planning and resource allocation.

The U.S. national parks are a passion for Douglas Noble, associate dean for academic affairs at the USC School of Architecture. He credits a childhood spent visiting the parks as a Boy Scout for cultivating his love of America's wilderness. This spring, he and faculty across USC introduced a new interdisciplinary course, "An Exploration of America's National Parks," that centers on how humans interact with the national parks. We spoke with Noble about the flooding at Yellowstone, how climate change affects our national parks and his favorite national park.

What does the situation with Yellowstone flooding tell us about how climate change is affecting the national parks system?

The climate conditions are really troubling. It's not so much that it's warmer—people will say, "Oh, it's only 2 degrees warmer, what possible harm could that cause?" First off, 2 degrees centigrade is a big jump. It also changes the kind of things that can live or adapt to be there. It also changes migratory patterns. Water access in some places will dry up, and the lifeforms that lived where a tiny creek or pond used to be can no longer survive.

Yellowstone is a water-based place. Old Faithful, for instance: If you visit, there's a chalkboard that says how often it will erupt—usually around 55–65 minutes—and they're usually accurate to within a minute. But what happens when the conditions have changed? If there's more water? What if there's less? What has been a fairly predictable phenomenon now becomes an unknown. Maybe it erupts twice as often, or maybe it stops altogether. That's all to say we no longer can entirely know what's going to happen because the conditions have changed.

What is the impact of this unpredictability?

If you know what's going to happen in a climate, whether it's hot or cold, then you can make confident personnel and resource decisions to maintain the parks. There are impacts on tourism and agriculture—you know that based off predictive weather models that the last frost will take place after such-and-such date. If suddenly it's less predictable, there might be another frost later in the season, it could be warmer, it stops raining sooner or it might rain a lot harder. I'm a lot happier when things are just like last year—even if last year there was a week in the summer where it was too hot in L.A.—because I know that if we do the same as last year, we know how it works and we know what the impact is going to be.

In what other ways is climate change affecting the national parks?

Not long ago the biggest challenges were wildfires and, again, it goes back to climate change. Part of it was direct impacts—the fires wiping out vast chunks of forests—but it also affected the management strategies in place. Now we look back and say, "OK, maybe that was not a great strategy putting out all fires" because the amount of debris and dead stuff piled up. Where there had been a fire here and there to clear that debris, once we began putting out every single fire the amount of dead stuff really begins to pile up. Now when it catches fire, instead of 1,000 little fires, you get a really big one and the really big ones act a lot differently.

Glacier National Park has a rough idea when the last glacier will finally melt down. They can tell you how many there used to be just a few years ago, and how many there are now—the number is fewer and they're smaller. In some cases, a lot smaller and they keep shrinking. How much longer do they have? It's decades, not centuries.

What's your favorite national park?

I always answer that question by saying that it changes every time someone asks. There are 63 that many people think of as the so-called "regular" national parks, and almost 450 National Park [Service] units, including national battlefield parks, national historic sites, national monuments and others. Some are like Yellowstone that are large, and then there are others where something culturally important took place. I'm going to Joshua Tree this weekend, so maybe that is my favorite today. Climate change is being felt there, too. There are a small number of oases in the park—one of the most famous is the Oasis of Mara, which has been used by civilizations for millennia. There are six oases in a park nearly the size of Rhode Island, so these are rare treasures. Now the water table has fallen so much that the Oasis of Mara would die without human intervention. We're keeping it alive in the hopes that things will change for the better.

Yellowstone Park closed as swollen river destroys roads

Provided by University of Southern California

Modern wind turbines can more than compensate for decline in global wind resource

by University of Freiburg

wind power — Credit: Pixabay/CC0 Public Domain

Wind energy contributes significantly to the energy sector's sustainable, low-CO2 transformation. However, the efficiency of wind turbines depends on available wind resources and the technical characteristics of the turbines. Climate change, of all things, is causing the global wind resource to diminish in the 21st century. At the same time, the technical properties of wind turbines are steadily improving.

Based on global climate models and newly developed techno-projections, researchers Dr. Christopher Jung and Prof. Dr. Dirk Schindler were able to estimate these two opposing influencing factors and calculate their impact on the global and regional efficiency of wind turbines by 2060. One finding is that the efficiency of the global wind turbine fleet could increase by as much as 23.5% by 2035, assuming favorable climate trends, if the use of wind energy were optimized. The findings of the two scientists from the Institute of Earth and Environmental Sciences at the University of Freiburg were published in the journal Nature Energy.

