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It’s Getting Harder for Some Trees to Breathe

February 11, 2024

Ocean Sponges Show Global Warming Is Greater than Thought

For the last 12 months, the average global temperature reached 1.52 degrees Celsius above the pre-industrial era, according to Europe’s Copernicus Climate Change Service—levels never before endured by humans and above the 1.5 C limit set in the 2015 Paris climate agreement. Whether this 12-month average persists will be determined over decades.

This sclerosponge (Ceratoporella nicholsoni) (in orange) was collected in the Bahamas.  |  Credit: I. Macintyre/Smithsonian Institution, CC0 1.0

Scientists said it was a warning to humanity that urgent action is needed to cut greenhouse gas emissions to slow warming. As the Washington Post reports, the world’s infrastructure, including homes and power grids, was not designed for this heat and will be more strained with every tenth of a degree rise.

The global average temperature may have actually surpassed the 1.5 C limit some time ago, according to another indicator—sponges. Analyzing sclerosponges in the Caribbean, a team of researchers from the University of Western Australia, Indiana State University, and the University of Puerto Rico, have concluded that we reached 1.7 C more than three years ago.

Sponges, like ice cores and tree rings, are used by scientists as proxies that record changes in the environment over millennia. Sclerosponges grow very slowly and store centuries of climate information in their limestone skeletons that resemble coral. The researchers told the Associated Press that these sponges can record a larger area of ecological change than ice cores or tree rings, because water flows through them from large areas.

The scientists also concluded that the industrial-era warming began in the mid-1860s—more than 70 years earlier than records suggested from measurements of sea-surface temperatures.

The study was published in the journal Nature Climate Change.

Atlantic Ocean Circulation May Be Reaching a Tipping Point

Earth’s weather is affected significantly by ocean currents.  In the Atlantic Ocean, water moves along a giant conveyor belt that takes warmer, saltier waters from tropical regions northward toward Greenland, where it cools and can become diluted with fresh water from the melting ice sheet.

How the Atlantic Ocean circulation changes as it slows.  |  Credit: IPCC 6th Assessment Report

The cooler water then sinks and returns in a southerly direction. This natural process, called the Atlantic Meridional Overturning Circulation or AMOC, has been shown by recent research to be deteriorating faster than expected.  Scientists have warned for decades about climate change warming the ocean and melting ice that interferes with the AMOC.

Now, a new study from Utrecht University suggests that we may be on course to reach a critical tipping point at which the circulation would shut down completely and irreversibly. A tipping point is like a person rocking back in a chair that falls over if it reaches a certain angle and then can’t right itself. The study says the consequences for people in North America, Europe, and Asia would be severe as average temperatures would drop by several degrees. At the same time, other parts of the world would continue to warm because of greenhouse gases trapping heat.

One of the researchers told Inside Climate News that there could be up to a meter rise in sea level in the North Atlantic on top of the amount caused by global warming. The Washington Post explained that, if the system passes the tipping point, Western Europe would cool down by as much as 5.4 F (3C) every decade. In addition, creatures at the depths of seas would perish from a lack of oxygen.  

The study was published in the journal Science Advances.

Some Trees Are Struggling to Breathe with Global Warming

Trees have been promoted as a climate solution for their ability to remove carbon dioxide from the atmosphere, but according to a new study, some trees are struggling to “breathe” as the planet warms. Researchers from Penn State found that trees in warmer, drier climates are essentially coughing instead of breathing—sending more CO2 into the atmosphere than trees growing in cooler, wetter conditions.

With an analysis of a global dataset of tree tissue, a team led by Penn State researchers demonstrated that the rate of photorespiration in trees is up to two times higher in warmer climates, especially when water is limited. They found the threshold for this response in subtropical climates, like this portion of the Appalachian Ridge and Valley Region, begins to be crossed when average daytime temperatures exceed roughly 68 degrees Fahrenheit and worsens as temperatures rise further.  |  Credit: Warren Reed, Penn State / Creative Commons

Trees absorb carbon dioxide from the air through photosynthesis; however, when they’re stressed from heat or drought, a reverse process kicks in called photorespiration, where the CO2 is released instead. Following an analysis of global tree tissue data, the team found that rates of photorespiration are up to two times higher in warmer climates, especially when water is limited—a response that can start when average daytime temperatures go above 68 degrees Fahrenheit in subtropical climates and worsen from there.

There has already been some skepticism that trees could be a silver bullet to mitigate the climate crisis, with a few studies saying we don’t have enough land to add the numbers needed, and even if we did, it couldn’t counter the huge amount of greenhouse gases being added to the atmosphere anyway.

However, there are still numerous reasons to plant trees. They provide shade to help cope with extreme heat, filter air pollutants, capture stormwater runoff, maintain ecosystem health, and support biodiversity, to list a few. And studies have showntrees make you feel good—reducing stress, improving mental health, and  strengthening immune systems, among other benefits.

The research was published in the journal Proceedings of the National Academy of Sciences.

Utah Plays Role of Cupid for Anglers Looking for the “One”

They say there’s plenty of fish in the sea, but apparently not enough in streams, rivers, and lakes in Utah to make anglers happy. The field is getting crowded, but luckily the state has a plan: “speed baiting.”

Credit: Utah State University

The idea is to pair angler “personalities” with a water body to help them find the one, as an ongoing megadrought shrinks fishing opportunities. It’s matchmaking—of the rod and reel kind.

In a solution to keep recreation sustainable developed by a team of researchers from Utah State University, surveys were conducted to classify people into groups that matched their preferred fishing experience. A resulting report identified five “profiles”—Explorers, Social Anglers, Catch-Focused Anglers, Ambivalent Anglers, and Catch & Consume Anglers.

Explorers like more secluded areas to have solitude and are comfortable in rivers and streams, while Social Anglers, placed higher value on being a mentor and spending time with friends and family and would try to hook cool-water species at a lake or reservoir. Catch & Consume Anglers are more likely to stick with tried-and-true areas with good water quality where they’d have a better chance of catching fish that they could take home to eat.

The hope is that, as it becomes more expensive to raise and stock fish, state fisheries managers can provide biologically and economically sustainable opportunities for all—including that guy who forever needs to tell you about the one that got away.