IVL Swedish Environmental Research Institute

In a future warmer climate, extremely dry, warm summers might become more common. Soil weathering is affected by temperature and precipitation, and climate change and droughts can therefore affect soil chemistry and plant nutrition. In this study, climate change and drought effects on soil weathering rates and release of Ca, Mg, K and Na were studied on seven forest sites across different climates in Sweden, using the dynamical model ForSAFE.

Two climate scenarios were run, one medium severity climate change scenario from IPCC (A1B) and one scenario where a future drought period of 5 years was added, while everything else was equal to the first scenario. The model results show a large geographical variation of weathering rates for the sites, without any geographical gradient, despite the strong dependence of temperature on weathering and the strong gradient in temperature in Sweden. This is because soil texture and mineralogy have strong effects on weathering.

The weathering rates have a pronounced seasonal dynamic. Weathering rates are low during winters and generally high, but variable, during summers, depending on soil moisture and temperature. According to the model runs, the future yearly average weathering rates will increase by 5 %–17 % per degree of warming. The relative increase is largest in the two southeastern sites, with low total weathering rates. At sites in southern Sweden, future weathering increase occurs throughout the year according to the modelling.

In the north, the increase in weathering during winters is almost negligible, despite larger temperature increases than in other regions or seasons (5.9 ∘C increase in winter in Högbränna; the yearly average temperature increase for all sites is 3.7 ∘C), as the winter temperatures still will mostly be below zero. The drought scenario has the strongest effect in southern Sweden, where weathering during the later parts of the drought summers decreases to typical winter weathering rates.

Soil texture and amount of gravel also influence how fast the weathering decreases during drought and how fast the soil rewets and reaches normal weathering rates after the drought. The coarsest of the modelled soils dries out and rewets quicker than the less coarse of the modelled soils. In the north, the soils do not dry out as much as in the south, despite the low precipitation, due to lower evapotranspiration, and in the northernmost site, weathering is not much affected. Yearly weathering during the drought years relative to the same years in the A1B scenario are between 78 % and 96 % for the sites.

The study shows that it is crucial to take seasonal climate variations and soil texture into account when assessing the effects of a changed climate on weathering rates and plant nutrient availability.

Aquaculture has been highlighted in Sweden and the EU as a sustainable food production method with significant potential for the future. This report focuses on extractive aquaculture, which includes the cultivation of mussels, oysters, algae, sea squirts, and other species that do not require supplemental feeding nor fertilizer. Currently, the aquaculture sector in Sweden is relatively small, and for aquaculture to become a significant part of Swedish and European food production, it needs to expand.There are several obstacles to the development of the aquaculture sector in Sweden.

A significant hindrance is the high degree of competition for suitable marine areas, which can lead to new or intensified conflicts of interest. Coastal zone planning has been proposed as an essential tool for managing these conflicts, but previous studies have shown that existing plans have not resulted in proactive management of how the sea is utilized.To enhance our understanding of the challenges faced by the aquaculture sector, this report focuses on the relationship between aquaculture and other interests – in particular, outdoor recreation and boating in and around the sea in the Lysekil area. Specifically, it aims to investigate how involved stakeholders perceive the conflict of interest and explore potential opportunities for coexistence and synergies between aquaculture and other interests.

The research includes document analysis of coastal zone plans and permit applications, as well as interviews with relevant stakeholders.The findings show that municipal coastal zone planning, along with permit assessments conducted by both the County Administrative Board and the court, attempts to manage and prevent conflicts of interest. This is pursued through the geographical separation of assumed opposing interests. However, the interviews indicates that the conflict of interest between aquaculture and other interests is not perceived as prominent at present. It is likely that the perceived low level of conflict stems from the relatively small-scale nature of aquaculture activities in the studied area. Some interviewees have expressed concern that an expansion of aquaculture operations in the area may change the appearance of the archipelago and alter the unique character of coastal communities. Specifically, there is concern that aquaculture activities could encroach upon areas and locations frequently used by recreational boats, and potentially diminish the experiential value associated with leisure boating. Aquaculture and boating both seek to utilize sheltered shallow water areas for their respective activities.

At the same time, municipal coastal zone planning and interviewed stakeholders highlight that values associated with boating are also jeopardized by the activity itself, as the use and size of leisure boats have significantly increased.Opportunities for coexistence and synergies between aquaculture and other interests, and conditions that could enable such opportunities, have been emphasized by some of the interviewed stakeholders. One noteworthy example is the collaborations between tourism and aquaculture that have occurred in the area. In that case, boat charter tours would stop at aquaculture sites to provide information about the operations and allow observation of the cultivation process.

Another example mentioned by the interviewees is that aquaculture could reduce the disturbing aspects of recreational boat traffic by requiring boats to slow down in their vicinity. This approach could potentially reduce conflicts related to recreational boating, such as noise, wake, and safety concerns. Some interviewees also emphasize aquaculture as an opportunity for coastal communities to create local employment within sectors that build upon the cultural heritage associated with traditional coastal fishing.While the study relies on a limited number of interviews, it offers intriguing insights that provides the foundation for more in-depth research in the future. One conclusion is that conflicts of interest associated with aquaculture largely lie in the future as the aquaculture sector grows. To avoid conflicts of interest, and enable coexistence and synergy effects, it is important that coastal zone planning is developed, and that the link between plans and permit examination is strengthened.

The aim of this report is to summarise information about relevant policy actions to reduce black carbon emissions from key polluting sectors, as well as options to better monitor how different initiatives affect black carbon emissions and their environmental and health effects. Several relevant policy areas are identified – In situ observations of black carbon in the Arctic, black carbon emission inventories, Gas flaring, Small-scale domestic heating, Shipping, On-and off-road engines, and Open biomass burning. Within these areas, possible actions are described in detail and presented in terms of their time horizon, societal impact, jurisdictional scope and relevant policy fora. 

 The presented actions can act as a reference list of options for interested policymakers, synthesising existing knowledge about relevant policy actions rather than giving prescriptive recommendations on which of them to implement.

 This report serves as a background document to the EUA-BCA Policy landscape report that informs on possible ways to implement these actions in practice and clarify how enhanced international cooperation would contribute to actions in the key areas.