High spatial resolution

The calculations of the two researchers provide an important basis for the future global expansion potential of wind energy. In their study, they identify accessible regions where wind resources can be used most efficiently under future climate conditions. The approach enables the determination of the best locations worldwide with particularly high spatial resolution for individual wind turbines and wind farms.

"What was surprising was the low impact of climate change on the wind resource compared to the projected technical development of wind turbines," says Jung. Thus, the climate change-induced decline in the wind resource can be more than offset with modernization of the wind turbine fleet. Also more significant than the overall impact of climate change on usable wind are fluctuations in resource availability between individual years.Offshore wind farms could disturb marine mammal behavior

More information: Christopher Jung et al, Development of onshore wind turbine fleet counteracts climate change-induced reduction in global capacity factor, Nature Energy (2022). DOI: 10.1038/s41560-022-01056-z
Journal information: Nature Energy

Provided by University of Freiburg

How keeping trees when clearing pastures could reduce climate consequences

by University of New Hampshire

farmer field — Credit: CC0 Public Domain

Land use change, like cutting down a forest to make way for agriculture, can be a major contributor to climate change by releasing greenhouse gases into the atmosphere. Researchers at the University of New Hampshire studied a practice known as silvopasture which intentionally preserves trees in pastures where livestock graze. They found that compared to a completely cleared, tree-less, open pasture, the integrated silvopasture released lower levels of carbon dioxide and nitrous oxide and soil carbon storage remained the same, offering a possible alternative for farmers with less climate consequences.

"We talked to a lot of farmers in the Northeast who are interested in the silvopasture approach but there aren't a lot of data to help guide them through implementation, and responsible and strategic management," said Alexandra Contosta, research assistant professor at UNH's Earth Systems Research Center. "We wanted to see if silvopastures made a difference and found that there are benefits to this approach that could help both the farmer and the planet."

In their study, published in the journal Agriculture, Ecosystems & Environment, researchers conducted land use change experiments in both New Hampshire and New York. In both locations, the land was divided into plots with a reference forest, open pasture and silvopasture. In the silvopasture plots, trees were thinned by 50 to 60% and tree stumps were left in place. Orchard grass, white clover and other foraging sources were planted.

After the seeding, either dairy or beef cows were introduced. The team set up meteorological stations in each of the experimental areas, known as treatments, and monitored emissions of carbon dioxide, nitrous oxide and soil carbon storage. The researchers found that the silvopasture offered a reduction in the climate consequences of a typical forest clearing to open pasture, and the climate regulating benefits of silvopasture extended to soil greenhouse gas emissions. However, they did not find any difference in air temperatures between the plots and were not able to document any changes in soil carbon storage among different land use change treatments.

"New England has a lot of trees which can reduce our options for agriculture and our ability to produce our own food," said Contosta. "So, what is exciting about this study is that it shows silvopasture could be a viable alternative that is also more climate conscious."

The researchers say that ultimately their study highlights the need to better understand how silvopasture can improve the negative climate consequences of forest clearing for agriculture and has implications for the Northeast and other temperate, forested regions across the globe.Silvopasture could tackle Colombian Amazon's high deforestation rates and help achieve COP26 targets

More information: Alexandra R. Contosta et al, Climate consequences of temperate forest conversion to open pasture or silvopasture, Agriculture, Ecosystems & Environment (2022). DOI: 10.1016/j.agee.2022.107972

Provided by University of New Hampshire

ICYMI

The Amazon rainforest is disappearing quickly and threatening Indigenous people who live there

by Félix Bhérer-Magnan, The Conversation

Forests throughout the world are shrinking year after year—and Brazil is the epicenter. According to the World Wildlife Fund, more than a quarter of the Amazon rainforest will be devoid of trees by 2030 if cutting continues at the same speed

If nothing is done to stop it, an estimated 40% of this unique forest will be razed by 2050.

Beyond the material and environmental consequences, this deforestation also threatens human rights, including the rights of marginalized communities to life, physical integrity, a reasonable quality of life and dignity. Brazil is one of the most worrying cases in this regard.

