‘This shouldn’t be happening’: levels of banned CFCs rising

Researchers have detected increased emissions for five ozone-depleting chlorofluorocarbons.

Katherine Bourzac

Nature | April 03, 2023

Researchers detected a surprising rise in levels of chlorofluorocarbons between 2010 and 2020 using a monitoring network that includes the Jungfraujoch research station in Switzerland.Credit: Shutterstock

The Montreal Protocol, which banned most uses of ozone-destroying chemicals known as chlorofluorocarbons (CFCs) and called for their global phase-out by 2010, has been a great success story: Earth’s ozone layer is projected to recover by the 2060s.

So atmospheric chemists were surprised to see a troubling signal in recent data. They found that the levels of five CFCs rose rapidly in the atmosphere from 2010 to 2020. Their results are published today in Nature Geoscience1.

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Nord Stream pipeline blasts stirred up toxic sediment

The explosions happened in a dumping ground for chemical warfare, but other contaminants proved most toxic to marine life.

Katharine Sanderson

Nature | March 15, 2023

The harbour porpoise is among the species threatened by the Nord Stream blasts.Credit: Minden Pictures/Alamy

The explosions that blasted holes in the underwater Nord Stream gas pipelines kicked up long-buried toxins at levels high enough to threaten marine life for more than a month, analysis of the site suggests.

Last September, a series of four explosions ruptured the Nord Stream 1 and 2 gas pipelines — which run from Russia to Germany — close to the Danish island of Bornholm in the Baltic Sea, releasing more than 100,000 tonnes of methane into the sea and the atmosphere. It isn’t clear who was behind the explosions, but the most recent speculation is that a pro-Ukrainian group was responsible.

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Why rain on snow in the California mountains worries scientists

Rain-on-snow events have resulted in some of the nation’s most destructive and costly floods

Keith Musselman

Down To Earth | March 15, 2023

Another round of powerful atmospheric rivers is hitting California, following storms in January and February 2023 that dumped record amounts of snow. This time, the storms are warmer, and they are triggering flood warnings as they bring rain higher into the mountains – on top of the snowpack.

Professor Keith Musselman, who studies water and climate change at the University of Colorado’s Institute of Arctic and Alpine Research, explained the complex risks rain on snow creates and how they might change in a warming climate.

What happens when rain falls on snowpack?

For much of the United States, storms with heavy rainfall can coincide with seasonal snow cover. When that happens, the resulting runoff of water can be much greater than what is produced from rain or snowmelt alone. The combination has resulted in some of the nation’s most destructive and costly floods, including the 1996 Midwest floods and the 2017 flood that damaged California’s Oroville Dam.

Contrary to common belief, rainfall itself has limited energy to melt snow. Rather, it is the warm temperatures, strong winds and high humidity, which can transport substantial energy in the form of latent and sensible heatthat predominantly drive snowmelt during rain-on-snow events.

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Glimpse beneath iconic glacier reveals how it’s adding to sea-level rise

Data-gathering instruments under the melting Thwaites Glacier are helping researchers to figure out how the ice will change in future.

Nicola Jones

Nature | February 15, 2023

Previous studies have shown that the Thwaites Glacier is rapidly retreating.Credit: Cover Images via ZUMA Press

Researchers have dropped a submersible vehicle down a hole in Antarctic ice to get their closest-ever look at the underside of Thwaites Glacier — a massive and increasingly unstable body of ice that has become an icon of climate change — and the first-ever glimpse at the spot where the ice meets the land.

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Accra is congested, but relocating Ghana’s capital is not the only option

Accra could keep its political role, but some of its facilities and services should be distributed around the country

Stephen Appiah Takyi, Owusu Amponsah

Down To Earth | February 01, 2023

Capital cities play an important role in the socio-economic development of every country. People generally move to cities where there are opportunities.

Accra, Ghana’s capital, demonstrates this pull effect — and the problems it can create, like congestion and development planning issues.

One of the consequences has been regular flooding, which has claimed lives and property. Over the years, the city authorities have tried to decongest Accra, without success. The city is now demolishing illegal structures, especially those close to waterways.

Some people have suggested that Accra’s congestion problem could be solved if the capital were to be moved to another city. Others disagree.

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Plastic pollution in Nigeria: whose job is it to clean up the mess?

