Human CO2 emissions are the driving force behind climate change, and most of those emissions come from fossil fuels. We have sunk a lot of money into building our fossil fuel infrastructure, but fossil fuels are not the only way to power a modern economy. There are several alternative energy sources that not only emit no CO2, but are also cost-competitive (or nearly so) with fossil fuels.
Geothermal: Geothermal energy uses heat from within the earth’s crust to generate electricity. While not as widely applicable as wind or solar, geothermal energy could be used in some places to supplement power from solar and wind energy.
Wind: Wind energy is another clean-energy option. In 2012, the U.S. produced 140 terawatt hours of wind power, and could potentially produce much more. Depending on the area, wind energy output can have significant day-to-day variations, but when paired with other energy sources, such as solar or hydroelectric, it can be an important contributor to a clean, reliable energy supply.
Solar: Earth’s surface absorbs about 5.1 quintillion joules of energy from the sun every minute. In two hours, it absorbs more energy than the entire world used in 2012.18 If we can harness even a tiny fraction of that energy, we would never need to burn fossil fuels again. Photovoltaic solar energy, which turns sunlight directly into electricity, is already a popular energy source. Solar thermal power plants use heat from the sun to drive steam turbines. By storing that heat in a medium such as molten salts, they can generate electricity even when the sun isn’t shining.
No single alternative energy source will be able to replace fossil fuels. However, there are enough options available that, when used together, they can more than meet our energy needs. It will cost money to switch over to a clean energy economy, but the health benefits will offset some of the costs (fossil fuel combustion being responsible for the formation of harmful smog), and every dollar we spend reducing carbon emissions is a dollar we don’t have to spend trying to adapt to climate change.
Switching to clean energy is the big, dramatic step to combat climate change, but conserving energy, while not as flashy, is just as important. Many of our homes and buildings were built decades ago, with materials and techniques that just aren’t as energy-efficient as the ones we have today. By making sure that new homes and buildings meet a minimum standard for energy efficiency, and retrofitting old ones to bring them up to code, we can reduce the amount of electricity needed to power them and thus the amount of fossil fuels we need to burn. This not only reduces the amount of CO2 we emit; it also saves us money on our energy bills.The
Real Price of Fossil Fuels
An external cost is basically when an economic activity—like manufacturing, transportation, or generating electricity—has a side effect that harms an uninvolved third party. Air pollution is a classic example of an external cost. Smog is harmful to human health, so a factory that emits smog-forming chemicals is imposing an external cost, in the form of increased rates of respiratory disease and higher medical bills, on people who live nearby. In many cases, external costs are not factored into the price of a good or service.
At the moment, fossil fuels are among the world’s cheapest energy sources. But that’s only because their price does not reflect the economic and environmental damage that climate change (of which CO2 emissions from fossil fuel combustion are the primary driver) will cause. In other words, fossil fuels have huge external costs. Taking into account the damage that they do to human health and the environment, energy from coal and oil should be at least 50% more expensive than it is now. The underpricing of fossil gules gives them an unfair competitive advantage over other, non-CO2-emitting energy sources. If we are to switch to a clean-energy economy and mitigate the effects of climate change, fossil fuels have to be fairly priced.
Getting the Price Right
When it comes to bringing the price of fossil fuels in line with their real cost, there are two main options. The first is simply to tax carbon dioxide. The goal of a CO2 tax would be to internalize the external costs of fossil fuels and eliminate their unfair market advantage. The second option, known as cap and trade, offers a more market-friendly option to reduce CO2 emissions. In a cap and trade program, the government sets a limit on national CO2 emissions. Companies that emit CO2 must then purchase permits for their emissions (one permit usually being equal to a ton of CO2), with the number of permits not to exceed the total emissions allowed by the national cap. Companies that manage to reduce their emissions can sell their excess permits to companies that are having a harder time bringing their emissions down. Over time, the cap gets smaller and smaller, with the goal being to eventually bring overall CO2 emissions down to zero. And we know that cap and trade programs can work: In the U.S., a cap and trade program designed to reduce sulfur dioxide emissions has helped cut the nationwide occurrence of acid rain by close to 50% since 1990.
Cutting CO2 emissions is crucial to mitigating climate change’s effects. We can’t eliminate all our emissions at once, though, so in the meantime there are steps we can take to help offset them. Plants are excellent carbon sinks: they pull CO2 out of the air and incorporate it into their bodies. And long-lived plants, like trees, keep that CO2 out of the atmosphere longer. By encouraging reforestation, we can help pull back some of our CO2 emissions and slow down climate change, at least a little. Changing the way we grow our food can also help offset some of our emissions. Soils are important carbon reservoirs. Unfortunately, tilling soil reduces its ability to store carbon. Less intensive tilling, as well as other green agricultural practices, such as crop rotation, can help improve the amount of carbon that our soils can store.