With oil near $50 a barrel, alternatives to gasoline are attracting more attention - including fuel cells, devices that convert hydrogen into electric current with no waste products except heat and pure water.

Fuel cells have found their way into power systems for laptop computers and into many experimental cars. The main drawback to automotive use of fuel cells, though, has been their cost, which at $100,000 can be 25 times the $4,000 for a gasoline engine of equal power. Lately, some companies, including Honda, have been trying to come up with cheaper versions of the most expensive part of a fuel cell: the membrane that takes the hydrogen fuel and separates it into protons and electrons.

This morning, a California company, PolyFuel, plans to announce that it has achieved a breakthrough in fuel-cell membranes by using an alternative material: a hydrocarbon that it says costs only about half as much per square meter.

Compared with the fluorine compounds that are the most commonly used for membranes in fuel cells now under testing, PolyFuel says that hydrocarbon membranes allow production of more electricity per square centimeter of membrane. That could mean that a fuel cell could produce the same power as a fluorine-membrane version, but would be smaller and lighter, further adding to efficiency, according to the company.

The blackout that left 50 million North Americans without power in August 2003 had an unexpected benefit - the air became cleaner.

As power plants were turned down in south-east Canada and the north-east and mid-west US, levels of pollutants fell, says meteorologist Russell Dickerson.

Environmentalist Paul Ehrlich has proved himself to be a stupendously bad prophet. In 1968 he declared: "The battle to feed all of humanity is over. In the 1970s, the world will undergo famines--hundreds of millions of people are going to starve to death." They didn't. Indeed, a "green revolution" nearly tripled the world's food supply. In 1975, he predicted that, by the mid-1980s, "mankind will enter a genuine age of scarcity," in which "accessible supplies of many key minerals will be facing depletion." Far from it. Between 1975 and 2000 the World Bank's commodity price index for minerals and metals fell by nearly 50%. In other words, we abound in "key minerals." Naturally, Mr. Ehrlich has won a MacArthur Foundation genius award--and a Heinz Award for the environment.

New underwater turbines could be cheap and eco-friendly.

A British company has invented a simple tidal power system that is relatively easy to install and has little impact on its environment. The device could soon be added to our range of renewable energy resources, and be used to bring power to remote seaside locations.

The TidEl system uses floating turbines that are anchored to the seabed by chains. The underwater windmills drift back and forth with the tide, so they point in the best direction to get power from the spinning blades.

Power capacity generated by the wind surged by more than a quarter last year, mainly thanks to an expansion in Germany and other European countries, according to industry figures released Wednesday.

Wind generators installed around the world by the end of 2003 had the capacity to produce 39,294 megawatts, an increase of 8,133 MW, or 26 percent over 2002, they said.

The future of manufacturing will be built on industrial-strength ecology, says architect William McDonough. The first step: Turn Ford's legendary River Rouge plant into a lean, green profit machine.

A sign up ahead reads WARNING: SLAG HAULER CROSSING. Sitting in the back of a sedan, architect William McDonough is riding through Ford's aging River Rouge factory complex in Dearborn, Michigan. At 1,100 acres, it's the largest industrial site of early- to mid-20th century America, a testament to the scale of Henry Ford's vision. The Armani-clad McDonough surveys the ruins strung along the dark, slack river, cruising past eye-level piles of black, powdery ash heaps, a spindly gas tower, and the proto-industrial blast ovens. A red oxygen furnace belches as it haltingly refines coke into steel.

It hardly looks like the site of the next industrial revolution, yet that is exactly what McDonough intends to make it. In late 2000, the Ford Motor Company hired McDonough, a designer cum environmentalist, to blueprint the site's 20-year, $2 billion redesign. The centerpiece will be a vast but energy-efficient truck assembly plant, not far from a new low-emission paint plant. Company CEO William Clay Ford Jr., Henry's great-grandson, says that the goal is nothing less than transforming River Rouge into "the model of 21st-century sustainable manufacturing."

Green architecture is an emerging field, and McDonough, who was trained at Dartmouth and Yale, spent most of the '80s experimenting with it. His highly lauded Herman Miller factory in Zeeland, Michigan, and Gap corporate offices in San Bruno, California, are designed to maximize natural lighting and air circulation. At Oberlin College, in Ohio, he built a solar- and geothermal-powered facility for the environmental studies department designed to generate more energy than it uses.

NASA scientists say soot, mostly from diesel engines, is causing as much as a quarter of all observed global warming by reducing the ability of snow and ice to reflect sunlight.

Now that the human genome has been sequenced, sequencing know-how is turning to other organisms. A team of researchers, including some from the University of Iowa, has sequenced the genome of a highly versatile and potentially useful bacterium. The multidisciplinary effort determined the complete genetic sequence of Rhodopseudomonas palustris, a bacterium that could potentially be used for cleaning up toxic industrial waste and as a biocatalyst for producing hydrogen as a bio-fuel.

In 1985, a geography researcher called Atsumu Ohmura at the Swiss Federal Institute of Technology got the shock of his life. As part of his studies into climate and atmospheric radiation, Ohmura was checking levels of sunlight recorded around Europe when he made an astonishing discovery. It was too dark. Compared to similar measurements recorded by his predecessors in the 1960s, Ohmura's results suggested that levels of solar radiation striking the Earth's surface had declined by more than 10% in three decades. Sunshine, it seemed, was on the way out.