March 9, 2026 Add Us On Google Add SciAm U.S. measles cases surge, AI powers wars, global warming is in a hurry Why measles cases are rising in the U.S., how artificial intelligence is shaping warfare, and what accelerated global warming means for the world By Kendra Pierre-Louis , Sushmita Pathak , Joseph Howlett & Alex Sugiura wildpixel/Getty Images SUBSCRIBE TO Science Quickly Apple | Spotify | YouTube | RSS Kendra Pierre-Louis: For Scientific American ’s Science Quickly , I’m Kendra Pierre-Louis, in for Rachel Feltman. You’re listening to our weekly science news roundup. First, we have an update on measles cases in the U.S. South Carolina’s measles outbreak grew to nearly 1,000 cases last week, according to data from the state department of health . The outbreak, which began last October, was part of a wave of measles outbreaks across the country that began in 2025. According to the Centers for Disease Control and Prevention , there were 50 reported measles outbreaks last year, contributing to more than 2,200 confirmed cases and three deaths. That was the largest number of confirmed measles cases since the U.S. was declared measles-free in 2000 . So far this year there have been more than 1,100 confirmed cases, according to the CDC. The vast majority have been among unvaccinated people. The surge in cases is pushing the U.S. dangerously close to losing its measles-free status. A country having measles-free or measles elimination status doesn’t mean that it has zero cases of measles but rather that it has not had continuous homegrown transmission of the virus lasting over 12 months. Canada lost its elimination status in 2025. Spain, Austria, Armenia, Azerbaijan, the U.K. and Uzbekistan all lost their measles-free status in January. A special meeting originally slated for April to determine if the U.S. would retain its elimination status has been pushed back to November. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing . By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Among infections that spread through human-to-human contact the measles virus is one of the most contagious known to science. In the early days of the COVID pandemic much attention was paid to the coronavirus’s R 0 , a metric used to estimate how many people an infected person will go on to infect. In early 2020 the World Health Organization estimated that the coronavirus’s R 0 was between 1.4 and 2.5, meaning a person with the virus was likely to spread it to between 1.4 and 2.5 people. The R 0 for measles is between 12 and 18 , meaning a person with measles is expected to infect more than a dozen people, assuming the people they encounter are not vaccinated or otherwise immune. Measles is such an effective spreader in part because the virus can linger in the air and remain infectious for up to two hours. That means a person can be infected with measles and never directly encounter the person who sickened them. In fact, in 1991 during an international sporting competition a single athlete with measles infected 16 people, including two spectators sitting roughly 100 feet away from him , according to a study. In the U.S. approximately one in five individuals who get measles, or 20 percent, will be hospitalized. Roughly one in 1,000 will develop brain swelling that can lead to brain damage. Up to three in 1,000 will die. For those who survive, the effects of the infection can endure long after they’ve seemingly beaten back the virus. Even a decade after infection it’s possible to develop subacute sclerosing panencephalitis, a rare but fatal neurological condition. A measles infection can also trigger something known as “ immune amnesia ,” wiping out up to 70 percent of a person’s antibodies, thus causing their body to “forget” how to fight off infections. The person remains more vulnerable to secondary infections for some time—potentially up to five years, according to one study. Human Health Secretary Robert F. Kennedy Jr. has spent much of the past year muddying the waters on the benefits of vaccinations. But last week acting CDC director Jay Bhattacharya posted a video on X, formerly Twitter, urging people to get vaccinated. [CLIP: Jay Bhattacharya speaking in an X video posted by the CDC on March 2: “Measles is preventable, and vaccination remains the most effective way to protect yourself and those around you.”] Pierre-Louis: Next, let’s dive into how AI is potentially accelerating warfare. The U.S. military reportedly used Anthropic’s AI model Claude as it began its recent airstrikes against Iran, according to the Wall Street Journal . Airstrikes from the U.S. and Israel have reportedly killed a significant number of Iran’s senior leader