Atmospheric carbon dioxide (CO2) has been a driver of climate change during many periods of Earth’s history. This is true even though aspects of Earth’s environment, such as solar insolation, have not remained constant over time. Because such aspects relate to different climate feedbacks, their variation would likely have corresponded to variations in their climatic effects.

A recent study employs a three-dimensional climate system model to study how increasing CO2 could have affected the planet’s climate under scenarios that include solar inputs for the paleo, present, and future Earth. Researchers found that the sensitivity of Earth’s climate to changes in atmospheric CO2 has likely varied through history. This variation was related to the amount of solar energy received by Earth, the starting concentration of CO2 in the atmosphere, and the mean temperature of the planet.

The study, “ Evaluating Climate Sensitivity to CO2 Across Earth’s History,” was published in the journal JGR Atmospheres.
The work was supported through NASA’s Habitable Worlds Program. The NASA Astrobiology Program provides resources for Habitable Worlds and other Research and Analysis programs within the NASA Science Mission Directorate (SMD) that solicit proposals relevant to astrobiology research.