National Academies of Sciences Archives

April 13, 2023

Amid efforts to cool the planet, solar geoengineering draws heated debate

By Shannon Kelleher

Luke Iseman got tired of waiting for the world to stop climate change so he decided to try it himself. The founder of a controversial two-person startup called Make Sunsets has begun launching balloons filled with sulfur dioxide high into the sky with the intention of imitating the effects of volcanic eruptions. The molecules are meant to act like little clouds, cooling the planet by reflecting sunlight back into space before it reaches the Earth’s lower atmosphere.

Iseman’s venture into the relatively new arena known as solar geoengineering is drawing its own heat in the form of criticism from scientists amid an intensifying debate – should the world at least explore once-unthinkable measures that some say might buy time to address climate change?

The window to keep warming under 1.5 degrees Celsius (2.7 degrees Fahrenheit) in order to prevent dramatically more severe global impacts is closing fast. Earth is on track to hit that threshold “in the first half of the 2030s,” according to an Intergovernmental Panel on Climate Change (IPCC) report released last month.

Many scientists oppose geoengineering strategies, defined as interventions in the earth’s oceans, soils and atmosphere that reduce climate impacts such as extreme temperatures, variability in water availability, and the severity of storm systems. Solar engineering specifically focuses on masking the effects of climate change caused by greenhouse gases, although it isn’t a permanent fix since it doesn’t actually get rid of these gases.

Critics say further tinkering with Earth’s climate using new technologies could have dire unintended consequences such as acid rain and health problems, as well as rapid global temperature rises if such interventions were stopped without fixing the problem at its root. Some fear that investing research into such drastic avenues could create illusions of a cheap fix at a moment when there is no time to spare.

Even those in favor of studying solar geoengineering say they still have no idea if it should actually ever be used –the research is too early and the risks and effectiveness of such strategies are not well understood.

But Iseman, who has a history of launching startups and holds an economics degree from the Wharton Business School, says it’s past time to begin deploying and scaling up the untested technology.

March 8, 2023

Communities wrestle with pricey PFAS clean-up efforts

By Sascha Brodsky

On a recent wintry day, Deborah Brown walked along the edge of Lake Washington in Newburgh, New York, and pointed to a sign warning people not to fish because the waters are known to be contaminated with toxic chemicals.

“You wouldn’t want to eat the fish you catch,” Brown, a member of the Newburgh Clean Water Project, told a visitor.

Newburgh is one of many communities around the United States – indeed, around the world – now grappling with the knowledge that their landscapes and lives have come under threat from a class of chemicals known as per- and poly-fluoroalkyl substances (PFAS) that are being found throughout the environment.

Scientists have linked PFAS exposure to various health problems, including cancer, congenital disabilities, and liver disease. PFAS are known as “forever chemicals” because they do not break down easily and accumulate over time. Studies have estimated PFAS to be present in the blood of an estimated 97% of Americans and in hundreds of species of wildlife around the globe.

Last year, the Biden administration announced plans to “research, restrict, and remediate harmful PFAS,” and the US Environmental Protection Agency (EPA) has rolled out an array of strategies, including sharply lowering the allowable levels of certain types of PFAS in drinking water. The action is expected to trigger billions of dollars in spending on clean-up efforts across the country.

But for impacted communities, eradicating PFAS contamination – if that is even possible – can’t come fast enough.

July 28, 2022

PFAS testing needed for people with elevated exposures, US science advisors warn

US government health agencies need to move quickly to launch broad testing of people exposed to types of toxic chemicals known as PFAS to help evaluate and treat people who may suffer PFAS-related health problems, according to a report issued today by the National Academies of Sciences, Engineering, and Medicine (NASEM).

The report recommends that the Centers for Disease Control and Prevention (CDC) advise clinicians to offer PFAS blood testing to their patients who are likely to have a history of elevated exposure to the toxins. Those test results should be reported to state public health authorities to improve PFAS exposure surveillance, NASEM said.