As a Ph.D. student in political science, my research interests include climate justice, the energy transition, the green economy and international environmental politics.

Chainsaw massacre

Article 25 of the United Nations Declaration on the Rights of Indigenous Peoples rules that these communities fully possess the "the right to maintain and strengthen their distinctive spiritual relationship with their traditionally owned or otherwise occupied and used lands, territories, waters and coastal seas and other resources."

This article is not being respected by the Brazilian government in the Amazon.

Although the country had pledged to significantly reduce deforestation and limit clear-cutting to 3,925 square kilometers, data from Human Rights Watch shows that chainsaws have razed nearly 13,000 square kilometers of tropical forests, making communities of Indigenous peoples even more vulnerable.

The rate of deforestation in these territories increased by 34% between 2018 and 2019, despite Brazil's commitment in 2009 to reduce it by 80%. This has led to the forced displacement of communities over hundreds of kilometers, as well as major health problems and a loss of reference points. According to Human Rights Watch, nearly 13,235 square kilometers of the Amazon rainforest was clear cut between August 2020 and July 2021, an 22% increase, compared to the same period in the previous year.

This coincides with Jair Bolsonaro's accession to power. In the month of January 2022 alone, 430 square kilometers of tropical forest was destroyed, five times more than in January 2021.

Threats and assassinations

Multiple abuses have been documented in Brazil since the beginning of colonization, including the illegal encroachment of the Brazilian state on Indigenous territories. Under Bolsonaro, the number of criminal networks contributing to the deforestation of the Amazon has multiplied. Organized crime views the large timber and agriculture industries as opportunities to move and launder money. The groups illegally exploit forest land, then hide drugs in timber shipments destined for Europe or Asia.

Experts qualify this illegal activity as "narco-deforestation." Numerous illegal gold and mineral extraction sites are also operating in the Amazon, and the companies running them often make threats to the Munduruku that live there.

People and activists who have protested the ongoing deforestation have been threatened, harassed and killed. In 2019, the NGO Global Witness recorded 24 deaths of environmental activists and land defenders, almost all occurring in the Amazon. This puts Brazil in third place among the countries with the highest number of deaths of environmental defenders, after Colombia and the Philippines.

There are reminders of this in the news. Bruno Araujo Pereira, a defender of environmental and Indigenous rights, and British journalist Dom Phillips have been missing since June 5, in an area called the Javari Valley, which has a reputation of being "lawless."

According to a local organization, the two had received death threats shortly before disappearing. Brazilian police first said search teams had discovered their belongings and later that bodies were spotted in the area of their disappearance. Police reported on June 15 they had found human remains while searching for the pair and that a fisherman who had fought with the pair had confessed to their killing.

The number of deaths of people involved in environmental and territorial defense may be greatly underestimated, as data are not available and transparent for all countries.

Women and children, the main victims of deforestation

A recent United Nations report reveals a strong correlation between worsening climate change and deteriorating human rights around the world.

Deforestation disproportionately affects Indigenous communities, especially women and children. It increases the pressure already placed on women to feed their children and families, while limiting their access to essential goods, including medicine.

Indeed, the health of these communities depends on access to natural medicinal products found in biodiversity. The Amazon is a major reservoir of substances used in the manufacture of several pharmaceutical products available on the South American continent.

Nearly 80% of the population in developing countries relies on natural medicinal products for their primary health care. In the majority of communities, it is also women who are responsible for cultivating the land and providing transportation and water treatment.

Children are equally at risk. For example, a study conducted in sub-Saharan African countries shows a link between the loss of forest cover and the deterioration of health conditions of the youngest. Malnutrition, caused by reduced availability of fruits, vegetables and nuts, can affect children's growth. The exposure to smoke from the multiple fires in the Amazon is also likely to cause respiratory problems and even more serious conditions in children.

More farming, more deforestation

Deforestation in Brazil offers a preview of the impact that climate change will have on human rights, both in Latin America and elsewhere in the world. In addition, due to the war in Ukraine, Brazil is looking to fill the food gap on world markets with crops such as wheat and grain.

Brazil's contribution is appreciated by countries such as Sudan, Pakistan and Haiti, which are among those most affected by the food crisis. But increased production may dangerously accelerate deforestation and human rights abuses can be expected to increase.

