PlioMax is a five-year research project funded by the US National Science Foundation that aims to increase the accuracy of global sea level estimates for the mid-Pliocene warm period, between 3.3 and 2.9 million years ago. Numerous proxy methods suggest that atmospheric CO2 levels at that time ranged between 350 and 450 ppm (the current atmosphere level is~396 ppm). Proxies also suggest that mean global surface temperature was 2-3°C warmer than the preindustrial level but estimates of ice volume and/or sea level at that time are far more uncertain. The mid-Pliocene warm period thus provides a natural analogue for a warmer, higher CO2 world that can be used as a testing ground for the climate and ice sheet models that are being used to predict the future response of Earth’s climate to increasing levels of greenhouse gases. Here we document our efforts at reducing uncertainty in the sea level/ice volume estimates derived from the geologic record of this time period.
Scientific details on PLIOMAX activities can be found at our wiki page