Plants may be absorbing more CO2 than previously thought, according to a new study.

Newswise — New research published today in a leading international journal Scientists progress paints an unusually optimistic picture of the planet. Indeed, more realistic ecological modeling suggests that the planet’s plants may be able to absorb more atmospheric CO.₂ human activities than expected.

Despite this major finding, the environmental scientists behind the research are quick to point out that this should in no way be interpreted to mean that governments around the world can ease up on their obligations to reduce carbon emissions the fastest. possible. Planting more trees and protecting existing vegetation is not a silver bullet, but research highlights the multiple benefits of retaining such vegetation.

“Plants absorb a significant amount of carbon dioxide (CO₂) each year, thereby slowing the harmful effects of climate change, but to what extent they will continue to produce these CO emissions₂ future adoption is uncertain,” explain Dr Jürgen Knauerwho led the research team led by the Hawkesbury Institute for the Environment at Western Sydney University.

“What we found is that a well-established climate model, used to power global climate forecasts made by bodies like the IPCC, predicts stronger and more sustained carbon uptake through the end of the 21^st century when reporting the impact of certain critical physiological processes that govern how plants carry out photosynthesis.

“We considered aspects such as how efficiently carbon dioxide can move inside the leaf, how plants adapt to changes in temperature, and how plants distribute nutrients in the most economical way possible in their canopy. These are three very important mechanisms that affect a plant’s ability to ‘fix’ carbon, but they are generally ignored in most global models,” Dr Knauer said.

Photosynthesis is the scientific term for the process by which plants convert – or “fix” – CO.₂ in the sugars they use for growth and metabolism. This carbon sequestration serves as a natural mitigator of climate change by reducing the amount of carbon in the atmosphere; it is this increased absorption of CO₂ by vegetation, which is the main driver of the increase in the terrestrial carbon sink reported in recent decades.

However, the beneficial effect of climate change on carbon uptake by vegetation may not last forever and it has long been unclear how vegetation will respond to CO.₂, temperatures and precipitation changes very different from what is observed today. Scientists believe that intense climate change, such as more intense droughts and intense heat, could significantly weaken the retention capacity of terrestrial ecosystems, for example.

However, in the study published this week, Knauer and colleagues present the results of their modeling study aimed at assessing a high-emissions climate scenario, to test how carbon uptake by vegetation would respond to global climate change until ‘at the end of the 21st.^st century.

The authors tested different versions of the model that varied in their complexity and realism in how plant physiological processes are accounted for. The simpler version ignored the three critical physiological mechanisms associated with photosynthesis, while the more complex version accounted for all three mechanisms.

The results were clear: more complex models that better integrated our current understanding of plant physiology consistently predicted greater increases in carbon uptake by vegetation on a global scale. The processes considered reinforced each other, so the effects were even stronger when considered in combination, which would occur in a real-world scenario.

Silvia Caldararu, assistant professor at Trinity School of Natural Sciences, participated in the study. Contextualizing the results and their relevance, she said:

“Given that the majority of terrestrial biosphere models used to assess the global carbon sink fall at the lower end of this range of complexity, only partially accounting for these mechanisms or ignoring them completely, it is likely that we We currently underestimate the effects of climate change on vegetation. as well as its resilience to climate change. We often think of climate models as a matter of physics, but biology plays a huge role and it’s something we really need to consider.

“These kinds of predictions have implications for nature-based solutions to climate change, such as reforestation and afforestation, and how much carbon these initiatives can absorb. Our results suggest that these approaches could have a greater impact on climate change mitigation and over a longer period of time than we thought.

“However, planting trees will not solve all our problems. We absolutely must reduce emissions from all sectors. Trees alone cannot offer humanity a get out of jail free card.