CO2 levels just broke another record. Here’s what that means

When man first walked on the moon, the carbon dioxide concentration in Earth’s atmosphere was 325 parts per million (ppm). By 9/11, it had risen to 369 ppm, and when COVID-19 disrupted normal life in 2020, it had surged to 414 ppm. This week, our planet reached the highest levels ever directly recorded: 430 parts per million.

For 67 years, the observatory on Hawaii’s Mauna Loa volcano has been diligently taking these measurements daily, tracking the invisible gas that is accumulating in our atmosphere and altering life on Earth. This record is known as the Keeling Curve, named after Charles David Keeling, who initiated these recordings – some of the first in the world to monitor CO2 concentration over time.

Measurements of CO2 at the Mauna Loa Observatory demonstrate a steady increase in levels since record-keeping commenced in 1958. Charles David Keeling’s son, Ralph Keeling, who was born just a year before the observatory’s inception, has witnessed this rapid escalation firsthand throughout his lifetime.

“I was a teenager when I first began to comprehend the significance of my father’s work and how it could be impactful,” Keeling shared with CBC News. At that time, the CO2 concentration was around 330 ppm. Ralph, now a geochemistry professor at the Scripps Institution of Oceanography at the University of California, San Diego, took over the research after his father’s passing in 2005.

“This issue is not going away, and we are delving deeper and deeper into uncharted and undoubtedly perilous territory,” Keeling remarked.

The escalating buildup of carbon dioxide in the atmosphere may not be visible to the naked eye, but its concentration is critical due to the greenhouse effect. Similar to the way glass walls trap heat from the sun in a physical greenhouse, gases in our atmosphere, such as CO2 and methane, also trap heat from the sun.

Ice core samples from the beginning of the Industrial Revolution suggest that CO2 levels were approximately 280 parts per million. As these levels climbed, warming increased by about 1.3°C over the pre-industrial average. Scientists can estimate atmospheric CO2 levels from before record-keeping began by analyzing ice core samples, which indicate fluctuations over the past 800,000 years within a limited range until levels surged following the Industrial Revolution.

The consequences of rising temperatures include more frequent and severe weather events like heatwaves, floods, wildfires, and droughts. While the target of limiting warming to 1.5°C or 2°C above pre-industrial levels is well-known, efforts have also been made to reduce CO2 levels to below 350 parts per million to mitigate the effects of climate change.

Unfortunately, the record highs persist. In the past year alone, CO2 readings from May have increased by over three parts per million, adding more CO2 molecules to the atmosphere and intensifying warming.

“We understand why it is rising faster than ever – it is because we are burning more fossil fuels each year,” emphasized Keeling.

Damon Matthews, a climate scientist and professor at Concordia University in Quebec, shares his concerns, stating that he is not surprised by the annual record-breaking CO2 levels. He asserts that to stabilize atmospheric CO2 levels, global emissions must be slashed by more than 50%, a goal that remains far from reach.

As each May brings a new record of atmospheric CO2, the need for significant progress in climate mitigation becomes increasingly urgent. While there have been some advancements in reducing CO2 emissions in recent years, more decisive action is necessary to combat the escalating crisis.

“We need to cease debating whether climate change is a priority and start implementing solutions that we know will address the problem,” Matthews urged. With the International Energy Agency advocating for a halt to new coal, oil, and gas projects to limit global warming and achieve net-zero emissions by 2050, the time for decisive action is now.