Understanding greenhouse gases
Planet Earth is warm enough to sustain life thanks to gases in the planet’s atmosphere that hold heat. These gases are called greenhouse gases because they act just like a greenhouse — trapping the heat inside the planet’s atmosphere, making the average temperature on Earth 59 degrees Fahrenheit (15 degrees Celsius). Humans have increased the amount of greenhouse gases in the atmosphere by about 35 percent. The more greenhouse gases in the atmosphere, the warmer the average temperature gets.
The main greenhouse gases
The two major greenhouse gases both occur naturally and can be increased due to human activity.
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Carbon dioxide (CO2): Responsible for 63 percent of global warming over time, and 91 percent in the last 5 years, this gas is produced from burning fossil fuels, such as coal and oil. It also occurs naturally as it flows in a cycle between oceans, soil, plants and animals.
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Methane (CH4): Responsible for 19 percent of global warming, this gas is produced by rotting garbage and wastewater, gas from livestock, and rice crops. Swamps and anything that decomposes without air naturally creates methane.
Two main sources of greenhouse gases
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Energy use: Humans derive energy from burning fossil fuels, which releases almost three quarters of all human-produced greenhouse gases into the atmosphere. Half of all fossil fuels are burned to provide electricity and heat; the next big users of fossil fuels are manufacturing and transportation.
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Land use: How humans remove forests and use land contributes over one quarter of all human-produced greenhouse gases to the atmosphere. Trees absorb carbon dioxide from the atmosphere, so logging and clearing forest land for agriculture and development means more carbon dioxide stays in the air.
Five ways to reduce your greenhouse gas emissions
What you can do to help reduce your carbon footprint depends on where you live, the resources you have, and how much time you can give. If you want to do something about global warming, however, then simple changes can have a big impact. Here are some straightforward solutions that you can implement right away:
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Eat less (or no) meat. Going vegetarian has the same impact on reducing greenhouse gas emissions as if you trade in a regular car for a hybrid. The process of making a pound of commercial meat uses ten times more energy than making a pound of beans or grains.
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* Hook your home up to clean energy. If you can’t afford to install solar panels or wind turbines on your roof, you can tap into an independent clean energy supplier. Let them build the wind turbine, and you reap the benefits. This step reduces your own emissions and helps build the renewable energy industry.
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Insulate your house. The average home has the equivalent of a basketball-sized hole in the side of its wall. That’s how much heating and cooling you can keep from escaping if you properly insulate your home’s ceilings, walls, windows, and doors.
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Travel smart. Reducing the number of flights you take in a year has a huge impact. One long-haul flight can be enough to double your impact on climate change, so think twice before taking that long trip. Whenever possible, take the train or bus. Minimize your driving by carpooling, walking, biking, or taking public transit.
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Use only the energy you need. Develop energy saving habits — turn off the lights and TV when you leave the room, and turn down your thermostats when the house is empty in winter, and up in summer. Choose low-energy technologies by looking for the ENERGY STAR or Energy Savings logos on all appliances, electronics, computers, and more. These qualification standards highlight products that use the least energy.
Major potential effects of global warming
The impact of global warming will increase in the coming years, but the degree of change will vary greatly, depending on where you live and depending on how rapidly nations around the world reduce greenhouse emissions. No matter where you live, though, the unchecked impacts of climate change are potentially catastrophic in the long-term.
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It affects people: Depending on their location, people may be affected by disease, rising sea levels, drought, or major storms. The impact of these effects will be greatest on those with the least financial resources to adapt to or recover from the effects.
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It causes extreme weather: While the atmosphere warms, the climate is changing, and so is the weather. More frequent and more intense storms, flooding, droughts, heat waves, and even extreme snowfalls are all part of the changes.
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It increases extinctions: Changing climates mean that some environments may no longer be hospitable for certain plants or animals, which will need to relocate to survive. Some species, such as polar bears, have nowhere to go. Extinction is a possibility for many species of animals and plants, which may be unable to adapt to their environment at the same speed at which the climate is changing it.
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It melts ice at the poles: The Arctic ice is melting so rapidly that within a few years the North Pole will be ice covered only seasonally. This has a dramatic impact on the planet’s climate: Polar ice reflects sunlight and deflects heat; when it melts, more of that heat stays in the atmosphere. The melting of the Greenland and Western Antarctic Ice Sheets threatens an extreme rise in sea levels.
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It warms oceans: While the oceans warm, water is expanding and causing sea levels to rise. Warmer waters are killing coral reefs and krill — essential to supporting the sea food web.
Key global warming terms
The phrase “global warming” hasn’t been around long, but climate change, as it’s also known, is nothing new. In fact, it has been a constant throughout history. Earth’s climate today is very different from what it was 2 million years ago, let alone 10,000 years ago. Here are the key terms that are crucial to understanding global warming:
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Carbon cycle: The natural system that, ideally, creates a balance between carbon emitters (such as humans) and carbon absorbers (such as trees), so the atmosphere doesn’t contain an increasing concentration of carbon dioxide. (Concentrations of carbon dioxide in the atmosphere are expressed as parts per million, or ppm.)
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Carbon sinks: Anything that absorbs carbon dioxide from the atmosphere and stores carbon. The ocean, trees, and soil are all carbon sinks.
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Fossil fuels: Fuels, such as oil and coal, that are made from the fossils of old plants, which have taken hundreds of thousands of years to form underground.
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Intergovernmental Panel on Climate Change (IPCC): An international body of the United Nations, composed of over 2,000 scientific experts. The IPCC compiles peer-reviewed climate science to create an objective source of climate information.
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Kyoto Protocol: The international agreement under the United Nations to reduce global greenhouse gas emissions from industrialized countries by 5.2 percent below 1990 levels by the year 2012. The Protocol is ratified by 177 countries.
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Renewable energy: A continual source of energy, such as energy from the sun, wind, flowing water, heat from the Earth, or movement of the tides.