Study on the changes of the largest terrestrial carbon tank in the world, conducted for the first time worldwide, run at UB

A scientific study conducted at the Faculty of Geography of the University of Bucharest investigated, for the first time internationally, the recent global changes in organic carbon in the soil, considered the largest terrestrial carbon reservoir on the planet.

Thus, in October 2021, the scientific paper entitled “Global changes in soil organic carbon and implications for land degradation neutrality and climate stability” was published in the prestigious journal “Environmental Research”.

The interdisciplinary research, funded by the Romanian Young Academy (RYA), was coordinated by lecturer Remus Prăvălie, PhD, professor and researcher at the Faculty of Geography and founding member of RYA.

The study, valued by the United Nations Convention to Combat Desertification (UNCCD), was included in the famous UNCCD online bookstore.

The results were obtained for the first time in the world of massive carbon losses in the world’s soils after 2001.

The research conducted by lecturer Remus Prăvălie, first author and coordinator of the study, together with an interdisciplinary team of Romanian researchers, started from the premise that global soils, the largest terrestrial carbon reservoir in the world, have not yet been investigated from the perspective of pedological changes recent levels of organic carbon content.

With a huge global reservoir of organic carbon, estimated at about 1500 gigatons (Gt) only in the first meter depth, the planet’s soils contain twice the amount of carbon in the atmosphere (about 750 Gt) or almost three times that present in the biomass of terrestrial vegetation (approximately 560 Gt).Starting from the importance of knowing the dynamics of this huge Earth’s carbon reservoir, the paper was based on the detailed analysis of extremely rare multitemporal data of global organic carbon stocks in the soil from the first 30 cm depth (pedological profile extremely vulnerable to various natural disturbances and anthropogenic), which were acquired from an international database.

Carefully investigating geospatial data (annual global surveys with tons of carbon/km2) between 2001 and 2015, the study found that in just 15 years, the world’s soils had total net carbon losses that exceeded 3 billion tons (or 3 Gt) worldwide. It appears that over 80% of this global carbon decline has occurred in 7 countries around the world, identified as global hotspots of this environmental disturbance – Canada (30%), Russia (27.9%), the United States (9, 6%), China (4.7%), Brazil (4.7%), Indonesia (3%) and Finland (2.9%). Overall, the authors showed that 79% of all countries in the world investigated in this research were affected by net carbon decreases in soil surface profile.

In an interesting comparative perspective, the authors of the study note that the more than 3 Gt of carbon lost from the soil and transferred to the atmosphere represent about 8% of all soil carbon losses recorded globally in the last 12,000 years (Holocene era), in the same pedological profile, although they occurred in only about 0.1% of this time. This comparison highlights an extremely worrying recent acceleration in the decline of the world’s carbon stock. It is also impressive that the quantified losses occurred only in the analyzed profile of 0.3 m depth, without considering the potential additional losses of organic carbon, recorded at higher soil depths.

According to the study, the causes of this massive carbon leakage from the soil into the atmosphere are generally related to accelerated global warming in the boreal regions, aggressive urbanization in temperate environments and expansion of agricultural areas to the detriment of natural ecosystems, through deforestation, especially in intertropical regions.

Based on these alarming results, Remus Prăvălie and his research team have called on the United Nations (UN) to urgently stabilize organic carbon in the soil, through the actions of UNCCD, the global authority on land degradation within the UN. Otherwise, the authors point out that the negative effects of constant carbon losses in the world’s soils are related to the intensification of global climate change, by increasing the greenhouse effect, but also to increase land degradation and loss of soil fertility, with potential repercussions. food crisis in many planetary regions. The full article can be accessed here.

Lecturer Remus Prăvălie, PhD, is the coordinator of several global scientific studies on current environmental issues, such as climate change, land degradation, desertification or radioactive pollution of the environment. Some of his scientific work has attracted the attention of the UN in 2021, which promoted through the UNCCD two other studies on the multi-degradation of global arable land and the examination of all existing land degradation processes on a global scale. Also, some results of his academic activity were disseminated in the international press and, especially in the national one, through a series of interviews given to Radio Romania Cultural and Radio Romania News.

The latest interviews given to these radio stations are related to Earth Day, Environment Day, World Day to Combat Desertification and Drought, International Day against Nuclear Tests and International Day for the Total Elimination of nuclear weapons.