Climate Change Basics
Climate is the average weather in a place over many years. Weather changes every day; it can even change in hours, while climate changes over decades or longer.
Global Climate Change is a pattern of changes that is happening over many years. One of these trends is the average temperature of the Earth, which has been rising for decades, and is referred to as Global Warming.
Earth's climate is changing, and people's activities are the main cause. Earth is getting warmer because people are producing more greenhouse gases, mainly by using fossil fuels, which trap heat in the atmosphere. This warming results in other effects, such as rising sea levels, more frequent and dramatic storms, flooding in some areas and drought in others. While Earth's climate has changed before, this time it's different because people are the cause. By joining together, we can prevent this global crisis.
Why it is happening
We are producing too much greenhouse gases, trapping too much of the Sun’s heat and increasing the Earth’s temperature.
Our atmosphere is made up of a bunch of gases. Mostly it contains nitrogen, along with oxygen, which we need to breath. Among the remaining gases are a group called greenhouse gases: carbon dioxide (CO2) being the most prevalent. They are called greenhouse gases because they trap heat in the atmosphere, similar to the way a greenhouse keeps plants warmer in the winter. However, if you have too much of these greenhouse gases, too much heat is trapped and the Earth’s climate starts getting warmer.
The vast majority of scientists believe we are causing the increase in greenhouse gases, mainly by burning fossil fuels and secondarily by cutting down forests.
How Greenhouse Gases Cause Climate Change
Global Warming Leads to Climate Changes
Global Warming does not just make Earth warmer, it leads to many other effects because Earth's temperature, water and air are all connected. For example, the extra heat warms the oceans and melts glaciers, leading to rising sea levels and stronger storms.
Global GHG emissions due to human activities have grown by about 70% just from 1970 to 2004
The Earth depends on receiving energy from the Sun. About half of the light from the Sun makes it thought the atmosphere warms the surface of the Earth and is then radiated back towards space. Most of this energy is absorbed by greenhouse gases in the atmosphere, and result in additional warming of the Earth’s surface and lower atmosphere.
Greenhouse Gases (GHG) are important for keeping the Earth warm; you just do not want to have too much of them. GHGs trap heat in the atmosphere, but they do not all have the same impact. Some gases trap much more heat than CO2, the most common GHG. GHGs also last in the atmosphere for different amounts of time, which makes a significant difference in global warming. More/Less info
From 1970 to 2004, global greenhouse gas emissions due to human activities grew by about 70%
There are many different greenhouse gases; the most prevalent ones are: water vapor, carbon dioxide, methane, nitrous oxide and chlorofluorocarbons.
- Water vapor. The most abundant greenhouse gas, but it acts to regulate the amount that the Sun warms the planet. As the atmosphere warms, water vapor increases, but so do clouds and precipitation, which have a cooling effect.
- Carbon dioxide (CO2). When people discuss rising greenhouse gases, carbon dioxide is usually at the forefront, since it represents about 55% of global warming due to human activity. Humans have increased the amount of CO2 in the atmosphere by an nearly 35% since the beginning of the Industrial Revolution. CO2 lasts in the atmosphere from 50 to thousands of years, making the increase a long-term problem.
- Methane. After CO2, methane is the next most significant contributor to global warming, representing about 30% of the total. Methane is a roughly 25 times more powerful GHG than CO2. However, it only lasts about 12 years in the atmosphere. Methane is produced by both natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as raising livestock. Certain animals, such as cows and sheep, produce methane as they digest food, and the resulting manure releases methane when it decays. Methane can also be released during coal mining or in the transport of natural gas, which is mainly methane.
- Nitrous oxide. A powerful greenhouse gas representing about 5% of global warming. Per molecule, it traps 298 times the heat than CO2, and last about 114 years in the atmosphere. It is produced farming practices that use lots of fertilizers, burning fossil fuels and some industrial processing that produce nitric acid.
- Chlorofluorocarbons (CFCs). These are synthetic compounds used in industry, including coolants in air conditioners. Many of these gases are now regulated, but enforcement is often limited. Depending on the type of CFC, they can be 100 to 23,000 times more potent than CO2, and can last in the atmosphere for up to thousands of years.
We can compare the global warming of potential (GWP) of different chemicals over a 100 year time horizon. This shows the importance of making sure we eliminate certain chemicals from everyday use.
Source: Intergovernmental Panel on Climate Change, Fourth Assessment Report (2007), EPA and NASA.
Where do greehouse gases come from?
We produce GHG’s during our normal daily activity.
We produce GHGs during our normal daily activity. If you drive, take a bus, use electricity, heat your home, fertilize your garden or even raise cows, you are producing GHGs.
This means that solving the problem is up to us as well. We can fight global warming and Sustain:Green can help.
The Origination of Greenhouse Gases (GHGs)
The two greatest contributors to rising greenhouse gas levels are the burning of fossil fuels and the destruction of forests. Many of our daily activities led to emissions of greenhouse gases. For example, driving your car, heating your home with oil or gas, or using electricity generated from coal, natural gas, or oil. You may not realize that some of your activities could be contributing to the destruction of rainforests. For example, palm oil is used in a wide range of food products, from foods to lotions. However, sourcing it often contributes to rainforest destruction, and thereby contributes to rising GHG levels.
