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Kicking the Salt Habit

November 05, 2023

Two New Studies: It’s Getting Hotter, Faster

Two sobering reports on global warming were released last week, warning that the planet is heating up faster than previously forecast. One report is about our “carbon budget”—the amount of carbon we can burn and still have a 50-50 chance of limiting global warming to 1.5C above pre-industrial levels, which was the goal of the Paris Agreement set in 2015.  According to the new study, we may not have as much time as we thought. The British and Austrian authors said that we effectively have just six years to stay within that budget and get to net zero carbon emissions, which is about three years earlier than had been projected.

Hurricane Otis hit Mexico’s Pacific Coast as a ferocious category 5 storm on October 25, 2023, breaking regional records for the strength and speed of its intensification.  |  Credit: NASA

The researchers write in The Conversation that 1.5C itself is not a hard boundary beyond which climate chaos occurs.  It’s not as if we will go over a climate cliff if we break the 1.5C degree limit, but it will increase the risk of catastrophic changes, according to scientist Bill Hare of Climate Action Tracker, who spoke to Euronews. However, temperatures above 1.5C increase the risk of triggering tipping points, like the Amazon rainforest dying, the melting of polar ice sheets—which would raise sea levels—and the collapse of coral reefs.  Plus, droughts, storms, and wildfires would happen more frequently and intensely.

A second study by James Hansen and colleagues concluded that global warming is accelerating and we will be in a crisis situation earlier than thought. Hansen, who was a NASA scientist, warned Congress 35 years ago that humans are changing the climate by increasing greenhouse gas emissions. In a call with reporters, Hansen said that the 1.5C limit is “deader than a doornail,” and that in the next several months we will go well above it on a 12-month average. The research concluded that the limit will be passed this decade, rather than the early 2030s, which had been predicted by the United Nations recently. However, noted climate scientist Michael Mann at the University of Pennsylvania disagreed with Hansen, writing that the increase is steady and not accelerating.  

The New York Times reports that, according to most experts, the 1.5C target has already been missed, but 2C is possible with much more action by governments.

Salt Poses an Existential Threat to Ecosystems and Biodiversity

Humans are making Earth’s air, soil, and fresh water saltier, which poses an existential threat to biodiversity and ecosystem vitality if the trend continues. A study by the University of Maryland shows that mining and land development along with agriculture and road treatments are rapidly accelerating the planet’s natural “salt cycle.” The research described how salinization affected about 2.5 billion acres—about the size of the U.S.—and during the last 50 years has increased in streams and rivers. Additionally, as lakes dry in some regions, plumes of saline dust are sent into the air.

The natural salt cycle is characterized by the uplifting of salts to Earth’s surface and the weathering and transport of salts to the oceans. Humans accelerate these natural processes through mining and resource extraction, which also sends more saline dust into the atmosphere. |  Credit: University of Maryland

Salt is not just what’s in your kitchen cabinet—sodium chloride (NaCL)—but also calcium, magnesium, and other compounds that can occur in detergents and road deicers. The U.S. puts out 44 billion pounds of road deicing agents each year and nearly 15 percent of those end up in streams. In the five years ending in 2017, road deicers made up more than 40 percent of the country’s entire salt consumption, which can concentrate in watersheds. Road salts can also become aerosolized, creating sodium and chloride particulate matter.

Only about three percent of Earth’s water is fresh, and because the salt is contaminating that supply, the authors say we need to establish a “planetary boundary for safe and sustainable salt use” in much the same way that we are working to limit CO2 in the atmosphere.

The study was published in Nature Reviews Earth & Environment.

FDA Proposes to Ban an Additive Found in Drinks

Ever heard of the food additive brominated vegetable oil or BVO? It’s been an ingredient in sodas and fruit juices for decades but last week the U.S. Food and Drug Administration proposed revoking a regulation that had authorized it.

Credit: SMC/Creative Commons

BVO is vegetable oil that’s been modified with bromine and has been employed since the 1920s as a stabilizer in beverages to keep the citrus flavoring from floating to the top. Bromine is found naturally in the earth’s crust and in seawater and has been historically also used in fire retardants and as a sedative. When used in food, BVO is required to be listed as an ingredient on the label as “brominated vegetable oil” or as the specific oil that has been brominated, such as “brominated soybean oil.” In the late 1950s and early 1960s, the FDA considered BVO to be “generally recognized as safe,” (the GRAS standard), but amounts allowed in food started to be regulated in the 1970s, following studies into its potential toxicity.

Now, a new FDA study shows bioaccumulation of bromine and toxic effects on the thyroid—a gland that produces hormones that play a key role in regulating blood pressure, body temperature, heart rate, metabolism, and the reaction of the body to other hormones. California banned BVO in October and the additive is already prohibited in the European Union and Japan.

Many beverage makers have reformulated their products to remove BVO, but according to the Environmental Working Group, it’s still in smaller grocery store beverages, including some Food Lion and Walmart brand sodas, as well as Sun Drop citrus soda made by Keurig Dr Pepper. While the ingredient had been in Mountain Dew up until 2019, PepsiCo no longer uses the ingredient, the Washington Post reports.

The FDA advises consumers to check product labels and will issue its final ruling following a public comment period that ends on January 17, 2024.

Food Choices Can Take a Bite Out of Climate Change

Hope is still alive to avert climate disaster and it might start on your dinner plate. A new study from Stanford University has found that simple swaps in food choices could help cut carbon emissions significantly.

The climate warning label shows an image of a deforested area with factory smoke in the distance and warning text  |  Credit: Durham University

The research, which was co-authored by Tulane University, found that small substitutions of protein—rather than a drastic overhaul of a diet—could reduce the average carbon footprint from food production in the U.S. by about 37 percent. Food production accounts for roughly one-third of U.S. greenhouse gas emissions with beef production being a primary contributor.

Steering away from cows offered the biggest benefit by, for example, replacing beef with chicken in a burrito or choosing a plant-based milk over dairy. That’s because bovines produce the potent greenhouse gas methane, require a lot of land to graze, which can result in deforestation, and live longer than other animals, so their lifelong footprint is greater.

The study, which analyzed diet data from over 7,700 Americans, identified commonly eaten foods with the highest climate impact and then modeled replacing them with nutritionally similar, lower-emission options. The team found the swaps would not only have a climate benefit but also, as lead author Anna Grummon wrote to H2O Radio in an email, improve the average diet quality by four to ten percent. To realize these benefits (such as lower risk of cardiovascular disease, cancers, and other conditions) people would need to keep making the swaps as often as they consumed the high-carbon food. Grummon added that although people may not be able to substitute all the time, the good news is even small actions can really add up.

Still need more persuasion to quit cows? Perhaps seeing cigarette-style warnings on beef might do the trick. In a study out last week from Durham University in the UK , researchers tested three labels describing a food’s potential damage to either climate, health, or the risk of pandemics. They found that labels with graphics depicting someone having a heart attack or of a clear-cut forest were effective at discouraging people from choosing meat around ten percent of the time with the climate warnings being the most credible.  

The diet carbon footprint study was published in the journal Nature Food. The food label study was published in the academic journal Appetite.