Fifty Degrees Below by Kim Stanley Robinson

but Diane took up a towel and said, “Wait a second, let me wipe up the wet spot.”
    “Oh I hate the wet spot,” the young woman said, and immediately threw a hand to her mouth, blushing vividly. Frank and Diane laughed, and seeing it the young woman did too, glowing with embarrassment. Diane gave the bench a final flourish and handed it over, saying, “There, if only it were always that easy!”
    They laughed again and Frank and Diane moved to the next machine. Military press, leg curls; then Diane looked at her watch and said, “Oops, I gotta get going,” and Frank said “Me too,” and without further ado they were off to their respective locker rooms. “See you over there.” “Yeah, see you.”
    Into the men’s room, the shower, ahhhh. Hot water must have been unusual in the hominid world. Hot springs, the Indian Ocean shallows. Then out on the street, the air still cool, feeling as benign as he had in a long time. And Diane emerged at the same time from the women’s locker room, transformed into work mode, except wetter. They walked over to NSF together, talking about a meeting they were scheduled to attend later in the day. Frank arrived in his office at eight A.M. as if it were any ordinary morning. He had to laugh.
             
    The meeting featured a presentation by Kenzo and his team to Diane, Frank’s committee, and some of the members of the National Science Board, the group that oversaw the Foundation in somewhat a board-of-directors style, if Frank understood it correctly. By the time Frank arrived, a large false-color map of the North Atlantic was already on the screen. On it the red flows marking the upper reaches of the Gulf Stream broke apart and curled like new ferns, one near Norway, one between Iceland and Scotland, one between Iceland and Greenland, and one extending up the long channel between Greenland and Labrador.
    “This is how it used to look,” Kenzo said. “Now here’s the summer’s data from the Argos buoy system.”
    They watched as the red tendrils shrank in on themselves until they nearly met, at about the latitude of southern Ireland. “That’s where we’re at now, in terms of temperature. Here’s surface height.” He clicked to another false-colored map that revealed what were in effect giant shallow whirlpools, fifty kilometers wide but only a few centimeters deep.
    “This is another before map. We think these downwelling sites were pretty stable for the last eight thousand years. Note that the Coriolis force would have the currents turning right, but the land and sea-bottom configurations make them turn left. So they aren’t as robust as they might be. And then, here’s what we’ve got now—see? The downwelling has clearly shifted to southwest of Ireland.”
    “What happens to the water north of that now?” Diane asked.
    “Well—we don’t know yet. We’ve never seen this before. It’s a fresh-water cap, a kind of lens on the surface. In general, water in the ocean moves in kind of blobs of relative freshness or salinity, you might say, blobs that mix only slowly. One team identified and tracked the great salinity anomaly of 1968 to ’82, that was a huge fresher blob that circled in the North Atlantic on the surface. It made one giant circuit, then sank on its second pass through the downwelling zone east of Greenland. Now with this fresh-water cap, who knows? If it’s resupplied from Greenland or the Arctic, it may stay there.”
    Diane stared at the map. “So what do you think happened to cause this fresh-water cap?”
    “It may be a kind of Heinrich event, in which icebergs float south. Heinrich found these by analyzing boulders dropped to the sea floor when the icebergs melted. He theorized that anything that introduces more fresh water than usual to the far North Atlantic will tend to interfere with downwelling there. Even rain can do it. So, we’ve got the Arctic sea ice break-up as the main suspect, plus Greenland is melting much more