You really cannot avoid creating greenhouse cases, but you can make smart choices that will help you reduce your carbon footprint, which is a measure of the GHG emissions resulting from your activities and lifestyle.
The Sustain:Green cards can be a powerful tool to reduce your carbon footprint. Not only is carbon offset through the use of the card, but through our partnership with Mata No Peito and the non-profit American Carbon Registry, the money we spend on carbon offsetting is then donated to rainforest reforestation projects, creating a double benefit.
These are some other factors that determine your carbon footprint:
- The types of fuel your power plant uses to generate the electricity and the amount you use.
- The efficiency of your furnace and air conditioner, the size and insulation of your house, and the amount and type of fuel used.
- How much you drive and your vehicle's fuel efficiency.
Do you know what your carbon footprint is? Try our Carbon Footprint Calculator to estimate your household's annual greenhouse gas emissions.
CO2 is the most prevalent GHG - its levels have increased about 41% since the industrial revolution
People often talk about carbon dioxide (CO2) interchangeably with GHGs. This is because CO2 is the most prevalent GHG. It represents about three-quarters of all global GHG emissions, and the amount in the atmosphere has risen dramatically. Before the industrial age, levels were around 275 parts per million (ppm), now they are at 395 ppm, with some areas at 400 or higher. This is significant, since the last time the planet had levels that high was likely 800,000 years ago.
The levels of carbon dioxide—the most prevalent GHG—have increased by about 41% since the Industrial Revolution1
Source: TP Whorf Scripps, Mauna Loa Observatory, Hawaii, Institution of Oceanography (SIO), University of California La Jolla, California, United States, 1999. Graphics adapted from UNEP/GRID-Arendal.
People often talk about carbon dioxide (CO2) interchangeably with GHG. This is not surprising when you learn that CO2 represents about three-quarters—and rising—of all global GHG emissions. Prior to the Industrial Revolution, levels were around 275 parts per million (ppm), today they are at 395 ppm, with some areas reaching 400 or higher. Scientists have long considered the 400 ppm level an important, and worrisome, milestone which suggests that time is quickly running out to address this global climate crisis. The best available evidence suggests the amount of atmospheric greenhouse gases have not been this high for at least three million years, before humans evolved, and scientists believe the rise portends large changes in the climate and the level of the sea.2
When people talk about CO2 or carbon dioxide, they often just say carbon—as in "let’s reduce our carbon footprint." This is because CO2 is part of the carbon cycle. All living things on Earth are made from carbon. We eat carbon, we build our houses from carbon and we power our cars and houses using carbon. Most of the Earth’s carbon is contained in rocks; the rest moves in a cycle between the ocean, the atmosphere, and the ground. A great deal of carbon is tied up in fossil fuels. Left alone, this carbon is trapped. But when we burn fossil fuels, such as gas for your car or coal for a power plant, the carbon is released into the atmosphere as CO2. This is the main reason why the amount of CO2 in the atmosphere has increased so much since the start of the Industrial Revolution.
Cutting down trees also has a significant impact on the amount of CO2. Scientists estimate that tropical deforestation causes about 15% of global warming. Trees absorb CO2 from the atmosphere as part of photosynthesis. When we cut down forests, we lose part of the system that reduces GHGs. Additionally, if these cut trees are then burned or allowed to decay, the carbon which was trapped in the tree is then released back into the atmosphere. So not only do we lose an ally for reducing GHGs, we end up causing an additional increase.
The Sustain:Green card works to address both of these problems. Not only is CO2 reduced through the use of the card, but through our partnership with Mata No Peito and the non-profit American Carbon Registry, the money we spend on carbon offsetting is then donated to rainforest reforestation projects, creating a double benefit.
REDD (reducing emissions from deforestation and degradation in developing countries) programs are designed to reward developing countries for reducing their deforestation rates. You can learn more about United Nations REDD programs.
1Gillis, Justin and Broder, John. "With Carbon Dioxide Emissions at Record High, Worries on How to Slow Warming." The New York Times, December 2, 2012.
2Gillis, Justin. "Heat-Trapping Gas passes Milestone, Raising Fears." The New York Times, May 10, 2013.
The Greenhouse effect
The greenhouse effect helps Earth regulate its temperature
Greenhouse gases help keep the Earth warm, through a process called the greenhouse effect. However, with too much GHG in the atmosphere, too much of the Sun’s heat is absorbed, resulting in global warming and climate change.
The greenhouse effect is how light from the sun is able to shine through the Earth’s atmosphere, while the heat from the sun is trapped by the atmosphere, warming the planet. The effect is similar to a greenhouse used to grow plants, letting sunlight in while trapping heat, even though the actual way they work is different. In the atmosphere, greenhouse gases absorb some of the Sun’s heat, and re-emit it back to the Earth. Without the GHGs trapping the Sun’s heat, the Earth would be much colder, too cold to support life as we know it.
Greenhouse gases help keep the Earth warm, through a process known as the greenhouse effect. This video helps explain what it is, and the role it plays in global warming.