One thing is certain, one of the lungs of our planet is seriously ill and time is running out.

Amazon deforestation hits monthly record in Brazil

Provided by The Conversation

India's rejection of global environment report 'perilous'

by SciDev.Net

The principal investigator of a key environmental report that ranked India as the least environmentally sustainable country in the world has criticized the country's dismissal of the findings.

Reacting to India's rejection of the Environmental Performance Index (EPI) 2022, Martin Wolf said that "flatly rejecting data that underscores the severity of environmental issues is unproductive and perilous." He urged policymakers instead to use the findings to put the country back on track to a more sustainable future.

The EPI 2022 report, produced by Yale and Columbia universities and released on the World Environment Day (5 June), assessed and ranked 180 countries on 40 performance indicators covering climate change, environmental public health and ecosystem vitality.

India ranked last in the report and was categorized as the least environmentally sustainable country. Its close neighbors—Bangladesh, Bhutan, Nepal and Pakistan—have all scored better than India.

The indicators provide a gauge at a national scale of how close countries are to established environmental policy targets. A brief about the report on Yale University's website offers a scorecard that highlights "leaders and laggards" in environmental performance and provides practical guidance for countries that aspire to move toward a sustainable future.

According to the EPI report summary, high-scoring countries exhibit longstanding and continuing investments in policies that protect environmental health, preserve biodiversity and habitat, conserve natural resources, and decouple greenhouse gas emissions from economic growth.

Denmark tops the 2022 rankings—an achievement rooted in strong performance across nearly all issues tracked by the EPI, with notable leadership in efforts to promote a clean energy future and sustainable agriculture. The U.K. and Finland, placed second and third in the rankings, have earned high scores for slashing greenhouse gas emissions.

The U.S. is ranked 20th among 22 wealthy democracies and 43rd overall. This relatively low ranking reflects the rollback of environmental protections during the Trump Administration, the report summary explains, adding that U.S. withdrawal from the Paris Climate Agreement and weakened methane emissions rules, in particular, meant the U.S. lost precious time to mitigate climate change.

India rejects the report

Miffed by the findings in the report, India's Ministry of Environment, Forest and Climate Change issued a strong rebuttal, asserting that some of the indicators used for assessing performance were "extrapolated and based on surmises and unscientific methods."

India insists on its own assessment, the Projected GhG Emissions levels in 2050. "This is computed based on average rate of change in emission of the last 10 years instead of modeling that takes into account a longer time period, extent of renewable energy capacity and use, additional carbon sinks, energy efficiency etc. of respective countries," the ministry's rebuttal stated.

The ministry argues that the country's forests and wetlands, which are crucial carbon sinks, were not factored in when calculating the projected greenhouse gas emissions trajectory up to 2050. It says the principle of equity, or per capita emissions, has also been given very low weight insisting that its contribution to global emissions is far less than the U.S. or EU.

Commenting on the EPI report, Sharachchandra Lele, distinguished fellow at the Bangalore-based AshokaTrust for Research in Ecology and the Environment, said that while the EPI report looks like "a flawed exercise," India's environmental performance has been "very poor in the past decade or so because the government is not serious about environmental issues."

Lele said that the environmental condition of a country is multi-dimensional and context-specific. "Trying to rank countries on the basis of a common aggregate performance index is a tricky exercise at the best of times, involving many value judgements as to which dimensions to include and how to weight them," he told SciDev.Net.

"The EPI's biased approach on climate mitigation has provided the government an excuse to reject the index altogether, even when it shows the poor performance on other fronts."

'We are concerned'

Wolf told SciDev.Net that the EPI team upholds the idea that data-driven environmental metrics can improve policymaking—but only if leaders embrace scientific insights and act on what the data is telling them.

"We are concerned that the Indian government has rejected the scientific basis underlying the 2022 EPI's analyses. The EPI provides a chance for all countries to reflect on their environmental performance, identify their most critical sustainability challenges, and work to revise and enhance their policies," Wolf said.

"We hope the Modi administration views the EPI as a tool to illustrate how empirically-grounded findings can improve India's environmental conditions on multiple fronts, including air quality, climate change and biodiversity."

