On an ordinary October day a couple years ago, the United Nations news office issued a press release saying that world population that morning hit 7 billion. That was up from 6 billion only 13 years earlier. By 2043 or so, the population of planet Earth is expected to reach 9 billion.

The secret to sustaining all those people will be energy in unimaginable quantities—energy for agriculture, food production and processing, heating, cooling, transit, construction, business, manufacturing of houses, steel and Ohio Class submarines.

The story is familiar. Around 86% of global energy will come from where it does now—coal, oil, natural gas, nuclear power stations and dams. But other forms called renewables—wind, solar, biomass, geothermal—will turn out more energy over the next two decades at a far faster rate and swiftly gain more importance.

A report by the Renewable Energy Policy Network says that 50% of global renewable energy capacity is in developing countries. The top five renewable countries are: the U.S., China, Germany, Spain and India.

China, in fact, is sizzling. Though it still burns more coal than any country, China ended 2010 with renewables accounting for 26% of installed energy capacity and 18% of energy consumed. It plans a 2,000-megawatt solar thermal project, five times bigger than the current largest one: California’s Solar Energy Generating System. China is building a wind corridor that could swell to a staggering 20,000 megawatts, 25 times the size of Texas’ Roscoe Wind Farm. China is also planning a 2,000-megawatt solar photovoltaic farm, 33 times bigger than the world’s largest, a 60-megawatt installation in Spain.

Most countries are moving, to one degree or another, to escape fossil fuels or at least rely less on them. New Zealand’s Energy Efficiency and Conservation Authority last year slapped new efficiency standards on television sets. Portugal so far this year is producing 70% of its energy from wind and hydropower. Bangladesh gets more than half its electricity from dung, wood and crop residues.

Brazil generates 85% of its power from sugarcane ethanol, that country’s reaction to the oil shocks of the 1970s. With a 4,600-mile coastline, Brazil also has high potential for wind power. Endowed with constant sunshine, Costa Rica is aiming for a carbon-free economy by the middle of the decade, when 95% of its power will come from dams, solar and wind.

“A diverse portfolio of energy technologies will replace our reliance on fossil fuels.”
—David LePoire, analyst, Argonne National Laboratory

For its part, despite huge strides and the vast technology at its disposal, the United States ranks ninth in the world in clean-air quality, behind Japan, Germany and Italy, among others. This from the county that gave the world the Environmental Protection Agency, the Clean Air Act and the Clean Water Act some four decades ago. The main reason: particle pollution from the burning of fossil fuels in buildings and cars and stiff political opposition to change from powerful energy interests. About 60% of Americans in the largest cities are affected.

As for entirely new energy sources, most are barely out of the laboratory but will play larger roles as the 21st century unfolds. One of the most promising is SolarWindow, wherein a coating sprayed on glass can generate electricity when struck by sunlight. Developed by New Energy Technologies of Columbia, Maryland, SolarWindow is in the second phase of study by the U.S. Department of Energy’s National Renewable Energy Laboratory.

Meanwhile, scientists at the Massachusetts Institute of Technology found a process for generating electricity using nanotechnology. They plan to create an environmentally friendly battery, among other products.

Other sources are much further out and geared heavily to experimental physics. Says David LePoire, analyst at Argonne National Laboratory, “A diverse portfolio of energy technologies will replace our reliance on fossil fuels.”

Scientists are exploring not just wind and solar energies, LePoire says, but also esoteric technologies, such as artificial photosynthesis, dark energy, traveling wave reactors and mini-black holes. The latter could power future spaceships.

None of these is within decades of practical use—it takes the force of a hydrogen bomb to produce a mini-black hole, for example, although LePoire concedes that “a surprise might arise from this area.”

Hundreds of other new energy technologies were displayed last winter at the Energy Department’s Advanced Research Projects Agency-Energy summit. It included the creation of some 250 companies.

Not surprisingly, the greatest concentration of new ideas was in carbon capture—devices and processes to prevent carbon dioxide from escaping into the atmosphere, one cause of global warming, the chief effect on the environment of burning fossil fuels.

