It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Financial payments made by land developers to offset their impacts on threatened species may fall short, according to University of Queensland-led research.
Professor Jonathan Rhodes from the School of the Environment focused on koala populations in the fast-developing South East Queensland region and a government scheme which allows developers to make financial payments to compensate for environmental consequences.
“Just like when you make a financial contribution to offset your carbon emissions when purchasing a flight, developers can make a financial payment to the Queensland Government to offset their impacts on koala habitat,” Professor Rhodes said.
“These payments are then used to plant trees to restore koala habitat in offset sites elsewhere.
“But we found that when suitable places to restore koala habitat are difficult to find, the financial payments required under the Queensland Environmental Offset Policy are often insufficient to achieve its intended outcomes and this is a major problem.
“In the South East Queensland region, only 0.7 of 13.4 hectares of impacts on koala habitat offset through financial payments since 2018 so far have offset sites in place and this is concerning for the future of this beloved, endangered species.
“Unfortunately, land supply can make suitable offset sites hard to find and this pushes up the cost of delivering habitat restoration and securing those sites in the long-term can fail to guarantee sufficient gains in habitat to counterbalance losses.”
Professor Rhodes said funding from developer payments may be insufficient to buy enough offset sites for habitat restoration.
“South East Queensland is the most densely human-populated area in the state, growing from 2.4 million people in 2001 to 3.5 million people in 2016, with 5.3 million people expected by 2041,” Professor Rhodes said.
“It is also home to an enormous number of threatened species, including some of the most significant koala populations in Australia which have declined 50 to 80 per cent over the past two decades.
“This problem will become worse as the region expands and competition for land for development intensifies, making offset sites either impossible to find or more expensive to secure.”
The study mapped and modelled development in eight Local Government Areas (LGAs) within the South East Queensland Planning Region, applying ecological data and projecting anticipated development and offset outcomes.
While the researchers propose some solutions, they also call for consideration of immediate changes to the current offset policy.
“On one hand, financial payments by developers can provide flexibility for the State Government to deliver the most effective offsets to help threatened species such as koalas, but on the other hand, it’s essential that developers pay the true cost of those offsets,” Professor Rhodes said.
“Otherwise, offsets will fall short of compensating for habitat losses and species will continue to decline or taxpayers via the State Government will have to make up the shortfall in developer contributions.”
Performance of habitat offsets for species conservation in dynamic human-modified landscapes
ARTICLE PUBLICATION DATE
10-Jul-2023
Do investors incorporate financial materiality of environmental information in their risk evaluation?
Evaluating a company’s environmental performance based on financial materiality provides a better perspective for investors to understand the environmental risk involved.
IMAGE: FINANCIAL MATERIALITY PROVIDES BETTER LENS FOR INVESTORS TO ADEQUATELY CAPTURE THE ENVIRONMENTAL RISKview more
CREDIT: JUN XIE, YOSHITAKA TANAKA, ALEXANDER RYOTA KEELEY, HIDEMICHI FUJII, SHUNSUKE MANAGI
Financial materiality pertains to crucial and pertinent data that a company is obligated to reveal in its financial statements. It provides companies with the insights necessary to discern elements influencing their performance and profitability, thereby enabling them to mitigate risks and captivate potential investors. There have been conflicts between shareholders and stakeholders regarding issues that are not directly related to finances, like environmental and social concerns. However, ignoring these factors like ESG (environmental, social and governance) could pose risks to both companies and investors.
Researchers at Kyushu University found that investors consider a company’s response to material environmental issues as a significant risk when deciding whether to invest in it. This highlights the importance of providing information that promotes communication between companies and investors for sustainable investment.
The more people become interested in sustainable investing, the concept of financial materiality is being closely examined. The Sustainability Accounting Standards Board (SASB) has developed standards specifically for different industries to help companies disclose sustainability information that is financially relevant.
The study analyzed data from 1,766 companies listed in the US between 2011 and 2020. By incorporating financial materiality into environmental performance assessments, this study provides new evidence of sustainability investments from the perspective of shareholders. The researchers made three important findings:
・The importance of each evaluation criterion for sustainable investment varies depending on the characteristics of each company.
