IU geography professor Natasha MacBean and her team recently received a nearly $900,000 NASA grant to study water-scarce regions and climate change.
MacBean said she will lead a three-year study investigating the role regions with little precipitation play in the global carbon cycle. Dryland regions cover over 40% of the Earth’s surface and are home to over a third of the world’s population, MacBean said.
Her new project will research how carbon moves through these ecosystems to further understand how drylands influence the climate. The project will use these findings to improve global climate models forecasting potential impact, she said.
This field of research is important in light of increased carbon dioxide emissions from fossil fuel combustion, MacBean said.
“Understanding the role of drylands and semi-arid ecosystems in the carbon cycle is well overlooked,” she said. “We know on a global scale that the land and the ocean are absorbing about 50% of our emissions which is good news, but what we don’t know as well is which ecosystems are driving that.”
MacBean said dryland ecosystems have an influential role in controlling the yearly variability of the global carbon cycle because of the ecosystems’ limited water availability. In years with a lot of precipitation, more plants grow in drylands and absorb carbon dioxide from the atmosphere through photosynthesis. In years with less precipitation, she said fewer plants grow and absorb less carbon dioxide.
These ecological processes are lacking in current climate change models, MacBean said. To address this gap, MacBean’s research collaborators from the United States Geological Survey will conduct field research in Utah drylands on different factors relating to carbon cycling in drylands. She said she will then include the findings into a global carbon cycle model showing different simulations of possible climate impacts.
IU environmental science professor Kimberly Novick said MacBean’s research findings will be applicable to non-dryland areas as the drought is expected to increase with climate change.
“The work Natasha is going to do has a lot of relevance for us here in Indiana,” she said. “Climate change is a global problem and the carbon dioxide in the atmosphere is really well mixed, so whatever affects the climate in one part of the world is going to affect the climate in another part of the world.”
O’Neill School professor Mallory Barnes works on similar research at IU and said MacBean’s research on how plants interact with the atmosphere will have implications for the public’s daily lives beyond climate change.
“We don’t just care about plants because of the carbon cycle, but also because they can cool things off when water evaporates,” she said. “If you’re walking from a parking lot into Bryan Park, you’ll notice it's cooler because vegetation has a cooling effect.”