We know that the Arctic exerts a critical influence on the Earth's climate and has done so for millions of years. Locked in Arctic ice and sediments are vital records of what the Earth's environment was like in the past. To more accurately predict the future of the Earth's climate, we need to know more about the extremes. Finding out how hot and how cold the Earth was in the past, and how much, as well as how little of it was covered by ice are key questions that APEX hopes to help answer.

The overall goal of this initiative is to advance our knowledge of climate warming in the Arctic, by studying past climate change. We will focus mainly on the ocean circulation and climate of the NW Eurasian continental margin. The present climate in the Arctic shows signs of rapid change with decreasing sea ice cover and increasing temperature of the Atlantic Water. The implications of this warming are highly uncertain, as modelling experiments projecting temperatures for the next 100 years show a largescatter at high northern latitudes.

The Antarctic Peninsula is one of the Earth’s three most rapidly warming regions: most of the glaciers there are in retreat and large ice shelves have broken up. This project investigates the impact of these changes on the plants and animals that live on the land, the shore and coastal sea around the Antarctic Peninsula. Organisms are facing a barrage of complex effects including warming, decreased ice and snow cover, increased iceberg grounding, sedimentation and freshening. A wide range of apparatus and techniques will be used from remote operated vehicles (ROV) and simple underwater light meters to satellite imagery and counting microscopic life. ClicOPEN scientists from 15 countries will study changes in the environments and organisms around a number of retreating glaciers of the Western Antarctic Peninsula. Most of Antarctica's very rich biodiversity lives nowhere else in the world and we know little about how it will responding to such exceptional and unprecedented warming.

The Circumpolar Flaw Lead (CFL) System Study is a major international effort under Canadian leadership that aims at understanding how changes in the physical system affect biological processes, towards a better understanding of the potential effects of climate change. The CFL project is part of the PAN-AME cluster.

Scientists from Europe, North America and New Zealand will investigate how the presence of snow and ice affects the chemistry of air above the polar ice caps. In the Arctic and Antarctic, sunlight triggers the release of chemicals from surface snow into the lower atmosphere. Salty sea ice surfaces host some very interesting chemistry (involving bromine compounds) during the polar spring when the sun comes back. These processes affect air quality and the interpretation of past climate using ice cores. If the amount of sea ice changes the chemical content of the lowest parts of the polar atmosphere will also change.

Sea level rise will be responsible for one of the most profound and costly impacts of climate change on human society, so gathering accurate data on sea levels worldwide is vitally important. Although sea level is monitored at hundreds of sites through the Intergovernmental Oceanographic Commission and World Meteorological Organization's Global Sea Level Observing System, there are large gaps in data from the Arctic and Antarctic because measuring sea level along polar coastlines is a huge technical challenge. By enhancing existing sea level gauges in the Antarctic, and installing new, high-tech devices in the Arctic that will provide high-frequency, real time data, this project will provide the missing piece of the jigsaw for scientists monitoring sea level rise across the globe. The same sea level data can also be used to monitor changes in the circulation of the high-latitude oceans, which in turn may provide clues as to why sea level is rising.