Cyanobacterial glycolipids as tracers of continental climate change

ongoing

Global surface temperatures are increasing in a manner unprecedented in modern Earth history. The extent of future warming on regional to global scales is difficult to predict but crucial for developing climate-resilient pathways and strategies for adaptation and sustainability. The study of ancient climates allows a mechanistic exploration of the Earth system and the opportunity to quantitatively and qualitatively evaluate and improve new generations of climate models. Particularly on the continents, however, the spatiotemporal reconstruction of ancient climates is often associated with large uncertainties due to the scarcity of proxy records. CYANITE takes an innovative approach to fill the ‘proxy record’ gap by tapping lacustrine sediment deposits as high-resolution archives of continental climate change. This will, for the first time, be feasible by the PI’s recent discovery of a novel suite of lipids, known as heterocyte glycolipids (HGs), that are ubiquitously present in lakes worldwide. CYANITE will interrogate the sensitivity of HGs to climate forcing in space and time and will develop, validate and apply HG-based lipid palaeothermometers that will provide essential new insights on the magnitude and timing of past continental climate change. CYANITE will go beyond the current state-of-the-art and through an integrated approach deliver i) culture and sediment calibrations to transfer HG-based proxy values to absolute temperatures and ii) high-resolution Cenozoic proxy records of continental climate change to facilitate palaeoclimate model-data comparison. As such, CYANITE will open new pathways in palaeoclimate research and significantly advance our capabilities to reliably forecast future climate change.