Dear all,
The Earth is very impressive - and we are priveleged to live on it, at a time when it provides us a benign environment, partly of our own making. This is personally how I see it... Although the Earth appears as a stable system, it has been through various crises, with five mass extinction events because of marked changes to the environment, eventually leading to a series of ice ages and us. During these ice ages, the temperature has been oscillating wildly between limits. The upper limit seems to have been controlled by the Arctic sea ice, acting as a thermostat - when it was getting hotter globally, an increasing proportion of sea ice would give way to water, the whole Arctic region would heat, but then meltwater would flow into the NorthWest Atlantic and turn off the Gulf Stream to cool the Arctic region and allow the sea ice to reform to cool the region. We have remained at near this upper limit of temperature oscillation for at least 8000 years. If mankind had not cut down forests, ten thousand years ago, and initiated some global warming, we would almost certainly be in an ice age now. Instead we are into the Anthropocene, where climate is to some extent controlled by our own behaviour. In the past century we have injected a huge pulse of CO2 into the atmosphere. This threatens to melt the Arctic sea ice completely, which has never happened between previous ice ages. Thus we are about to destroy the thermostat for the global climate, letting the temperature climb through the roof, and creating the 6th great mass extinction event. Mankind has survived many glaciations - some say it is how we have involved our intellegence. We now have to apply our intellegence to get out of the new situation we find ourselves in. Let us hope that this intellegence will prevail to find a way in 2009 to save the Arctic sea ice. Best wishes for Christmas and the New Year, John ----- Original Message ----- From: "Andrew Revkin" <anr...@nytimes.com> To: <geoengineering@googlegroups.com> Sent: Wednesday, December 24, 2008 6:14 PM Subject: [geo] stepping back to remember what it's all about... > > Dear all, > > I thought you'd appreciate my holiday post on Dot Earth -- > http://tinyurl.com/dotEarthrise -- which affords a fresh look at that > remarkable view a few lucky astronauts have gotten of Earth rising > over the sterile horizon of the Moon. If you haven't seen the > Japanese VIDEO version of Earthrise (and Earthset) -- shot last year > from Kaguya satellite -- you really owe it to yourself to click. > > Make sure to click on "watch in high quality" on YouTube for the best > 'view.' > > I added the voices of the Apollo 8 astronauts and music by one of my > Uncle Wade bandmates. > > Would love comments, thoughts from you on the blog. > > Best wishes for 2009 and well beyond. > > Andy > -- > Andrew C. Revkin > The New York Times / Science > 620 Eighth Ave., NY, NY 10018 > Tel: 212-556-7326 Mob: 914-441-5556 > Fax: 509-357-0965 > www.nytimes.com/revkin > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
