Worst case:
“A new analysis has concluded that the magnitude of climate
change during Earth''s deep past suggests that future
temperatures may eventually rise far more than projected if
society continues its pace of emitting greenhouse
gases. “Building on recent research, the study examines
the relationship between global temperatures and high levels of
carbon dioxide in the atmosphere tens of millions of years ago.
It warns that, if carbon dioxide emissions continue at their
current rate through the end of this century, atmospheric
concentrations of the greenhouse gas will reach levels that
existed about 30 million to 100 million years ago, when global
temperatures averaged about 29 degrees Fahrenheit (16 degrees
Celsius) above pre-industrial levels. “National Center for
Atmospheric Research (NCAR) scientist Jeffrey Kiehl said that
global temperatures might gradually rise over centuries or
millennia in response to the carbon dioxide. The elevated
levels of carbon dioxide may remain in the atmosphere for tens
of thousands of years, according to recent computer model
studies of geochemical processes that the study
cites.”
--Source: “Earth’s hot past points to drastic
global warming,” TopNews Network, Jan 14,
2011-01-14
http://www.topnews.in/usa/earths-hot-pa ... ming-26826
"I'm not a skeptic because I want to believe, I'm a skeptic because I want to know." --Michael Shermer