The Complete Idiot's Guide to 2012 - Dr. Synthia Andrews Nd [96]
The variations of the earth’s orbit bring the earth closer to the sun and farther away from the sun in 100,000-year cycles.
Variations in the Milankovitch cycle are believed to have caused the earth’s ice ages and may be part of the current heating cycle. We are now in orbit A, at almost the closest position the earth will get to the sun and its warming effects. But can this 100,000-year cycle explain changes that have happened over the last 100-year period?
The bottom line of the natural cycle theory is that the planet has its own climate controlling mechanisms that are responsible for global warming. While this is obviously true, it’s equally true that human activity has an effect as well. What people wonder is whether the homeostatic mechanisms of the planet are capable of overcoming the increasing stress of human impact.
Human Impact
Most climate scientists agree that the main cause of global warming is human activity. Driving your car, using electricity in your house, and using aerosol products all contribute to greenhouse gases.
Trees help reduce greenhouse gases and produce oxygen. Rainforests have been one of the main sources of oxygen in the atmosphere. Right now, the rainforests are being destroyed at an unprecedented rate. Every second we cut down one and a half acres of rainforest. It’s estimated that given the current rate of destruction, all the rainforests will be gone within 40 years. That doesn’t give us much hope for reversing global warming naturally.
Is global warming related to human activity, and can we reverse it?
Celestial Connection
According to the United Nations Intergovernmental Panel on Climate Change (IPCC), most of the increased temperature in the twentieth century is related to human industrialization. The World Health Organization, the United Nations, and over 60 independent scientists and organizations are looking for ways to slow down the impending disaster by changing human activity. They believe that climate change over the next 20 years will result in “global catastrophe costing millions of lives in natural disaster.”
Greenhouse Gases
As you’ve already learned, the greenhouse effect is essential for life; but you really can have too much of a good thing. Our current lifestyle is accelerating natural processes, possibly throwing them out of balance. So instead of a warming blanket around the earth, we have a heated electric blanket.
It’s unquestionable that human activity has increased greenhouse gases like carbon dioxide (CO2), methane, nitrous oxide, water vapor, and the very important chlorofluorocarbons (CFCs). Although all greenhouse gases have increased due to human activity, let’s look at the two most important gases, CO2 and CFCs.
CO2 contributes about 50 percent to the greenhouse effect. The concentration of CO2 has risen by 25 percent in the last century, and half of that has been in the last 30 years. According to the UN special report on emissions, by the end of this century we can see concentrations 75 to 350 percent higher than preindustrial concentrations.
What raises CO2? Deforestation is a key component. Even more so, burning coal, oil, and fossil fuels has a major impact especially in the face of increased population. We all know that driving our cars increases CO2 but every time you turn on your television, a light, or your computer, you’re using electricity that is created mainly from fossil fuels.
CFCs are man-made chemicals used in refrigerators and air conditioners, fire extinguishers, and propellants in aerosol cans. Although there are lower concentrations of CFCs in the atmosphere than CO2, they trap more heat, and CFCs last in the atmosphere for 110 years. This is why people want to ban CFCs completely.
Ozone Layer
Ozone in the lower atmosphere is a dangerous pollutant that adds to the greenhouse effect, damages plants, and damages lung tissue. However, ozone is essential in the upper atmosphere for reflecting excess rays from