It’s official: the Arctic set a record for ice loss this summer as 50 percent more per day melted than in 2007, the year the previous record was set for Arctic summer ice melt. The potential results include more climate destabilization and polarization between flood and drought, with the attendant shortages of water and damage to food crops.

As climate change becomes more immediate and obvious, events designed to educate people about it—and what can be done about it—are scheduled for the Valley this weekend.

Bill McKibben of 350.org, one of the world’s most prominent fighters against climate change and the popularizer of the term “global warming,” will speak at a free event at Amherst College’s Johnson Chapel Friday, September 7 at 7 p.m. McKibben cites climate scientists’ warnings that 565 more gigatons of carbon dioxide is the most we can put into the atmosphere by mid-century without inviting disaster (see www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719#ixzz24sPcUGU2); if present trends continue, he says, we’ll have put in that much in only 16 years.

The latest phase of McKibben’s war on global warming is a call to divest from the energy companies that, according to the math he cites, will ruin the world’s climate if they release for sale all that’s in their fuel reserves. A rally organized by students will follow his talk.

On Saturday, Sept. 8, a flotilla and rally to protest thermal and radioactive pollution at the Vermont Yankee nuclear power plant near Brattleboro begins at 11 a.m. as boats of all sizes leave from Prospect Street Boat Launch in Hinsdale, N.H. (check www.sagealliance.net/actions/river-9-8-12). Participants are asked to launch in time to join the full flotilla by 1 p.m. Watchers are welcome on the shore, along the nearby Fort Hill Rail Trail. Music and speakers will keep things lively.

On Sunday, Sept. 9, the Climate Action NOW! Conference, a response to the McKibben speech, takes place at the First Congregational Church, 165 Main St., Amherst, from 1 to 5 p.m. On the program are meetup sessions, workshops, and discussions of how to divest from (and reduce pollution by) the coal, oil and nuclear industries and companies fracking for oil and natural gas. At issue, say the organizers, is not only the preservation of the planet but the creation of “a sustainable and just economy that includes all people.”