Trees surprise with new climate protection aspect
The Consequences of Climate Change are Immense. The Need for Solutions is Urgent. Two research teams independently discovered that natural resources could play a greater role in the fight against climate change than previously assumed. A study revealed that trees can absorb methane, primarily through microorganisms on their bark. Another study suggests that the Southern Ocean surrounding Antarctica could absorb up to 25 percent more CO2 than previously thought.
Trees as Methane Absorbers
"The most significant way to consider the contribution of trees to the environment is through the absorption of carbon dioxide through photosynthesis and the storage as carbon," Vincent Gauci from the University of Birmingham is quoted as saying in a statement from his university. Gauci is the lead author of a study published in the journal "Nature", in which the ability of trees to bind methane was investigated for the first time on a larger scale.
Methane is a 28-times stronger greenhouse gas than CO2 and has contributed 23 percent to global warming since 1750, according to a 2020 study.
Some trees were already known to absorb methane, but not to what extent. Gauci and his team conducted analyses in forested areas in various climate zones - specifically in the Amazon, Panama, Great Britain, and Sweden. They measured the methane flux at different heights on 166 trees. The results were consistent across all climate zones: Trees emit more methane from the lower parts of their trunks, while they absorb more methane above this height. Carbon isotope analysis in the methane provided evidence that microorganisms in the wood and bark are responsible for the gas absorption.
Methane Uptake varies with height
The amount of methane absorption varies depending on the tree species, location, and climate zone within a stem height of 0.5 to 1.5 meters: Above this height, stems and branches absorb more methane than they release. The analysis of carbon isotopes in the methane also indicated that microorganisms in the wood and bark were responsible for methane consumption.
The team led by Gauci measured more than 2000 trees using laser measurement devices to create 3D models of tree surfaces. Based on earlier forest inventories based on satellite images, they found that all trees worldwide absorb between 24.6 and 49.9 million tons of methane per day. This means they could be approximately 10 percent more effective in mitigating global warming than previously thought.
At the Climate Summit COP26 in 2021, the "Global Methane Pledge" was made, committing to reducing global methane emissions by 30 percent by the end of the decade. "Our results suggest that planting more trees and reducing deforestation are certainly important components of any strategy to achieve this goal," said Gauci.
CO2 Uptake in the Southern Ocean Underestimated
In the Southern Ocean, humans do not need to take any action to benefit from nature's power: It is known that the Southern Ocean surrounding Antarctica absorbs CO2. However, the absorption capacity is not consistently answered by various studies depending on the method used.
A group led by Yuanxu Dong from the University of East Anglia in Norwich, UK, has now conducted extensive measurements of CO2 exchange between the atmosphere and the ocean using a new atmospheric measurement technique called Eddy-Kovarianz, for 2500 hours over 175 days. As a result, the scientists found that the Southern Ocean can absorb about 25% more CO2 than is typically considered in climate models.
The researchers explain the difference from previous measurements in part because the high temporal resolution allows for the detection of short-term intensive CO2 uptake events. Additionally, cooling effects at the water surface can be considered in air measurements, according to the study published in the journal "Science Advances". In a statement from his university, Dong states: "This is the first time that a large number of direct observations of the CO2 flux between air and sea have been used to evaluate existing results in the Southern Ocean."
- To combat climate change, Vincent Gauci from the University of Birmingham suggests focusing on nature protection strategies, such as promoting tree planting and reducing deforestation, as trees not only absorb CO2 through photosynthesis but also bind methane, contributing to the mitigation of global warming.
- Education plays a crucial role in climate change awareness, with recent studies showing that trees can absorb methane, a potent greenhouse gas, through microorganisms on their bark, and the Southern Ocean surrounding Antarctica can absorb up to 25% more CO2 than previously thought.
- Preheating buildings is a common practice, but researchers have found that natural preheating, such as the absorbed heat from greenhouse gases in forests, can be a more sustainable approach to heating, reducing the reliance on fossil fuels and contributing to a decrease in CO2 emissions.
