Environment Climate Crisis Greenhouse Gas Effect on the Economy and You How Rising CO2 Levels Are Making Your World a Hothouse By Kimberly Amadeo Kimberly Amadeo Writer MIT Sloan School of Management Boston College University of Rochester Kimberly Amadeo has over 20 years of senior-level corporate experience in economic analysis and business strategy. Learn about our editorial process Updated August 13, 2019 Share Twitter Pinterest Email Photo by Filo/Getty Images Environment Planet Earth Climate Crisis Pollution Recycling & Waste Natural Disasters Transportation The greenhouse effect is when carbon dioxide and other gases in the Earth's atmosphere capture the Sun's heat radiation. Greenhouse gases include CO2, water vapor, methane, nitrous oxide, and ozone. They also include small but lethal amounts of hydrofluorocarbons and perfluorocarbons. We need some greenhouse gases. Without any, the atmosphere would be 91 degrees Fahrenheit cooler. The Earth would be a frozen snowball and most life on Earth would cease to exist. But since 1850, we've added too much gas. We’ve burned massive amounts of plant-based fuels such as gasoline, oil, and coal. As a result, temperatures have risen about 1 degree Celsius. Carbon Dioxide How does CO2 trap heat? Its three molecules are only loosely connected to each other. They vibrate vigorously when radiant heat passes by. That captures the heat and prevents it from going into space. They act like the glass roof on a greenhouse that traps the sun's heat. Nature emits 230 gigatons of CO2 into the atmosphere each year. But it keeps it in balance by reabsorbing that same amount through plant photosynthesis. Plants harness the sun’s energy to make sugar. They combine carbon from CO2 with hydrogen from water. They emit oxygen as a by-product. The ocean also absorbs CO2. This balance changed 10,000 years ago when humans began burning wood. By 1850, the CO2 level had risen to 278 parts per million. The term 278 ppm means there are 278 molecules of CO2 per million molecules of total air. The pace increased after 1850 when we began burning oil, kerosene, and gasoline. These fossil fuels are the remains of prehistoric plants. The fuel contains all the carbon the plants absorbed during photosynthesis. When they burn, the carbon combines with oxygen and enters the atmosphere as CO2. In 2002, the CO2 level had risen to 365 ppm. By July 2019, it had reached 411 parts per million. We are adding CO2 at an ever-faster rate. The last time CO2 levels were this high was in the Pliocene era. Sea levels were 66 feet higher, there were trees growing at the South Pole, and the temperature was 3 C to 4 C higher than today. It would take 35,000 years for Nature to absorb the extra CO2 we’ve added. That’s if we stopped emitting all CO2 immediately. We must remove these 2.3 trillion tons of "legacy CO2" to stop further climate change. Otherwise, the CO2 will warm the planet to where it was during the Pliocene. Sources The United States is responsible for most of the carbon currently in the atmosphere. Between 1750 and 2018, it emitted 397 gigatons of CO2. One-third was emitted since 1998. China contributed 214GT and the former Soviet Union added 180Gt. In 2005, China became the world's largest emitter. It's been building coal and other power plants to improve its residents' standard of living. As a result, it emits 30% of the total per year. The United States is next, at 15%. India contributes 7%, Russia adds 5%, and Japan at 4%. All told, the five largest emitters add 60% of the world's carbon. If these top polluters could stop emissions and expand renewable technology, the other countries wouldn't really need to be involved. In 2018, CO2 emissions increased by 2.7%. That's worse than the 1.6% rise in 2017. The increase brings emissions to a record high of 37.1 billion tons. China increased by 4.7%. Trump's trade war is slowing its economy. As a result, leaders are allowing coal plants to run more to boost production. The United States, the second-largest emitter, increased by 2.5%. The Energy Information Administration predicts emissions will decline by 1.2% in 2019. That's not enough to meet the 3.3% decline needed to meet its Paris Climate Agreement targets. In 2017, the United States emitted the equivalent of 6.457 million metric tons of CO2. Of that, 82% was CO2, 10% was methane, 6% was nitrous oxide, and 3% was fluorinated gases. Transportation emits 29%, electricity generation 28%, and manufacturing 22%. Businesses and homes emit 11.6% for heating and handling waste. Farming emits 9% from cows and soil. Managed forests absorb 11% of U.S. greenhouse gases. Fossil fuel extraction from public lands contributed 25% of U.S. greenhouse gas emissions between 2005 and 2014. The European Union, the third-largest emitter, reduced by 0.7%. India increased emissions by 6.3%. Methane Methane or CH4 traps heat 25 times greater than an equal amount of CO2. But it dissipates after 10 to 12 years. CO2 lasts for 200 years. Methane comes from three primary sources. The production and transport of coal, natural gas, and oil make up 39%. Cow digestion contributes another 27%, while manure management adds 9%. The decay of organic