Since the beginning of the Industrial Revolution, the generation of carbon dioxide has increased about 41%. Its level is higher now than in the last 650,000 years, and scientists fear it could double or triple before emissions are controlled.

Warming helps create massive weather anomalies. Last summer a severe drought stretching across eight countries in West Africa left more than 18 million people facing hunger. Closer to home, last October Superstorm Sandy killed 125 people and caused $82 billion in damage in the United States alone, leaving thousands of families homeless and wiping out hundreds of thousands of small businesses. Nearly a year later, in New York City, Connecticut and New Jersey, the cleanup continues.

Yet innovators are finding that carbon dioxide may not be entirely without use. West Texas oilman Elliott Roosevelt, FDR’s grandson, is buying CO2 emissions to pump into the ground to force oil up, and he is not alone in finding uses for the gas beyond the bubbly in soft drinks. Biofuels manufacturer Joule says it has converted waste CO2 into gasoline and jet fuel components.

Such advances in the lab, in the skies and in the fields create pressure on corporations to get greener, and the movement has a structure all its own called corporate sustainability. Companies have found that what’s good for the environment is good for them. An elaborate expansion of the corporate social responsibility of an earlier era, corporate sustainability aims to make companies greener by tuning their functions to the natural environment. It also measures how effectively a business functions in social, cultural, and economic environments.

Microsoft, for example, levies an internal carbon tax on its business divisions to encourage managers to push toward carbon-neutrality. Unilever has set ambitious goals to reduce the environmental footprint of its products by 50% to help more than 1 billion people improve their health and to source 100% of its agricultural raw materials sustainably.

“From a greenhouse point of view, it would be better to replace coal electrical facilities with nuclear plants, wind farms and solar panels, but replacing them with natural gas stations will be faster and cheaper.”
—Lawrence Cathles, professor, Earth and Atmospheric Sciences Department, Cornell University

Norway’s Brundtland Commission came up with one definition of sustainability about a quarter century ago: “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” A hydroelectric dam fits that definition perfectly because it supplies power over many generations. Oil doesn’t, of course, because once it’s used there’s that much less for people who come later.

At Owens Corning, the sustainability program is driven from the R&D function because it is responsible for developing insulation products that help homes and commercial buildings operate efficiently and conserve energy. The products Owens Corning sells prevent more than a billion tons of greenhouse emissions.

Sustainability, says Toby Heaps, editor-in-chief of Corporate Knights, a publication of the similarly named Toronto-based media and investment research company, told Forbes.com that sustainability occurs when what is good for a company is also good for the planet, and vice-versa. “It means creating more wealth than we destroy,” Heaps said. “It means that a company is, on balance, increasing our overall stock of wealth, grounded in human, produced, financial, natural and social capital.”

The Belgian firm Umicore, a materials technology and recycling company, topped Corporate Knights’ list of the 100 most sustainable companies for 2013. Rounding out the top 10 were Natura Cosmeticos (Brazil); Statoil ASA (Norway); Neste Oil (Finland); Novo Nordisk (Denmark); Storebrand (Norway); Koninklijke Philips Electronics (Netherlands); Biogen Idec (U.S.); Dassault Systemes (France) and Westpac Banking (Australia).

Suitable Sources

The most dramatic recent change in world energy production is the huge production increase in natural gas. Surprisingly, so much natural gas is being produced in the United States and Western Europe these days that it is seen as the perfect bridge fuel until energy renewables, such as solar and wind, can produce larger quantities of electricity. So says a new study by Cornell professor Lawrence Cathles, published in the December edition of the peer-reviewed journal Geochemistry, Geophysics and Geosystems.

At its current pace, natural gas should surpass coal as the world’s primary fuel by 2020.

Cathles, of Cornell’s department of Earth and Atmospheric Sciences, reviewed the most recent government and industry data on natural gas “leakage rates” during extraction, as well as new climate models. Substituting natural gas for all coal and some oil production, Cathles found, provides 40% of the global warming benefit that a complete switch to low-carbon sources would deliver.

