Greenhouse Effect on the Economy and You
How Rising CO2 Levels Are Making Your World a Hothouse
The greenhouse effect is when carbon dioxide and other gases in the Earth's atmosphere capture the Sun's heat radiation. Greenhouse gases include carbon dioxide, water vapor, methane, nitrous oxide, and ozone.
The greenhouse effect functions like the glass roof on a greenhouse that traps the sun's heat. Without greenhouse gases, the atmosphere would be 91 degrees Fahrenheit cooler. The Earth would be a frozen snowball and most life on Earth would cease to exist.
Since the 1850s, humans have been burning massive amounts of plant-based fuels such as coal, oil, and trees. These emit the carbon dioxide they had absorbed and stored during their lifetimes. Temperatures have risen 1.5 degrees Celsius since then.
Nature emits 230 gigatons of carbon dioxide into the atmosphere each year. But it also absorbs that same amount through plants and the oceans. It remained balanced until 10,000 years ago when humans began burning wood.
Oil and other fossil fuels are the remains of prehistoric plants. When they were alive, the plants absorbed carbon from the atmosphere during photosynthesis. In that process, they harness the sun’s energy to make sugar. They combine hydrogen from water with carbon from carbon dioxide. They emit oxygen as a byproduct. When they die, their remains contain all the carbon they absorbed. When we burn them as fuel, the carbon combines with oxygen and enters the atmosphere.
As proof of the impact of photosynthesis, every spring the Northern Hemisphere becomes green and the concentration of carbon dioxide in the atmosphere dips. In the fall and winter, the foliage dies, and CO2 rises. Some scientists say it's like the earth is breathing.
Heat and power generation releases 25 percent of the carbon man has put into the atmosphere.
Often overlooked is land use. Food production has released 135 gigatons of carbon into the atmosphere. The most damaging methods are clear-cutting, plowing, and heavy grazing. These methods obliterate carbon dioxide-absorbing plant life.
In 2015, there were 400 parts per million of carbon dioxide in the Earth's atmosphere. It's much higher than at any time in the past 800,000 years. It exceeded the prior record high of 300 ppm in 1950, gaining 100 ppm since then. Scientists warn that we need to remove this 2 trillion tons of "legacy C02" to stop further climate change.
There is so much excess CO2 that it would take 35,000 years for it all to dissipate at natural absorption rates. For that to work, humanity would have to stop emitting all CO2 effective immediately.
But will people stop emitting CO2 anytime soon? There are goals to reduce carbon emissions, but the significant emitters have no plans to stop using carbon-based fuels. Daniel Cziczo, Ph.D., associate professor of atmospheric chemistry at the Massachusetts Institute of Technology, estimates it could reach 600 ppm before humanity changes its ways. That could drive the temperature increase to 2, 3, or 4 degrees Celsius.
In 2017, carbon dioxide emissions increased 1.4 percent.
The International Energy Agency said two-thirds of the increase came from Asia. An unusually hot summer in China led it to run coal plants more often in order to run air conditioners.
The European Union saw emissions rise 1.5 percent. The United States reduced its emissions by 0.5 percent. One big reason for this is the switch from coal to shale gas. But people in both economies are buying larger vehicles, which would increase oil use. Britain, Mexico, and Japan also cut their emissions.
Methane or CH4 traps heat 25 times greater than an equal amount of carbon dioxide. But it dissipates after 10 to 12 years. CO2 lasts for hundreds of years, if not thousands.
Methane comes from three primary sources. The production and transport of coal, natural gas, and oil make up 40 percent. Cow digestion contributes another 26 percent, while manure management adds 10 percent.
The decay of organic waste in municipal solid waste landfills kicks in 16 percent.
Researchers have found a simple solution to the emission of methane from cows. Farmers should add seaweed to the animals' diet. Researchers found that replacing 2 percent of the feed with Australian red algae would reduce methane emissions by 99 percent. The researchers are testing milk and beef to make sure the seaweed doesn't affect the product.
In 2016, California said it would cut its methane emissions 40 percent 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.
Nitrous oxide, also called N2O, contributes 6 percent of greenhouse gas emissions. It remains in the atmosphere for 114 years. It absorbs 300 times the heat of a similar amount of carbon dioxide. 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 are the longest lasting. They are thousands of times more dangerous than an equal amount of carbon dioxide. 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 Is Well Established by Science
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 percent 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. Since they are so potent, a 40 percent increase is huge. The volume is having huge impacts on temperatures.
In 1896, Svante Arrhenius found that if you doubled CO2, which was then at 280 ppm, it would increase temperatures by 4 degrees Celsius. The term 280 ppm means there are 280 molecules of carbon dioxide per million molecules of total air.
In 1880, CO2 was 280 ppm. In 2012, it was 400 ppm. That’s a 43 percent increase in CO2. The average temperature is 1 degree Celsius warmer. Over large land areas, it’s 1.5 degrees Celsius warmer. It’s the warmest it’s been in thousands of years. Why hasn’t the temperature increased by Arrhenius’ predictions?
Clouds, fog, particles, and ice sheets reflect the sun’s radiation back into space before it ever reaches the earth’s surface. Scientists call it the Direct Effect. The Indirect Effect of particles creates more clouds. They cool the temperature at the same time greenhouse gases warm the temperature. Without the clouds created by pollution, it would be as warm as Arrhenius predicted. According to Cziczo, that’s what makes it so difficult to predict temperatures.
But Isn't More Carbon Dioxide Good for Plants?
Only a fraction of CO2 emissions benefit vegetation. Most of it goes into the atmosphere and the ocean. But scientists believe that the 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 remove carbon from the atmosphere. Even if we stopped emitting gases, there are already enough greenhouse gases in the air to create a catastrophe. These include the collapse of polar glaciers and flooded coastal cities.
In 2015, the Paris Climate Accord was signed by 195 countries. They pledged to cut greenhouse gas emissions by 26 to 28 percent below 2005 levels by 2025. Its goal is to keep global warming from worsening another 2 degrees Celsius above pre-industrial levels. Many experts consider that the tipping point. Beyond that, the consequences of climate change become unstoppable.
In 2017 alone, China installed as many solar panels as those that exist in France and Germany. But renewables only meet 19 percent of global energy demand. To meet the Paris Agreement climate goals, clean energy must grow five times as fast as it did in 2017.
To reverse the greenhouse effect, man must pull carbon dioxide out of the atmosphere and render it inert.
Several strategies have been discussed. None of these approaches are yet proved or affordable at the scale needed to make a difference. The most obvious hurdle is the additional energy some of them require. Unless this increased energy comes from a free, renewable source, it would add more costs.
- Scrubbing the air with great air conditioner-like machines.
- Fertilizing the oceans with iron dust to prompt algal blooms that, when they die, carry captured carbon to the bottom of the sea.
- Capturing and storing the carbon dioxide that results when energy is produced by burning trees and other plants that removed carbon from the atmosphere during their growth.
- Crushing and spreading certain types of rock, like basalt, that naturally absorb atmospheric carbon.
Carbon farming does this more affordably by growing plants. For example, builders are putting plants into bio-roofs. Agroforestry grows trees and crops together to increases carbon retention. No-till agriculture reduces the erosion and carbon loss caused by plowing. Keeping farmland covered would store more carbon than bare dirt bleeds carbon.
Whendee Silver is an ecologist at the University of California, Berkeley. She found that the best approach was to use manure as compost on the fields. It kept it from emitting carbon gases while it festered in lagoons. It also nourished grasses that absorbed more carbon. If only 41 percent of the rangeland were treated, it would offset 80 percent of California's agricultural emissions.