Past & Present Climate Change

The climate system is always changing. The atmosphere, oceans, biosphere and frozen Earth are interlinked in feedback loops that both amplify and diminish global change. By studying climate changes, we learn how these feedbacks operate, allowing us to investigate the response of the climate system to factors that cause it to change. By studying climate changes of the past, we can take advantage of the natural experiments that the Earth has already conducted to investigate how ecosystems change with climate. By studying past and recent changes in the carbon reservoirs, we can better identify important carbon-cycle feedbacks and how they might affect future climate. This understanding can be used to test and improve our predictive models. Models that include both natural and human factors will no doubt give more accurate projections.

Our research into past and present climate change addresses scientific questions including:

• How does the climate system change on decadal to millennial time scales as it responds to natural and anthropogenic forcings?
• How can we improve earth-system models, especially models used to foresee the effects of climate change, by using real-world data?
• How will the terrestrial biosphere respond to (and influence) future climate and changes in atmospheric CO2 concentrations?
• How can the physical and chemical properties of ice be used to model past climates, and quantify ice-sheet history in polar regions?
• How has climate impacted pre-historic and pre-industrial human societies?

We are developing leading-edge approaches to:

• Developing and analyzing major databases of long-term climate to better characterize past changes and to compare with the output of Earth system models to investigate climate-system variability and change.
• Creating the next generation reconstructions of long-term climate change from sedimentary records by exploiting new numerical models that encode a process-based understanding of earth-system interactions.
• Quantifying the sensitivity of terrestrial biosphere to climate extremes, changing atmospheric CO2 concentrations, and other environmental drivers.
• Evaluating models to identify which features are most important to improve for future carbon cycle and coupled carbon-climate projections.

Projects

• Southern Alaska lakes
• Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP)
• Mega-droughts, Climate Change and the Southwest: Stoneman Lake, Arizona, Paleoenvironments Drilling Project
• Quantifying Holocene climate variations through data assimilation using proxies and climate-model simulations
• Abrupt change in climate and ecosystems: Where are the tipping points?
• The drought-dust nexus in the Four Corners region and impacts on society
• The impact of climate on Viking-age societies in the North Atlantic
• IODP Expedition 379: Amundsen Sea West Antarctic Ice Sheet History
• South Pole Ice Core Paleo-records
• West Antarctic Ice Sheet Divide Ice Core Paleo-records

Who we are

For students