Environmental writer and advocate Bill McKibben, in a talk co-hosted by Lexington Global Warming Action Coalition and Lexington Community Farm Coalition, apologized to the large crowd at Cary Hall Sunday evening for drawing people inside on a warm, sunny day.

"Now, I'm going to dump bad news on you," McKibben said, admitting the talk would be cathartic for him.

McKibben gained fame for penning The End of Nature, one of the first books explaining climate change. His latest book, Eaarth discusses the advance of climate change and the ways local action can contribute to the fight against fossil fuel usage. 

Across most of the Northern hemisphere, McKibben said, people are glad to see this summer draw to a close. He told listeners that 19 nations set new all-time temperature records. In Asia, the temperature reached 129 degrees, and in Russia, it touched 100 degrees eight times in August, causing a drought that halted crop yields.

McKibben also revealed that rainfalls drenched New England; Nashville, Tenn.; and Oklahoma City, Okla. Furthermore, due to intense monsoonal rains, 1/5 of Pakistan is now underwater, sending 20 million people on the move.

"This is what global warming looks like – at least the beginning of global warming," said McKibben.

According to McKibben, the global temperature has already risen one degree, and may increase another four to five degrees by the end of the century. The only good news, said McKibben, is that scientists can now identify the "red line" – how much carbon dioxide is too much.

"How are we going to keep from going further down the most dangerous road humans have ever gone down?"  McKibben said.

In 2007, McKibben decided to build a large-scale movement to take on the fossil fuel industry. He became the force behind 350.org, a worldwide campaign to fight global warming.

The number 350 represents the upper limit of carbon dioxide parts per million (ppm) in the atmosphere allowing for life on Earth as we know it. McKibben revealed that, at the time he was giving his talk, the atmosphere contained a reported 392 parts per million. The carbon dioxide count continues to increase, he said.

"One light bulb at a time is not enough," said McKibben. "We have to move with great speed, which means we can't avoid the political. Nor can we do it with money; the oil companies will always have more."

McKibben said it's a question of whether people can summon the political will to stop using fossil fuels. The number 350 "is not a political number in any way," he said. "It's what physics and chemistry tell us about the world."

However, McKibben suggested, the fight against climate change has made the issue political. The evidence of government willingness to raise the price of fossil fuels is bleak, said McKibben, who pointed out that the most recent Congress had decided not to take a vote on the matter. 

McKibben also said the fossil fuel industry is one of the most profitable industries in the world. Last year, Exxon Mobil made more money than anyone in the history of money, he said, and it's no wonder the company – and others like it – are not willing to cooperate with anti-oil advocates.

As 350.org took shape, McKibben found another currency: People. McKibben and friends walked for days, slept in fields and eventually got a thousand volunteers marching for climate change. Rallies took place all over the United States. As the movement evolved, it persuaded political candidates, among them Barack Obama and Hillary Clinton, to work towards an 80 percent cut in carbon emissions by 2050.

McKibben's 350.org keeps in touch with volunteers via Internet and Skype, and began offering training sessions across the globe. To date, there have been more than 5,200 demonstrations in 51 countries, he said.

Due to language barriers, "people don't do global organizing very often," McKibben noted. "But numbers have the same meaning across different languages."

McKibben showed a slideshow of photographs promoting 350.org's message. As revealed by the photographs, demonstrations have taken place in the United States; Afghanistan; Wellington, Australia; Bangladesh; the Congo; Nepal; Turkey; India and at the Great Barrier Reef.

"Most of the people in the pictures don't look like what you might expect an environmentalist to look like," McKibben said. "Many of them are poor, black, brown, Asian. But they're just as interested in the future as anyone else."

In December 2009, when McKibben and his group arrived in Copenhagen for a U.N. climate-change conference, they convinced 117 nations to sign on to the 350.org pledge. However, the nations that did were not the ones that mattered most. The meeting ended badly, he said.

"After Copenhagen, I was more depressed and angry than I'd been in a long time," McKibben said.

His fellow 350.org workers kept him going. Now, McKibben is working on 101010, a global work party to take place on Oct. 10 in thousands of locations across the globe. Project volunteers will put up solar panels and maintain community gardens and bike paths, among other projects.

Furthermore, in the next 10 days, McKibben and group members will travel to Washington, D.C., with their eyes on an old White House solar panel. The panel, first installed by Jimmy Carter in the 1970s and later removed by Ronald Reagan, serves as a symbol for the team's purpose: McKibben and his volunteers hope to encourage President Obama to re-install solar panels at the White House.

"So far, the Obama administration has not chosen to spend much of its immense political capital on (the climate change issue)," said McKibben. 

He later said that while the Obama administration has done more for climate-change prevention than any other administration, the bar was set very low.

McKibben, whose mother was in the audience, said it felt good to be back in Lexington, and lauded local efforts to battle climate change. He mentioned that, among other things, there are plans in place for Carleton-Willard Village, an assisted living project in Bedford, to work on composting.

McKibben also encouraged Lexingtonians to get involved by signing up at 350.org and www.LexGWAC.org. He asks that attendees make donations for Pakistan flood relief, in particular, and after the talk signed books and talked with people.

"An awful lot of us will keep on fighting to do the best we can as long as we can," said McKibben.