The Earth is bathed in a flood of sunlight. A fierce inundation of photons on average, 342 joules per second per square meter. 4185 joules (one calorie) will raise the temperature of one kilogram of water by one degree Celsius. If all this energy were captured by the Earth’s atmosphere, its temperature would rise by ten degrees Celsius in one day.

Luckily much of it radiates back to space. How much depends on albedo and the chemical composition of the atmosphere, both of which vary over time.

A good portion of Earth’s albedo, or reflectivity, is created by its polar ice caps. If polar ice and snow were to shrink significantly, more solar energy would stay on Earth. Sunlight would penetrate oceans previously covered by ice, and warm the water. This would add heat and melt more ice, in a positive feedback loop.

The Arctic Ocean ice pack reflects back out to space a few percent of the total annual solar energy budget. When the Arctic ice pack was first measured by nuclear submarines in the 1950’s, it averaged thirty feet thick in midwinter. By the end of the century it was down to fifteen. Then one August the ice broke up into large tabular bergs, drifting on the currents, colliding and separating, leaving broad lanes of water open to the continuous polar summer sunlight. The next year the breakup started in July, and at times more than half the surface of the Arctic Ocean was open water. The third year, the breakup began in May.

That was last year.

WEEKDAYS ALWAYS begin the same. The alarm goes off and you are startled out of dreams that you immediately forget. Predawn light in a dim room. Stagger into a hot shower and try to wake up all the way. Feel the scalding hot water on the back of your neck, ah, the best part of the day, already passing with the inexorable clock. Fragment of a dream, you were deep in some problem set now escaping you, just as you tried to escape it in the dream. Duck down the halls of memory gone. Dreams don’t want to be remembered.

Evaluate the night’s sleep. Anna Quibler decided the previous night had not been so good. She was exhausted already. Joe had cried twice, and though it was Charlie who had gotten up to reassure him, as part of their behavioral conditioning plan which was intended to convey to Joe that he would never again get Mom to visit him at night, Anna had of course woken up too, and vaguely heard Charlie’s reassurances: “Hey. Joe. What’s up. Go back to sleep, buddy, it’s the middle of the night here. Nothing gets to happen until morning, so you might as well. This is pointless this wailing, why do you do this, good night damn it.”

A brusque bedside manner at best, but that was part of the plan. After that she had tossed and turned for long minutes, trying heroically not to think of work. In years past she had recited in her head Edgar Allan Poe’s poem “The Raven,” which she had memorized in high school and which had a nice soporific effect, but then one night she had thought to herself, “Quoth the raven, ‘Livermore,’” because of work troubles she was having with some people out at Lawrence Livermore. After that the poem was ruined as a sleep aid because the moment she even thought of “The Raven” she thought about work. In general Anna’s thoughts had a tropism toward work issues.

Shower over, alas. She dried and dressed in three minutes. Downstairs she filled a lunch box for her older boy. Nick liked and indeed insisted that his lunch be exactly the same every day, so it was no great trouble to assemble it. Peanut butter sandwich, five carrots, apple, chocolate milk, yogurt, roll of lunch meat, cheese stick, cookie. Two minutes for that, then throw in a freeze pack to keep it chilled. As she got the coldpacks out of the freezer she saw the neat rows of plastic bottles full of her frozen milk, there for Charlie to thaw and feed to Joe during the day when she was gone. That reminded her, not that she would have forgotten much longer given how full her breasts felt, that she had to nurse the bairn before she left. She clumped back upstairs and lifted Joe out of his crib, sat on the couch beside it. “Hey love, time for some sleepy nurses.”

Joe was used to this, and glommed onto her while still almost entirely asleep. With his eyes closed he looked like an angel. He was getting bigger but she could still cradle him in her arms and watch him curl into her like a new infant. Closer to two than one now, and a regular bruiser, a wild man who wearied her; but not now. The warm sensation of being suckled put her body back to sleep, but a part of her mind was already at work, and so she detached him and shifted him around to the other breast for four more minutes. In his first months she had had to pinch his nostrils together to get him to come off, but now a tap on the nose would do it, for the first breast at least. On the second one he was more recalcitrant. She watched the second hand on the big clock in his room sweep up and around. When they were done he would go back to sleep and snooze happily until about nine, Charlie said.

She hefted him back into his crib, buttoned up and kissed all her boys lightly on the head. Charlie mumbled “Call me, be careful.” Then she was down the stairs and out the door, her big work bag over her shoulder.

The cool air on her face and wet hair woke her fully for the first time that day. It was May now and the late spring mornings had only a little bit of chill left to them, a delicious sensation given the humid heat that was to come. Fat gray clouds rolled just over the buildings lining Wisconsin Avenue. Truck traffic roared south. Splashes of dawn sunlight struck the metallic blue sheen of the windows on the skyscrapers up at Bethesda Metro, and as Anna walked briskly along it occurred to her, not for the first time, that this was one of the high points of her day. There were some disturbing implications in that fact, but she banished those and enjoyed the feel of the air and the tumble of the clouds over the city.

She passed the Metro elevator kiosk to extend her walk by fifty yards, then turned and clumped down the little stairs to the bus stop. Then down the big stairs of the escalator, into the dimness of the great tube of ribbed concrete that was the underground station. Card into the turnstile, thwack as the triangular barriers disappeared into the unit, pull her card out and through to the escalator down to the tracks. No train there, none coming immediately (you could hear them and feel their wind long before the lights set into the platform began to flash) so there was no need to hurry. She sat on a concrete bench that positioned her such that she could walk straight into the car that would let her out at Metro Center directly in the place closest to the escalators down to the Orange Line East.

At this hour she was probably going to find an open seat on the train when it arrived, so she opened her laptop and began to study one of the jackets, as they still called them: the grant proposals that the National Science Foundation received at a rate of fifty thousand a year. “Mathematical and Algorithmic Analysis of Palindromic Codons as Predictors of a Gene’s Protein Expression.” The project hoped to develop an algorithm that had shown some success in predicting which proteins any given gene sequence in human DNA would express. As genes expressed a huge variety of proteins, by unknown ways and with variations that were not understood, this kind of predicting operation would be a very useful thing if it could be done. Anna was dubious, but genomics was not her field. It would be one to give to Frank Vanderwal. She noted it as such and queued it in a forward to him, then opened the next jacket.