This Saturday, Oct. 24, Portland will join with Tokyo, London, Buenos Aires and hundreds of cities worldwide in displaying the number 350 on shop windows and T-shirts and in every other conceivable shape,size and form.

People will form "350" in human chains, hang "350" banners from rooftops, and run 350-meter races. The Masai Mara tribe is even planning a traditional "350 Jumps" ceremony in rural Kenya.

And on the banks of the Willamette River, hundreds of kayaks and canoes will form a massive "350" before joining a larger rally at Pioneer Courthouse Square.

So what's the significance of 350? In January 2008, NASA climatologist James Hansen published a report concluding that 350 parts per million is the maximum safe level of carbon dioxide levels in the earth's atmosphere.

Higher levels will initiate major chemical and physical reactions that the vast majority of scientists say will cause dramatic changes to weather conditions with catastrophic consequences for humans worldwide. The current number of CO2 globally is about 390 parts per million, according to the latest U.N. figures.

Since Hansen's report, the number 350 has become accepted by leading environmentalists and climatologists. And Saturday's Global Day of Action aims to raise public awareness and highlight the upcoming U.N. Conference on Climate Change in Copenhagen, scheduled to begin Dec. 7.

In the United States, a bill that passed the House in June commits only to 450 ppm, a target shared by the Obama administration.

Currently, the 350 number is included in draft treaty proposals in Copenhagen. And the global rallies are intended to "tell the delegates in Copenhagen as well as Obama to keep the number in" as a bottom-line requirement for CO2 emission limits, says Bill McKibben, author of the acclaimed 1989 book The End of Nature and founder of, the organization behind the worldwide rally.

"The real negotiation is not between the U.S. and China and India over economic responsibility," McKibben says, "but between human beings on the one hand and physics and chemistry on the other. Physics and chemistry have laid their cards on the table: Above 350, the world doesn't work. They are not going to negotiate further. It's up to us to figure out how to meet their bottom line."

Relying mostly on Internet-based social networking tools such as Twitter and Facebook and a user-friendly interactive website, 350.orgquickly established chapters in more than 150 countries.

The Oregon chapter,, has assembled an impressive day of events.

Longtime Portland environmental activist Phil Carver has organized a "350-mile trek" from Coos Bay to Portland (already under way) for runners and walkers.

Former schoolteacher Bonnie McKinlay and her husband, Jim Plunkett, an engineer, have helped organize the main public rally beginning at 1 pm in Pioneer Courthouse Square along with other members of Ecumenical Ministries of Oregon. The rally hopes to attract at least 5,000 people and will feature a range of music, dance, public speakers and media activities.

"I can think of few other issues that merit Portland's attention [as much] as this," Plunkett says.

Perhaps the most colorful local event is the synchronized kayak and canoe formation in which hundreds of boaters on the Willamette River will form a floating "350" at 1 pm, just south of the Burnside Bridge. Organized by local filmmaker and professional kayaker Andy Maser, the event will be open to public participation, including free use of kayaks. Maser will film the Portland kayak event for National Geographic.

"Theres a lot of awareness here," Maser says. "Portland's voice can be one of the stronger ones we send to Copenhagen."


The entire day's events, including those in Portland, will be broadcast live at Times Square in New York, and at U.N. headquarters.