What is Keeling Curve ?

The change in CO2 content with time is widely referred to as the Keeling Curve .

In 1858, Charles Keeling began measuring CO2 at a newly established observatory on the top of Hawaii’s Mauna Loa Volcano 

The Keeling Curve shows two interesting features 

First , each year, carbon dioxide (CO2) concentrations peak in May before gradually declining until October, when they start to climb again. 

This fluctuation is primarily due to seasonal changes in plant activity in the Northern Hemisphere. During early summer, plants undergo rapid growth, effectively absorbing CO2 from the atmosphere. However, as fall approaches, many plants either become dormant or die, leading to decay and a subsequent release of CO2 back into the atmosphere. This cyclical process resembles a natural rhythm of breathing, albeit on a much larger scale.

The Keeling Curve 

Second , Since the initiation of measurements by Keeling in 1958, atmospheric CO2 levels have experienced a significant and rapid increase. At that time, the average concentration of CO2 was recorded at 315 parts per million (ppm). By 2006, the CO2 levels had risen to 380 ppm, showing a trend of approximately 2 ppm increase annually. This rate of rise is substantially higher than what can be accounted for by common natural phenomena and is unprecedented in the historical climate record. 

The increase in atmospheric CO2 and other greenhouse gases is primarily a result of human activities, which include the burning of fossil fuels, cement production, and various other industrial processes. Collectively known as anthropogenic emissions, these activities are significant contributors to the rise in greenhouse gas levels.