・Shareholders see a lack of consideration for financial materiality in management strategies as a significant risk.
・Evaluating a company’s environmental performance based on financial materiality provides a better perspective for investors to understand the environmental risk involved. (See the reference figure)
With the growing interest in sustainable investing, there is a need to reevaluate how environmental information is reported by companies. Considering ESG factors in investment strategies provides scientific evidence for the importance of including financial materiality to achieve a sustainable and resilient economy. Using the financial materiality standards provided by SASB could be an effective way to assess and manage corporate environmental risks.
This research was supported by Ministry of Education, Culture, Sports, Science and Technology, Grant/Award Numbers: 20H00648, 22K20176; New Energy and Industrial Technology Development Organization, Grant/Award Number: P14026
About Kyushu University Kyushu University is one of Japan’s leading research-oriented institutes of higher education since its founding in 1911. Home to around 19,000 students and 8,000 faculty and staff, Kyushu U's world-class research centers cover a wide range of study areas and research fields, from the humanities and arts to engineering and medical sciences. Its multiple campuses—including one of the largest in Japan—are located around Fukuoka City, a coastal metropolis on the southwestern Japanese island of Kyushu that is frequently ranked among the world’s most livable cities and historically known as Japan’s gateway to Asia. Through its Vision 2030, Kyushu U will ‘Drive Social Change with Integrative Knowledge.’ Its synergistic application of knowledge will encompass all of academia and solve issues in society while innovating new systems for a better future.
JOURNAL
Corporate Social Responsibility and Environmental Management
IMAGE: CHRISTIAN BAUER, WISSENSCHAFTLER IM LABOR FÜR ENERGIESYSTEM-ANALYSE AM PSIview more
CREDIT: PAUL SCHERRER INSTITUT/MARKUS FISCHER
Researchers at the Paul Scherrer Institute PSI and ETH Zurich have performed calculations to work out how air traffic could become climate-neutral by 2050. They conclude that simply replacing fossil aviation fuel with sustainable synthetic fuels will not be enough. Air traffic would also have to be reduced. The researchers are publishing their results today in the journal Nature Communications.
The European Union aims to be climate neutral by 2050, a target that was set by the European Parliament in 2021. Switzerland is pursuing the same goal. The aviation sector, which is responsible for 3.5 percent of global warming, is expected to contribute its fair share – especially since the greenhouse gas emissions of aircraft are two to three times higher per passenger or freight kilometre than in other transport sectors. The International Civil Aviation Organisation (ICAO) and many airlines have therefore announced their intention to reduce CO2 emissions to zero by 2050 or to become climate neutral.
In a new study, researchers at PSI and ETH Zurich have now calculated whether this can be achieved, and how. “An important question is what exactly we mean by zero carbon or climate neutrality,” says Romain Sacchi of PSI’s Laboratory for Energy Systems Analysis, one of the study’s two lead authors. If this is only referring to the CO2 emitted by aircraft actually in the air, adds his co-author Viola Becattini from ETH Zurich, this does not go nearly far enough. Because assuming that air traffic continues to grow as it has in the past, the calculations predict that the CO2 emissions of aircraft will only account for about 20 percent of their total climate impact by 2050. In order to make aviation as a whole climate neutral, it is necessary to ensure that not only flying but also the production of fuel and the entire aviation infrastructure have no further impact on the climate.
However, the study concludes that this cannot be achieved by 2050 using the climate measures that are currently being pursued in flight operations. “New engines, climate-friendly fuels and filtering CO2 out of the atmosphere in order to store it underground (carbon capture and storage, or CCS) will not get us there on their own,” says Marco Mazzotti, Professor of Process Engineering at ETH. “On top of this, we need to reduce air traffic.”
Non-CO2 effects play a major role
In their study, Sacchi and Becattini looked at various different scenarios. These showed, on the one hand, that while the climate impact of the infrastructure, i.e. manufacturing aircraft and building and operating airports, does need to be taken into account, it is comparatively small overall for the period up until 2050 and beyond. The impact of flying itself on the climate, and of the emissions from producing the fuel are far greater. That in itself was nothing new.
