The Ozone Layer Is Healing, Thanks to an International Ban on Harmful Man-Made Chemicals

NASA
NASA

The ozone layer is on the mend, thanks to a decrease in human-produced chemicals called chlorofluorocarbons, or CFCs, in the atmosphere. Using data from NASA's Aura satellite, scientists were able to measure the chemical composition of the thinned gas layer above the Antarctic and found about 20 percent less ozone depletion than there was in 2005. They published their findings on January 4 in the journal Geophysical Research Letters.

In 1985, UK scientists published a landmark study in the journal Nature announcing their discovery of an annually recurring hole in the ozone layer above Antarctica. (Each September, as the Southern Hemisphere's winter arrives, the Sun's UV rays trigger a reaction between the ozone and chemical elements from CFCs, chlorine and bromine, which destroys the ozone molecules.) The finding led to the Montreal Protocol in 1987, an international treaty that gradually banned the production and use of CFCs in refrigerants, aerosol sprays, solvents, and air conditioners.

In July 2016, Antarctic researchers published a study in the journal Science reporting that the ozone layer appeared to be healing (although it wasn't projected to completely patch up for decades). They tracked this progress by monitoring the Antarctic ozone hole's area, height, and chemical profile. Still, they didn't know whether this progress could be attributed to the Montreal Protocol's mandate.

NASA itself has used Aura to monitor the hole since the mid-2000s. After analyzing data produced by the Microwave Limb Sounder, a satellite instrument aboard Aura that measures trace gases, the space agency has confirmed that the CFC ban has led to the big decrease in ozone depletion during the Antarctic winter.

By winter, ozone-busting chlorine compounds have converted into hydrochloric acid, a process that occurs after it's destroyed ozone particles and reacts with methane. "By around mid-October, all the chlorine compounds are conveniently converted into one gas, so by measuring hydrochloric acid, we have a good measurement of the total chlorine," researcher Susan Strahan said in a NASA statement. Scientists compared these hydrochloric acid levels with nitrous oxide, which is similar in nature to CFCs but isn't diminishing in the atmosphere.

Their study is billed as "the first to use measurements of the chemical composition inside the ozone hole to confirm that not only is ozone depletion decreasing, but that the decrease is caused by the decline in CFCs," according to NASA. But while these initial results are promising, scientists say that the ozone layer's full recovery is still a long way off.

"As far as the ozone hole being gone, we're looking at 2060 or 2080,” study co-author Anne Douglass said. “And even then there might still be a small hole."

Human Body Temperatures Are Dropping, and Science Might Know Why

dcdp/iStock via Getty Images
dcdp/iStock via Getty Images

In 1868, German physician Carl Reinhold August Wunderlich started to popularize what’s become the most recognizable number in all of medicine: 98.6°F or 37°C, which is thought to be the normal average human body temperature. Though his methods later came under scrutiny—Wunderlich stuck an enormous thermometer under the armpits of patients for 20 minutes, a less-than-accurate technique—this baseline has helped physicians identify fevers as well as abnormally low body temperatures, along with corresponding illnesses or diseases.

More than 150 years later, 98.6° may no longer be the standard. Humans seem to be getting cooler. Researchers at Stanford University School of Medicine, in a paper published in the journal eLife, compared three large datasets from different time periods: American Civil War records, a national health survey from the 1970s, and a Stanford database from 2007-2017. By comparing recorded body temperatures, the researchers founds that men are now averaging a temperature .58°C less than what's long been considered normal, while women are .32°C lower. On average, each has decreased roughly .03°C every decade since the 1860s.

What drove us to chill out? Scientists have a few theories. A number of advances in human comfort have been ushered in since the 1800s, including better hygiene and readily available food, which may have slowed our metabolic rate (temperature is an indication of that rate). Chronic inflammation, which also raises body temperature, has decreased with the advent of vaccines, antibiotics, and better healthcare. The researchers propose that, on average, our bodies are healthier and slightly less warm.

After all, the average life expectancy in Wunderlich’s era was just 38 years.

[h/t The Independent]

You Should Never Put Batteries In Your ‘Junk’ Drawer. Here’s Why

naumoid/iStock via Getty Images
naumoid/iStock via Getty Images

The junk drawer is the MVP of making your home seem meticulously tidy, and it’s also proof that “organized chaos” is a valid method of organization. But you should still be careful about what you toss in there; loose batteries, for example, are a fire hazard.

If metal comes into contact with both the positive and negative posts of a battery, it could cause a short circuit that generates enough heat to start a fire. And chances are pretty good that your junk drawer is currently housing a few metallic materials: paper clips, hardware, coins, keys, tacks, spare chargers, steel wool, pens, and aluminum foil can all pose a threat.

As Reader’s Digest explains, 9-volt batteries are especially unsafe because their positive and negative posts are right next to each other. But even if you’re only storing AA or AAA batteries—or any other batteries where the posts are on opposite ends—it’s probably not worth the risk.

The easiest way to prevent a fire is simply to keep your batteries out of your junk drawer and away from metal objects altogether. If you’re short on space, however, there are a couple other safety measures you can take. The National Fire Protection Association recommends storing batteries in their original packaging, or covering the posts with masking, duct, or electrical tape when you’re not using them [PDF]. You also shouldn’t throw 9-volt batteries in a container with other batteries, since those count as metal objects, too.

Once you’ve fire-proofed your junk drawer, find out how to avoid six other common household fire hazards here.

[h/t Reader’s Digest]

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