waste in municipal solid waste landfills kicks in 16%. In 2017, there were 94.4 million cattle in the United States. That compares to 30 million bison before 1889. Bison did emit methane, but at least 15% was absorbed by soil microbes once plentiful in prairie grasslands. Today's farming practices have destroyed the prairies and added fertilizers that further reduce those microbes. As a result, methane levels have increased dramatically. Solutions Researchers found adding seaweed to the cows' diet reduce methane emissions. In 2016, California said it would cut its methane emissions 40% below 1990 levels by 2030. It has 1.8 million dairy cows and 5 million beef cattle. The seaweed diet, if proven successful, would be an inexpensive solution. The Environmental Protection Agency has launched the Landfill Methane Outreach Program to help reduce methane from landfills. The program helps municipalities use the biogas as a renewable fuel. In 2018, Shell, BP, and Exxon agreed to limit their methane emissions from natural gas operations. In 2017, a group of investors with roughly $30 trillion under management launched a five-year initiative to push the biggest corporate emitters to reduce emissions. Nitrous Oxide Nitrous oxide, also called N2O, contributes 6% of greenhouse gas emissions. It remains in the atmosphere for 114 years. It absorbs 300 times the heat of a similar amount of CO2. It is produced by agricultural and industrial activities. It's also a byproduct of fossil fuel and solid waste combustion. More than two-thirds results from its use in fertilizer. Farmers can reduce nitrous oxide emissions by reducing nitrogen-based fertilizer use. Fluorinated Gases Fluorinated gases are the longest lasting. They are thousands of times more dangerous than an equal amount of CO2. Because they are so potent, they are called High Global Warming Potential Gases. There are four types. Hydrofluorocarbons are used as refrigerants. They replaced chlorofluorocarbons that were depleting the protective ozone layer in the atmosphere. Hydrofluorocarbons, though, are also being replaced by hydrofluoroolefins. These have a shorter lifespan. Perfluorocarbons are emitted during aluminum production and the manufacturing of semiconductors. They remain in the atmosphere between 2,600 and 50,000 years. They are 7,390 to 12,200 times more potent than CO2. The EPA is working with the aluminum and semiconductor industries to reduce the use of these gases. Sulfur hexafluoride is used in magnesium processing, semiconductor manufacturing, and as a tracer gas for leak detection. It's also used in electricity transmission. It’s the most dangerous greenhouse gas. It remains in the atmosphere for 3,200 years and is 22,800 times as potent as CO2. The EPA is working with power companies to detect leaks and recycle the gas. Nitrogen trifluoride remains in the atmosphere for 740 years. It is 17,200 times more potent than CO2. Greenhouse Effect Was Discovered in 1850 Scientists have known for more than 100 years that carbon dioxide and temperature are related. In the 1850s, John Tyndall and Svante Arrhenius studied how gases responded to sunlight. They found that most of the atmosphere has no effect because it is inert. But 1% is very volatile. These components are CO2, ozone, nitrogen, nitrous oxide, CH4, and water vapor. When the sun's energy hits the earth's surface, it bounces off. But these gases act like a blanket. They absorb the heat and reradiate it back to the earth. In 1896, Svante Arrhenius found that if you doubled CO2, which was then at 280 ppm, it would increase temperatures by 4 C. Today's CO2 levels are almost doubled, but the average temperature is only1 C warmer. But it takes time for temperatures to rise in response to greenhouse gases. It's like turning on the burner to heat the coffee. Until greenhouse gases are reduced, the temperature will continue to climb until it’s 4 C higher. Impact Between 2002 and 2011, 9.3 billion tons of carbon were emitted per year. Plants absorbed 26% of that. Almost half went into the atmosphere. The oceans absorbed 26%. Oceans absorb 22 million tons of CO2 per day. That adds up to 525 billion tons since 1880. That's made the ocean 30% more acidic in the past 200 years. This destroys the shells of mussels, clams, and oysters. It also affects the spiny portions of urchins, starfish, and corals. In the Pacific Northwest, oyster colonies have already been affected. As the oceans absorb CO2, they also warm. Higher temperatures are causing fish to migrate northward. As much as 50% of coral reefs have died off. The ocean's surface is warming more than the lower layers. That keeps lower, colder layers from moving to the surface to absorb any more CO2. These lower ocean layers also have more plant nutrients such as nitrate and phosphate. Without it, phytoplankton starve. These microscopic plants absorb CO2 and sequester it when they die and sink to the bottom of the ocean. As a result, the oceans are reaching their capacity to absorb CO2. It's likely that the atmosphere will warm at a faster rate than in the past. It also affects the ability of fish to smell. It dampens scent receptors fish need to locate food when