30/09/2024

By Brooke Coupal

Climate change affects the world around us.

Long-term changes in weather patterns have resulted in higher temperatures, rising sea levels and loss of wildlife. This has implications for agriculture and human health. It has played a role in the increase in extreme weather events, from droughts to extreme rainfall.

Climate change has also led to physical changes in plant life, and these changes in turn exacerbate climate change.

“It’s a whole cycle,” says Christopher Skinner, assistant professor in the Department of Environmental, Earth and Atmospheric Sciences (EEAS). “As the climate changes, the vegetation itself begins to change in many different ways, and any of these ways can then cause further climate change.”

Skinner is working with Professor Mathew Barlow from the EEAS to better understand how changes in vegetation such as wild dune grass and towering oak trees contribute to climate change. The National Science Foundation is funding their research with a grant worth almost $400,000.

Photo: Brooke Coupal

Scientists are focusing on three changes in vegetation that are influenced by climate change, the first of which is changes in the plant’s life cycle. Climate change has caused premature leaf emergence, causing plants to draw water from the soil earlier than before.

“This affects soil moisture and can influence extreme weather events such as heatwaves and rainfall,” says Skinner.

Skinner and Barlow are also investigating carbon dioxide (CO2) fertilization, where an increase in CO2 concentration in the atmosphere causes plants to grow faster and more. This causes plants to take up more water from the soil, which also affects soil moisture.

On the other hand, an increase in CO2 levels in the atmosphere can lead to increased water use efficiency, whereby plants do not need as much water to sustain growth. This can cause the soil to become saturated, which promotes flooding during heavy rains.

“We suspect that changes in seasonal patterns and the amount of vegetation could have a significant impact on the risk of several types of extreme events, including wildfires, droughts, floods and heat waves,” Barlow says. “This project will enable us to get a much clearer picture of these relationships.”

Photo: Brooke Coupal

Skinner and Barlow will use computer models from the National Center for Atmospheric Research to analyze the impact of each change in plant life on climate. Models now show how vegetation change as a whole affects climate change, rather than isolating each vegetation change to see what effect it has individually.

“We design model experiments where we can isolate individual effects and quantify them to understand how they affect climate,” Skinner says. “That’s the novel element of what we’re doing — finding a way to isolate these three vegetation processes.”

Scientists involve students in the project, providing them with experience working with climate models. PhD in Earth System Sciences student Ali Fallah ’23 has already gotten involved.

“Vegetation processes are extremely complex,” he says. “Understanding changes in vegetation will enable better predictions of future climate and extreme events.”

Skinner echoed Fallah.

“We hope to determine which vegetation processes are most important so that we can improve these models and better understand future climate,” he says. “We are narrowing down the uncertainty of the future.”