What had been less clear before was the importance of so-called non-CO2 effects, which occur in addition to CO2 emissions. The bulk of the greenhouse effect caused by aviation is not due to the carbon released into the atmosphere by burning aviation fuel, but to the particulate matter (soot) and nitrogen oxides that are also released and that react in the air to form methane and ozone, water vapour and the condensation trails that lead to the formation of cirrus clouds in the upper atmosphere. “Many analyses and ‘net zero’ pledges so far have ignored these factors,” says Romain Sacchi. “Or they have not been calculated correctly.”
It is customary to express emissions and effects like these in terms of CO2 equivalents when calculating the overall balance. “But the methods and values used to date have proved to be inappropriate,” says Marco Mazzotti. “We therefore adopted a more precise approach.” The methods they used take into account one major difference between the various factors: non-CO2 effects are much more short-lived than CO2, which is why they are also called “short-lived climate forcers”, or SLCFs for short. While about half of the emitted carbon dioxide is absorbed by forests and oceans, the other half remains in the air for thousands of years, dispersing and acting as a greenhouse gas. Methane, on the other hand, has a much greater impact on the climate, but decomposes within a few years; contrails and the resulting clouds dissipate within hours. “The problem is that we are producing more and more SLCFs as air traffic increases, so these are adding up instead of disappearing quickly. As a result, they exert their enormous greenhouse impact over longer periods of time,” says Viola Becattini. It’s like a bathtub with both the drain and the tap open: as long as the tap lets in more water than can escape through the drain, the bathtub will keep getting fuller – until eventually it overflows.
Climate-friendly fuel alone does not achieve the goal – but it helps
“But this analogy also demonstrates that the crucial lever is under our control: the volume of air traffic,” Romain Sacchi points out. “By flying less instead of more often, in other words closing the tap instead of opening it, we can actually cool the atmosphere and push the greenhouse effect caused by aviation towards zero.” This is not to say that we must stop flying altogether. The calculations performed in the study show that for aviation to achieve climate neutrality by 2050, air traffic will need to be reduced by 0.8 percent every year – in conjunction with underground carbon dioxide storage – if we continue to use fossil fuels. This would bring it down to about 80 percent of today’s volume by 2050. If we manage to switch to more climate-friendly fuels based on electricity from renewables, 0.4 percent per year will be sufficient.
The study also took a closer look at these new fuels. Researchers around the world are working to replace conventional petroleum-based engines. As in road transport, this could be achieved by using electric batteries, fuel cells or the direct combustion of hydrogen. However, the available energy density is only sufficient for small aircraft on short routes, or in the case of hydrogen also for medium-size planes on medium-haul flights. Yet large aircraft on long-haul flights of more than 4000 kilometres account for the majority of global air traffic and greenhouse gas emissions from aviation.
Synthetic aviation fuel has pros and cons
In addition, propulsion technologies for the aviation industry based on electricity or hydrogen are far from being ready for a widespread roll-out. So-called Sustainable Aviation Fuel (SAF) is therefore viewed as the industry’s great hope. This man-made aviation fuel could replace petroleum-based aviation fuel more or less one-to-one, without the need to redesign turbines and aircraft.
SAF can be produced from CO2 and water via a production cascade. The CO2 is extracted from the air using a process known as air capture, and hydrogen can be obtained from water by electrolysis. “If the necessary processes are carried out entirely using renewable energy, SAF is virtually climate-neutral,” says Christian Bauer from the PSI Laboratory for Energy Systems Analysis, who was involved in the study. “This makes us less dependent on fossil fuels.” Another advantage of SAF is that it produces fewer SLCFs, which would have to be offset by capturing equivalent amounts of CO2 from the air and storing them underground. This is significant because CO2 storage capacity is limited and not reserved exclusively for the aviation industry.
