Alarming surge in CO2 levels unveiled by ancient ice, study shows

Researchers from Oregon State University have determined that the rate at which atmospheric carbon dioxide levels are increasing is ten times faster than the fastest rate observed over the last 50,000 years. This finding comes from analyzing Antarctic ice cores, allowing scientists to piece together the Earth's atmospheric composition changes over millennia.

The analysis showed that while carbon dioxide levels have fluctuated and generally increased over millennia, the rate of increase we're seeing today is unprecedented.

In the past, the most rapid changes observed were about 14 parts per million (ppm) over 55 years during the Heinrich Events. These were periods when large ice masses broke away from glaciers in the Northern Hemisphere, affecting global water circulation and climate. In stark contrast, we now see similar increases in carbon dioxide levels every 5-6 years, indicating a tenfold acceleration in the pace of change.

Studying ice cores provides insights into the climate of the distant past. In some regions of Antarctica, where temperatures have consistently stayed below freezing for hundreds of thousands of years, ice samples as old as 2.7 million years are found. These ice cores, containing continuous air bubble records, enable scientists to reconstruct the atmosphere's composition across vast timescales, including greenhouse gas concentrations.

Yet, such research is challenging. Only about 1.67 percent of the Antarctic ice sheet surface is suitable for these studies due to melting from geothermal heat and the movement of ice masses. The most valuable ice cores come from glacial blue ice, the oldest and deep within the ice sheet.

The findings from ice core data, combined with ongoing atmospheric measurements, are stark. Continuous measurements since 1958 at Mauna Loa in Hawaii have shown record-breaking levels of CO2 concentration and an unprecedented pace of increase. For instance, CO2 levels rose from 419 ppm to 426 ppm within just two years, a rate of growth that, while partially attributable to natural phenomena like El Niño, underscores the accelerating pace of climate change. According to the latest IPCC report, these climate changes now impact 3.6 billion people.