US Life Expectancy rises to 79 years in 2024

For the first time, USA's life expectancy exceeded pre-pandemic levels, which had peaked at 78.8 years in 2014. Decreases in mortality rates from 2023 to 2024 occurred for unintentional injuries, COVID-19, heart disease, cancer, and homicide, according to the CDC.

The USA's life expectancy remains 3.7 years behind the average among comparably wealthy countries. Explanations for the higher mortality in the USA often focus on highly processed foods and a sedentary lifestyle, in addition to substance abuse, violence, and motor vehicle injuries.

For details on the 2024 life expectancy estimate, see the CDC Report. The “Results” section begins on page 5, where Figure 1 shows historical trends in life expectancy in the USA. This is one of many reports from the CDC's National Vital Statistics division.

CO2 levels reach 432ppm in May 2026

CO2 levels in May of 2026 were 2 parts per million higher than in May of 2025 and 24 ppm higher than May of 2016, according to data from the Mauna Loa Observatory in Hawaii. For more information, see NOAA's “Earth Indicators” website.

About STEM briefs

The purpose of this blog is to provide brief updates on topics in Science, Technology, Engineering, and Math, with links to high quality, freely accessible sources that can provide the full story.

Sometimes the briefs will be updates about ongoing issues, just providing the most recent developments on the topic (e.g. Atmospheric CO2 and Global mean temperatures). Others will be notices about authoritative summaries on a topic that were just released (e.g. reports from The National Academies).

I will avoid sensationalism that keeps you coming back for more updates, and will instead try to provide a chunk of information that lets you walk away with a better understanding of the world. I do not intend to include 'breaking news', especially before findings have been replicated or when the implications are largely speculative. However, if a recent announcement immediately fits into a well understood body of theory (e.g. detection of gravitational waves), I may point to a story describing the significance. I'll stay away from politicized hyperbole and 'inside baseball' about scientific institutions, but will include reviews that describe how scientific institutions operate.

The briefs are meant to keep you up to date on developments in STEM since you took high school science class 20 years ago.