What exactly do people mean by "renewable energy"?
We are surrounded by energy from dozens of different sources. Everything from sunlight and gamma radiation from outer space to the wind blowing across a meadow can be a source of energy. When these sources are constant and renewing -- like the water cycle that sends rain from clouds to the ground, down a river to the ocean and then evaporating back up into the atmosphere -- they're considered renewable energy.
Aren't all sources of energy renewable?
No. Many types of energy are finite and have a limited run. Oil, coal and other fossil fuels, for example, are in limited supply -- nobody's making any more coal -- and when we run out of them, we're all out for good. Renewable energy sources like the sun and wind aren't going to run out, so they're considered infinite or renewable (even though astrophysicists tell us the sun will eventually burn out in roughly 5 billion years -- but don't worry about that just yet).
But we keep finding new sources of fossil fuels, like oil and natural gas.
While new pockets of coal, oil and natural gas are being discovered, that doesn't disguise the fact that these are still small pockets finite, non-renewable, dead-end sources of energy. Additionally, developing these energy sources has tremendous financial and environmental costs. Natural gas found through fracking
, for example, causes irreparable harm to drinking water supplies. And the use of oil, coal and natural gas causes air pollution, including the greenhouse gases
that are causing global warming.
Don't renewable energy sources also contribute to air pollution and climate change?
Not really. Developing wind farms and manufacturing solar panels contributes a small, one-time increase in air pollution. But once these clean energy sources are up and running, they add almost zero emissions to the atmosphere, so they contribute nothing to the greenhouse effect
or climate change. On the other hand, burning coal or heating oil contribute immense amounts of air pollution to the atmosphere. There's simply no comparison between the massive amounts of toxic pollution caused by a coal-burning power plant and the near-zero emissions caused by a wind farm or other green energy source.
I hear that wind turbines kill birds.
It's entirely possible that a handful of birds are killed each year by wind turbines. That small number, however, is dwarfed by the horrific slaughter of millions of plants and animals -- birds, fish, mammals, insects, reptiles, you name it -- that occurs each year as a result of petroleum exploration, oil spills, coal burning, oil and natural gas pollution and all the other devastation caused by fossil fuels. And the human health costs of fossil fuels are just as bad.
How do fossil fuels affect human health?
It would take an encyclopedia to catalog all the human health impacts that burning coal, oil and gas cause -- cancer, heart disease, birth defects and brain damage are just a few. Suffice it to say that carbon monoxide, mercury
, arsenic, sulfur dioxide and other toxic compounds are released into the environment each hour of the day by the ton
because we live in a fossil fuel-based economy.
So if renewable energy is so great, why isn't it used more?
In recent years, many countries have made impressive strides toward developing more sources of renewable energy. Denmark, for example, gets 20 percent of its energy from wind power. Portugal got a whopping 52 percent of its power in 2010 from renewable energy sources like hydroelectric dams and wind farms. And a number of large solar energy plants have recently been installed in the United States, Spain and India. But overall, the world has been slow to adopt clean energy because the fossil fuel economy is so deeply entrenched in our lives. In the United States, just 11 percent of our energy comes from clean energy sources.
Is nuclear power a renewable source of energy?
No. Not only does nuclear energy
rely on a finite resource -- uranium -- to create energy, the impacts of mining and the dangerous radioactive waste created by nuclear power plants makes this neither a reliable or clean source of power for the 21st century.
What can anyone do to help make clean energy a bigger part of our energy profile?
Raise hell. Besides telling your electricity provider that you want to convert to a renewable source of energy -- a relatively easy step -- the best way to break our addiction to oil and other fossil fuels is to demand that politicians stop working for the oil and gas companies -- that contribute millions in campaign donations -- and instead start working for the voters who put them into office.