In 1985, a sizable hole in our planet’s ozone layer was discovered in the Antarctic region, causing ultraviolet radiation from the sun to impact the Earth without the ozone acting as a buffer. Since then, scientists and world leaders have posited theories as how to heal up the hole. Today, a new study led by the Massachusetts Institute of Technology (MIT) is not only showing that the hole is healing, but it is healing due to mankind’s worldwide efforts.

The ozone layer helps act as a filter or buffer for ultraviolet (UV) rays that come from the sun. While UV rays have some positive effects, there are serious problems when the biosphere is overexposed, according to NASA. Overexposure of UV rays caused by a weakened ozone layer causes issues in the production and yield of crops such as rice, soybeans, and corn. It not only disrupts our food sources, but how other plants and animals eat as overexposure can disrupt photosynthesis in certain plant life and reduce the population of phytoplankton in the ocean. Phytoplankton is not only a food source for many fish species, but also stores large amounts of carbon, which is also an environmental issue.

infrared image of the ozone
The hole in the ozone layer in 2015. Photo credit: Wikimedia Commons

Overexposure to UV radiation also causes several health issues for humans, too. According to the EPA, it increases the risk of and could cause various skin cancers, skin damage, eye damage, and suppression of the immune system.

Given all of these issues, global action had to be taken to see if this rift in the ozone layer could be fixed or, at minimum, the damage could be slowed. In 1976, prior to the discovery of the hole in the ozone layer, F. Sherry Rowland and his team discovered that chlorofluorocarbons (CFCs) damage stratospheric ozone. At the time, CFCs were widely used in various products worldwide such as refrigerators, air conditioners, and aerosol spray cans. By 1986, this was further confirmed. This began the drafting of 1987’s Montreal Protocol, a global agreement to phase down the usage of chemicals and products that have been found to cause damage to the ozone layer.

close up of a an aerosol spray can spraying
In the 1980s, CFCs found in products like aerosol spray cans were found to cause harm to our ozone layer. Photo credit: Canva

Within the past decade, there have been several reports of the ozone layer healing. However, there was no concrete evidence showing that this ozone comeback was due to manmade effort to reduce the usage of ozone depleting substances versus other potential influences, like increased greenhouse gas emissions to the stratosphere or variables in natural weather.

That’s where this recent MIT study comes in. By observing different simulations of the ozone layer’s healing process, the MIT team observed a key pattern or “fingerprint” pointing at a direct correlation between the ozone’s healing and the lessening of CFCs and other harmful chemical gases.

“After 15 years of observational records, we see this signal to noise with 95 percent confidence, suggesting there’s only a very small chance that the observed pattern similarity can be explained by variability noise,” said Peidong Wang, lead author of the study. “This gives us confidence in the fingerprint. It also gives us confidence that we can solve environmental problems. What we can learn from ozone studies is how different countries can swiftly follow these treaties to decrease emissions.”

group photo
Group photo taken at the 30th Anniversary of the Montreal Protocol. From left to right: Paul Newman (NASA), Susan Solomon (MIT), Michael Kurylo (NASA), Richard Stolarski (John Hopkins University), Sophie Godin (CNRS/LATMOS), Guy Brasseur (MPI-M and NCAR), and Irina Petropavlovskikh (NOAA) Photo credit: Wikimedia Commons

In short, this means that human intervention through the Montreal Protocol and other efforts is now proven to be having an impact on our planet. The MIT team predicts that we could see the Antarctic hole in the ozone layer completely healed by 2035 if we maintain our efforts. If we were to turn away from the Montreal Protocol and other such global environment agreements, it would likely reverse the progress being made. After all, this study is showing that mankind has the ability to both break the ozone layer and restore it depending on our collective choices.

  • The drawer problem: Why so many of us can’t let go of our old electronics, and what we can do about it
    Photo credit: Peter Dazeley/Photodisc via Getty ImagesThis look familiar?

    Think about the last smartphone, tablet or smartwatch you stopped using. Odds are it is not in a recycling bin or a new owner’s hands; it is sitting in a drawer.

    From our survey of 4,000 American consumers, we found the single most common thing people did with a device they were finished with was nothing at all: 39% simply stored it. Recycling and reselling, outcomes better for the environment, each accounted for only about 1 in 10 devices. Throwing devices in the trash claimed another 9%.

    What people do with old electronics

    Funded by the National Science Foundation, our multidisciplinary team blended our expertise in causal inferencesustainability and cybersecurity, to work on the tangled question of what people do with their consumer electronics when they’re done using them. We used statistical models to connect what people say – that is, their stated knowledge and attitudes – to what they actually did.

