BC3. Basque centre for climate change – Klima aldaketa ikergai

Realistic and effective climate policies require a clear understanding of the physical basis of climate change. Which BC3 achieves through activities that are carried on in an integrated manner through four dimensions of integration: observation (field campaigns and development of new methodologies for sampling and recording of observations at extreme and vulnerable environments), theory (conceptual and mathematical modelling of physical phenomena, including development of completely new complex-system models and theories -e.g. the theory of Continuous Diversity-, as well as digital and statistical analysis of records) experiment (BC3’s IzotzaLab: low-temperature science & technology laboratory for innovative microscopic studies of frozen samples -ice cores- and development of new technologies optoelectronics, planetary science, etc.) and understanding (knowledge co-production and transfer through citizen science and the study of indigenous knowledge, collaborations with social groups and researchers of social sciences and humanities) and education (e.g. through the GIGAKU Network). While the first three dimensions build up the classical physical sciences triad (theoretical, field, and laboratory work), the fourth dimension relates the physical processes to their human perception and awareness.

Activity 1.1. Learning from the past: analysis of ancient and recent climate and environmental history.

The study of climate records —from recent instrumental observations to ancient paleoclimate records extracted from multiple natural archives— is fundamental for improving our understanding of climate change and its relation to human endeavours. The key topics investigated through climate records are detection and attribution of climate change, variability and emergence of the climate signal, causes of abrupt climate changes and tipping points, and drivers of extreme weather events. Furthermore, we have special interest in investigating the origins, scope, reliability, and integrity of climate records. The main climate archives that we investigate are ice cores, snow pits, instrumental and historical records (including narratives from indigenous knowledge), tree rings, speleothems, and sediment cores. Most natural archive samples are analysed directly the IzotzaLab, using multiple microscopy techniques, geochemical and thermomechanical tests, and digital image analysis. Climate data, ranging from narratives to time series and geospatial big data, are studied using semantic–pragmatic analysis, descriptive and inferential statistics, statistical learning, map processing, regression and time-series analysis, downscaling and reanalysis techniques.

Activity 1.2. Exploring the present: changes in extreme and vulnerable environments.

Vulnerable environments often represent effective early-warning systems for climate and environmental change. In particular, extreme environments characterized by extreme climatic conditions tend to be notably vulnerable, not only because of their fragile and unique ecosystems, but also because such extreme climatic conditions are often susceptible to abrupt changes and tipping points. Examples are polar regions, high-mountain environments, deserts, caves and karsts. BC3 investigates the ongoing changes in such environments through diverse approaches, ranging from theory, modelling, and data analysis to experimental and field work in sites like Antarctica, Greenland, Alaska, Siberia, Arctic Canada, Hindu-Kush–Himalaya, Tibetan Plateau, Patagonia, the Andes, Pyrenees, European Alps, Sahel, South Atlantic, Amazonia, and solar system environments, among others.

Activity 1.3. Looking upon the future: Climate and environmental modelling, projections and scenarios.

Models are the prevailing tools in climate and environmental sciences to look upon the future, and at BC3 we deal with a wide variety of them. BC3 researchers employ an assortment of modelling approaches similar to those used in the IPCC reports, including high-complexity multiscale climate models and downscaling (currently CMIP6 models and CORDEX downscaling) as well as lower complexity climate models and emulators (e.g. MAGICC and FaIR). We use historic runs of these and other models to validate downscaled results by multiple regional databases and reanalyses. Selected models are run and downscaled under various Shared Socioeconomic Pathway (SSP) scenarios to study regional climate variability and project future changes in essential climate variables, including mean and extreme temperatures, precipitation, snow cover, glacier mass, etc.