He said the report highlighted how Indian policies remained "largely at odds with the principles of sustainable development," adding: "Air quality continues to worsen, greenhouse gas emissions are accelerating, and poor water quality kills hundreds of thousands of Indian residents each year.Air quality is leading environmental threat to public health, EPI report shows

Provided by SciDev.Net

From price shock to independence from fossil fuels

by Florian Meyer, ETH Zurich

Oil and gas prices are currently on the rise, raising questions about the security of Switzerland's energy supply. In a policy brief, researchers from the Energy Science Center at ETH Zurich have now shown what Switzerland can do to make its energy system independent of fossil fuels such as oil and natural gas.

Prices for oil and gas have risen sharply since Russia invaded Ukraine in February. This increase has also shown consumers in Switzerland how vulnerable a country's energy security can be if supply depends heavily on imports of natural gas and other fossil fuels. A relatively large proportion of Switzerland's energy is imported: according to figures from the Swiss Federal Office of Energy, Switzerland imported around half of its primary energy requirements via fossil fuels (oil, natural gas and coal) in 2020 alone. If imported nuclear fuel for electricity production in nuclear power plants is added, as much as 72% of the country's primary energy comes from abroad.

Should the energy-political conflict intensify or further conflicts emerge, this could end up threatening Switzerland's energy supply. In light of current energy-political developments and with a view to the climate policy goal of net zero greenhouse gas (GHG) emissions by 2050, a logical strategy would be to drastically reduce dependence on foreign oil and gas imports. This is the conclusion reached by ETH energy researchers from the fields of mechanical engineering, electrical engineering and climate finance and policy in the policy brief "Steps to Fossil-Fuel Independence for Switzerland," published today.

The latest findings in condensed form

The policy brief was written by six professors and five scientists involved in energy research at ETH, who formed an expert group to tackle key questions about security of supply in Switzerland. The position paper outlines the ways in which Switzerland could increase its independence from fossil fuels in the coming years, and the political steps needed to achieve a fossil-free energy system with net zero greenhouse gas emissions by 2050.

With the exception of one survey, the expert group did not conduct any new research, but rather summarized established scientific facts and findings—including available statistical data from the Swiss Federal Office of Energy (SFOE) and the International Energy Agency (IEA)—to outline the need for action in terms of both policy and practice. The Security of Supply expert group will be followed by others in the future, and they will also address current issues from the energy sector.

Exchange with Europe is key

In the current position paper, ETH researchers conclude that a Swiss energy system that is free of greenhouse gases by 2050 is both technically and economically feasible—and the scientific basis for this was developed by researchers at the Paul Scherrer Institute (PSI) and ETH Zurich. They point out, however, that the costs and benefits of energy supply can vary greatly depending on the energy policy priorities and measures in place.

One example is cooperation with neighboring countries: in the future, Switzerland will still not always be able to produce enough electricity to ensure self-sufficient coverage of its entire domestic demand. When it comes to ensuring secure domestic supply, it will be a question of Switzerland working more closely with the European system.

"An isolated solution for the Swiss energy system is less efficient and massively more expensive than exchange with neighboring countries," says Christian Schaffner, Executive Director of the ESC, who coordinated the expert group's work together with Kirsten Oswald.

No silver bullet

Switzerland will achieve its greatest contribution to reducing energy demand and greenhouse gas emissions by electrifying transport and buildings, i.e. by phasing out fossil fuels such as petrol and kerosene and heating systems that run on oil or natural gas.

In industry, phasing out oil and natural gas will be more difficult, and it will require alternative fuels such as synthetic gas and hydrogen. The idea is for natural gas to only be used in conjunction with new negative emission technologies (NETs) that can capture and store CO2. "A net-zero energy system will be based on a diverse combination of technical, policy, and social measures. There's no silver bullet in the form of a single technology," says Schaffner. "The biggest challenges are not necessarily technical or economic, but social: without society's commitment, these ambitions cannot be achieved."

Acceptance of fossil fuel phase-out

It has already become apparent that the Swiss population's acceptance of the idea of phasing out oil and natural gas for heating residential buildings, or cars with combustion engines, has increased since the start of the war. This was revealed in a new representative survey conducted by ETH researchers Anthony Patt and Bjarne Steffen with 1,000 participants in April 2022 and incorporated into the position paper.

