Plants may be able to absorb more carbon dioxide than expected

Recent research suggests that plants could absorb more atmospheric carbon dioxide than previously thought, providing an optimistic perspective on climate change mitigation. However, scientists stress the continued importance of reducing emissions, noting that this discovery does not provide a complete solution.

A new study reveals that plants may absorb more carbon dioxide₂ than expected, providing hope in the fight against climate change. However, reducing emissions remains crucial, because planting trees alone is not a sufficient solution.

New research published on November 17 in Advancement of science He paints an uncharacteristically optimistic picture of planet Earth. This is because more realistic ecological models suggest that the world’s plants may be able to absorb more atmospheric carbon dioxide₂ More human activities than previously expected.

Despite this key finding, the environmental scientists behind the research were quick to stress that this should in no way be taken to mean that the world’s governments can back away from their commitments to reduce carbon emissions as quickly as possible. Simply planting more trees and protecting existing plants is not a golden solution, but research confirms the multiple benefits of preserving such plants.

Understanding Plant Company₂ to exploit

Plants absorb a large amount of carbon dioxide (CO2).₂) every year, thus slowing the harmful effects of climate change, but how long will this carbon dioxide last₂ “Future uptake was uncertain,” explains Dr Jürgen Knauer, who led the research team led by the Hawkesbury Institute of the Environment at the University of Western Sydney.

“What we found is that the well-established climate model used to fuel global climate predictions from the likes of the Intergovernmental Panel on Climate Change predicts stronger and sustained carbon uptake until the end of the 21st century.^street century when it explains the influence of certain critical physiological processes that govern how plants behave Photosynthesis.

“We took into account aspects such as how efficiently carbon dioxide moves through the interior of the leaf, how plants adapt to temperature changes, and how plants economically distribute nutrients in their shade. These are three really important mechanisms that affect a plant’s ability to Carbon “fixation,” however, is commonly ignored in most global models.

Photosynthesis and climate change mitigation

Photosynthesis is the scientific term for the process by which plants convert — or “fix” — carbon dioxide₂ In the sugars they use for growth and metabolism. Carbon fixation is a natural mitigator of climate change by reducing the amount of carbon in the atmosphere; This is increased absorption of carbon dioxide₂ Through vegetation, which is the main driver of the increase in terrestrial carbon stocks reported over the past few decades.

However, the beneficial effect of climate change on plants’ carbon uptake may not last forever, and it has long been unclear how plants will respond to carbon dioxide.₂And temperature and precipitation changes that differ significantly from what we observe today. Scientists have thought that extreme climate change such as extreme droughts and extreme heat could significantly weaken the absorption capacity of terrestrial ecosystems, for example.

Modeling the future of plant carbon uptake

However, in the recently published study, Knauer and colleagues present results from their modeling study set to evaluate a high-emissions climate scenario, to test how carbon uptake by plants responds to global climate change through the end of the 21st century.^street a century.

The authors tested different versions of the model, which varied in their complexity and the realism of how they account for plant physiological processes. The simpler version ignored the three crucial physiological mechanisms involved in photosynthesis, while the more complex version captured all three.

The results were clear: more complex models that incorporated more of our current plant physiological understanding consistently predicted stronger increases in plant carbon uptake globally. The studied processes reinforced each other, such that the effects were stronger when taken together, which is what would happen in a real-world scenario.

Implications for climate change strategies

Silvia Caldararo, assistant professor at Trinity College of Natural Sciences, participated in the study. In the context of the results and their importance, she said:

“Because the majority of terrestrial biosphere models used to assess the global carbon sink are at the lower end of this complexity spectrum, only partially accounting for or completely ignoring these mechanisms, we are likely currently underestimating the impacts of climate change on vegetation as well as its resilience to changes.” Climate We often think of climate models as being about physics, but biology plays a big role and is something we really need to take into account.

“These types of predictions have implications for nature-based solutions to climate change such as reforestation and afforestation and how much carbon such initiatives can sequester. Our findings suggest that these approaches could have a greater impact in mitigating climate change and over A longer period of time than we thought.

“However, simply planting trees will not solve all our problems. We definitely need to cut emissions from all sectors. Trees alone cannot offer humanity a get-out-of-jail-free card.

Reference: “Higher global gross primary productivity under a future climate with more advanced representations of photosynthesis” by Jürgen Knauer, Matthias Kuntz, Benjamin Smith, and Josep J. Canadel, and Belinda E. Medlin, and Alison C. Bennett, Sylvia Caldararo, and Vanessa Havird, 17 years. November 2023, Advancement of science.
doi: 10.1126/sciadv.adh9444