    Why the drawer wins

    Two main forces keep devices in the drawer. The first is anxiety about data. People who worried that recycling or reselling a device would compromise their data were 14% and 9% more likely to store it instead.

    The second force is simply not knowing how to. People who did not know where to recycle were 10% more likely to hold onto a device, and many also kept old gadgets as a perceived data backup.

    Recycling and reselling electronics are a lot easier than a lot of people think. In the U.S., the national chain Best Buy accepts devices for recycling; reselling online is convenient with vendors such as Back Market and Gazelle.

    Just be sure to wipe data before parting with a phone or computer. Also, remove the device from your account, for instance with Apple or Android. Unless you do, the device stays locked to you, and no one else can use it.

    We also compared what people intended to do with what they had actually done. This led to a telling detail: Data security worries led to people storing devices at a greater rate than they said they intended to.

    In other words, the fear of leaking personal data kicks in only when someone is facing the real decision of whether to hand off their device to a recycler or secondhand buyer.

    Getting at why people don’t recycle

    Researchers have long studied why people do or don’t recycle electronics: Convenience, awareness and incentives showed up as affecting the decision. But prior work examined recycling as the only option.

    Instead of considering the issue as a yes-or-no vote on recycling, we treat it as a comparison between different options: Storing, reselling, donating, trading in, recycling and throwing away the device in the trash. When modeling this way, trade-offs became visible.

    Knowing where to recycle, for instance, made recycling 47% more likely, but it also pulled people away from reselling, which is often the more environmentally friendly choice. You can explore the survey results in our interactive dashboards.

    Getting people to let go

    Storage is the worst of both worlds: A device sitting unused for years loses its resale value, and erasing its data only gets harder over time. The good news is that the main barriers – data concerns and not knowing where to turn – can be addressed with better information.

    We are experimenting with information interventions that walk people through their options, including how to securely wipe their data. We are testing nudges with randomized, controlled trials to test what leads people to give their old electronics a second life.

    It might be a good time to remember what old devices you’re holding onto and revisit your reasons for not letting go of them.

    This article originally appeared on The Conversation. You can read it here.

  • How window‑mounted heat pumps can give tenants efficient heating and cooling
    Photo credit: Spencer Platt/Getty ImagesMany U.S. apartments have individual heating and cooling systems that are less efficient than current technology.

    People who rent their homes, or don’t have enough money to make major upgrades to their homes, have for many years been left out of a major shift in heating and cooling technology that can improve efficiency, save money and be better for the global climate: heat pumps.

    Heating and cooling buildings consumes 35% of all the energy used in the United States each year. Many homes and businesses are converting their fossil fuel-powered heating and cooling systems to electric-powered heat pumps, which use electricity not to generate hot or cold air but to move heat into spaces needing warmth and out of spaces needing cooling.

    Until recently, that process has required a significant amount of sizable and expensive equipment to be permanently installed in a building, which needs a professional contractor and can cost as much as US$10,000 just for the installation – in addition to the actual equipment. Often called mini-splits, these systems usually have a condenser outside the building that exchanges heat with the outdoor air and an evaporator inside that exchanges heat with the indoor air.

    A woman stands in a room looking at a boxy piece of equipment in her window.
    The New York City Housing Authority has been installing window-mounted heat pumps in apartments, like this one in Queens. AP Photo

    But now window heat pumps are becoming available in the U.S. Much like a window air conditioner, these self-contained devices can be installed without professional help and plugged into a wall outlet. Unlike window air conditioners, though, they can provide heat as well as cooling. They cost much less than a permanent system – between $3,000 and $4,000 – and can be moved to a new property if the owner relocates.

    There aren’t many options commercially available yet, and those on the market can’t heat or cool very large spaces on their own. And they work less efficiently when heating homes in places with extremely cold outdoor temperatures. A few models are available on the market that are even cheaper, but they don’t have efficiency ratings, don’t work when outdoor temperatures are very cold, and are louder when running.

    I have designed and evaluated a wide range of building energy efficiency technologies; here’s how these window heat pumps work, and why they may allow apartment dwellers and residents of older houses to easily and relatively inexpensively make significant improvements to their homes’ heating and cooling systems. Federal subsidies for this type of equipment expired in 2025, but some utility companies, states and local governments may still offer money to help pay the costs.

    Two window heat pumps available now are very similar

    Moving heat from one place to another

    Heat pumps use a reversible refrigeration cycle and can provide similar heating and cooling as electric-powered space heaters, furnaces and baseboard heaters, while using less than half the electricity.

    The most common heat pumps transfer heat between air indoors and outdoors, but other systems can exchange heat with the ground or with bodies of water, such as lakes.