visibility is poor. They would also be less likely to avoid predators. In the atmosphere, rising CO2 levels help plant growth since plants absorb it during photosynthesis. But higher CO2 levels lower the nutritional value of crops. Global warming would force most farms to move further north. Scientists believe that the negative side effects outweigh the benefits. Higher temperatures, rising sea levels and an increase in droughts, hurricanes, and wildfires more than offset any gains in plant growth. Reversing the Greenhouse Effect In 2014, the Intergovernmental Panel on Climate Change said countries must adopt a two-pronged global warming solution. They must not only stop emitting greenhouse gases but must also remove existing carbon from the atmosphere. The last time CO2 levels were this high there were no polar ice caps and sea levels were 66 feet higher. In 2015, the Paris Climate Accord was signed by 195 countries. They pledged that, by 2025, they will have cut greenhouse gas emissions by at least 26% below 2005 levels. Its goal is to keep global warming from worsening another 2 C above pre-industrial levels. Many experts consider that the tipping point. Beyond that, the consequences of climate change become unstoppable. Carbon sequestration captures and stores CO2 underground. To meet the Paris Agreement goal, 10 billion tons a year must be removed by 2050 and 100 billion tons by 2100. One of the easiest solutions is to plant trees and other vegetation to halt deforestation. The world's 3 trillion trees store 400 gigatons of carbon. There is room to plant another 1.2 trillion trees in vacant land across the earth. That would absorb an additional 1.6 gigatons of carbon. The Nature Conservancy estimated that this would only cost $10 per ton of CO2 absorbed. The Nature Conservancy suggested that restoring peatland and wetland areas as another low-cost carbon sequestration solution. They contain 550 gigatons of carbon. The government should immediately fund incentives for farmers to manage their soil better. Instead of plowing, which releases CO2 into the atmosphere, they could plant carbon-absorbing plants such as daikon. The roots break up the earth and become fertilizer when they die. Using compost or manure as fertilizer also returns carbon into the ground while improving the soil. Power plants can efficiently use carbon capture and storage because CO2 makes up 5% to 10% of their emissions. These plants filter the carbon out of the air using chemicals that bind with it. Ironically, retired oil fields have the best conditions to store carbon. The government should subsidize the research as it did with solar and wind energy. It would only cost $900 million, far less than the $15 billion Congress spent on Hurricane Harvey disaster relief. Seven Steps You Can Take Today There are seven global warming solutions you can begin today to reverse the greenhouse effect. First, plant trees and other vegetation to halt deforestation. You can also donate to charities that plant trees. For example, Eden Reforestation hires local residents to plant trees in Madagascar and Africa for $0.10 a tree. It also gives the very poor people an income, rehabilitates their habitat, and saves species from mass extinction. Second, become carbon neutral. The average American emits 16 tons of CO2 a year. According to Arbor Environmental Alliance, 100 mangrove trees can absorb 2.18 metric tons of CO2 annually. The average American would need to plant 734 mangrove trees to offset one year’s worth of CO2. At $0.10 a tree, that would cost $73. The United Nations program Climate Neutral Now also allows you to offset your emissions by purchasing credits. These credits fund green initiatives, such as wind or solar power plants in developing countries. Third, enjoy a plant-based diet with less beef. Monoculture crops to feed the cows causes deforestation. Those forests would have absorbed 39.3 gigatons of CO2. Beef production creates 50% of global emissions. Similarly, avoid products using palm oil. Carbon-rich swamps and forests are cleared for its plantations. It's often marketed as vegetable oil. Fourth, reduce food waste. The Drawdown Coalition estimated that 26.2 gigatons of CO2 emissions would be avoided if food waste was reduced by 50%. Fifth, cut fossil-fuel use. Where available, use more mass transit, biking, and electric vehicles. Or keep your car but maintain it. Keep the tires inflated, change the air filter, and drive under 60 miles per hour. Sixth, pressure corporations to disclose and act on their climate-related risks. Since 1988, 100 companies are responsible for more than 70% of greenhouse gas emissions. The worst are ExxonMobil, Shell, BP, and Chevron. These four companies contribute 6.49% alone. Seventh, hold the government accountable. Each year, $2 trillion is invested in building new energy infrastructure. The International Energy Administration said that governments control 70% of that. Similarly, vote for candidates who promise a solution to global warming. The Sunrise Movement is pressuring candidates to adopt a Green New Deal. There are 500 candidates who have vowed not to accept campaign contributions from the oil industry.