4thchance
Search Members
Type in a member you wish to find
Most Active Members
Most Recent Groups
In the News
My Profile:
4thchance
Talkin’ to 4thchance View All (1) »
-
RickyDawkins9 months, 3 weeks ago
Global Warming Fast Facts
http://news.nationalgeographic.com/news/2004/12/12...
• Industrialization, deforestation, and pollution have greatly increased atmospheric concentrations of water vapor, carbon dioxide, methane, and nitrous oxide, all greenhouse gases that help trap heat near Earth's surface.
• Humans are pouring carbon dioxide into the atmosphere much faster than plants and oceans can absorb it.
• These gases persist in the atmosphere for years, meaning that even if such emissions were eliminated today, it would not immediately stop global warming.
• Some experts point out that natural cycles in Earth's orbit can alter the planet's exposure to sunlight, which may explain the current trend. Earth has indeed experienced warming and cooling cycles roughly every hundred thousand years due to these orbital shifts, but such changes have occurred over the span of several centuries. Today's changes have taken place over the past hundred years or less.
• Other recent research has suggested that the effects of variations in the sun's output are "negligible" as a factor in warming, but other, more complicated solar mechanisms could possibly play a role.
