Do Bans on Plastic Bags Work?

Last week, a new study from researchers at Stanford University found that a market-based approach could help sustain not only farmers but also fish. According to the new research, 44 out of 49 fish species native to the Colorado River are threatened, endangered, or extinct. Unless there are considerable cutbacks in water usage in the basin, there could be serious consequences for fish during at least one month of the irrigation season.

The researchers say that existing programs don't prioritize sustaining critical habitats, but if water were directed to the right places, fish could be saved at nominal additional cost. The study shows that by paying those with senior rights to conserve water and then sending it strategically to certain areas, even in drought, fish and ecosystems could be saved. The team says that the “use it or lose it” principle of western water law can be a disincentive to conservation. 

The study modeled water transactions and their impacts in the river’s headwaters, from which about 25 percent of the average annual flows into Lake Powell come. They showed that farmers, irrigating organizations, and municipalities with senior water rights could lease them to governments and environmental groups to protect fish habitat. These strategic transactions would benefit more than 380 miles of the river, and hundreds of ecologically significant miles could see at least partial restoration of fish habitat.

To fund the conservation, the authors suggest that one possible source could be the increasing number of technology companies and corporations that seek to offset water use from data centers and other operations.

The study was published in the journal Nature Sustainability.

The five-day conference in Nice, France—the third and largest ever, with over 15,000 people attending—included the leaders of 60 nations, along with thousands of environmentalists, scientists, and business leaders. Countries are working to ratify the High Seas Treaty, which is meant to protect thousands of species and has so far been ratified by 50 nations, 19 of which delivered their approvals last week at the conference. As soon as 60 nations confirm it, it will come into force.

Ocean health is declining due to rising global temperatures, overfishing, and acidification. According to Earth.com, countries that sign the High Seas Treaty are required to determine the potential effects of any planned activity beyond their national territory. 

At the conference, 95 nations signed a declaration calling for an agreement that would bind countries to end plastic pollution by placing a cap on production, but petrostates, including Saudi Arabia, Russia, and Iran, are against that, and they were supported by the U.S., China, and South Korea.

Currently, only eight percent of the world’s oceans contain Marine Protected Areas (MPAs), which restrict human activity to protect habitats and animals. At the conference, the governments of Tanzania, Chile, and Colombia said they would create or expand their MPAs, and French Polynesia announced it would create the largest MPA in the world, encompassing five million square kilometers.

Attendees of the conference also discussed seabed mining, a practice that French president Emmanuel Macron called madness, as he pressed for a global moratorium. Scientists have warned that there would be irreversible loss of ecosystems and habitats from the mining, not to mention destruction of carbon storage. Greenpeace posted on its website that progress made at the conference was hollow in the absence of more tangible commitments to end deep-sea mining. Recently, the Trump administration has taken steps to allow seabed mining even in international waters. 

When the High Seas Treaty was adopted in 2023, the U.S. actively participated in the process, but it sent only observers to the conference in Nice this June.

Typically, hurricanes form—and grow—with the right mix of sea surface temperature, ocean heat content, and wind shear, but a team from the University of South Florida found that another factor can influence whether a storm will gain strength—rivers.

In a new study, researchers analyzed Hurricane Idalia, which jumped from a Category 1 to a Category 4 in less than 24 hours, as it raced toward Florida’s west coast in 2023. Right before Idalia formed, intense rain fell along the Florida Panhandle and coastal Alabama, dumping a massive plume of fresh water into the Gulf of Mexico. When that fresh water encountered the seawater, it formed a thick barrier that prevented deeper, cooler water from being brought to the surface by the hurricane’s winds, something that typically would weaken storms. Instead, Idalia fed off the trapped warm water and grew, causing widespread damage as it made landfall in Florida’s Big Bend region as a Category 3 storm. 

Meteorologists were caught off guard by Idalia’s rapid intensification, and while the researchers don’t want to overstate the role the rivers play in supercharging storms, they say it’s worth factoring local and regional river activity into forecasts to make them as accurate as possible.

The study was published in the journal Environmental Research Letters.

Now, a new study led by researchers from the University of Delaware and Columbia University says bag policies are working. The team analyzed data from thousands of shoreline cleanups across the U.S. and found that areas with bans or fees had fewer bags on beaches—and in turn, less of the waste entering the ocean. Because regulations across the U.S. vary widely, it made for a useful laboratory to compare the effects of different policies. They found that regulations led to a 25 to 47 percent decrease in the share of plastic bags collected in the cleanups relative to places without policies. 

While that’s good news, they say that laws or ordinances are reducing—but not eliminating—shoreline plastic bag debris, and are most effective in places where plastic was already a big problem. They also found that state-level policies were more successful than ones implemented by a city or county—and interestingly, fees on bags were more useful than bans at reducing the litter.

Despite one in three U.S. residents living in places where bag policies have been instituted, the researchers say the overall percentage of plastic bags is increasing in both places with and without policies. That’s because the pollution is growing in general, and policies can mitigate only so much. Nevertheless, their findings that regulations can make a difference will be useful evidence for the upcoming UN Environment Programme negotiations in August, when countries will gather toward finalizing an international plastics treaty.

The study was published in the journal Science.