On Feb 16, 7:58 pm, "Michael Tobis" <[EMAIL PROTECTED]> wrote: > Seriously, the runaway term is used to describe a planet where the > water vapor feedback is such that entire ocean evaporates and the > planet becomes completely unviable. This is believed to be the story > of the evolution of Venus. > > I have seen formal calculations about this; apparently we are a bit > too far from the sun for this to happen here, but not by a huge > margin. If the sun warms up just a little bit it will happen. If the > earth were a cylinder and not a sphere, hence tropical everywhere, the > oceans would boil away post haste. Unfortunately I didn't track this > down on the first attempt. > > (It's a Ray P question if there ever was one, though I don't think he > was the author of the definitive analysis of the question if I recall > right.) > > That doesn't mean there aren't exacerbating feedbacks. The clathrates > may provide one on a millenial time scale. There are other candidates. > But "runaway" isn't the right word for that unless you think the world > will tip into complete uninhabitability as a result. > > mt
Is the Runaway Greenhouse Effect really a closed question? Seems Nasa was studying it recently: http://astrobiology.arc.nasa.gov/news/expandnews.cfm?id=1386 But perhaps your information post-dates this. Note that the "Earth's future habitability" link on this page is dead. I tracked down an old version of the link here: http://astrobiology.arc.nasa.gov/roadmap/1998/objectives/o15_future_habitability.html Apparently, "Earth's future habitability" was a objective of study by NASA till 2005 (inferring from the wayback machine). It has been replaced by: "Understand the principles that will shape the future of life, both on Earth and beyond": http://astrobiology.arc.nasa.gov/roadmap/g6.html --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