Air tickets three times more expensive
SAF also has certain disadvantages though, in that it takes far more energy to produce than conventional aviation fuel. This is mainly because producing hydrogen via electrolysis takes a lot of electricity. In addition, energy is lost at every step in the production process – air capture, electrolysis and synthesisation. Using large amounts of electrical power, in turn, means expending more resources such as water and land. SAF is also expensive: not just in terms of the electrical power required, but also the cost of carbon capture and electrolysis plants, which makes it four to seven times more expensive than conventional aviation fuel. In other words, the widespread use of SAF makes carbon-neutral aviation a possibility, but it also costs more resources and more money. This means that flying will have to become even more expensive than it already needs to be in order to meet the climate targets. “Anyone buying a ticket today can pay a few extra euros to make their flight supposedly carbon neutral, by investing this money in climate protection,” says Romain Sacchi. “But this is greenwashing, because many of these measures for offsetting carbon are ineffective. To fully offset the actual climate impact, tickets would have to cost about three times as much as they do today.”
“Such a hefty price hike should significantly reduce the demand for flights and bring us closer to the goal of climate neutrality,” says Viola Becattini. In addition, SAF production is expected to become cheaper and more efficient over the years as quantities increases, and this will have a positive effect on the carbon footprint. The study took such dynamics into account – including the fact that the electricity mix used to produce SAF is shifting. This distinguishes the analysis from most others.
“The bottom line is that there is no magic bullet for achieving climate neutrality in aviation by 2050,” says Sacchi. “We cannot continue as before. But if we develop the infrastructure for storing CO2 underground and producing SAF quickly and efficiently, while also reducing our demand for air travel, we could succeed."
Text: Jan Berndorff
About PSI
The Paul Scherrer Institute PSI develops, builds and operates large, complex research facilities and makes them available to the national and international research community. The institute's own key research priorities are in the fields of matter and materials, energy and environment and human health. PSI is committed to the training of future generations. Therefore about one quarter of our staff are post-docs, post-graduates or apprentices. Altogether PSI employs 2200 people, thus being the largest research institute in Switzerland. The annual budget amounts to approximately CHF 420 million. PSI is part of the ETH Domain, with the other members being the two Swiss Federal Institutes of Technology, ETH Zurich and EPFL Lausanne, as well as Eawag (Swiss Federal Institute of Aquatic Science and Technology), Empa (Swiss Federal Laboratories for Materials Science and Technology) and WSL (Swiss Federal Institute for Forest, Snow and Landscape Research). Insight into the exciting research of the PSI with changing focal points is provided 3 times a year in the publication 5232 - The Magazine of the Paul Scherrer Institute.
Contact:
Christian Bauer
Senior Researcher at the Laboratory for Energy Systems Analysis, Technology Assessment Group
Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
This study is led by Dr. Taihua Wang and Dr. Dawen Yang (Tsinghua University), together with experts in the field of both permafrost and glacier including Dr. Tandong Yao, Dr. Xin Li (Institute of Tibetan Plateau Research, Chinese Academy of Sciences), Dr. Guodong Cheng and Dr. Huijun Jin (Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences). In a warming climate, the sustainability of cryospheric meltwater on the Tibetan Plateau has raised concerns because of its importance for the fragile ecosystem in the headwater regions and the dense populations in the downstream. Existing studies mainly focused on glacier melt and snow melt on the Tibetan Plateau, which are above the ground surface can be detected from the surface using in-situ or satellite observations. However, the hydrological implications of thawing permafrost below the ground surface remain largely unknown.
“For the study of permafrost hydrology changes, the ground surface observations have to be combined with physically-based models to examine what is happening below the ground surface.” Taihua says. Therefore, a hydrological model that could reflect the complex interactions between cryospheric and hydrological processes is urgently needed.
The research group led by Dr. Dawen Yang has endeavored to develop such a model for years. Twenty years ago, Dr. Dawen Yang developed a distributed hydrological model named “Geomorphology-Based Hydrological Model (GBHM)”. In 2010, Dr. Dawen Yang participated in a major research plan entitled “Integrated research on the eco-hydrological process of the Heihe River Basin” led by Dr. Guodong Cheng funded by the National Natural Science Foundation of China. With the support of the research plan and collaboration with experts from different disciplines, the distributed Geomorphology-Based Ecohydrological Model (GBEHM) was developed which could simulate the coupled water-heat processes and has been successfully applied in many headwater regions of the Tibetan Plateau.
