Carbon dioxide becomes more potent as climate changes, study finds

A team of scientists has discovered that carbon dioxide becomes a more potent greenhouse gas as it is released into the atmosphere.

The new study, led by scientists at the University of Miami’s Rosenstiel School of Marine, Atmospheric and Earth Science, was published in Science and comes as world leaders gather this week in Dubai, United Arab Emirates, for the United Nations Climate Change Conference, COP28.

“Our finding means that as the climate responds to increased carbon dioxide, carbon dioxide itself becomes a more potent greenhouse gas,” said the study’s lead author, Brian Soden, professor of atmospheric sciences at the Rosenstiel School. “This is further confirmation that carbon emissions must be reduced as soon as possible to avoid the most severe impacts of climate change.”

In this study, researchers used state-of-the-art climate models and other tools to analyze the effect of increasing CO₂ a on a region of the upper atmosphere, known as the stratosphere, that scientists have long known is cooling with increasing CO₂ concentrations. They discovered that this cooling of the stratosphere causes a subsequent increase in CO₂ have a greater heat-trapping effect than previous increases, making carbon dioxide more potent as a greenhouse gas.

The amount of heat trapped in the atmosphere due to a proportional increase in CO₂which scientists call radiative forcing, has long been considered a constant that does not change over time.

“This new finding shows that radiative forcing is not constant but changes as the climate responds to increasing carbon dioxide,” said Ryan Kramer, a physicist at the National Oceanic and Geophysical Fluid Dynamics Laboratory. Atmospheric Administration (NOAA) and alumnus of the study. Rosenstiel School.

Carbon dioxide leads to global warming by trapping heat energy in the climate system.

“Future increases in CO₂ “This will have a more powerful warming effect on the climate than an equivalent increase in the past,” said the study’s lead author, Haozhe He, who carried out his work as part of his doctoral studies at the Rosenstiel school. “This new understanding has significant implications for the interpretation of past and future climate changes and implies that high levels of CO₂ climates may be inherently more sensitive than low CO₂ climates.”

The work was conducted using a suite of climate model simulations provided by the Coupled Model Intercomparison Projects (CMIP), which provide a series of coordinated experiments performed by dozens of the most comprehensive climate models in the world supporting the IPCC assessments. To make their work conclusive beyond the simulated world of climate models, the research team also carried out numerous “offline” radiative flux calculations with very precise radiative transfer models as well as analytical models.