The year 2008 closes with two enormous scientific and technological challenges unresolved: How to create renewable and benign sources of energy and how to lessen the damage we're doing to the global climate system.
Those twin issues are the "greatest challenge facing modern science," according to Nobel laureate Steven Chu, the gifted physicist who has been nominated to head the Department of Energy. He will be at the center of the effort to deal with these vexing problems, and his nomination signals a new day in that effort.
Clearly, those two issues dominated the world of science during 2008, a year that also saw much progress in fields as diverse as genetic engineering, the imaging of new planets outside our solar system and the maturing of social media that has altered everything from how we meet people to financing a costly and victorious campaign for the presidency of the United States. It's difficult to pick a single scientific achievement that stands out above all others because science, as a whole, doesn't work that way.
Science is and always will be a work in progress. Discoveries today are built upon past discoveries as progress is achieved, inch by inch. But rarely has there been a year when two inseparable issues dominated so much of our lives.
Energy and climate moved science from the lab to our living rooms and they were the "hot button" scientific issues of 2008.
The "breakthrough" in this case is not just hardware; it's a growing understanding of the urgency in solving these critical problems. Here's our list of the top 10.
The year the earth stood still. Polluted air, a lopsided dependence on shaky sources of foreign oil and congested highways couldn't convince Americans that it was time to get serious about new sources of energy. But more than four bucks per gallon at the gas pump did the trick.
Biofuels, hybrids and photovoltaic cells slipped into our conversations like invaders from another planet. Progress was reported from all areas of energy production but not all roads led us closer to energy independence. Corn isn't going to replace gasoline. That may be the most important energy "discovery" in 2008. Corn displaces agricultural land normally used for food production and, according to one study, it takes about 28 gallons of water to produce enough biofuel from corn to push a car just one mile. Substitute water wars for gas wars.
That disappointment grew out of research that was dictated by funding. Washington thought corn was a good idea and that's where a lot of research funds went. It should be the other way around. Let discoveries chart the course; let the funding follow. Stay fluid.
Throughout the year, discoveries flowed in from hundreds of labs: wearable electronic circuits that can use body movements to recharge batteries; solar panels so flexible they can be "painted" on a roof; photovoltaic cells that are twice as effective at converting sunlight to electricity; and a new generation of fuel-efficient vehicles.
Construction is under way on new wind farms, with huge turbines generating electricity from the passing breeze, and vast acreage is being converted to solar collectors. Scientists at several institutions made progress in creating a way to store solar energy by using solar power to split water into oxygen and hydrogen and using the hydrogen as fuel.