The concentration of carbon dioxide (CO₂) in the atmosphere is measured using precise instruments that analyze the chemical composition of the air. The most common method is infrared spectroscopy, which uses the absorption properties of CO₂ for infrared light. Measurements are made at a worldwide network of monitoring stations, the best known of which is the Mauna Loa Observatory in Hawaii.

🛠️ CO₂ concentration measurement methods

• Direct measurements: Starting in 1958, Charles David Keeling began systematically measuring CO₂ concentrations on Mauna Loa, which led to the creation of the so-called Keeling curve, which documents the continuous increase in CO₂ concentrations in the atmosphere.
• Global network of stations: In addition to Mauna Loa, there are dozens of other stations around the world, including in the polar regions, that provide data on CO₂ concentrations at different latitudes and altitudes.
• Ice core analysis: Analysis of air bubbles trapped in glaciers is used to determine historical CO₂ concentrations. This data allows scientists to reconstruct atmospheric conditions up to 800,000 years ago.

📈 Historical trends in CO₂ concentration

• Pre-industrial era: Before the Industrial Revolution, the concentration of CO₂ in the atmosphere was approximately 280 ppm.
• 20th century: Due to industrialization and increased burning of fossil fuels, CO₂ levels began to rise significantly.
• Exceeding 400 ppm: In 2013, the border was crossed for the first time in recorded history 400 ppm on Mauna Loa.
• Current values: By 2023, CO₂ concentrations continued to rise and values exceeded 420 ppm, which represents an approximately 50 % increase over pre-industrial levels.
• Long-term trends: Ice cores show that current CO₂ concentrations are the highest in the last 800,000 years (and probably longer).

⚠️ Consequences and significance

• Global warming: The rapid increase in CO₂ concentrations is a major cause of climate change because CO₂ traps heat in the atmosphere.
• Historical context: The measurements provide important context for understanding how quickly and to what extent human activity is changing the composition of the air.
• Political decisions: CO₂ monitoring is crucial for assessing the success of international emissions agreements and for forecasting future climate conditions.

Measurements of atmospheric CO₂ concentrations have revealed a relentless upward trend due to human activity. These precise and long-term measurements are essential for understanding the extent of climate change and for making informed decisions on environmental policy and sustainable development. Spring