Two
Time to Get Serious
Off the northeastern coast of Australia, below the surface of the Pacific Ocean, is the breathtaking Great Barrier Reef, often called one of the Seven Natural Wonders of the World. This limestone formation was constructed by animals called stony corals. Their bodies are brightly colored in vivid shades of red, yellow, orange, blue, or green, depending on the species. Each individual coral, or coral polyp, has a limestone skeleton around the lower half of its body. The skeleton grows together with the skeletons of dead and other living coral polyps, creating a rigid structure called a reef. The Great Barrier Reef contains more than three thousand individual reefs stretching for more than 1,800 miles (3,000 km). Besides corals, the reef is home to thousands of species of tropical fish, turtles, sea snakes, starfish, clams, whales, dolphins, marine plants, and other aquatic life. Yet many of the reef’s corals are dying.
Coral polyps have a mutualistic (mutually beneficial) relationship with a type of algae called zooxanthellae. The algae live in the bodies of coral polyps. The polyps give the algae a safe home and some of the materials they need to carry out photosynthesis. In exchange, during photosynthesis, the algae produce substances vital to coral, including oxygen and compounds used to make food and to build stony skeletons.
Fish and other sea creatures make their homes in the Great Barrier Reef, a series of coral formations off the coast of northeastern Australia. Warming ocean waters and excess carbon dioxide in the water are harming corals and the plants and animals that live with them.
Changing environmental conditions—such as warming waters, cooling waters, or excess carbon dioxide in the water—can stress coral polyps. This stress leads them to expel the algae they rely on. Without this source of food and oxygen, the normally colorful polyps bleach, or turn white. Eventually they die.
A coral reef is a complex ecosystem—a community of living things that depend on one another for food and reproduction. For instance, many fish that live along coral reefs eat coral polyps and the plants and sea creatures that live with them. Many fish and other sea animals lay eggs in the sheltered cracks and crevices of coral reefs. When coral polyps begin to die, the entire ecosystem starts to fall apart. The plants and animals there have less food to eat. And the same environmental changes that can damage corals, such as excess carbon dioxide in the water, can also damage other members of the ecosystem.
In the twenty-first century, large portions of the Great Barrier Reef and Earth’s other ocean reefs are bleaching and dying. Biologists say that warming ocean waters and excess carbon dioxide in the water are to blame. And the situation is far from unique. Around the globe, higher air temperatures and increasing levels of carbon dioxide are threatening thousands of plant and animal species. How might humans halt—or at least lessen—this kind of damage caused by climate change?
Incomplete Solutions
Experts agree that the best way to fight climate change is to cut back on the use of fossil fuels. This isn’t an easy task, though. Did you take the bus or a car to school today? Chances are, that vehicle burned gasoline, which is derived from petroleum, a fossil fuel. Feeling hot? You might turn on a fan or an air conditioner. Both of these run on electricity, and to make that electricity, power plants often burn coal or natural gas—fossil fuels. Feeling cold? You can turn on a heater. It might run on electricity, or it might burn petroleum or natural gas. In 2015 fossil fuels provided more than 67 percent of the energy used in the United States. Approximately 86 percent of the world’s energy used comes from fossil fuels.
Some individuals, governments, and businesses are trying to reduce fossil fuel emissions by adopting “green,” or environmentally friendly, policies and technologies. Mainly this involves switching to alternative energy technology, such as wind power, solar power, waterpower, and geothermal power. These technologies provide energy without the use of fossil fuels. For instance, solar systems collect energy from the sun and use it to produce heat and electricity. Windmills and wind turbines spin around with air currents, and this spinning motion can generate electrical power. Similarly, the movement of ocean waves and water flowing over dams or waterfalls can power electric generators. Geothermal systems pump hot water or steam from deep inside Earth and use it to power electric generators.
In the United States and other industrialized nations, most people rely on cars for transportation. The majority of cars run on gasoline, which comes from petroleum, a fossil fuel. Experts say that to reduce the amount of carbon dioxide in the atmosphere, we must cut down on fossil fuel use. Electric cars are an alternative.
The fossil fuels we use in modern times took hundreds of millions of years to form. Once these fuels are gone, they’re gone—unless we want to wait hundreds of millions of years for new ones to form. Alternative fuels, on the other hand, are called renewable energy sources. A renewable energy source replaces itself naturally or never runs out. For instance, wind is a renewable energy source because the wind blows again and again. You can’t use up the wind. The sun has been shining for 4.6 billion years and will continue to shine for another 5 billion years—probably longer than humans will live on Earth. Biomass—or plant materials that are burned for fuel—are also renewable, since people can grow new plants to replace those they burn.
