The Earth has cycled through many phases of warming and cooling over the billions of years of its history due to the greenhouse effect. There are many natural factors that contribute to the greenhouse effect, but most of these occur very slowly over many millennia.
Temperature is increasing faster than ever on a global scale that cannot be explained by these natural processes. It is now clear that humans are responsible. But you can help change this. Find out how you can help.
The Reason: Humans Are Causing The Problem
While there are many natural causes of global warming, these causes do not account for the extra warming we are currently seeing on our planet. The current warming is anthropogenic, created by humans.
How do humans cause global warming? We are accelerating the natural climatological cycles with our human-created emissions of greenhouse gases. The primary gas, carbon dioxide, is released every time you use fossil fuels- currently our main energy source. Unless you help stop those emissions, there is little hope of a secure future for humans.
You’ll see that dangerous shifts in the Earth’s climate are happening as we speak due to human induced global warming, and as it continues the consequences will worsen. Furthermore, such changes may be self-reinforcing. From an objective perspective, it looks like we are playing Russian roulette with all of life on Earth!
How Do You Contribute?
- Carbon Dioxide from:
- Fossil Fuel
- Failing Sinks
- Methane from:
- Cattle and Rice Paddies
- the Artic Tundra
- Nitrogen Oxides from Farming
- Other Gases
The Most Significant Cause
The buildup of carbon dioxide in the atmosphere, mainly from your fossil fuel emissions, is the most significant human cause of global warming. Carbon dioxide is released every you burn something, be it a car, airplane or coal plant. This means you must burn less fossil fuel if you want the Earth’s climate to remain stable! And unfortunately, we are currently destroying some of the best known mechanisms for storing that carbon– plants.
Deforestation increases the severity of global warming as well. Carbon dioxide is released from the human conversion of forests and grasslands into farmland and cities. All living plants store carbon. When those plants die and decay, carbon dioxide is released back into the atmosphere. As forests and grasslands are cleared for your use, enormous amounts of stored carbon enter the atmosphere.
An unstoppable feedback loop may happen if you let this continue. If the activities mentioned above warm the Earth just enough, it could cause natural carbon sinks to fail. A “carbon sink” is a natural system that stores carbon over thousands of years. Such sinks include peat bogs and the arctic tundra. But if these sinks destabilize, that carbon will be released, possibly causing an unstoppable and catastrophic warming of the Earth.
The oceans are no longer able to store carbon as they have in the past. The ocean is a huge carbon sink, holding about 50 times as much carbon as the atmosphere. But now scientists are realizing that the increased thermal stratification of the oceans has caused substantial reductions in levels of phytoplankton, which store CO2. Increased atmospheric carbon is also causing an acidification of the ocean, since carbon dioxide forms carbonic acid when it reacts with water. The tiny plants of the ocean, the very bottom of that vast watery food chain, are suffering from the effects of global warming, which means they are becoming less able to store carbon, further contributing to climate change.
Methane’s Huge Impact
Per unit of volume, it is twenty times more potent than carbon dioxide when its impact is measured over the course of a century. When you consider its effects within a single decade, methane is 100 times as powerful as carbon dioxide as a greenhouse gas! Carbon levels in the atmosphere are about 385 parts per million (ppm) currently, whereas methane is only about 1.8 ppm. But because methane is so powerful, it has the potential to have significant impacts on the future of global warming.
Methane is created when bacteria break down organic matter under oxygen-starved conditions. This occurs when organic matter is trapped underwater, as in rice paddies. It also takes place in the intestines of herbivorous animals, such as cows, sheep, and goats. Because human agriculture has grown over time to engulf most of the arable land on the planet, it is now adding a lot of methane to the atmosphere. Landfills and leakage from natural gas fields (methane is a component of natural gas) are also significant sources of methane.
Clathrates are a hidden source of Methane. Clathrates are frozen chunks of ice and methane that rest at the bottom of the world’s oceans. As the water warms, the ice melts, and the methane is released. If the current global warming, which is caused by humans, were to cause changes in the Earth’s ocean currents, then a rapid melting of clathrates would be possible. This too would create a positive feedback loop that would cause further global warming. It is believed that some of the warming cycles in the Earth’s history have been caused by the sudden thawing of clathrates.
A Growing Problem
The “green revolution” of the twentieth century has allowed the farmers of the world to use chemical fertilizers and machines to produce far more food than they ever did before. One of the primary components of the green revolution has been the development of nitrogen fertilizers that dramatically accelerate the growth and productivity of plants in the field. Plants “fix,” or capture, nitrogen on their own as well, but green revolution technologies have become so popular that humans are now adding more nitrogen to the earth than all of the plants in the world combined!
Nitrogen oxides have 300 times more heat-trapping capacity per unit of volume than does carbon dioxide, and we release them every time we apply fertilizer to soil. A recent United Nations Food and Agriculture Organization study found that modern farming is contributing more to global warming than all of the transportation sector combined! This is due partly to the fuel burned in modern farming, but more significantly, to the release of methane and nitrogen oxides.
The Few But Strong
CFCs and HCFCs (chlorofluorocarbons and hydrochlorofluorocarbons) used in refrigeration are also powerful greenhouse gases. These gases occur in lower concentrations in the atmosphere, but because they are so much more potent than carbon dioxide — in some cases hundreds of times more potent per unit of volume — they contribute to global warming as well.
You Can Help
You can make a big difference to help stop this unprecedented problem. Want to find out how?
Author: Brown, Nathan. A Cooler Climate, 2008.