Displaying items by tag: global warming

Wild turkeys forage in charred hardwood forest soon after the 2016 Gatlinburg fires, which moved from the Smokies to developed areas in Sevier County. An ORNL model predicts wildfire threats will increase in the Southern Appalachians because of climate change. Thomas Fraser/Hellbender Press via Knoxville Mercury

ORNL report: Local wildfire danger will likely loom larger because of climate change

OAK RIDGE — This cruel summer, the Southern Appalachian region is already baking in above-normal temperatures and basking in poor air quality. 

Air temperatures in Knoxville flirted with 100 degrees on July 6, which were well above average and prompted the National Weather Service to issue a heat advisory for much of the metropolitan area.

It’s hard to definitively link a heat wave to global warming, but one oft-cited consequence of climate change is the growing intensity of wildfires, even in the traditionally moisture-rich Appalachians. The range of climate change effects is difficult to pin down, but one constant in the study of climate change is an expected increase in overall temperatures, which can power wildfires via both fuel increases and volatility.

Southern Alliance for Clean Energy's fourth annual “Tracking Decarbonization in the Southeast: Generation and Carbon Emissions” report will be released Wednesday, June 22

Amy Rawe is communications director for Knoxville-based Southern Alliance for Clean Energy.

KNOXVILLE — The report examines power-sector generation and emissions throughout the Southeast, which is home to some of the biggest utility systems in the nation, including Duke Energy, Southern Company, NextEra Energy, and the Tennessee Valley Authority.

Many of these Southeastern utilities have been in the national spotlight for their professed commitment to decarbonization, but there are often inconsistencies between stated goals and resource plans.

Scientists discuss climate challenges and solutions during 2021 One Health Day

As climate experts and scientists huddled in Glasgow in an international effort to stem potentially disastrous global environmental changes, a panel of doctors representing multiple disciplines at the University of Tennessee and beyond offered their assessments of climate challenges and solutions.

Their take on climate change? We have problems, but we also have solutions. Hopelessness will drive you crazy. Stay healthy, stay informed and do your part to mitigate the long-term environmental consequences of a changing Earth. 

Above all: Don’t despair and don’t lose hope.

The panel, held Nov. 3 at the UT Student Union and presented by the UT One Health Initiative, consisted of the following experts:

— Dr. Gus Engman, Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture 

— Dr. Kate Evans, Computational Sciences and Engineering Division, Oak Ridge National Laboratory

— Dr. Joshua Fu, Department of Civil and Environmental Engineering, University of Tennesse

— Dr. Sindhu Jagadamma, Biosystems Engineering and Soil Science, University of Tennessee Institute of Agriculture

— Dr. Kristina Kintziger, Department of Public Health, University of Tennessee

Answers have been edited for clarity and brevity and don’t include the full response. Questions were submitted ahead of time or during the panel discussion. 

What do you see as the largest threats of climate change, especially related to your individual research interests?

Engman: Changing precipitation patterns are something I think about a lot.

Pretty much all the rivers in the world are expected to have changes to their flow regime.

These changes in droughts and floods are a really large issue.

I think a lot about aquatic communities. If we are scarce on drinking water, we are always going to prioritize people having that water, over the fish or the bugs in the streams. 

There are all kinds of impacts to life histories and interactions with communities in streams. 

When animals are stressed because of these changes in precipitation patterns and changes in flow patterns, they might become more susceptible to other stressors, like disease. 

Changes in algal community composition can impact the entire water quality of a stream, and that might happen because of these changes in precipitation patterns.

These places that are experiencing these extreme droughts really worry me. The Colorado River already doesn’t even flow all the way to the ocean anymore. That’s a huge change. Because we take up so much water for agriculture. 

If a stream runs out of water, it’s not a stream anymore.

Evans: From a meteorological perspective, the biggest event that hurts people's health is actually heat waves. A lot of press goes to tornadoes and hurricanes and storms but in fact these large domes of hot air (are deadly), which happen because of changes in the large-scale weather patterns.

The greenhouse effect insulates the earth, it makes it more uniform in temperature and so that changes the flow patterns that go around the earth. That changes those big weather systems that come in and how long they stick around. 

When you talk about these long droughts, we know that’s what's we have to understand: Will they last longer, be more humid, less humid, and that has huge impacts for human health as well as the food they eat and the plants that grow. 

Kintziger: Heat also has a bigger impact on a more indirect pathway to human health. Not just heat-related illness but also cardiovascular impacts, renal impacts and even mental health impacts.

Heat is the one that keeps me up at night. We are seeing increasing temperatures globally and we also have this urban heat island affect. 

Our vulnerable populations in the cities — inner cities with lower-income housing, homeless populations — they are going to experience heat very differently than people who live in newer buildings with better cooling and infrastructure and have better capabilities for adapting to heat. 

Smithsonian: In Russia, even rocks emit greenhouse gases

The melting Siberian tundra north of the Arctic Circle released millions of tons of methane last year as regional temperatures rose to 11 degrees (°F) above average.

