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- From: roberts@cmr.ncsl.nist.gov (John Roberts)
- Newsgroups: sci.space
- Subject: Re: averting doom
- Message-ID: <C0Gv9L.Lnq.1@cs.cmu.edu>
- Date: 7 Jan 93 04:29:51 GMT
- Article-I.D.: cs.C0Gv9L.Lnq.1
- Sender: news+@cs.cmu.edu
- Distribution: sci
- Organization: National Institute of Standards and Technology formerly National Bureau of Standards
- Lines: 34
- Approved: bboard-news_gateway
- X-Added: Forwarded by Space Digest
- Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
-
-
- -From: u108502@beta.lanl.gov (Andrew Poutiatine)
- -Subject: Re: averting doom
- -Date: 6 Jan 93 15:52:12 GMT
- -Organization: Los Alamos National Laboratory
-
- ->In article <JMC.92Dec29211051@SAIL.Stanford.EDU> jmc@cs.Stanford.EDU writes:
- ->>from a U.P. story
- ->>
- ->> WASHINGTON (UPI) -- Life on Earth as we know it will
- ->> come to an end in 1,500 million years and the planet will
- ->> look more like its dusty, volcanic sister Venus in 2,500
- ->> million years, scientists said Wednesday.
-
- -I believe the above prediction is based not on earth climate and weather
- -considerations (for which I must agree predictions of more than a few days
- -are not very dependable), but rather on the evolution of the sun.
-
- -I am not an astronomer, but as I recall, theory predicts that stars of our
- -sun's size go through a stage in their evolution at the end of their lives
- -when they become hotter and expand. It is this, I believe, that would
- -parch the earth, killing life "as we know it."
-
- A significant feature of the recent calculations is that as temperatures
- rise, CO2 levels drop (thus regulating the surface temperature of the Earth
- to some extent). Eventually CO2 drops too low to support photosynthesis,
- leading to the death of multicellular organisms. The recent addition to
- the model is the observation that certain plants such as corn and other
- grasses do not require as much CO2 for photosynthesis as most other plants,
- so there should continue to be functioning plant life for much longer than
- previously expected.
-
- John Roberts
- roberts@cmr.ncsl.nist.gov
-