Our traditional mathematics and classical sciences have always had difficulty with phenomena such as these, preferring instead to focus on patterns that seek closure, problems that have single answers, equations that can be "solved." But the new cybernetic sciences, armed with powerful computers, have embraced complexity. Indeed, every one of the scientists whom I have contacted over the past several years with regard to the ice riddle has been intimately involved in the study of complex systems. Parkinson's satellite-sensed data sets of sea ice growth and decay, Marko's correlations of side channel bridging and Baffin Bay sea ice cover, Broecker's convective processes for the production of North Atlantic Deep Water, Alley's compilations of ancient snowfall amounts as they relate to changing patterns of climate, Hakkinen's model of deep ocean mixing at the ice-ocean boundary-all exhibit the same involvement with complexity.

Like sailors learning how to read a crossing wave train, each of these scientists has needed to become familiar with the seeming randomness of the system he or she is trying to understand. Like sailors, they live with the systems day after day. They manipulate them, model them, feed them into computers and "run" them. Sometimes when nothing else seems to work, they simply store them in some out-of-the-way compartment of the brain and let them sit there unattended for a while. Eventually, with time and patience, they begin to sense emerging patterns and to grasp the intricate logic of how the various components fit together.

There is a sense, I think, in which this capacity for dealing with complex systems may simply be a matter of temperament. There are those who naturally seek out situations that are orderly. And there are others who seem drawn to process and pattern and to the inherent messiness of nonlinearity - people who say "ah, what a lovely, complicated business this is" and then just roll up their sleeves and dig in.

There is another sense, however, in which our ability to deal with complex systems may be growing more commonplace - a result, some have suggested, of an emerging "worldview of complexity." A century ago almost everyone in Western society thought in terms of the old equilibrium viewpoint - the idea that there is a fundamental duality between humans and nature and a point of natural equilibrium between them.

But increasingly today there is another way of understanding ourselves and our relationship to nature - a kind of interactive worldview in which there is no longer a division between ourselves and our natural surroundings. Instead, both are seen as components of the same complex system. One does not reside outside or beyond the other, but rather the two are integrally connected in a single, continuous, and highly interactive relationship.

What this means, among other things, is that as human beings we can now begin to think of ourselves as part of what may cause natural systems to change their mode of behavior. When we take a collective action in response to a particular situation in nature, we set in motion a sequence of events that may eventually come back and create a different situation for us to adjust to. There is no point of stasis. There is no "natural equilibrium." We are part of an ongoing process, and as such, we have the ability to provoke the system into any number of new and unpredictable responses.

It is this interactive worldview, I think, that informs many of the new sciences of complexity (such as the study of Earth climate) and that gives rise to statements like those of Wally Broecker about the" coming surprises" that we seem destined to experience as we continue to perturb the climate system. As Broecker admits, we really don't have any idea yet what these surprises may be-for the system that will generate them is complex, and the range of possible responses is still beyond our ability to predict.

But just as a crossing wave train will eventually result in a square-shaped sea, a tumbling crest, a rogue wave, so the climate system will eventually respond in dramatic and unforeseen ways to the perturbations that we collectively visit upon it. As we continue to multiply in numbers, as our waste stream increases, and as our technologies grow ever more powerful, we begin to behave like another train of waves marching across the surface of the sea-a strong and growing force interacting with all the other forces. We are not separate. We cannot escape our involvement with the patterns that are generated. As we add our own inputs to the process, the patterns will change, and we will be required to respond to new patterns that we ourselves have helped to create.

The ship's clock chimes eight bells - four o'clock - and I realize that I must return to the deck. I climb the companionway ladder to find Mike at the helm and Pete sitting next to him in the cockpit. At first I wonder why Pete isn't watching from the bow - then I realize that in the half hour I've been below, the dawn has begun to break and the light has already started to change.

A crimson glow grows under a layer of overcast behind us. The vague form of an iceberg looms on the horizon several miles to the west, and another appears dead astern framed against the rising light. I relieve Mike at the helm and we sail in silence for the next twenty minutes as the light grows - an angry color that washes the sky overhead with streaks of blood red and that casts an eerie glow on the surface of the sea.

There is no doubt now in any of our minds about the approaching weather. The boat heels to a gust of wind, and I strain ahead for a glimpse of the coast that we must find before the gale arrives.