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


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."

Yes, You Have Too Many Tabs Open on Your Computer—and Your Brain is Probably to Blame

If you’re anything like me, you likely have dozens of tabs open at this very moment. Whether it’s news stories you mean to read later, podcast episodes you want to listen to when you have a chance, or just various email and social media accounts, your browser is probably cluttered with numerous, often unnecessary tabs—and your computer is working slower as a result. So, why do we leave so many tabs open? Metro recently provided some answers to this question, which we spotted via Travel + Leisure.

The key phrase to know, according to the Metro's Ellen Scott, is “task switching,” which is what our brains are really doing when we think we're multitasking. Research has found that humans can't really efficiently multitask at all—instead, our brains hop rapidly from one task to another, losing concentration every time we shift our attention. Opening a million tabs, it turns out, is often just a digital form of task switching.

It isn't just about feeling like we're getting things done. Keeping various tabs open also works as a protection against boredom, according to Metro. Having dozens of tabs open allows us to pretend we’re always doing something, or at least that we always have something available to do.

A screenshot of many tabs in a browser screen
This is too many tabs.
Screenshot, Shaunacy Ferro

It may also be driven by a fear of missing information—a kind of “Internet FOMO,” as Travel + Leisure explains it. We fear that we might miss an important update if we close out of our social media feed or email account or that news article, so we just never close anything.

But this can lead to information overload. Even when you think you're only focused on whatever you're doing in a single window, seeing all those open tabs in the corner of your eye takes up mental energy, distracting you from the task at hand. Based on studies of multitasking, this tendency to keep an overwhelming number of tabs open may actually be altering your brain. Some studies have found that "heavy media multitaskers"—like tab power users—may perform worse on various cognitive tests than people who don't try to consume media at such a frenzied pace.

More simply, it just might not be worth the bandwidth. Just like your brain, your browser and your computer can only handle so much information at a time. To optimize your browser's performance, Lifehacker suggests keeping only nine tabs open—at most—at one time. With nine or fewer tabs, you're able to see everything that's open at a glance, and you can use keyboard shortcuts to navigate between them. (On a Mac, you can press Command + No. 1 through No. 9 to switch between tabs; on a PC, it's Control + the number.)

Nine open tabs on a desktop browser
With nine or fewer tabs open, you can actually tell what each page is.
Screenshot, Shaunacy Ferro

That said, there are, obviously, situations in which one might need many tabs open at one time. Daria Kuss, a senior lecturer specializing in cyberpsychology at Nottingham Trent University, tells Metro that “there are two opposing reasons we keep loads of tabs open: to be efficient and ‘create a multi-source and multi-topic context for the task at hand.’” Right now, for example, I have six tabs open to refer to for the purposes of writing this story. Sometimes, there's just no avoiding tabs.

In the end, it's all about accepting our (and our computers') limitations. When in doubt, there’s no shame in shutting down those windows. If you really want to get back to them, they're all saved in your browser history. If you're a relentless tab-opener, there are also browser extensions like OneTab, which collapses all of your open tabs into a single window of links for you to return to later.

[h/t Travel + Leisure]

Will the Sun Ever Stop Shining?

Viktor T. Toth:

The Sun will not stop shining for a very, very long time.

The Sun, along with the solar system, is approximately 4.5 billion years old. That is about one-third the age of the entire universe. For the next several billion years, the Sun is going to get brighter. Perhaps paradoxically, this will eventually result in a loss of carbon dioxide in the Earth’s atmosphere, which is not good news; It will eventually lead to the death of plant life.

Within 2.5 to 3 billion years from now, the surface temperature of the Earth will exceed the boiling point of water everywhere. Within about about 4 to 5 billion years, the Earth will be in worse shape than Venus today, with most of the water gone, and the planet’s surface partially molten.

Eventually, the Sun will evolve into a red giant star, large enough to engulf the Earth. Its luminosity will be several thousand times its luminosity at present. Finally, with all its usable nuclear fuel exhausted and its outer layers ejected into space, the Sun’s core will settle down into the final stage of its evolution as a white dwarf. Such a star no longer produces energy through nuclear fusion, but it contains tremendous amounts of stored heat, in a very small volume (most of the mass of the Sun will be confined to a volume not much larger than the Earth). As such, it will cool very, very slowly.

It will take many more billions of years for the Sun to cool from an initial temperature of hundreds of thousands of degrees to its present-day temperature and below. But in the end, the remnant of the Sun will slowly fade from sight, becoming a brown dwarf: a cooling, dead remnant of a star.

This post originally appeared on Quora. Click here to view.