Another challenge of relevant study is the limited data on the Tibetan Plateau. Thanks to recent accumulation of both in-situ and satellite observations, as well as the enhanced geoscience data sharing through platforms like the National Tibetan Plateau Data Center (https://data.tpdc.ac.cn) led by Dr. Xin Li, the simulation can be applied to the entire Tibetan Plateau with an unprecedented high spatial resolution (1 km × 1 km).
The results from the modelling study provide some novel insights into the magnitude and temporal changes of water supply from thawing permafrost and melting ground ice. Combining in-situ borehole observations with the spatial distribution of depositional types and paleo-precipitation information, the average ground ice storage across the Tibetan Plateau is estimated to be about half the size of glacier ice storage. However, the ground ice storage decline was almost twice the amount of glacier mass loss during 1980-2019, indicating a more severe decline in the subsurface ice reserve than the above-surface one at the plateau scale, although the former one has received much less attention.
By tracing the meltwater flow paths, the study also quantifies the ground ice meltwater contribution to river runoff. Despite the relatively small contribution at the plateau scale (~0.5%), the ground ice meltwater runoff can be locally important and larger than that from glacier melt in many sub-regions including the upper Yellow, the upper Yangtze and the Qiangtang Plateau.
However, the meltwater runoff from thawing permafrostis unsustainable over the coming decades, which could possibly threaten water security in certain regions relying on water supply from thawing permafrost. “This is similar to previous findings of unsustainable meltwater supply from glaciers on the Tibetan Plateau. The impacts could be more evident in arid regions and dry years, and we have to get prepared for this additional risk caused by unsustainable cryospheric meltwater supply.” Taihua says.
Despite uncertainties in the results of the study, the findings highlight the rarely examined yet non-negligible role of permafrost thaw and ground ice meltwater for the Asian water tower. In the future, high-resolution remote sensing observations and more publicly available in-situ observations across the Tibetan Plateau can be adopted to further reduce the uncertainty in the estimates. The impact of unsustainable cryospheric meltwater on the fragile alpine ecosystem and regional carbon budget on the Tibetan Plateau can also be examined by future studies.
See the article:
Unsustainable water supply from thawing permafrost on the Tibetan Plateau in a changing climate
IMAGE: SVALBARD IN THE ARCTIC IN SUMMER. DUST FROM THE LAND WITHOUT SNOW COVER GREATLY CONTRIBUTES TO THE FORMATION OF ICE CRYSTALS IN THE LOW-LEVEL CLOUDS.view more
CREDIT: YUTAKA TOBO, NATIONAL INSTITUTE OF POLAR RESEARCH
Researchers from Nagoya University and the National Institute of Polar Research in Japan have found that dust from land without snow cover in the Arctic is a major source of particles that form ice crystals in low-level clouds of the Arctic (at altitudes below about 3 km) during summer and fall.
The formation of ice crystals in low-level clouds is considered to affect climate because it can cause ice particles to grow at the expense of liquid droplets and then fall as precipitation, resulting in a lower sunlight reflectance and a shorter lifetime for clouds.
“The Arctic is said to be heating up two to four times faster than the rate of global warming,” said Dr. Kei Kawai of Nagoya University, the first author of the study. “Considering that the distribution and the lifetime of low-level clouds affect climate, our finding might help improve predictions of Arctic climate change.” The researchers published their findings in Geophysical Research Letters.
Dust is made up of very small mineral particles of earth or sand. It acts as a nucleus for the formation of ice crystals in clouds. Although mainly emitted from arid regions in low or mid latitudes, recent studies have shown that dust is also emitted from areas where there is no snow, ice, or vegetation in the Arctic. A previous study suggested that such Arctic dust serves as an efficient nucleus for forming ice crystals because it contains a tiny amount of organic matter that has high ice nucleating ability.
“In the Arctic, dust is mostly emitted in summer through early fall, when the surface temperature is high and the snow cover is low,” Kawai said. “In this season, Arctic dust is distributed in the lower troposphere of the Arctic (lower than an altitude of approximately 3 km), where temperatures are warmer than about –15°C. In general, dust particles from a desert in low or mid latitudes cannot work efficiently as nuclei to form ice crystals at temperatures warmer than –15°C. In contrast, Arctic dust particles can work as such nuclei between –20°C and –5°C because of their high ice nucleating ability.”
