Date: 2013-02-22 03:00 AM
Speaker: Michal Kucera
Local: IPMA Algês Lisboa
Email contact:
Phone contact: 214770000
Quantitative reconstruction of the state of the oceans in the distant past has the potential to constrain estimates on the rates and magnitudes of the response of the Earth’s climate to changes in critical boundary conditions. In this respect, the last ice age has long been considered particularly important and promising.
This interval, approximately 20,000 years ago, represents the time with the lowest carbon dioxide concentration in the atmosphere of the last glacial cycle. It is associated with similar solar forcing as the present day and all climatic boundary conditions are relatively well known. For these reasons, knowing the global temperature of the last ice age can help narrow down estimates of climate sensitivity – the scaling between temperature response and greenhouse gas forcing.
This talk with explain how past ocean temperatures can be reconstructed and present the latest dataset of temperature reconstructions for the last glacial ocean surface produced by the MARGO consortium. I will then discuss the main sources of uncertainties affecting these reconstructions and conclude by showing what the last ice-age ocean data indicate about the climate sensitivity and how important the assessment of uncertainties is in this endeavour.