According to the survey, the Swiss support almost all political measures aimed at ending dependence on fossil fuels and promoting the use of renewable energies. The survey results also show broad support among the political parties for the expansion of domestic wind and solar energy as a substitute for fossil fuels.

The study is currently being reviewed and prepared for publication in a research journal. As a working paper, it is now publicly available together with the policy brief on the Energy Science Center website.

The energy turnaround won't happen on its own

More information: Energy Science Center (2022). Steps to fossil-fuel independence for Switzerland. Policy brief of the expert group Security of Supply. ethz.ch/content/dam/ethz/speci … rch/publications/ETH%20Zurich%20ESC%20Policy%20Brief_Steps%20to%20fossil-fuel%20independence_20220617.pdf

Patt, A., & Steffen, B. (2022). A historical turning point? Early evidence on how the Russia-Ukraine war changes public support for clean energy policies. Working paper of the survey: ethz.ch/content/dam/ethz/speci … ch/publications/Patt%20Steffen%202022%20-%20Working%20paper%20public%20acceptance.pdf

Ramachandran Kannan et al, A net‐zero Swiss energy system by 2050: Technological and policy options for the transition of the transportation sector, Futures & Foresight Science (2022). DOI: 10.1002/FFO2.126

Florian Landis et al, Multi-model comparison of Swiss decarbonization scenarios, Swiss Journal of Economics and Statistics (2019). DOI: 10.1186/s41937-019-0040-8

Provided by ETH Zurich

Agriculture emissions pose risks to health and climate

by Rice University

Agricultural pollution comes from the prairie, but its economic impact on humans is a problem for cities.

A study led by environmental scientists at Rice University's George R. Brown School of Engineering puts numbers to the toll of reactive nitrogen species produced in America's croplands.

The study led by Daniel Cohan, an associate professor of civil and environmental engineering, and graduate student Lina Luo quantifies emissions of nitrogen oxides, ammonia and nitrous oxide from fertilized soils over three years (2011, 2012 and 2017) and compares their impacts by region on air quality, health and climate.

While seasonal and regional impacts differ across types of emission, the study found total annual damages from ammonia were much larger overall—at $72 billion—than those from nitrogen oxides ($12 billion) and nitrous oxide ($13 billion).

Air pollution damages are measured by increased mortality and morbidity and the value of statistical life, while monetized damages from climate change include the threats to crops, property, ecosystem services and human health.

On that basis, the researchers found the health impact of air pollution from ammonia and nitrogen oxides, which react to form particulate matter and ozone, substantially outweighed climate impact from nitrous oxide in all regions and years.

The highest social costs arose from agriculture-heavy regions of California, Florida and the Midwest, where ammonia and nitrogen oxides form air pollution upwind of population centers. For both pollutants, emissions peak in the spring after fertilizers are applied.

The study in the American Chemical Society journal Environmental Science & Technology concludes air pollution, health and climate should all be considered in future assessments of how farming practices affect reactive nitrogen emissions.

"We always talk about how carbon dioxide and methane contribute to greenhouse gases, but nitrous oxide is about 300 times more potent than carbon dioxide for its global warming potential," Luo said.

She noted farming strategies that reduce greenhouse gases can increase air pollutants and vice versa. "We need to see if they can reduce all three nitrogen species—or make some tradeoffs—and still not decrease crop yield," Luo said.

Nitrogen is essential for crop growth, Cohan added, but the study shows the importance of controlling agricultural emissions has been largely neglected by air quality management and climate policy, even as the Environmental Protection Agency considers tightening air quality standards and the Biden administration seeks to slash greenhouse gas emissions.

He said federal agencies have focused on controlling transportation and industrial emissions, leaving agriculture as the largest source of damaging nitrogen pollutants in the United States, a problem exacerbated by climate change and increased crop production.

"Our group had been studying nitrogen oxide emissions for a number of years and began to realize that we can't just focus on that," Cohan said. "We needed to consider the range of emissions that come from soils, and we became curious about the relative impacts of different air pollutants and greenhouse gases the emanate from agricultural soils.

"A big part of our motivation was realizing that choices in farming practices might cause some emissions to go up and other emissions to go down," he said. For instance, switching from surface broadcast to deep injection of fertilizers would lower ammonia but raise nitrogen oxide emissions. That would benefit nearby cities sensitive to particulate matter levels, but harm regions where ozone is of more concern.