However, until now, the importance of Arctic dust's high ice nucleating ability has remained unclear because it was not considered in any modeling studies. To address this shortcoming, Associate Professor Hitoshi Matsui and Dr. Kawai of Nagoya University, in collaboration with Associate Professor Yutaka Tobo of the National Institute of Polar Research, conducted a study using the global aerosol-climate model CAM-ATRAS.
First, they incorporated the recently observed high ice nucleating ability of Arctic dust into their model. Then, they compared simulations that considered this ability with simulations that did not. The results showed that in simulations that considered this ability, Arctic dust acted efficiently as ice nucleating particles in the Arctic region. The simulations also closely reproduced observations of ice nucleating particles at several locations in the Arctic. In contrast, in simulations that did not consider it, Arctic dust hardly acted as ice nucleating particles.
The results also showed that the number of ice nucleating particles from dust from all around the world in the lower troposphere of the Arctic during summer and fall was increased by more than 100 times considering the high ice nucleating ability of Arctic dust. Furthermore, almost all the ice nucleating particles were found to be derived from Arctic dust.
Therefore, the researchers confirmed that Arctic dust plays a dominant role as ice nucleating particles from dust in Arctic low-level clouds during summer and fall. “We demonstrated that it is important to fully consider Arctic dust's high ice nucleating ability to clarify the distribution and the origin of ice nucleating particles in the Arctic,” Dr. Kawai said. “We hope this finding will also help us understand what is happening regarding Arctic warming and more accurately project future Arctic climate change.”
In a new study, a group from Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, proposed a concept of ecosystem water stress and comprehensively compared the impacts of high atmospheric vapor pressure deficit and low soil water content on vegetation growth in Eurasian drylands
Drought, a multifaceted phenomenon encompassing atmospheric and soil drought, has sparked a lively debate over which type of dryness stress exerts a more significant impact on vegetation growth. "Through our defined concept of ecosystem water stress, we can discern where water-stressed vegetation growth is dominated by atmospheric vapor pressure deficit or soil moisture" Dr. Yu Zhang, first author of this work, says.
The team shows soil moisture dominated the dryness stress of vegetation growth over Eurasian drylands. Astonishingly, none of the 18 state-of-the-art vegetation gross primary productivity models describe soil water dominance. As climate change progresses, it is projected that soil moisture stress will continuously constrain vegetation growth towards 2100.
These findings lay a crucial scientific foundation for effective ecosystem management and drought mitigation across Eurasian drylands. Led by Prof. Yangjian Zhang and Dr. Yu Zhang from Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, the study has been published in National Science Review.
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See the article:
Enhanced dominance of soil moisture stress on vegetation growth in Eurasian drylands
Reduce greenhouse gases: Stop drainage and cultivate reed grass instead of potatoes on peat soil
Researchers from Aarhus University compare greenhouse gas emissions from a traditional potato crop rotation on drained peat soil with the cultivation of reed grass for biomass production on undrained or poorly drained peat soil.
IMAGE: RESEARCHERS FROM AARHUS UNIVERSITY ARE COMPARING GREENHOUSE GAS EMISSIONS FROM A CONVENTIONAL POTATO CROP ROTATION ON DRAINED PEAT SOIL WITH THE CULTIVATION OF REED CANARY GRASS FOR BIOMASS PRODUCTION ON UNDRAINED OR POORLY DRAINED PEAT SOIL.view more
CREDIT: POUL ERIK LÆRKE
Drained peat soils in Denmark account for about one-third of agricultural greenhouse gas emissions.
"One of the most effective climate measures we have is to stop draining peat soils. However, this means that the land cannot be cultivated in the same way as regular agricultural soil because it would become rewetted," explains Poul Erik Lærke, a senior researcher at the Department of Agroecology at Aarhus University.
If farmers are unable to cultivate the land, it would be necessary to compensate landowners for the loss of value, which would incur significant costs for society.
"But part of the loss could actually be offset if the land is used to cultivate crops that thrive in wet conditions. At the same time, it can also reduce the risk of other natural areas being converted into agricultural land as compensation for the loss of current agricultural production on peat soil," he explains.
