The Earth’s Atmosphere Reaches CO2 Levels Not Seen in Millions of Years

Recent data from the National Oceanic and Atmospheric Administration at the University of California, San Diego, indicates that the Earth’s atmosphere contains millions, and potentially tens of millions, of carbon dioxide molecules.

For the first time ever, the global average concentration of carbon dioxide—a greenhouse gas emitted from burning fossil fuels—surpassed 430 parts per million (ppm) in May. These measurements represent a record high, with an increase of over 3 ppm from last year.

The findings suggest that efforts to curtail greenhouse gas emissions and reverse the growing accumulation of CO2 are insufficient.

“Another year, another record,” stated Ralph Keeling, a professor of climate science, marine chemistry, and geochemistry at the Scripps Institution of Oceanography in San Diego, California; he commented. “I am saddened.”

Carbon dioxide, like other greenhouse gases, traps heat from the sun and can persist in the atmosphere for centuries. High levels of these gases contribute to rising global temperatures and other adverse effects of climate change, including increased sea levels, polar ice melt, and more frequent extreme weather events.

Since the pre-industrial era, CO2 levels in the atmosphere have sharply risen, primarily due to human activities that release greenhouse gases.

Just a few decades ago, crossing the 400 ppm threshold seemed unimaginable. This means that for every million molecules of gas in the atmosphere, over 400 would be carbon dioxide. The planet reached this daunting milestone in 2013. Current warnings suggest that CO2 levels could approach 500 ppm within the next 30 years.

Human society is now in uncharted territory.

According to Keeling, the planet likely experienced such high atmospheric CO2 levels over 30 million years ago, during a time with very different climatic conditions.

He noted the remarkable speed at which CO2 levels are rising.

“It’s changing very quickly,” he told NBC News. “If humans had evolved in an environment with high CO2 levels, the absence of suitable habitats would have likely shaped our evolution. We could have adapted to that world, but instead, we’ve constructed society and civilization based on the climate of the past.”

CO2 levels are typically illustrated using the Keeling Curve, named in honor of Keeling’s father, Charles David Keeling, who began daily atmospheric CO2 measurements in 1958 from the Mauna Loa Observatory in Hawaii.

The Keeling Curve prominently displays the steep rise in CO2 since the Industrial Revolution, attributed to human-induced climate change.

Ralph Keeling and his colleagues at the Scripps Oceanographic Institute reported that the average atmospheric CO2 concentration for May was 430.2 ppm, while NOAA’s Global Monitoring Institute, which has been conducting separate daily measurements since 1974, noted an average of 430.5 ppm for the same month.

Monitoring atmospheric carbon dioxide levels is crucial for understanding how human activities impact the Earth’s climate. These measurements also serve as key indicators of the planet’s overall health.

“These measurements provide insight into the health of the entire system with just one data point,” Keeling explained. “We achieve a comprehensive view of the atmosphere through relatively simple measurement techniques.”