The greenhouse effect is a natural phenomenon that allows life to survive on Earth. The effect is maintained by greenhouse gases within the atmosphere. The concentration of these gases regulates the temperature of the planet. Lately, the unusual increase of global warming has led many scientists to speculate that mankind’s influence has affected the greenhouse effect.
Greenhouse gases have been a favorite topic in the news long before the Kyoto Accord. In 1824, it was discovered that these gases actually create a greenhouse effect within the upper atmosphere of the planet. A greenhouse effect traps the planet’s heat within the cover of the clouds, thereby reducing the amount of heat that can escape into space. That doesn’t sound good – something trapped sounds like it can’t be released.
The commonly accepted idea is that the greenhouse effect is simply a bad thing. We have only to look at our planetary neighbors to help us decide if that’s true. The planet Venus is a victim of out of an out-of-control greenhouse effect. It’s smothered with impossibly thick clouds of carbon dioxide, so, almost all of the blistering heat, radiated from the sun, will remain locked within that hellish atmosphere. On the other end of the spectrum, the moon Titan has almost no greenhouse effect – it loses almost all of its heat into space. Like Earth, its atmosphere is mostly nitrogen, but unlike Earth, most of the nitrogen is completely frozen! The air itself has frozen… that’s insanely cold!
The Earth’s climate seems to have the right amount of greenhouse effect to support life as we know it. The greenhouse effect adds about 60oF to Earth’s average temperature. So, actually, the effect is a good thing, but lately, it seems to be veering off into warmer behavior. Since the 1970’s, there’s been much talk about how we can all help to change that trend. To know what can be done, we first have to understand what contributes to the greenhouse effect.
In the distant beginnings of our planet, volcanoes deluged the atmosphere with greenhouse gases, but, when oxygen-based plant life took a precarious hold upon the planet, the balance of greenhouse gases began to change radically, especially through the absorption of carbon dioxide. Over the eons, the atmosphere became the air we know of today. Nowadays, the greenhouse effect is mostly driven by four gases within the atmosphere: water vapor, carbon dioxide, methane and ozone. Apart from occasional volcanic upsurges, the greenhouse effect is usually a delicate balance that slowly changes over time.
This process was largely unaffected until the beginning of mankind’s industrial age (about 200 years ago). While mankind hasn’t created global warming, it is readily apparent that mankind has contributed to exacerbating the process. Unless the system (the Earth’s climate) is balanced again, the heating trend will continue, but no one knows for sure how long it will continue, whether it will stop or reverse itself into an ice age.
Human activity has definitely affected the climate system, but to what extent, no one can truly be sure. Some of it is inevitable: we exhale carbon dioxide, we drink water, and, yes, we even contribute some methane. The main problem is related to the choices we make in our civilization, mainly, the creation of carbon dioxide due to the burning of fossil fuels. Other actions are also changing the balance of greenhouse gases: aerosols depleting the ozone layer, rampant deforestation reducing carbon dioxide recapture, agricultural demands depleting watersheds, waste products creating methane (much of it from cows!) and land use activities destroying ecosystems and shifting water vapor cycles.
Startling environmental changes have occurred that are no longer easy to shrug off as random aberrations: altered weather patterns, long lasting droughts, unpredictable flooding, glacial melting and rising sea levels. Many nations have begun to take action to stabilize mankind’s effect upon the environment. Further actions will hopefully reduce the undesired greenhouse trend or maybe even begin to reverse it, but a new paradigm of environmental awareness will need to be cultivated to make that happen.
The greenhouse effect provides life-giving warmth on Earth. However, the delicate balance of greenhouse gases has been disturbed by mankind’s technological advances. Recent awareness of global warming has resulted in many nations taking proactive steps to reduce greenhouse gas emissions.
