ERC FUNDED PROJECTS

Arctic sea ice decline is the exponent of the rapidly transforming Arctic climate. The ensuing local and global implications can be understood by studying past climate transitions, yet few methods are available to examine past Arctic sea ice cover, severely restricting our understanding of sea ice in the climate system. The decline in Arctic sea ice cover is a ‘canary in the coalmine’ for the state of our climate, and if greenhouse gas emissions remain unchecked, summer sea ice loss may pass a critical threshold that could drastically transform the Arctic. Because historical observations are limited, it is crucial to have reliable proxies for assessing natural sea ice variability, its stability and sensitivity to climate forcing on different time scales. Current proxies address aspects of sea ice variability, but are limited due to a selective fossil record, preservation effects, regional applicability, or being semi-quantitative. With such restraints on our knowledge about natural variations and drivers, major uncertainties about the future remain. I propose to develop and apply a novel sea ice proxy that exploits genetic information stored in marine sediments, sedimentary ancient DNA (sedaDNA). This innovation uses the genetic signature of phytoplankton communities from surface waters and sea ice as it gets stored in sediments. This wealth of information has not been explored before for reconstructing sea ice conditions. Preliminary results from my cross-disciplinary team indicate that our unconventional approach can provide a detailed, qualitative account of past sea ice ecosystems and quantitative estimates of sea ice parameters. I will address fundamental questions about past Arctic sea ice variability on different timescales, information essential to provide a framework upon which to assess the ecological and socio-economic consequences of a changing Arctic. This new proxy is not limited to sea ice research and can transform the field of paleoceanography.

2 615 858 €

Start date: 2019-08-01, End date: 2024-07-31

Interfaces in oxide materials offer amazing opportunities for fundamental and applied research, giving a new dimension to functional properties, such as magnetism, multiferroicity and superconductivity. Ferroelectric domain walls recently emerged as a new type of interface, where the dynamic characteristics of ferroelectricity introduce the element of spatial mobility, allowing for the real-time adjustment of position, density and orientation of the walls. This mobility adds an additional degree of flexibility that enables domain walls to take an active role in future devices and hold great potential as functional 2D systems for electronics. Up to now, application concepts rely on injecting and deleting domain walls in micrometer-size devices to control electric conductivity. While this approach achieves a step beyond conventional interfaces by utilizing the wall mobility, it does not break the mould of classical device architectures. Completely new strategies are required to functionalize the versatile electronic properties and atomic-scale feature size of ferroelectric domain walls. ATRONICS will establish a new conceptual approach for developing domain-wall-based technology. At the length scale of only a few atoms, we will use individual walls in improper ferroelectrics to emulate key electronic components such as diodes, transistors and logic gates. Crucially, as the functionality of the components is intrinsic to the domain walls, the walls themselves are the devices, instead of the previous approach of writing and erasing domain walls within a much larger classical device architecture. Beyond demonstrating individual devices, we will integrate multiple domain-wall devices, and develop quasi-2D circuitry and networks with a higher order of complexity then is currently achievable. ATRONICS will represent a major advancement in 2D functional materials for future technologies and play an essential role in the transition from nano- to atomic-scale electronics.

1 845 338 €

Start date: 2020-09-01, End date: 2025-08-31

The detection of primordial gravity waves created during the Big Bang ranks among the greatest potential intellectual achievements in modern science. During the last few decades, the instrumental progress necessary to achieve this has been nothing short of breathtaking, and we today are able to measure the microwave sky with better than one-in-a-million precision. However, from the latest ultra-sensitive experiments such as BICEP2 and Planck, it is clear that instrumental sensitivity alone will not be sufficient to make a robust detection of gravitational waves. Contamination in the form of astrophysical radiation from the Milky Way, for instance thermal dust and synchrotron radiation, obscures the cosmological signal by orders of magnitude. Even more critically, though, are second-order interactions between this radiation and the instrument characterization itself that lead to a highly non-linear and complicated problem. I propose a ground-breaking solution to this problem that allows for joint estimation of cosmological parameters, astrophysical components, and instrument specifications. The engine of this method is called Gibbs sampling, which I have already applied extremely successfully to basic CMB component separation. The new and ciritical step is to apply this method to raw time-ordered observations observed directly by the instrument, as opposed to pre-processed frequency maps. While representing a ~100-fold increase in input data volume, this step is unavoidable in order to break through the current foreground-induced systematics floor. I will apply this method to the best currently available and future data sets (WMAP, Planck, SPIDER and LiteBIRD), and thereby derive the world's tightest constraint on the amplitude of inflationary gravitational waves. Additionally, the resulting ancillary science in the form of robust cosmological parameters and astrophysical component maps will represent the state-of-the-art in observational cosmology in years to come.

1 999 205 €

Start date: 2018-04-01, End date: 2023-03-31

Recent uprisings across the world have accentuated claims that food insecurity is an important trigger of political violence. Is the Arab Spring representative of a general climate-conflict pattern, where severe droughts and other climate anomalies are a key driving force? Research to date has failed to conclude on a robust relationship but several notable theoretical and methodological shortcomings limit inference. CLIMSEC will address these research gaps. It asks: How does climate variability affect dynamics of political violence? This overarching research question will be addressed through the accomplishment of four key objectives: (1) Investigate how food security impacts of climate variability affect political violence; (2) Investigate how economic impacts of climate variability affect political violence; (3) Conduct short-term forecasts of political violence in response to food and economic shocks; and (4) Develop a comprehensive, testable theoretical model of security implications of climate variability. To achieve these objectives, CLIMSEC will advance the research frontier on theoretical as well as analytical accounts. Central in this endeavor is conceptual and empirical disaggregation. Instead of assuming states and calendar years as unitary and fixed entities, the project proposes causal processes that act at multiple temporal and spatial scales, involve various types of actors, and lead to very different forms of outcomes depending on the context. The empirical component will make innovative use of new geo - referenced data and methods; focus on a broad range of insecurity outcomes, including non-violent resistance; and combine rigorous statistical models with out-of-sample simulations and qualitative case studies for theorizing and validation of key findings. Based at PRIO, the project will be led by Research Professor Halvard Buhaug, a leading scholar on climate change and security with strong publication record and project management experience.

1 996 945 €

Start date: 2015-09-01, End date: 2021-06-30