New research shows CO2 levels rising faster than ever before

A slice from an Antarctic ice core. Researchers study the chemicals trapped in old ice to learn about past climate. Credit: Katherine Stelling/Oregon State University.

Researchers have discovered that the current rate of carbon dioxide (CO2) increase in the atmosphere is 10 times faster than at any point in the last 50,000 years.

This significant finding comes from a detailed chemical analysis of ancient Antarctic ice and highlights the unprecedented nature of today’s climate change.

CO2 is a greenhouse gas naturally present in our atmosphere, contributing to the warming of our planet through the greenhouse effect.

Historically, CO2 levels have fluctuated due to natural factors such as ice ages. However, today, human activities, especially the burning of fossil fuels, are causing CO2 levels to rise rapidly.

Scientists study ancient ice from Antarctica, which contains tiny air bubbles trapped over hundreds of thousands of years. By drilling deep ice cores up to 2 miles (3.2 kilometers) and analyzing these bubbles, researchers can learn about past climate conditions.

A new study published in the Proceedings of the National Academy of Sciences focuses on the West Antarctic Ice Sheet Divide ice core. This research reveals that during certain periods of the last ice age, CO2 levels experienced sudden jumps. These findings provide a more detailed understanding of how quickly CO2 levels can change and what that means for today’s climate.

Lead author Kathleen Wendt from Oregon State University explained that the team identified the fastest natural CO2 increases ever observed. These natural increases occurred alongside cold periods in the North Atlantic known as Heinrich Events, which are linked to abrupt climate shifts globally.

During the largest natural CO2 increase, levels rose by about 14 parts per million (ppm) in 55 years. In contrast, today’s rate of CO2 increase, driven largely by human activities, achieves this in just 5 to 6 years.

One key discovery is that past CO2 rises were associated with strengthening westerly winds, which play a crucial role in ocean circulation. These winds caused a rapid release of CO2 from the Southern Ocean, a major carbon sink.

Christo Buizert, a co-author of the study, noted that these Heinrich Events likely involved dramatic changes, such as the collapse of the North American ice sheet, affecting weather patterns and causing large CO2 releases.

Researchers warn that similar changes in wind patterns due to current climate change could reduce the Southern Ocean’s ability to absorb CO2. This is concerning because we rely on the Southern Ocean to absorb a significant portion of human-generated CO2.

“If the westerly winds strengthen as predicted, the Southern Ocean will become less effective at absorbing CO2,” Wendt explained. This means more CO2 could remain in the atmosphere, further accelerating global warming.

The findings underscore the urgency of addressing human-caused CO2 emissions. By learning from past climate events, we gain valuable insights into the potential impacts of today’s rapid CO2 increase.

Reducing emissions and understanding these natural processes are crucial steps in mitigating climate change and protecting our planet for future generations.