CO2 levels highest in human history

Published 2019-05-14

Within the past week, sensors at the Mauna Loa Observatory in Hawaii recorded carbon dioxide levels reaching 415 part per million, the highest in human history. Carbon dioxide is a greenhouse gas released by the burning of fossil fuels including coal, oil, and natural gas, which then trap solar radiation in the Earth’s atmosphere. Anthropogenic, or human-caused, release of carbon dioxide is responsible for global temperature increases associated with climate change.

In 2018 alone, carbon dioxide levels in the atmosphere increased 2.7% (approx. 2.5ppm) and this rate is expected to increase in 2019 (approx. 3ppm). The last point at which carbon dioxide reached a similar level was between 5.3 and 2.6 million years ago, during the Pliocene period, far before the emergence of modern humans approximately 300,000 years ago. This increase in carbon dioxide underscores the need for rapid and significant action to reduce fossil fuel emissions and address the impacts of climate change.

You can follow official updates on atmospheric carbon dioxide concentrations on Twitter at @Keeling_Curve. Check out the most recent @Keeling_Curve animation of carbon dioxide levels here: