To make advances in the area of distinguishing between anthropogenic-induced changes and natural variability in ice sheets, we need to fill the knowledge gap that currently exists regarding changes in ice volume over multi-decadal timescales. However, projecting this contribution is difficult due to the non-linear nature of the underlying multi-decadal scale processes forcing ice sheet mass balance.
There is an ever-expanding database of proxy climate observations tracking climate changes over the past millennium, but synthesis with model output is in its early stages. For example, sea-level rise of 40cm per century has been observed in western Greenland during 1400-1600AD – a rise similar in magnitude to projected global mean under the moderate-high end climate scenarios. The same data suggest a period of ice loss initiating around 1600AD and continuing until present– a paradox to the widely perceived climate conditions thought to characterise the Little Ice Age.
The main focus of my current research is to build on previous studies of Greenland Ice Sheet mass balance throughout the last 1000 years and to produce a realistic, constrained Greenland Ice Sheet evolution for the past millennium in order to gauge ‘natural’ variability of ice sheet mass balance in the absence of anthropogenic influence.