As the EU Wildlife Restoration Act continues to be a hot topic in public and academic debate, we begin our review of the literature with a critical analysis of one of its demands. It concerns the reforestation of drained peatlands. Scientists prove that this is not the way to go. Another group of scientists is going deep beneath the Earth to see how new human activities related to energy transition (lithium mining, geothermal energy extraction or geologic carbon sequestration) can affect fluid flow in the Earth’s deep subsurface.
There is also an interesting publication about intrusions in oceanic waters, which act as elevators that carry organic matter from the near-surface layers into deep aphoric zones. The report verifies our knowledge of vertical carbon transport in tropical oceans. Unfortunately, the impact of human activity on these unique ecosystems is manifested in their pollution, including by toxic metals. The level of thallium in the Baltic Sea has increased significantly in the postwar period, scientists report on the basis of examination of water samples and sediment cores. Finally, we present a new and user-friendly tool for probabilistic climate projection analysis, based on open-science R software. Let’s use responsibly!
1. active afforestation of drained peatlands is not a viable option under the EU Nature Restoration Law
Jurasinski G., Barthelmes A., Byrne K.A. et al. (2024). Active afforestation of drained peatlands is not a viable option under the EU Nature Restoration Law. Ambio (2024).
The EU’s Nature Restoration Law (NRL) is key to restoring degraded ecosystems, and one of the measures proposed under the NRL and aimed at increasing carbon sequestration is afforestation of degraded peatlands. The action seems right, but the devil, as usual, is in the details, and we should take a close look at the balance of its effects before acting on it. This was done by an international team of dozens of scientists (including from Poland), who reviewed the state of knowledge and scientific evidence on the impact of peatlands under afforestation on climate change mitigation.
As the authors show, in a paper published in Ambio, evidence of the long-term benefits of such an action is currently very sparse, and it is unclear whether forest carbon sequestration on drained peatlands can offset the loss of carbon from these areas. It is known that in the forested peatlands of the northern areas much more carbon is stored in peat than in forest biomass, so long-term losses are likely to be greater than the amount stored.
The authors point out that active afforestation of drained peatlands is not an appropriate option under EU nature restoration law, and may hinder rewetting/restoration efforts in degraded areas. As the researchers point out, afforestation in this case is not restoration. The only way to restore these valuable ecosystems is to irrigate them again, and to introduce natural peatland vegetation, which can speed up the recovery process. Even if rewetting does not restore all the functions of peatlands, it is still worth it.
2. Acceleration of Deep Subsurface Fluid Fluxes in the Anthropocene
Ferguson G., Bailey L.R., Kim J.-H. et al. (2024). Acceleration of Deep Subsurface Fluid Fluxes in the Anthropocene. Earth’s Future, 12 (4).
The impact of human activities, including greenhouse gas emissions and deforestation, on changes in the water cycle at the Earth’s surface and near-surface layers is relatively well recognized. Much less attention, however, has been paid to the scale of anthropogenic changes at greater depths, below typical wells. Hydrologists at the University of Arizona have studied how humans affect flows in the deep subsurface (at depths of hundreds of meters to several kilometers), as well as how they will change in the coming century and how this may affect geochemical cycles and microbial communities.
Anthropogenic impacts on fluid fluxes in the deep subsurface (>500 m) are and are likely to continue to be dominated by groundwater, oil and natural gas extraction. However, this process will be exacerbated by energy transition activities, such as lithium extraction from underground brine, geothermal energy extraction, hydrogen storage and production, or geologic carbon sequestration (the capture and storage of atmospheric carbon dioxide in underground porous rocks).
These activities are likely to leave a mark on the Earth’s geological record. They can also change the composition of the microorganisms living there by modifying the chemical conditions of the water or by introducing communities from the Earth’s surface. However, the scale and significance of these changes are difficult to predict due to a lack of sufficient knowledge regarding how deep subsurface hydrological and geochemical cycles and associated microbial life affect the rest of the Earth system.
3. 3D intrusions transport active surface microbial assemblages to the dark ocean
Freilich M.A., Poirier C., Dever M. et al. (2024). 3D intrusions transport active surface microbial assemblages to the dark ocean. Proceedings of the National Academy of Sciences, 121 (19).