Is the switch to alternative and renewable fuels helping in the fight against climate change? Yes and no. According to a report from the National Renewable Energy Laboratory (NREL, an agency of the US Department of Energy), Americans are getting more and more of their electricity from renewables like wind and solar power. In 2004 only 9.5 percent of the nation’s electricity came from renewable power sources. By 2013 the percentage was 14.8, with wind power accounting for most of that increase. Between 2000 and 2013, the amount of electricity generated from renewable fuels more than doubled. Around the world, renewable fuels accounted for 23 percent of all electrical generation in 2013. Both China and the United States, the world’s largest consumers of energy, are building wind power facilities at a fast clip. Solar energy is also skyrocketing in the United States, China, and Japan.
Wind power doesn’t add carbon dioxide or other greenhouse gases to the atmosphere.
But the NREL report also notes that “while renewable and alternative fuels (including electric vehicles) are growing fast, they’re still minuscule compared to petroleum-based fuels.” And renewable energy is not cheap. Sun and wind power come to us free of charge, but we need solar panels, wind turbines, and a lot of other equipment to turn that power into electricity or heat and to transport it to those who need it. Building and installing all that equipment costs money, and the costs get passed on to consumers. For example, according to the US Department of Energy, it costs 24 cents to produce one kilowatt-hour of energy from a solar thermal (heat) power system but only 7 to 14 cents to produce one kilowatt-hour of energy from natural gas. Since the typical US household uses 10,932 kilowatt-hours of energy per year, the difference in cost between fossil fuels and alternatives can amount to hundreds or thousands of dollars a year, making it uneconomical to switch. (Some alternative fuels are cheaper than others, though, and as more alternative energy facilities are built and the technology improves, prices will likely come down.)
So while alternative and renewable fuels are helping in the fight against climate change, they are not making much of a dent in fossil fuel consumption. It takes a long time (and a lot of money) for power grids, businesses, and homeowners to switch to alternative energy and an even longer time for the changes to create a noticeable impact on the atmosphere. Climate scientists worry that time is running out. They estimate that Earth’s temperature has already increased 1.5ºF (0.8°C) since the preindustrial age. They say it could reach the 3.6ºF (2°C) mark by 2050—a change that would be disastrous for the planet.
Beyond switching to alternative fuels, what can humans do to fight climate change? Some say that geoengineering is the answer. Climatologists and engineers could create large-scale technologies to interfere with Earth’s existing systems, such as the biological carbon cycle, in ways that would counteract climate change. This is a radical idea but one that just might work—and work quickly.
How Will It Work?
One of the primary goals of geoengineering is to physically remove carbon dioxide from the atmosphere. A drastic reduction in carbon dioxide might bring global temperatures back to safe levels. Geoengineers have identified several different methods of doing this. One of them is reforestation, which means planting large forests. The trees in these forests would capture large amounts of carbon during photosynthesis. Another approach is carbon capture and sequestration (CCS)—giant machines would pull carbon dioxide from the atmosphere and the carbon would be sequestered (isolated) somewhere, such as underground.
Besides removing carbon from the air, geoengineers could try to lower Earth’s temperature by allowing less sunlight to reach the ground. Some engineers propose creating large clouds to reflect sunlight away from Earth and back into space. Others want to place giant mirrors into orbit. These would also reflect sunlight away from Earth. With less solar radiation reaching Earth, greenhouse gases would trap less heat from the sun.
Capturing carbon, reflecting sunlight, and other ideas to fight climate change are based in scientific theory, but humans haven’t put any of the methods into widespread use. Geoengineering is a relatively new science, with only limited testing to back up the important results it might be able to deliver. And as with all major actions, messing with global climate systems comes with big risks. For example, if humans interfere with Earth’s climate by removing carbon from the atmosphere or deflecting sunlight away from Earth, might this create even more droughts, floods, and other weather extremes beyond those we’re already seeing? And if we change the climate in one part of the world, how will that impact the climate in another part of the world?
The First Geoengineers
Since geoengineering is the large-scale manipulation of the climate, one could argue that humans have been unintentionally geoengineering Earth’s climate for centuries. Since the Industrial Revolution, we have been burning fossil fuels and cutting down forests, both of which increase atmospheric carbon levels and lead to climate change. You could say that the climate we have in the twenty-first century was created through geoengineering.
