Earth Speak

Kyoto Protocol
The Kyoto Protocol is an agreement that went into effect in 2005. Its primary goal is to reduce the output of greenhouse-gas emissions in industrialized countries. The protocol commits Annex I members to cut their emissions 5 percent below 1990 levels between 2008 and 2012. Many countries are practicing carbon trading to offset the greenhouse-gas emissions. Carbon trading refers to the act of governments setting an emissions-output cap. Companies would then buy credits if they needed them, or sell credits if they didn't. To learn more about carbon trading and what it can really do for the environment, read this article from HowStuffWorks.

La Nina
The opposite of El Nino, La Nina refers to the buildup of colder than normal ocean temperatures in the Pacific Ocean. It occurs every few years and can last as long as two years. La Nina can have varying effects depending on the region of the world. In the United States, the Southeast, Southwest and Central Plains regions are much drier than normal, while the Pacific Northwest is wetter than normal. The continent of Australia is also much wetter than normal. To see all the regions of Australia and the surrounding islands, take a look at this map from HowStuffWorks.

Latitude
Every place on Earth is marked on a map with lines of latitude and longitude. The latitude lines run horizontally to show whether a point is on the equator, or if it's above or below the equator. The distance is marked in degrees, with 0 degrees being directly on the equator, and 90 degrees being either North or South Pole. To find out how maps are made and how to use them properly, head on over to HowStuffWorks.com.

Lightning
With bolt temperatures hotter than the surface of the sun and shock waves beaming out in all directions, lightning is a lesson in physical science and humility. There is much to be learned about these amazing bolts of light, ranging from the different types of lightning -- from sheet lightning (which is reflected in the clouds) to jet blue (a cone-shaped burst that occurs above the storm cloud’s center and moves upward at a very high rate of speed). But beyond its powerful beauty, lightning presents science with one of its greatest mysteries: How does it work? What happens in an electrical storm, and what do multiple strikes mean? Learn more in this article from HowStuffWorks.com.

Longitude
Every place on Earth is marked on a map with lines of latitude and longitude. The longitude lines run vertically to show whether a point is on the prime meridian, or if it's east or west of the prime meridian. The distance is marked in degrees, with 0 degrees being directly on the prime meridian, and +180 degrees to the east and -180 degrees to the west. To find out how maps are made and how to use them properly, head on over to HowStuffWorks.com.

Ozone
Everyone has heard of the ozone layer -- and what humans are doing to it with all of our pollution. But what is ozone itself? Ozone is a gas that can be good or bad, depending on where it is. Ozone found in the stratosphere, around 6 to 30 miles above the Earth's surface, is considered good ozone. There it protects against the sun's UV rays, which are harmful to humans. However, ozone found at the ground level is bad. At this level, it's commonly referred to as smog, and it can hurt children with asthma and pose other health risks. It can also damage crops and other vegetation. To learn more about the qualities of ozone, check out this HowStuffWorks article.

Particulates
Particulates aren't just one thing found in our environment; they're many different things: dust, soot, ash, smoke and the other gases found all around us. If you've ever breathed any of these things in, you know unpleasant they are to taste. But the foul smell and taste aren't the only harm they cause. Studies are now showing particulates to be harmful to your health, as well. To find out what some of these particulates are and what they can do to you, visit HowStuffWorks.com and check out our library of articles.

Permafrost
Permafrost is best described as a permanent frost. Anything that has remained frozen below 32 degrees Fahrenheit for more than two years falls into this category. The Arctic permafrost is melting after being frozen for tens of thousands of years. A group of Russian scientists studying the permafrost theorize that its rich organic matter could possibly release billions of tons of greenhouse gases and further contribute to global warming. Watch this video on HowStuffWorks.com to see what the ramifications really are.

Precipitation
Precipitation comes in a variety of forms: hail, rain, sleet, snow and freezing rain. When the particles that are suspended in the air become too heavy, they're released from the sky down to Earth in one of these forms. Which form it takes depends on the temperature of the area where the precipitation is falling. The amount of precipitation that falls usually depends on the region of the world you're in. To determine which regions get the most rainfall, take a look at the world precipitation map at HowStuffWorks.

Prime Meridian
The prime meridian is an imaginary line that circles the globe from north to south, acting as a line for the axis of the Earth. It distinguishes between the Eastern and Western Hemispheres and runs through England, France, Spain, Algeria, Mali, Burkina Faso, Togo and Ghana, and then through Queen Maud Land to the South Pole. Lines of longitude are called meridians, as well. To find out other useful terms for things used on maps, read this article from HowStuffWorks.