Fossil fuel use, land use change and cement production have perturbed the global carbon cycle and have led to the accumulation of carbon dioxide in the atmosphere. This has two major consequences, namely global warming and ocean acidification (?the other CO2 problem?). Sea surface water pH has decreased already by 0.1 unit since pre-industrial time, and based on atmospheric CO2 scenarios, it is projected to further decline by 0.0015-0.002 unit per year over the coming century. However, observations on the Washington coast and in the North Sea (Rijkswaterstaat monitoring) show stronger decreases of 0.045 and 0.02 unit per year, respectively. The North Sea is apparently acidifying 10 times faster than global ocean model predictions. Here we propose a detailed investigation of the spatial and temporal patterns of pH in the North Sea at a basin-wide scale using the high quality methodology in use by the international CO2 research community. This will generate the needed data to see whether the acidification of the North Sea is indeed occurring at such high pace. In addition, we will also elucidate the biogeochemical mechanisms governing the pH in North Sea waters, in particular the balance between production and respiration and the generation of alkalinity. As part of this investigation, we will apply a recently developed modelling technique to attribute pH changes to changing environmental parameters.

How can we keep our densely populated country livable? There is an increasing demand for space for living, industry, energy transition and food production. To date, approximately 60% of the Netherlands is flood prone, and due to climate change the threat of flooding increases. The water may however also offer an opportunity for creating safe space: large-scale floating developments. “Floating Future” integrates Governance, Technology and Ecology to investigate how we can achieve large scale floating developments and what would be the social acceptance. We develop climate adaptive pilot cases for inland (IJmeer), coastal (port city) and offshore (North Sea) applications.

Accelerated sea-level rise (SLR) seriously threatens coastal areas globally. Sand nourishments – the addition of sand to increase the beach volume – are potentially a key method to sustainably adapt to accelerated SLR and keep the low-lying hinterland protected against coastal flooding. The SOURCE project will deliver the scientific knowledge, models and design tools to develop and evaluate nourishment strategies in a multi-stakeholder co-creation process. These carefully planned sand nourishments will create the required and desired resilient and dynamic multifunctional coastal landscapes of the future.

Solar systems are implemented at increasingly large scale to meet demands for sustainable energy, including placing them on inland waters. SPARKLES unites scientists and stakeholders across domains (energy, ecology, society) to develop nature-positive solutions for floating solar for humans and nature. By putting nature front and center we look for integrative solutions that solve multiple problems in the living environment, rather than creating trade-offs between humans and nature.

The observation dome, measuring food and mud filtered by mussels and anemones, was further improved and applied at sea. A paper on satellite data of changes in the amount of mud in the water was published. Observations of wakes of wind turbines were collected and compared with models. Model scenarios of mussel growth were run for the Borssele wind farm. System understanding of potential knowledge-based governance arrangements was improved by including other projects.