Amid Climate Change Crisis, Some Plants Found to Worsen Air Pollution on a Warming Planet

A new study has unveiled a concerning connection between rising global temperatures and increased emissions of harmful compounds from plants like oaks and poplars.

These emissions were found to contribute to deteriorating air quality, leading to elevated levels of problematic particulate matter and low-atmosphere ozone.

Examining Isoprene Emission From Poplar Plants

Conducted by a team of researchers at Michigan State University, the research focused on examining isoprene emissions from poplar plants.

Isoprene is a significant atmospheric hydrocarbon with both protective effects against environmental stress and contributions to ozone and aerosol formation.

The research sought to comprehend the impact of heightened CO2 levels on isoprene emissions, an essential element in understanding the consequences of climate change.

The findings suggest that elevated CO2 concentrations reduced isoprene emissions, a phenomenon associated with specific alterations in plant metabolic pathways.

Raising Questions

This dilemma has prompted Professor Tom Sharkey of the Plant Resilience Institute to ponder a critical question of considering the removal of all oak trees.

Interesting Engineering reported that he raises essential questions about the trade-off between enhancing a plant's resilience through increased isoprene production and mitigating the worsening air pollution caused by these emissions.

Sharkey emphasized the significance of a comprehensive understanding, as it enables more informed responses to these challenges.

Sharkey noted that isoprene, a hydrocarbon emitted by plants, ranks as the second-highest in terms of emissions on Earth, surpassed only by methane emissions from human activities. Surprisingly, isoprene remains relatively unfamiliar to most people.

According to the study, isoprene undergoes chemical reactions with nitrogen oxide compounds found in air pollution stemming from various sources such as coal-fired power plants and vehicle engines.

These reactions give rise to the creation of ozone, aerosols, and other harmful byproducts. These pollutants harm human health and plant life, contributing significantly to the deterioration of air quality and environmental degradation.

Sharkey also explained the intriguing phenomenon where air flows across urban landscapes, accumulating nitrogen oxides, and subsequently passes over forests, creating a toxic mixture.

"There's this interesting phenomenon where you have air moving across a city landscape, picking up nitrogen oxides, then moving over a forest to give you this toxic brew... The air quality downwind of a city is often worse than the air quality in the city itself," Sharkey noted.

Abira Sahu, a postdoctoral research associate in Sharkey's research group and the study's lead author, said they aimed to identify a specific regulation point in the isoprene's biosynthesis pathway under high carbon dioxide, and they finally got it.

"For the biologists out there, the crux of the paper is that we identified the specific reaction slowed by carbon dioxide, CO2," Sahu noted.

Sahu pointed out that once the temperature reaches 95 degrees Fahrenheit, "there's basically no CO2 suppression," and "isoprene is pouring out like crazy."

During their investigation involving poplar plant leaf, the research team made an intriguing observation: when the leaf was subjected to warming at a temperature of 50 degrees Fahrenheit, it emitted 10 times more isoprene.

This discovery holds the potential to enhance our comprehension of future isoprene emissions from plants and their subsequent impact on the environment. Such knowledge could empower individuals and communities to make informed choices. The team's findings were published in the journal PNAS.