Three production scenarios
In a new study, Henrik Thers and other researchers from the Department of Agroecology used calculation methods typically used for life cycle assessments to investigate greenhouse gas emissions for three different cultivation scenarios.
"We used IPCC emission factors and cultivation conditions for peat soils in bogs and wet meadows," explains Henrik Thers. The study included three different scenarios, which are as follows:
Potato crop rotation on deep-drained raised bog peat soil
Perennial reed grass on undrained raised bog peat soil
Perennial reed grass on poorly drained wet meadow peat soil
The results show that greenhouse gas emissions can be significantly reduced by switching from the potato crop rotation to reed grass cultivation.
"We found that greenhouse gas emissions from the potato crop rotation in the raised bog, scenario 1, could be reduced by 35% by switching to cultivated reed grass on undrained raised bog, scenario 2," says postdoc Henrik Thers from the Department of Agroecology at Aarhus University.
Furthermore, the analysis showed that greenhouse gas emissions from scenario 3, reed grass cultivated in the wet meadow, were even lower than the emissions from scenario 2. According to the researchers, this is primarily due to differences in the average annual water level.
Biomass for biogas and biorefining
If traditional potato production is replaced by reed grass production, it is also necessary to find new uses for the crops. Unlike potatoes, reed grass cannot be consumed by humans.
"On the other hand, production and harvesting of biomass on undrained peat soil can be used for various purposes in biorefineries, for biogas, or for pyrolysis, thus replacing other protein sources or the use of fossil resources. This potentially increases the calculated reduction in greenhouse gas emissions when switching to grass production on undrained peat soil," explains postdoc Henrik Thers, adding that: "Our analysis does not include the use of the harvested biomass since such an analysis can only be performed on specific end products that include all by-products. As a simplified alternative, the reduction potential is therefore calculated based on the amount of produced biomass or raw protein, which shows an additional reduction when switching from the potato crop rotation to reed grass."
The study does not include production economics, and the researchers acknowledge that reed grass production will face challenges in competing economically with potato cultivation. (Read more about the economics in the report "Dyrkning af paludikulturer – Effekt på klima, miljø og Natur" [Cultivation of paludiculture - Effects on climate, environment, and nature – in Danish only])
Local knowledge is crucial
According to the researchers, it is not always possible to fully saturate previously drained raised bogs even if the current drainage is discontinued, but significant reductions in greenhouse gas emissions can still be achieved.
"It is likely that the original vegetation dominated by sphagnum mosses needs to be restored to make the bog wet again during the summer months, and that can take time. We do not see the same challenge in wet meadows, where the water level is primarily controlled by the water level in the stream that the fields drain into," explains Poul Erik Lærke.
The researchers emphasize in their study that having knowledge of local conditions is essential when estimating the reduction potential for greenhouse gas emissions related to wetting of drained peat soils. Therefore, the land use after discontinuing the drains can still be a new form of biomass production if the agricultural land is not converted into wild nature. Harvesting and removing biomass can also be an important tool in efforts to achieve nutrient-poor soil before the area is handed over to wild nature, thereby contributing to a more diverse vegetation.
Reed grass production can be used to restore original ecosystems
"The demonstration experiment with reed grass in Store Vildmose showed that it was possible to remove large amounts of nutrients from peat soil and net remove more nutrients with moderate fertilization compared to no fertilization. Therefore, reed grass production can also be a step towards the restoration of the original ecosystem with high biodiversity," says Poul Erik Lærke.
According to the researchers, their study highlights the need for further research and adaptation of methods to implement effective strategies for reducing greenhouse gas emissions from peat soils. There are still many challenges and complexities associated with wetting peatlands, but the results demonstrate the potential to reduce agricultural climate impact while maintaining some production on peat soils.
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CONTENT AND PURPOSE
Collaborators
Department of Agroecology, Aarhus University
Funding
This research was supported as part of CANAPE, an Interreg project funded by the North Sea Program under the European Union's Regional Development Fund, and the GO-GRASS project funded by the EU's Horizon 2020 research and innovation program under grant agreement number 862674
Comparison of GHG emissions from annual crops in rotation on drained temperate agricultural peatland with production of reed canary grass in paludiculture using an LCA approach
