Global Warming, the Greenhouse Effect and the Solar Greenhouse 

See what our planet  may look like in the next millennium by clicking the Earth.

Energy from the sun  heats the earth’s surface, makes clouds and creates weather.  Atmospheric greenhouse gases such as CO2 and clouds trap some of the outgoing energy like a great blanket. The greenhouse effect moderates temperatures and makes life possible on this small green planet. The threat of global warming may someday become a serious problem if the current trend of fossil fuel consumption continues.  
In the last 300 years the concentrations of carbon dioxide alone has increased by more than 30%.Without adequate emission control policies and alternative energies to choose from this concentration will most likely double during this century. If the greenhouse effect continues to escalate many scientists believe we will reach a point of no return. High temperatures mean increased plant growth, more rain, more vegetable growth, more decay and more carbon dioxide. More carbon dioxide increases the greenhouse effect, the cycle continues and the planet "hot balls" into an inferno like Venus.

How can people prevent global warming?
The answer to this question is simple. All we have to do is stop consuming vast quantities of fossil fuels and start searching for renewable energy supplies. We need to explore alternative energy options such as wind ,water and solar energy. Of these options solar energy appears to have the greatest potential over the largest area. To avoid excessive global warming we can use the same principle that' s causing  it. .That's right! The greenhouse effect is a fundamental method of trapping heat from the sun. High frequency radiation such as ultraviolet and visible light is allowed to pass through a glazing. Once the light is inside the greenhouse and it strikes a non reflective surface the high frequency radiation is transformed into a low frequency heat radiation that can not pass back out through the glazing. Heat is trapped.


A commercial greenhouse nursery is a great way to get plants off to an early start. 
A solar greenhouse can also be used to start plants although it's primary function is to heat a house. 


A solar greenhouse is specially designed for heat gain. The glazing is perpendicular to the angle of a winter sun. The upside-down funnel shape of the greenhouse concentrates hot air near the top flap. On a  20 F., windy, January day in Plattsburgh NY I measured temperatures in excess of 160 degrees F. at the solar greenhouse apex. Hot air is lighter than cold air so it naturally rises and pushes the top flap open. The cold air return flap is pushed open in a like manner. This allows cold air from the living space to be returned into the solar greenhouse  for heating.
At night the solar greenhouse cools down so that cold greenhouse air attempts to enter the house through the bottom flaps. This reverse circulation is prevented by the simple plastic one way flaps.



The solar greenhouse is a good example of a passive  application of the greenhouse effect.
Active solar energy systems also make use of the greenhouse effect.
Another good application would be the flat plate collector. Heat from the greenhouse effect is able to boil water inside a well constructed solar collector. Solar heating systems are now competive with fossil fuel heating systems. Explore the alternatives while there is still time.