Cohan said when all the emissions are quantified on a monetary basis, ammonia and nitrogen oxides that form air-polluting particulate matter and ozone and contribute to global warming have the greatest impact.

"Those of us who study these pollutants for a living know how potent ammonia is, but the message hasn't gotten through to most regulators and policymakers," Cohan said. "In fact, ammonia is one of the most potent sources of particulate matter because of how it binds with other pollutants to have a multiplying effect.

"That's an important message: We need to take more steps to control ammonia," he said.

If there's a silver lining, Cohan said, it's that pollution from other sources has dropped enough to make agriculture's impact prevalent.

"What's crucial is to take steps that have more of the nitrogen go to the crops, and less of it be released to the air and water," he said. That could involve adding biochar or other amendments to soil, a topic of ongoing study at Rice.

"Before we can do that, we needed to establish a baseline of emissions coming from the soil," Cohan said. "This paper lays that out."Livestock and poultry farming should be the future focus of agricultural ammonia emissions control

More information: Lina Luo et al, Integrated Modeling of U.S. Agricultural Soil Emissions of Reactive Nitrogen and Associated Impacts on Air Pollution, Health, and Climate, Environmental Science & Technology (2022). DOI: 10.1021/acs.est.1c08660

Journal information: Environmental Science & Technolo

Provided by Rice University

Little penguins' food struggles

by Flinders University

The latest floods have drowned out memories of drought in many parts of Australia, but ecosystems and native species are still battling with the effects of drought and bushfire.

Now a new Flinders University study has found a strong link between the major impacts of the Millennium Drought (2001–10) and a South Australian little penguin (Eudyptula minor) colony which is perilously verged on the edge of survival.

Freshwater river inflows affected by the 10-year drought earlier this century had a major impact on the little penguin population's main fish food source, with the Encounter Bay population also doing battle with human interference and other impacts of climate change.

The current Granite Island population has fallen to only 20 adults while all other populations in Encounter Bay are now extinct, says Flinders University expert Dr. Diane Colombelli-Négrel, who coordinates annual census counts of numbers on Granite Island in Encounter Bay, south of Adelaide.

"The fact that the Granite Island little penguin population still had not recovered in 2020—after larger river outflows in 2012–13 and at the end of 2016—suggests that the population may have reached some critical reduction in the number of breeding birds during the drought period," a new article in Frontiers in Marine Science states.

The study found a strong association between little penguin numbers, the river outflow and one of their main local food sources, southern garfish, and suggests that ocean warming and other factors—such as predation and low juvenile survival—could also have contributed.

Little penguins are colonial seabirds that become central-place foragers during breeding, with most of their prey being captured within less than 60 km of their colony when feeding their chicks.

The coastal and estuarine environment at Victor Harbor's Encounter Bay, the Lower Lakes and Coorong depends on regular outflows from the mouth of the River Murray, which regularly closes during periods of drought.

"Given droughts are becoming more and more frequent, future studies are needed both within Australia and elsewhere to identify which species may be affected by hydrological droughts (including) for seabird conservation and river management," researchers conclude.

"The results of this study suggest that decisions regarding river water management should consider not only human and terrestrial environmental requirements, but also the long-term impacts that this may have for the coastal environment outside the river system."

Researchers also called for:

Detailed studies to assess the diet and habits of long-nosed fur seals which compete for food in the area—and on the impacts of commercial fishing of southern garfishes and other food sources.
Monitoring of coastal waters' sea surface temperatures and chlorophyll-a concentrations alongside rainfall and freshwater river outflows to support seabird and other marine life.
Checks on effects on larval fish and predators numbers after increased nutrient loading from freshwater outflows raise phytoplankton and zooplankton production near river estuaries.
Long-term impacts of coastal productivity after the average annual outflow at the location now ceasing to flow to the Murray Mouth 40% of the time compared to 5% before increased extraction for human use occurred.Southern Ocean's health affected by River Murray's ebb and flow

More information: Diane Colombelli-Négrel et al, Combined Effects of Hydrological Drought and Reduced Food Availability on the Decline of the Little Penguins in South Australia, Frontiers in Marine Science (2022). DOI: 10.3389/fmars.2022.875259
Journal information: Frontiers in Marine Science
Provided by Flinders University