    Heat pumps’ capacities are defined by the amount of heat they can transfer in a particular period of time. A heat pump serving an entire home may need a capacity of 12,000 to 60,000 British thermal units (about 12,660 to 63,300 kilojoules) – but the window units’ capacities are much lower, getting up to only about 9,000 Btu (9,500 kJ).

    Performance varies based on the conditions outdoors, where the unit is either sending excess heat to cool the indoors or gathering heat to warm the indoors. In cooling mode, heat pumps are rated by their seasonal energy efficiency ratio, a figure that indicates how much cooling is achieved per unit of electricity used. The corresponding measurement for heating is called heating seasonal performance factor. In general, the larger these numbers are, the better they will perform. The U.S. Department of Energy has established minimum standards for those figures.

    While these units operate even when outdoor temperatures are -13 degrees Fahrenheit (-25 degrees Celsius), their heating output is reduced to almost half of its rated capacity, and their energy efficiency falls to one-third of its rated performance at that temperature.

    Apartment climate control costs less with a window unit

    In addition to their low cost compared to conventional split heat pumps, packaged window heat pumps meet heating and cooling needs with lower energy demands and costs. But each window unit serves just one room, while a more common split unit can serve multiple rooms.

    Packaged window heat pumps are easy and inexpensive to install and offer all-in-one heating and cooling options for apartments and older homes, with higher energy efficiency performance than traditional systems. Their main limitations include their low capacities and reduced energy efficiency in extremely cold climates or conditions.

    This article originally appeared on The Conversation. You can read it here.

  • Solar-powered boat feasts on trash and could solve the ocean’s plastic waste problem
    Photo credit: Ocean Cleanup on YouTubeThe Interceptor boat-barge could significantly clean our waters.

    Our oceans have a plastic problem. While it’s difficult to put a 100% accurate number on it, scientists estimated about 4.8 to 12.7 million metric tons of plastic waste entered the ocean in 2010 alone according to the journal Science. This issue has caused scientists and engineers to create a boat-barge in Los Angeles that skims the oceans to gobble up the plastic we leave behind.

    Devised by the non-profit Ocean Cleanup organization, the garbage-gulping Interceptor boat-barge is actually a smaller platform nestled within a larger boat. A floating barrier moves collected trash into the device onto a conveyor belt. An automatic shuttle then collects the trash from the conveyor to send it to a separate barge where there are six dumpsters to hold it. The solar-powered system can hold up to 20,000 lbs. of garbage. The trash is then separated into different categories (plastics, metal, etc.) so they can be disposed of responsibly.

    Catching ocean trash from the source

    Ocean Cleanup hopes to make a dent cleaning the Great Pacific Garbage Patch in the Pacific Ocean. However, they decided to first attack the plastic ocean problem at its source: rivers. When it rains, a lot of trash from the hills and valleys washes down into the nearest river. While there is significant ocean trash taken from beaches, they have found that the lion’s share of garbage that floats into our oceans actually comes from rivers and tributaries that lead into it. Essentially, the plan is to get ocean trash before it even enters the ocean.

    “We have to turn the faucet off before we can scoop the ocean, or else all we’re doing is taking out legacy trash to replace it with new trash,” James Patterson, the operations manager of Ocean Cleanup said to The Guardian. “Before you can clean out the Great Pacific Garbage Patch, you really need to turn off the source.”

    How the Interceptor is helping Los Angeles and beyond

    There is an Interceptor already doing its work at the mouth of Ballona Creek in Culver City, California. Since 2025, the Interceptor has prevented 143,710 lbs. of trash from entering the ocean via the creek. As a bonus, the Interceptor’s trash sweeping has lowered government budgets for beach grooming. Since there is less trash, the beach doesn’t need to be cleaned as often.

    There are two more Interceptors planned to be at the mouths of the San Gabriel River and the Los Angeles River. This can help clean up the rivers for the upcoming 2028 Summer Olympics for aquatic events.

    There are currently 21 Interceptor systems throughout the globe. Countries using them include Indonesia, Vietnam, Jamaica, Guatemala, the Dominican Republic, and Malaysia.

    If this is an issue that speaks to you, you can help even if you don’t live near an ocean. There may be a nearby river or creek that could benefit from volunteer cleanups. Do some research to find an organization near you to volunteer. If you can’t locate one, groups like River Cleanup can help you organize your own group. Much like how a small drop contributes to a large ocean, a small pick-up can make a big difference.

Explore More Science Stories

Science

How window‑mounted heat pumps can give tenants efficient heating and cooling

Environment

Solar-powered boat feasts on trash and could solve the ocean’s plastic waste problem

Science

A bonobo’s make-believe tea party has scientists rethinking whether imagination belongs only to humans

Environment

As climate change causes flooding in London, experts found an effective, low-cost solution: beavers