https://www.nytimes.com/2024/01/09/science/rocket-pollution-spacex-satellites.html By Shannon Hall , The New York Times.  Excerpt: In the past few years, the number of rocket launches has spiked as commercial companies — especially SpaceX...and government agencies have lofted thousands of satellites into low-Earth orbit. ...Satellites could eventually total  one million , requiring an even greater number of space launches that could yield escalating levels of emissions. ...scientists worry that more launches will scatter more pollutants in pristine layers of Earth’s atmosphere. ...Already, studies show that the higher reaches of the atmosphere are laced with metals from spacecraft that disintegrate as they fall back to Earth. ...By the time a rocket curves into orbit, it will have dumped in the middle and upper layers of the atmosphere as much as two-thirds of its exhaust, which scientists predict will rain down and collect in the lower layer of the middle atmosphere, the...

https://eos.org/articles/protecting-the-ozone-layer-is-delaying-arctic-melting By Sofia Moutinho , Eos/AGU.  Excerpt: Efforts to protect the ozone layer have unintentionally benefited Earth’s climate. The Montreal Protocol in particular has not only reduced the “ozone hole” but also  slowed global warming . The treaty, a groundbreaking 1989 international commitment to phase out production of ozone-depleting substances, has also delayed the occurrence of the first ice-free summer in the Arctic by up to 15 years, according to a new  analysis  published in the  Proceedings of the National Academy of Sciences of the United States of America ....

https://eos.org/articles/wildfire-smoke-destroys-ozone By Elise Cutts , Eos/AGU.  Excerpt: n the middle of the 20th century, humanity unleashed chlorofluorocarbons (CFCs) into the atmosphere. By the 1980s, CFCs had gnawed away at the planet’s ozone shield, endangering safety and health on Earth. Worldwide restrictions and bans have begun to heal the damage, but new results have suggested that increasingly severe wildfires could be stalling progress. Liquid droplets containing wildfire smoke act like tiny reaction chambers for chlorine in the stratosphere, producing reactive forms of the element that degrade ozone over the midlatitudes, researchers  reported  in  Nature . This chemical mechanism had “never been seen before,” said study coauthor and atmospheric scientist  Kane Stone  of the Massachusetts Institute of Technology. “This is a completely new chemistry that we’re looking at.” Large wildfires are expected to happen more often as the planet warms, s...

https://eos.org/features/setting-the-stage-for-climate-action-under-the-montreal-protocol By  Stephen O. Andersen ,   Marco Gonzalez  and   Nancy J. Sherman , Eos/AGU.  Excerpt:  Twelve papers formed the scientific basis for fast action to strengthen the treaty, which was already safeguarding stratospheric ozone, so it also protects the climate by reducing super pollutants.  ...Joseph Farman and colleagues provided observational evidence of a stratospheric “ ozone hole ” over the Antarctic potentially linked to rising CFC concentrations [ Farman et al. , 1985], which ultimately led to international agreement on the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, better known simply as the Montreal Protocol. Twenty years later, every United Nations (UN) member state had become a party to the Montreal Protocol, ...and the ozone layer was well on the way to recovery [ WorldMeteorological Organization  ( WMO ), 2018; ...

https://eos.org/articles/australian-wildfires-linked-to-ozone-layer-depletion By Krystal Vasquez , Eos/AGU.  Excerpt: The Australian “Black Summer” bushfires produced nearly  1 million tons of smoke  in 2019 and 2020,  wreaking havoc on local air quality . But new research has shown that this is far from the only impact that the smoke had on the atmosphere. According to the study , published in the  Proceedings of the National Academy of Sciences of the United States of America , thunderstorms generated by the intense wildfires thrust smoke particles well into the stratosphere, where they contributed to a 1% loss of the ozone layer. That’s the amount that should have been recovered over the past decade due to the adoption of the Montreal Protocol, said  Susan Solomon , a professor of environmental studies and chemistry at the Massachusetts Institute of Technology and lead author on the paper. “This fire offset that in one blow.”.…

Source: By Jenessa Duncombe , Eos/AGU. Excerpt: The Montreal Protocol halted the destruction of the ozone layer. In the process, it saved one of Earth’s most important carbon sinks. ...The international treaty that phased out the production of ozone-depleting chemicals has prevented between 0.65°C and 1°C of global warming, according to research. The study also showed that carbon stored in vegetation through photosynthesis would have dropped by 30% without the treaty, which came into force in 1989. Researchers from the United Kingdom, New Zealand, and the United States wrote in  Nature  that the  Montreal Protocol  was essential in protecting carbon stored in plants. Studies in the polar regions have shown that high-energy ultraviolet rays (UVB)  reduce  plant biomass and damage DNA. Forests and soil currently absorb  30% of human carbon dioxide  emissions. ...In the simulation, the UVB radiation is so intense that plants in the midlatitudes stop ...

https://www.washingtonpost.com/climate-environment/2021/02/15/these-gases-your-grocerys-freezer-are-fueling-climate-change-biden-wants-fix-that/ Source:  By  Juliet Eilperin  and  Desmond Butler , The New York Times.  Excerpt: Some of the climate impacts of a grocery store trip are obvious, like the fuel it takes to get there and the electricity that keeps its lights glowing, conveyor belts moving and scanners beeping. But then there are the invisible gases seeping out into the atmosphere when you reach for your ice cream of choice. In nearly every supermarket in America, a network of pipes transports compressed refrigerants that keep perishable goods cold. Most of these chemicals are  hydrofluorocarbons  — greenhouse gases thousands of times more powerful than carbon dioxide — which often escape through cracks or systems that were not properly installed. Once they leak, they are destined to pollute the atmosphere. The Biden administration now sees e...

https://eos.org/research-spotlights/an-extraordinary-winter-in-the-polar-north Source:  By   Kate Wheeling , Eos/AGU.  Excerpt: The winter of 2019–2020 in the Northern Hemisphere was one of extremes. The massive region of cold polar air encircled by stratospheric winds, known as the stratospheric polar vortex, was particularly strong, keeping the frigid air whirling above the polar region and leading to a very   mild winter   in many regions farther south. The strong polar vortex coincided with a record-breaking positive   Arctic Oscillation   circulation pattern and record low ozone levels in the Arctic that lasted into spring. In a review, published as part of an AGU   special collection ,   Lawrence et al. outline the unique conditions that allowed this “truly extraordinary” winter season to arise....  

https://eos.org/research-spotlights/model-of-solar-cycles-impact-on-climate-gets-upgrade Source:   By Mark Zastrow,  EoS Earth & Space Science News For Investigation:   10.3 Excerpt: ...Over the course of the 11-year cycle, the rotation of the Sun slowly twists its magnetic field into knots, creating dark sunspots. Although the overall brightness of the Sun varies by only 0.1%, the twisted bundles of magnetic energy can boost its ultraviolet (UV) radiation by 4%–8% at the solar cycle’s peak. These powerful UV rays trigger chemical reactions in the stratosphere that bind oxygen atoms and molecules to form ozone. Since ozone itself is a good absorber of UV radiation, it can heat the stratosphere near the equator, which affects the winds that circle the globe. Increased solar activity also excites Earth’s magnetic field, sending high-energy particles hurtling into the upper atmosphere. During the long polar night, this can generate large amounts of the nitrogen comp...