Methane has a shorter effect than carbon dioxide on global atmospheric change but is still 70 times more potent than CO₂ in its overall global-warming potential. Its accelerated release on such a vast scale represents an immediate challenge to restricting overall global warming to less than 3 degrees (°F) by the end of the century, which scientists agree is necessary to prevent dramatic climate change. Methane’s potent global warming potential is why many conservationists oppose the use of natural gas as an energy source.

But in Siberia, even the rocks are emitting methane. Scientists were surprised to find that limestone exposed by disappearing permafrost itself generated high levels of methane. Tundra fires have also accelerated the release of methane and other gases, and have come at great cost to the Russian government and the rural inhabitants of the vast region.

That means economical and practical means must be developed elsewhere, at least, for methane management.

But according to the United Nations Economic Council for Europe:

“Despite methane’s short residence time, the fact that it has a much higher warming potential than CO₂ and that its atmospheric volumes are continuously replenished make effective methane management a potentially important element in countries’ climate change mitigation strategies. As of today, however, there is neither a common technological approach to monitoring and recording methane emissions, nor a standard method for reporting them.“

Washington Post: Carbon dioxide levels at highest point in 2 million years

A United Nations climate report authored by 34 people mining 14,000 scientific studies concludes that substantial climate change and its effects are now largely unavoidable but nations, municipalities and individuals can still take steps to minimize the consequences as much as possible.

Here are some key points from the Intergovernmental Panel on Climate Change report:

— Human-caused global climate change is an irrefutable fact. Now the debate is what we do about it.

— Few if any signatories to the 2015 Paris Climate Accord met their pledged reduction targets.

— At current emissions rates, the Earth will have heated to or beyond 2.7 degrees (F) above pre-industrial levels by the 2030s.

— Hurricanes, cyclones, droughts, heat waves and other weather anomalies will worsen.

The report comes as many present disasters linked to global warming unfold around the world. The second-largest wildfire in California history burned in the drought-stricken state; Greece dealt with historic wildfires; and Germany and the European Lowcountry reeled from an unprecedented rainstorm that destroyed entire towns and killed more than 200 people. Another heat wave is supposed to arrive in the Pacific Northwest this week.

NYT: Database allows you to track the local increase in 90-degree days every summer since your birthday

If you were born in Knoxville in 1970, it got hot in the summer, sure. But you and your parents could expect temperatures to exceed 90 degrees only about 37 days a year, generally at the height of summer, according to an interactive database from Climate Impact Lab.

But if you were born in 1985, there were an average 44 days per year when the temperature rose above 90 degrees. Now there are about 63 such days each year in Knoxville. I think you can see the pattern here. 

To use the climate-change database, simply key in your birthdate (it goes back to 1960) and locality and you will see how summer temperatures (as measured by the number of daily high temperatures at or above 90 degrees) have steadily tracked upward over the course of your lifetime.

(If you have any doubt as to how this affects you, check your utility bill).

Washington Post: Sea level rise will be investigated as one possible factor in Florida condo collapse

There is no direct evidence yet that increased subsidence on a Florida barrier island caused by rising sea levels and saltwater intrusion contributed to the devastating collapse of an ocean-front condo complex near Miami, but the possibility will be examined in coming weeks and months.

Rising sea levels threaten seaside properties on an increasing scale, undermining the unstable land on which they sit and further contributing to erosion of steel and concrete.

In the case of Champlain Towers South, developers used fill from denuded mangrove stands to support the 12-story building, which was built in 1981.

“Land subsidence is a gradual settling or sudden sinking of the surface when material that supports it is displaced or removed, according to the U.S. Geological Survey. Erosion and the disappearance of groundwater are two of several factors that cause it,” the Washington Post reported.

A least one engineer has said the collapse could be related to a structural problem, not subsidence. The investigation continues, as does the search for bodies.

Washington Post: CO₂ levels hit highest point yet, even after 15-month idling of transportation, industry and overall carbon emissions.

Initial air pollution reductions during the Covid-19 pandemic had an immediate measurable impact on global and local air quality. Demand for oil dropped by nearly 9 percent. That didn't stop the atmospheric carbon dioxide level from reaching its highest concentration since records began.

It's a sign of how difficult it will be to curb overall global emissions enough to prevent the worst consequences of climate change and global warming.

"Even as international borders closed and global economic activity took a massive hit throughout much of 2020, researchers have found that human-caused emissions rebounded fairly quickly after decreasing sharply early in the pandemic," the Washington Post reported. 

NYT: NOAA map details U.S. climate change over last century

The map produced by the National Oceanic and Atmospheric Administration shows that virtually all of the U.S. has higher average temperatures than 100 years ago. The precipitation data shows where rainfall averages have increased (East Tennessee and most of the Appalachian Mountains and their adjacent foothills and valleys) and where they fluctuated beyond average (California and the Southwest). Some of the data predates the regular government weather and climate record-keeping that began 90 years ago.

"Because the normals have been produced since 1930, they also say a lot about the weather over a much longer term. That is, they show how the climate has changed in the United States, as it has across the world, as a result of emissions of heat-trapping gases over more than a century."

CBS News: Eye on Earth

This outstanding video summary by meteorologist and climate specialist Jeff Berardelli explains why scientists fear further deforestation of the Amazon or collapse of Antarctic ice shelves would wreak ultimate havoc in coastal areas around the world.