Marvel's current research centers on
climate modeling to better predict how much the Earth's temperature will rise in the future. This work led Marvel to investigate the effects of
cloud cover on modeling rising temperatures, which has proved an important variable in
climate models. Clouds can play a double-edged role in mitigating or amplifying the rate of global warming. On one hand, clouds reflect solar energy back into space, serving to cool the planet; on the other, clouds can trap the planet's heat and radiate back onto Earth's surface. While computer models have difficulty simulating the changing patterns of cloud cover, improved satellite data can begin to fill in the gaps. Marvel has also documented shifting patterns of
soil moisture from samples taken around the world, combining them with computer models and archives of tree rings, to model the effects of
greenhouse gas production on patterns of global
drought. In this study, which was published in the journal
Nature in May 2019, Marvel and her colleagues were able to distinguish the contribution of humans from the effects of natural variation of
weather and
climate. They found three distinct phases of drought in the data: a clear human fingerprint on levels of drought in the first half of the 20th century, followed by a decrease in drought from 1950 to 1975, followed by a final rise in levels of drought in the 1980s and beyond. The mid-century decrease in drought correlated with the rise in
aerosol emissions, which contribute to rising levels of
smog that may have reflected and blocked sunlight from reaching the Earth, altering patterns of warming. The subsequent rise of drought correlated with the decrease in global air pollution, which occurred in the 1970s and 1980s due to the passage of legislation like the
United States Clean Air Act, suggesting that aerosol pollution may have had a moderating effect on drought. At the 2017
TED conference, following computer theorist
Danny Hillis's talk proposing
geoengineering strategies to mitigate global warming, Marvel was brought on stage to share why she believes geoengineering may cause more harm than good in the long run. Marvel returned to the NASA Goddard Institute for Space Studies in 2024, but resigned her position as an associate research physicist in 2026. According to the
New York Times, "citing the
Trump administration's attacks on climate science," she "said in an interview that the administration's actions made it impossible to remain." She stated that "none of [her] internally funded science projects were funded." She remains a visiting scholar at New York University. == Public engagement ==