EarthPulse, Maps, Global Trends, Human Impact

The world is hungry for energy. Total consumption of coal, oil, and gas has doubled since the early 1970s, and electrical generation from all sources has nearly tripled. And still it isn't enough—more than one and a half billion people live without electricity, and even without filling that need, demand for energy will likely be up another 50 percent by 2030.

The benefits of energy use are as profound as they are obvious—human comfort, health, and commerce depend upon it. But the true costs, from worker exploitation to pollution, are not measured by electricity meters. Above all, there is the specter of global climate change, as carbon dioxide (CO2) and other greenhouse gases from burning fossil fuels turn Earth's atmosphere into a too-thick blanket on a warm summer day.

What to do? Carbon dioxide emissions from energy use are projected to increase 55 percent between 2004 and 2030. Energy conservation and increased efficiency are essential, as are halting deforestation and planting more trees—growing plants pulls CO2 out of the air. Capturing CO2 and storing it underground or under the sea may also play a key role, but large-scale efforts are years away.

Nonfossil energy sources are central to curbing climate change. Nuclear power generation doesn't emit CO2, but waste and safety concerns make new reactors controversial. Wind and solar are relatively benign, but they can't fuel automobiles. Lower-carbon biofuels such as ethanol and biodiesel can, but there are questions about how green they truly are. Alternative energy use is growing, but it remains a minor proportion of the total.

There is no one solution to global warming. Ensuring that all people benefit from energy use while backing away from the climate brink might be humanity's biggest challenge.