“From a greenhouse point of view,” he wrote, “it would be better to replace coal electrical facilities with nuclear plants, wind farms and solar panels, but replacing them with natural gas stations will be faster and cheaper. Gas is a natural transition fuel that could represent the biggest stabilization wedge available to us.”

Another big impact of the huge supplies of natural gas may be an onslaught of vehicles powered by natural gas in the United States and Europe, predicts Thomas Frey, innovation editor of The Futurist magazine. Here are some of Frey’s future trends:

  • Shell projects global demand for liquefied natural gas will double, to 400 million tons, by 2020 and rise to as much as 500 million tons by 2025.
  • In 2013, four major manufacturers will introduce a 12-liter liquefied natural gas engine, the optimum size for heavy-duty, 18-wheel trucks.
  • Liquefied natural gas costs about $1.50 a gallon versus about $4 for gasoline in the United States.
  • 112,000 natural gas-powered vehicles are in use in the United States, mostly delivery trucks and other local vehicles.
  • FedEx and UPS are switching more vehicles in their fleets to compressed natural gas.
  • Waste Management is converting 80% of its trash trucks to compressed natural gas.

Up to this point, however, no energy alternative has made much headway in countering fossil fuels’ production of carbon dioxide. For all its jazzy promotion in California and elsewhere, for example, solar and wind produces only 3% of U.S. energy. And both technologies are expensive when compared to natural gas or coal.
But change is afoot. The World Future Society predicts that by 2020 or 2025, about 30% of global energy will come from sources other than fossil fuel.

Here’s a rundown of what’s happening:

BATTERY-POWERED CARS: One in 10 cars will run on battery power by 2020, says Nissan CEO Carlos Ghosn. Even allowing for the emissions from generating equipment to charge batteries, CO2 injections into the atmosphere would decline by 30%.

“Given the history of emissions and the existing inequalities of both wealth and per capita emissions, it is highly unlikely that any international deal could be agreed that would commit all countries to make equal cuts in their emissions.”

GM’s contribution is the smartly designed Chevy Volt, right now too expensive for most buyers at around $40,000, even with a $7,000 federally subsidized discount. At about the same price is the Ford Focus Electric. The sleek Tesla Roadster, Silicon Valley’s contribution to the electric automotive world, lists for $109,000, although a cheaper model goes for $50,000.

Even with those innovations, critics say the United States is moving too slowly toward battery-powered vehicles. While the U.S. government has pledged $2.4 billion in federal grants for electric cars and batteries, China will spend $15 billion to initiate an electric car industry, and it’s doing some of it on U.S. soil.

In December, Wanxiang America, the U.S. arm of a Chinese automotive parts giant, won the bidding for a bankrupt Massachusetts-based lithium battery manufacturer, A123, that once was hailed as a cornerstone of President Obama’s quest for American dominance in electric vehicles and battery technology.

Wanxiang would pay $256.6 million for all of A123’s technology, its manufacturing facilities in the United States and China, and its contracts with utilities seeking grid storage and automakers seeking batteries for electric and hybrid vehicles.

WIND: Experts estimate wind could supply as much as half the world’s energy. The U.S. Department of Energy says wind could account for 20% of the nation’s supply of electricity by 2030. Denmark plans to generate 50% of its energy from wind by 2020, reports the World Future Society.

Maine is building a new generation of high-efficiency wind farms with composite turbines 20 to 30 miles into the Atlantic, where wind is stronger. The state expects to reap 5 gigawatts, more than the state uses, making Maine an energy exporter.

SOLAR: Despite such high-visibility bankruptcies as Solyndra, the third quarter of 2012 was the third largest for the U.S. solar industry and raised total installed capacity through the first three quarters of the year to 1,992 megawatts, surpassing the 2011 total of 1,885 megawatts, reports U.S. Solar Market Insight. There were 684 megawatts of photovoltaic capacity installed in Q3 2012, representing a 44% increase in deployment over the third quarter of 2011. The Solar Energies Industries Association forecasts close to 1,300 megawatts of photovoltaic capacity will be installed in the fourth quarter of 2012 alone, bringing the total for the year to 3,200 megawatts.