And although the term geoengineering emerged in the twenty-first century, humans have been intentionally geoengineering the climate since the mid-twentieth century. In 1946 the General Electric Research Laboratory in Schenectady, New York, sent a plane to seed a cloud. Seeding a cloud means adding something to it to create precipitation. In this case, meteorologist (weather and atmosphere scientist) Vincent Schaefer, who accompanied the pilot on the flight, released 3 pounds (1.4 kilograms) of frozen carbon dioxide (also called dry ice) into a cloud. His goal was to produce snow, and he did. Schaefer later noted that he “was thrilled to see long streamers of snow falling from the base of the cloud through which we had just passed.” He had just created the first human-made snowstorm.
The US government was excited about cloud seeding. With this ability, it could create precipitation where and when it was needed. Need rain in the drought-stricken Southwest? Done. Want to make heavy rain in an enemy nation to destroy its coffee crop? Done. Some government officials viewed the power to seed clouds as a brand-new weapon.
Although cloud seeding can have unintended results, governments and businesses sometimes use it to create precipitation. This photograph shows an airplane wing equipped with jets for spraying silver iodide, which can trigger clouds to make rain or snow.
In August 1953, the US government formed the Advisory Committee on Weather Control. Its goal was to investigate the effectiveness of weather-altering and to determine if the United States should do so. At the time, the United States and the Soviet Union (a nation of fifteen republics that included Russia) were bitter enemies. But meteorologists from the two nations discussed ways to change the weather worldwide. One idea was to release huge amounts of dust into the stratosphere to bring rain to drought-stricken farming areas. The Soviet Union even considered building dams across the Bering Strait, a body of water between Russia and Alaska, to redirect Pacific Ocean currents. The goal was to make the Northern Hemisphere warmer and to melt ice in the Arctic Ocean, thus opening up a new route for cargo ships.
In the following decades, government groups, businesses, and universities sometimes used cloud seeding to bring rain to US farmland. But a 1972 federal-government-led cloud-seeding project in South Dakota resulted in a disastrous flood. Angry farmers then sued the government. By then meteorologists had learned that weather modification was not easy to control. For example, you could seed a cloud in one place, but the rain might end up many miles away, where rain was not necessarily needed.
Still, the US government felt that weather modification might be a good weapon. During the Vietnam War (1957–1975), a conflict in Southeast Asia, the US military secretly seeded clouds over the Ho Chi Minh Trail in Laos, a supply line for enemy troops. The United States wanted to increase rainfall and turn the trail into mud to make travel there difficult. The effort was successful in bogging down movements of enemy troops and supplies over several years. But when news of the operation leaked to the press, Americans were concerned. Many felt that altering the weather in foreign nations was unfair. It could bring ruin to farmers and others who relied on predictable seasonal weather patterns. Citizens of other nations agreed, and in 1976, the United Nations, an international humanitarian and peacekeeping body, outlawed unfriendly or aggressive weather modification technology.
A Chinese artillery operator stands near a gun used to fire cloud-seeding rockets into the atmosphere. Before the 2008 Olympics in Beijing, China, the Beijing Meteorological Bureau fired hundreds of such rockets. The project kept the skies clear over Beijing and the Olympic venues while bringing rain to a city nearby.
Into the Future
In the twenty-first century, climate scientists use powerful computers to model their geoengineering ideas. But they can’t know for sure if the ideas will work in the real world. And geoengineering is still highly controversial. More than thirty years after banning weather modification after the Vietnam War, in 2010 the United Nations banned geoengineering in general because it could have unintended consequences. For instance, it could change weather patterns, bringing more rain to one region while reducing it elsewhere. Reduced rainfall could lead to droughts, which in turn could bring about crop failure and then famine. And instead of keeping Earth from getting warmer, geoengineering might make Earth too cold. It could lead to a new ice age, with temperatures far too low for the survival of many plant and animal species. Finally, some nations might use geoengineering as a weapon, deliberately creating floods or droughts in enemy nations, destroying crops and potentially leading to starvation of a civilian population.
While acknowledging the risks of geoengineering, climatologists caution that doing nothing to counteract increasing global temperatures could be just as harmful as geoengineering itself. So humans are stuck at a crossroads. Resetting the global thermostat is becoming a vital need. Geoengineering theoretically will do that, but at what cost? Will the reward be worth it? Only time will tell, and yet time also may be running out.