The Keeling Curve: Atmospheric CO2 Breathing

What is the Keeling Curve?

The Keeling Curve, named after its creator Charles David Keeling, is a graphical representation of the concentration of carbon dioxide (CO2) in Earth's atmosphere. It was first measured at the Mauna Loa Observatory in Hawaii and has been recorded since 1958 by the Scripps Institution of Oceanography. The curve shows how CO2 levels have changed over time, revealing both seasonal fluctuations due to plant growth cycles and long-term increases linked to human activities.

The Keeling Curve is significant because it provides a clear record of the impact of anthropogenic emissions on atmospheric composition, serving as an important indicator of global climate change.

Seasonal Variations in CO2

During spring and summer in the Northern Hemisphere, plants grow rapidly, absorbing CO2 from the atmosphere. This leads to a decrease in atmospheric CO2 concentrations, causing the curve to dip slightly during these months. Conversely, as autumn approaches and plant growth slows or stops, CO2 is released back into the air by respiration and decay processes, leading to an increase in atmospheric CO2 levels.

These seasonal variations are reflected in the sawtooth pattern of the Keeling Curve, with a small but noticeable decrease during spring and summer followed by a rise through autumn and winter.

Long-Term Trends and Human Impact

Over time, the overall trend shown in the Keeling Curve is an upward slope, indicating a long-term increase in atmospheric CO2 levels. This trend is primarily driven by human activities such as burning fossil fuels, deforestation, and industrial processes, which release large amounts of CO2 into the atmosphere.

The rate at which CO2 concentrations are increasing has accelerated over recent decades, highlighting the urgent need for global action to mitigate climate change.

Why Does the Keeling Curve Matter?

The Keeling Curve serves as a critical tool for understanding and monitoring changes in Earth's atmosphere. It provides empirical evidence of the impact human activities have on our planet, supporting scientific research and informing policy decisions related to climate change mitigation.

By tracking CO2 levels over time, scientists can better predict future climate scenarios and develop strategies to reduce greenhouse gas emissions.

Frequently asked questions

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Everything above runs in your browser — open Keeling Curve — Atmospheric CO2 Breathing and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.