Click Here

Why are greenhouse gases a problem?

For over the past 200 years, the burning of fossil fuels, such as coal and oil, and deforestation have caused the concentrations of heat-trapping "greenhouse gases" to increase significantly in our atmosphere. These gases prevent heat from escaping to space, somewhat like the glass panels of a greenhouse.

Greenhouse gases are necessary to life as we know it, because they keep the planet's surface warmer than it otherwise would be. But, as the concentrations of these gases continue to increase in the atmosphere, the Earth's temperature is climbing above past levels. According to NOAA and NASA data, the Earth's average surface temperature has increased by about 1.2 to 1.4ºF in the last 100 years. Eleven of the last twelve years rank among the 12 warmest years on record (since 1850), with the warmest two years being 1998 and 2005. Most of the warming in recent decades is very likely the result of human activities. Other aspects of the climate are also changing such as rainfall patterns, snow and ice cover, and sea level.

If greenhouse gases continue to increase, climate models predict that the average temperature at the Earth's surface could increase from 3.2 to 7.2ºF above 1990 levels by the end of this century. Scientists are certain that human activities are changing the composition of the atmosphere, and that increasing the concentration of greenhouse gases will change the planet's climate. But they are not sure by how much it will change, at what rate it will change, or what the exact effects will be.



0 Comments


Golo

Welcome to GOLO, where WRAL.com visitors can comment on stories and create profile pages, blogs and photo galleries.

You must be a registered WRAL.com user to use these tools. Click here to register or log in.

View Comments View Comments

Photo Spotlight
0
1
2
3
4
5
[+] more photos | submit your photos
Report It
Send us your news photos, videos, tips and story ideas.
Submit Videos Submit Photos Submit Reports
  1. 2009christmasparade
    Bands, marchers in holiday parade

    Choose your group to watch their performance in the 2009 WRAL-TV Raleigh Christmas Parade.

  2. 2009christmasparade26
    Web only: Complete 2009 WRAL-TV Raleigh Christmas Parade

    Watch the parade in its entirety from the comfort of your computer any time.

  3. taxes
    Search for missing IRS refunds

    The Internal Revenue Service released the names this week of more than 100,000 taxpayers who have not received their 2009 income tax refund.

  4. County Unemployment Rates
    North Carolina unemployment rates

    View an interactive map with county unemployment numbers.

  5. Drought Map
    A year of N.C. Drought Maps

    View a time lapse animation of drought conditions during the last year.

Click Here