In Earth's atmosphere there are many environmental problems coming from the increase concentration of greenhouse gases. As ABC NEWS reported by Jeff Rubin, there are many signs indicate that we have begun changing Earth's climate: glaciers and polar ice caps appear to be melting,increased water vapor in the atmosphere, floods and droughts coming more severe, and sea level rising continuously, on average, between 4 and 10 inches since 1990(www.abc.com/sections/us/global106.html). For global warming we are already began to see more flooding, more droughts. According to Jane Lubchenco if this situation is continuing we must see 2 foot rising sea level by 2100 and this level will continue to rise 2 or 3 feet per century, for 1000 years.
These rises in sea level cause coastal lands to be washed under the ocean as a result increase the
salinity of freshwater throughout the world. Increased humidity and Warmer water may encourage tropical cyclones, and changing wave patterns could produce more tidal waves and strong beach erosion on the coasts.
The greenhouse effect is the rise in temperature due to the presence of greenhouse gases. Greenhouse gases in the atmosphere behave much like the glass panes in a greenhouse. Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases. As it reaches the Earth's surface, land, water, and biosphere absorb the sunlight’s energy. Once absorbed, this energy is sent back into the atmosphere. Some of the energy passes back into space, but much of it remains trapped in the atmosphere by the greenhouse gases, causing the lower atmosphere to warm.
The greenhouse effect is important. The Earth would not be warm enough for humans to live without the greenhouse effect. But if the greenhouse effect becomes stronger, it would be harmful for us and it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.