Thursday, 23 June 2011 14:59
Key Objectives (Mission Statements)
The key objectives of the Past4Future program can be succinctly summarized by the following questions:
- What are the dynamics of the climate over interglacial periods?
- What causes climate changes and abrupt changes over the course of interglacial periods?
- Can we understand the greenhouse gas records of the interglacial periods?
- What can the past tell us about risks for climate changes/threats in the future?
What is the risk of abrupt changes in interglacials?
Abrupt changes during interglacials are caused by poorly understood complex interactions of internal and external forcings. Investigation of forcings, reaction of the climate system and impacts through integration of synchronized observations and models will allow us to advance our ability to predict the risk for abrupt changes in the next century when man made forcings such as increasing greenhouse gases add a dimension to the complexity.
Can we understand the greenhouse gas records of the interglacial periods?
On the long timescale greenhouse gases mirror climate changes with lower concentrations in cold periods and higher concentrations in warmer periods before the anthropogenic period started. The changes observed offer insight into aspects such as the capacity of the ocean and terrestrial biosphere to absorb increased CO2 emissions, and the possibility of methane release as a response to warming. Understanding the biogeochemical cycle in the past is crucial for predicting the future.
What is the risk of rapid collapse of the ice sheets?
Sea level changes are one serious risk that strongly influences the living conditions for the vast population placed in regions close to the sea. The UN IPCC AR4 report estimates a sea level rise of 30 cm in year 2100. The estimates did not include the full effects of possible changes in ice sheet dynamics and do not set a true upper bound for sea level rise due to changes in ice sheets. Past interglacials have experienced warmer climate than the present and can advance our ability to predict reaction times and thresholds for the ice sheets.
Did ocean circulation change significantly during the interglacial periods?
Ocean circulation strongly influences the climate of Europe, especially through the warm surface currents in the North Atlantic Ocean. During glacial periods the ocean circulation has abruptly changed resulting in very dramatic climate changes. The interglacial periods offer a chance to see to what degree shutdowns or slowdowns occurred in previous warm periods.