The subtropical oceans make a huge contribution to global primary production, but the role of picoplankton, which is the dominant element in these ecosystems, is poorly understood. The 2017-2019 research in the subtropical Mediterranean Sea shows how microorganisms that are too light to submerge deeper than 100 meters end up in the lower zones of the ocean, and what role they play in transferring organic carbon from well-lit surface layers to the aphotic zones. Mesoscale fronts and eddies, common in subtropical oceans, generate three-dimensional intrusions that connect the surface to the ocean depths.
These currents act like elevators, entrapping tiny plankton organisms, transporting a significant amount of carbon from the surface to the deeper layers of the ocean, while changing the food base available there. Moreover, the material carried into the depths by intrusions has a different composition than passively sinking detritus particles (hitherto considered the dominant mode of matter delivery to the deep layers), which significantly modifies the composition of microbial assemblages, the circulation of matter and energy, and the interactions between different layers of the ocean. This research is changing our understanding of how carbon converted to organic matter through photosynthesis in the euphotic layer is transported deep into the ocean and providing new insights into the mechanisms of vertical matter transport in these ecosystems.
4. Anthropogenic Forcing of the Baltic Sea Thallium Cycle
Ostrander Ch.M., Shu Y., Nielsen S.G., et al. (2024). Anthropogenic Forcing of the Baltic Sea Thallium Cycle. Environmental Science & Technology.
Anthropogenic activities cause the annual release of significant amounts of toxic thallium into the environment. It is considered the metal most toxic to mammals. Pollution with this element also affects the Baltic Sea. According to recent studies, humans are largely responsible for the amount of thallium (20 to 60 percent) that has entered the Baltic Sea over the past 80 years. To identify the circulation of the problematic element, the researchers analyzed data on its concentration and the ratio of two stable isotopes (ε203Tland ε205Tl) in seawater samples and sediment cores taken from the eastern Gotland Basin.
They determined that the water in this area is much more enriched in ε205Tl than had been assumed. Analysis of the sediment cores indicates that the increase in contamination began around 1940-1947, which is about the same time that other significant traces of human activity began to appear in the studied cores. Much of the thallium in the Baltic Sea, the largest anaerobic area on Earth caused by humans, is bound up in sediments thanks to sulfide minerals. As a result, its amount in seawater is still relatively low. However, studies suggest that this may change as a result of further anthropogenic activities or natural or anthropogenic increases in water oxygenation.
While thallium pollution is probably not the most pressing problem facing the Baltic Sea ecosystem, I have no doubt that there is a pressing need to take action to restore the ecosystem to a state that is not threatening to the organisms living in it and that allows for the enjoyment of its resources.
5. Matilda v1.0: An R package for probabilistic climate projections using a reduced complexity climate model
Brown J.K., Pressburger L., Snyder A., et al. (2024) Matilda v1.0: An R package for probabilistic climate projections using a reduced complexity climate model. PLOS Clim 3(5): e0000295.
The primary advantage of reduced complexity climate models (RCMs) is that they can be used to make rapid probabilistic climate predictions. These models are used, among others. to study the future coevolution of humans and Earth systems. In a paper appearing in this month’s PLOS Climate, researchers at the Joint Global Change Research Institute in College Park, USA present an open-science R software package for probabilistic climate projection analysis. It is based on the simple Hector climate model and offers a user-friendly structure.
The developers gave the tool the graceful name Matilda. Matilda improves probabilistic projection analysis and makes it more accessible to users of R. Extending Hector’s capabilities, it provides support for addressing climate uncertainty under various emissions scenarios and for conducting other probabilistic analyses. The package provides the freedom to choose different scoring criteria and algorithms for weighting layout elements, as well as the flexibility to implement custom criteria. In addition, the package’s architecture simplifies the process of building and analyzing parameter layouts without requiring much programming knowledge.
The availability of such simplified, user-friendly tools has great didactic value. It makes the knowledge obtained with their help less hermetic and more understandable to a wider range of users. On the other hand, it carries the risk of misinformation if used irresponsibly, without proper selection of parameters and critical interpretation of results. In such a situation, Matilda may become a razor in the hand of a monkey.