Conference Themes

1. Is the MOC Changing?

The potential climate impacts of MOC change make it essential to identify changes that may be happening now. Recent observations suggest a freshening of North Atlantic water, a possible reduction in the formation of deep water in the Norwegian Sea, decreased northward flow of upper waters, and a slow-down of deep southward flow - indicative of a recent and sizeable slowdown in the Atlantic MOC. This contrasts with recent dramatic increases in North Atlantic sea surface temperatures, which in coupled climate models are correlated with a stronger MOC. This session seeks to explore the implications of recent observations, and to what extent observed changes may constitute an early warning of rapid climate change.

2. What does the past tell us about rapid climate change?

The palaeoclimate record contains numerous examples of climate changes that appear as rapid or abrupt changes between relatively stable states. In this session we will concentrate particularly on events for which it has been proposed that the cause may be changes in ocean circulation and heat transport: the Dansgaard-Oeschger events of the last glacial period, the Younger Dryas, and the event at 8.2 kyr in the Holocene. What really triggered these events, what were the climatic consequences of them, and to what extent do they serve as tests of the ability of models to simulate the climatic effects of changing thermohaline circulation? Contributions discussing the causes of fast changes in climate in the last two millennia will also be welcome.

3. THC, climate and weather in the 21st century

What are the likely changes in the THC in the 21st century, given what we know of its past behaviour? If the THC changes, what are the implications for the climate globally and more locally on the weather patterns that affect the human population of the planet? This session seeks to explore these questions by examining how well models can explain recent observed changes in the THC, climate and weather, and by looking at what they predict could happen over the rest of the century. It will also explore how we can best estimate and reduce uncertainties in the predictions and test models using observations.

4. Outlook and Challenges

Climate change is inevitable, but while progress has been made in understanding some of the process and mechanisms by which rapid climate change may occur, many uncertainties remain. This session will seek to explore what the key challenges are in understanding the role of the ocean's thermohaline circulation in rapid climate change, and in quantifying the probability of such change in the future.