The amount of carbon dioxide in the atmosphere has reached a new high of 424 parts per million (ppm) in May 2023, according to the latest report from the US National Oceanic and Atmospheric Administration (NOAA).
This is more than 50% higher than the pre-industrial levels of around 280 ppm, and the highest level recorded in human history.
Carbon dioxide is the most common greenhouse gas that causes global warming and climate change. It traps some of the heat that Earth radiates as infrared energy, and thus prevents it from escaping into space.
The NOAA report said that the annual rate of increase in atmospheric carbon dioxide over the past 60 years was about 100 times faster than previous natural increases, such as those that occurred at the end of the last ice age 11,000-17,000 years ago.
“The science is irrefutable: humans are altering our climate in ways that our economy and our infrastructure must adapt to,” said NOAA Administrator Rick Spinrad. “We can see the impacts of climate change around us every day. The relentless increase of carbon dioxide measured at Mauna Loa is a stark reminder that we need to take urgent, serious steps to become a more Climate Ready Nation.”
The report also said that the ocean had absorbed enough carbon dioxide to lower its pH by 0.1 units, a 30% increase in acidity, which affects marine life and ecosystems.
The NOAA measurements were taken at Mauna Loa Observatory in Hawaii, where the modern carbon dioxide record began in 1958. The observatory recorded an annual average carbon dioxide level of 418.56 ppm in 2022.
The report echoed the findings of the Intergovernmental Panel on Climate Change (IPCC), which released a landmark assessment in August 2021. The IPCC said that carbon dioxide was the main driver of climate change, and that stabilizing the climate would require “strong, rapid, and sustained reductions” in greenhouse gas emissions.
“Carbon dioxide concentrations are now comparable to the Pliocene Climatic Optimum, between 4.1 and 4.5 million years ago, when they were close to, or above 400 ppm. During that time, sea levels were between 5 and 25 meters higher than today, high enough to drown many of the world’s largest modern cities,” the IPCC report said.
Scientists have warned that rising carbon dioxide levels will lead to more extreme weather events, such as heatwaves, droughts, floods, storms and wildfires. They have also urged governments and individuals to take action to reduce greenhouse gas emissions from burning fossil fuels, deforestation and other sources.
“How Exactly Does Carbon Dioxide Cause Global Warming?” asked a recent article by Columbia University’s Earth Institute. It explained the physics and chemistry behind the greenhouse effect, and how other factors such as water vapor and methane also contribute to climate change.
“Since the middle of the 20th century, annual emissions from burning fossil fuels have increased every decade, from close to 11 billion tons of carbon dioxide per year in the 1960s to an estimated 36.6 billion tons in 2022 according to the Global Carbon Budget 2022,” said another article by NOAA Climate.gov.
The articles also suggested some ways to learn more about climate change, and some actions to take to reduce greenhouse gas emissions. These included using renewable energy sources, improving energy efficiency, planting trees, eating less meat and dairy products, and supporting policies that promote a low-carbon economy.
Carbon dioxide levels hit new record, now more than 50% higher than pre-industrial times, The Indian Express, June 7, 2023
Climate Change: Atmospheric Carbon Dioxide, NOAA Climate.gov, May 12, 2023
How Exactly Does Carbon Dioxide Cause Global Warming?, Columbia University Earth Institute, February 25, 2021
Climate change widespread, rapid, and intensifying – IPCC, IPCC, August 9, 2021