SCIENCE

Don’t Forget to Count ‘Tree Farts’

Greenhouse gas emissions from forests of dead trees—also known as “tree farts”—should be considered when calculating emissions from these forests, a new study has found.

Stands of dead trees in coastal wetlands called “ghost forests” emit methane and other potent greenhouse gases from the sides of their trunks, acting as a straw that sucks gases from the soil into the atmosphere. These dead trees increase greenhouse gas emissions from the ecosystem by about 25 percent, compared to a marsh ecosystem without dead trees, the study, conducted by researchers at North Carolina State University and published earlier this month in the journal Biogeochemistry, found. 

“Wetlands naturally produce greenhouse gas emissions, especially methane in freshwater wetlands,” said Melinda Martinez, lead author and a former graduate student at North Carolina State. “Because there’s so much standing water for a long period of time, this creates this perfect environment of low oxygen level that these microbial communities love, and so they end up producing a lot of methane.”

Despite their natural methane emissions, these coastal wetlands tend to be carbon sinks: they absorb more carbon dioxide through photosynthesis and other processes than the greenhouse gases they emit. But when the trees die and the canopy of carbon-absorbing leaves disappears, the landscape can turn into a carbon source, and these emissions should be taken into account in greenhouse gas analyses.

“This basically provides one piece of the puzzle of the climate budget,” Martinez said. “A lot of studies don’t really take into account tree stems as a potential source of emissions, so this study shows, ‘Hey this is happening.’”

CULTURE

Hot Time, Summer (Olympics) in the City 

Climate change could make the Olympics dangerously hot this summer, because Tokyo, the host city for the games, has warmed by nearly 3 degrees Celsius since 1900 and is heated up further by what’s known as the urban heat island effect, a new report warns. 

The report, assembled by the British Association for Sustainable Sport, noted that temperatures at the July games are expected to average 25 degrees Celsius (77 degrees Fahrenheit), but could reach above 30 degrees Celsius (86 degrees Fahrenheit), with high levels of humidity. 

The city has been experiencing more frequent heat waves but its large concentrations of asphalt and little vegetation also make it hotter, and cause the heat to last through the night.

If there is a heat wave during the games, some events may need to be delayed, moved, shortened or even canceled if conditions are dire, said Mike Tipton, a professor of human and applied physiology at the University of Portsmouth who contributed to the report. High temperatures, humidity and solar intensity all combine to compromise the body’s ability to control its temperature, risking heat stroke.

“You cannot continue to exercise in the heat unless you’re able to compensate for the thermal challenge,” Tipton said. 

It’s not just continuous, energy-intensive events like tennis and the triathlon that are risky, Tipton said. Sports like pistol shooting can be affected by heat, too, if athletes are distracted by the sweat dripping off their brows while aiming a shot in which mere millimeters could decide who wins silver and who wins gold. 

Organizers of the Olympics have moved some events, like the marathon and road cycling, to cooler regions in Japan to address the heat issue, the report said, but Tipton added that athletes should still prepare to compete in hot, humid temperatures.

“There’s a reason for trying to address climate change and associated global warming,” he said. “Anyone who has an interest in sport or takes part in sports should be supporting those actions to limit the increase in temperatures.” 

CULTURE

A New App Takes the Long View of Climate Change

A soon-to-be-released game app for mobile phones shows players what a world devastated by climate change will look like in the year 2412, based on the actions taken today.

The Australia-based creators of “Descendants of Earth” likened the game to “Fallout” or an apocalyptic “Sims.” In the game, players communicate through a time pump with their descendants 400 years in the future, who live in a wasteland caused by the climate crisis during the 21st century. In the game, players can put in actions that they take in their real lives to send resources to their future descendants, helping them restore a thriving society. 

“By taking real action in this time, you’re saving resources in our timeline and sending them to the future and changing Earth’s timeline by regenerating Earth,” said co-creator Natalia Shafa. 

Actions people can take in the real world could include composting, planting trees, biking to work or installing solar panels to achieve rewards in the game.

Co-creator Edmund Weir said most projections about the future of climate change only go to the year 2100, but temperatures will keep rising beyond that if nothing is done to head off warming.

“We wanted to take a longer look at the timeline, but still keep it near enough that you still feel some connection to the people in the game,” he said.

The free app is not available yet, Weir said, but will begin to roll out later this year. 

SCIENCE

Visualizing Earth in 3-D

New NASA satellites will gather next-generation data on Earth’s interior, surface and atmosphere over the next decade.

The network of satellites will use the latest technology to create a “3-D” visualization of Earth’s systems, in an attempt to answer pressing research questions outlined by the National Academies of Science, Engineering and Medicine, according to NASA Earth Sciences Division director Karen St. Germain. The questions largely relate to climate change.

Some satellites will observe phenomena in the atmosphere, like clouds, precipitation and aerosols; some will look at vegetation and shifts in Earth’s surface after earthquakes and landslides; and others will measure what’s happening below ground, for example, in underground aquifers, St. Germain said.

“Taken together, this collection gives us a great core observatory for understanding how all of Earth’s systems are playing together,” she said.

Often when scientists talk about climate change it is at the global level, St. Germain said. But its effects actually play out very differently in different locations. Coastal communities may face sea level rise, while inland communities may be most affected by drought; some areas may see fierce heat waves while others experience regional cooling. 

She added that the data will be openly available, so researchers at all levels of government and even in the private sector and non-governmental organizations can apply the Earth systems data to human communities, “whether that’s looking at health and air quality or whether that’s looking at flooding and storm surge risk on the coastlines or food security issues associated with water availability in agriculture.”

CULTURE

But is That T-Shirt Really Green?

About half of clothing consumers want to shop sustainably, but don’t know how to do it, a new survey has found, and nearly 90 percent of respondents are wary of trusting brands that claim to sell sustainable products. 

The survey was administered to about 2,000 teenagers and adults in the United States this spring by Genomatica, a sustainable materials company that creates clothing fibers out of renewable resources. Less than half of the respondents knew that many synthetic fabrics are made from fossil fuels like crude oil and coal.

“You have a huge portion of people who just have no idea where their stuff comes from,” said Christophe Schilling, CEO of Genomatica. “Hopefully most people would say cotton comes from a crop and maybe wool comes from sheep, but where does nylon and polyester come from? It’s not really obvious how you turn a liquid barrel of crude oil into a piece of fiber.”

Brands are beginning to recognize that consumers want more sustainable products, Schilling said, and they expect clothing brands to be responsible and transparent.

“Consumers are putting that onus on the brand,” Schilling said. “It’s the brand’s responsibility, and the brands aren’t the ones that make those chemicals and fibers, but rightly so the consumer says, ‘That’s your problem, figure it out.’”