Nigeria’s rivers, lakes and ocean are also full of discarded plastic

Kehinde Allen-Taylor

Down To Earth | February 01, 2023

Take a walk or drive through the streets of most Nigerian cities, and you will see plastic waste everywhere. The country’s rivers, lakes and ocean are also full of discarded plastic. Nigeria is estimated to generate about 2.5 million tonnes of plastic waste annually. Plastic accounts for 15% of the total waste generated in Lagos State.

The situation is likely to worsen as Nigeria’s population grows, from more than 220 million people now to an expected 401 million by the end of 2050.

The production of plastic is growing too. Dangote Refinery, the largest petrochemical refinery in Africa, is starting operations in Nigeria in the first quarter of 2023. Aside from refining fuel, the plant will also produce plastic products.

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Floods, tornadoes, landslides: This January was the 6th-warmest on record for United States

From the end of December to January 17, there were 700 landslides in western US

Akshit Sangomla

Down To Earth | February 09, 2023

The United States witnessed an unusual January, characterised by colder-than-normal conditions with rain and ice in the south, warmer-than-normal conditions in the north and record-breaking rains and floods in the west. 

Overall, it was the sixth-warmest January on record for the country, according to the National Oceanic and Atmospheric Administration (NOAA).

The new year started off on a wet note for western US, especially California, as the atmospheric rivers that had formed in the last week of December continued to pour rain and snow, causing flash floods and mudslides for three weeks. 

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Seychelles is becoming overwhelmed by marine plastic — We now know where it comes from

Plastic debris is strewn across Aldabra’s coastlines, threatening nearby marine ecosystems

by Noam Vogt-Vincent, April Burt

Down To Earth | February 01, 2023

A green turtle on Aldabra entangled in abandoned fishing gear. Photo: Rich Baxter, CC BY-NC-ND A green turtle on Aldabra entangled in abandoned fishing gear. Photo: Rich Baxter, CC BY-NC-ND

More than 1,000km southwest of Mahé, the main inhabited island in Seychelles, lies a ring of coral islands called the Aldabra Atoll. The islands are a Unesco world heritage site and support a huge diversity of marine species including manta rays and tiger sharks.

The atoll is also a breeding site for endangered green turtles.

Aldabra has long been protected from threats to its biodiversity by its remoteness. But now plastic debris is strewn across Aldabra’s coastlines, threatening nearby marine ecosystems. Research finds the likelihood of coral disease increases from 4 per cent to 89 per cent when coral are in contact with plastic.

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Himalayan plunder: Certain Himalayan towns at greater risk

While the entire Himalayan region is fragile, the zones that receive snow and rain are the most unstable

by Manoj Kumar , Raj Kiran Dhiman

Down To Earth | February 06, 2023

This article is part of a special edition on the Himalayas, published in February 1-15, 2023, issue of Down To Earth magazine 

The last few decades have recorded rapid and magnified natural catastrophes across the world, with scientists linking such extreme events with global warming. The Himalayas have recorded such calamities like earthquakes, avalanches, cloud-bursts, intense rainfall landslide lake outburst floods (LLOFs are breaching of lakes formed by obstructions due to landslides), and glacial lake outburst floods (GLOFs are a sudden release of a significant amount of water retained in a glacial lake) in their most furious forms; ground studies indicate a warming climate as the cause.

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Earth’s 6th Mass Extinction: Climate Crisis, Pollution, Depleting Resources Could Extinct 27% Of World Animal Life

 Countercurrents Collective | December 20, 2022

The planet has entered the sixth mass extinction. Pollution, climate change and depleting resources could drive up to 27% of the world’s animal life to extinction, a new paper has claimed. The study used a supercomputer to map out how interdependent food chains could collapse in the coming decades.

Published on Friday and authored by European Commission scientist Giovanni Strona and Professor Corey Bradshaw of Flinders University in Australia, the study (Coextinctions dominate future vertebrate losses from climate and land use change, GIOVANNI STRONA HTTPS://ORCID.ORG/0000-0003-2294-4013 AND COREY J. A. BRADSHAW HTTPS://ORCID.ORG/0000-0002-5328-7741DOI: 10.1126/sciadv.abn4345) presented a series of increasingly grim scenarios. The researchers claimed that the magnitude of the coming extinctions will depend largely on how much carbon mankind emits over the coming century.

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