California’s electric utility companies are required to use renewable energy to produce 33% of the state’s power by 2020. A main source will be solar energy, and no fewer than a dozen large projects are under way. In the 1980s, Luz Industries, an Israeli company, built nine power plants, called Solar Energy Generating Systems, near Barstow, in the Mojave Desert. These plants have a combined capacity of 354 megawatts. The solar plants power 232,500 homes (during the day, at peak power) and displace 3,800 tons of pollution per year that would have been produced if the electricity had been provided by fossil fuels.

These systems convert heat from the sun into electricity. Because of their parabolic shape, trough collectors can focus the sun at 30 to 60 times normal intensity on a receiver pipe. Synthetic oil circulates through the pipe and captures this heat, reaching 735 degrees Fahrenheit. The hot oil is pumped to a generating station and routed through a heat exchanger to make steam. Finally, electricity is produced in a conventional steam turbine.

TIDES: Around in one form or another since the middle ages, modern tidal power harnesses the relative motion of the Earth and the moon—the forces that create ocean tides—driving underwater turbines and producing electricity. Currently, the United States, Brazil, Europe, Scotland, Germany, Portugal, Canada and France all lead the developing wave energy industry, which is expected to grow by at least 30% in five years.

WAVES: The world’s first commercial wave farm is in Portugal, at the Aguçadora Wave Park, consisting of three 750-kilowatt Pelamis generating devices. In the United States, the Pacific Northwest Generating Cooperative is funding the building of a commercial wave-power park at Reedsport, Ore. The project will use the PowerBuoy technology of Ocean Power Technologies, which consists of modular, ocean-going buoys. The rising and falling of the waves moves the buoy-like structure, creating mechanical energy, which is converted into electricity, then transmitted to shore.

HYDRODEN: This lighter-than-air gas has been promoted as an environmentally friendly synthetic fuel that can be used in fuel cells to generate electrical power at high efficiency while emitting no air pollutants. But getting the hydrogen is the problem since a major source is fossil fuels, say James Fay of the Massachusetts Institute of Technology and Dan Golomb of the University of Massachusetts, in their paper “Energy and the Environment.”

There is a bright spot. Hydrogen from fossil fuel makes CO2 recovery easier by allowing it to be “sequestered” or buried underground as it is produced. This means 60% to 80% of the fossil fuel’s heat can be used while reducing emissions of carbon dioxide.

NUCLEAR FUSION: This technology would fuse atoms to produce energy, as in the sun and, for that matter, the hydrogen bomb. While nuclear fission electrifies a big chunk of the world, not in 50 years have researchers managed to produce more energy than it takes to start a fusion reaction.

It’s not for lack of trying. Researchers at Lawrence Livermore National Laboratory in California, at a stadium-sized building called the National Ignition Facility, in July fired a system of 192 laser beams totaling more than 500 trillion watts to its target about the size of a BB. It was the largest artificial charge in history, but it still failed to start a fusion reaction. The World Future Society places nuclear fusion way into the future—off its charts, in fact.

If all these efforts—and others not foreseen—bear fruit, can the environment be cleaned up in the next few decades? Can global warming be stopped, possibly reversed? Or is the damage to Earth’s climate irrevocable?

“Given the history of emissions and the existing inequalities of both wealth and per capita emissions, it is highly unlikely that any international deal could be agreed that would commit all countries to make equal cuts in their emissions,” Lloyd’s reports. “Developing countries will continue to argue that the rich countries caused most of the problem and they can better afford to pay for the solution.”

What is certain is progress has been made in the four decades since people became conscious of what energy use has done to the environment. Maybe the moment was when pictures of Earth came back from the Apollo moon shot. The beautiful blue bowling ball in space confirmed that we’re all out here alone, floating on the only craft we’ve got.