Cover Story

Seawater inundation at high tide, Māpunapuna, June 22 .
Image: courtesy of hawai‘i sea grant

How 350 became the most important number in the world


Sat, Oct 24


Cover image for Oct 14, 2009

Later this month, Mohamed Nasheed, president of the Republic of Maldives, will chair the world’s first-ever underwater cabinet meeting.

On Oahu, hundreds of students will be let out of school in order to draw a giant chalk line, in blue, through the streets of Honolulu.

Near the shores of the Dead Sea, Israelis, Palestinians and Jordanians are planning to use their bodies to form the numbers 3, 5 and 0 across their national boundaries.

On October 24, Honolulu will join communities in 150 countries around the world for what organizers say will be the most geographically diverse day of activism in the history of the world.

It all comes down to a number: 350.

Atmospheric carbon is the principal agent responsible for global warming. Prior to the start of the Industrial Revolution, scientists have concluded that the atmosphere contained roughly 275 parts per million. Today, after decades of wild industrial growth and the fossil-fuel burning that has accompanied it, Earth’s atmosphere contains 385ppm–and rising fast.

Since the late 1970s, scientists have struggled to determine the red line for atmospheric carbon levels–the point beyond which climate change would be not just challenging but catastrophic for human civilization as it now exists. For a time, they settled on 450 ppm. As more historical data became available, however, that number proved high. Finally, during a 2008 meeting of climatologists in San Francisco, James Hansen, NASA’s top climatologist and one of the most respected researchers in the field, presented a paper in which he issued this startlingly direct assessment:

“If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm.”

With that, Hansen changed the dynamics of the global warming discussion. Al Gore’s An Inconvenient Truth, had brought a groundswell of new public attention to the problem of climate change, but Gore’s political past made him an imperfect evangelist for a crisis of chemistry. Global warming continued to be discounted as a concern of an anti-business, partisan political left with ulterior motives.

In addition, the push for greater attention to climate change had suffered from a lack of clear and meaningful goals. As Jeff Mikulina, executive director of the Honolulu-based energy policy organization Blue Planet Foundation, puts it, “When you talk about recycling ‘more,’ or using ‘less’ energy, it can be hard to know what that means. But we know what it means to say ‘I’m going to lose 20 pounds.’ We respond better when we have a target.”

Hansen’s 350ppm provided that target. Suddenly, concerned scientists, policymakers and citizens had a hard number to point at–a number that quickly got a lot of attention.

350 or bust

Bill McKibben, the environmental scholar and writer who has been prominent climate change activist since the 1980s, immediately saw the potential in Hansen’s number. With an eye on a looming international climate change meeting–the most important since Kyoto in 1997–McKibben founded the organization [] with the goal of making 350 the most famous number in the world–and putting pressure on negotiators to craft an agreement that will, as he puts it, “save our world.”

That meeting, the United Nations Climate Change Conference in Copenhagen, is planned for December. McKibben’s group, in a last-ditch effort to force a commitment to 350ppm, has organized a global day of action, with events planned in 150 countries and counting, all of them focused on the magic number.

“It’s shaping up to be way larger than anything we’d ever imagined,” McKibben said of the Oct. 24 event. “It looks like it’ll be the most geographically widespread day of action the planet has ever seen, with every corner of the world taking part.”

Including this corner. Led by Blue Planet and with a major scientific assist from a UH coastal geologist, local 350 efforts are focused on what is likely the most pressing climate-change threat facing the Hawaiian Islands–sea-level rise. Students around Oahu will be drawing a line on climate change, literally, by chalking a blue line through Honolulu to demonstrate the extent of one meter of sea level rise. That’s the level scientists say oceans are likely to rise by the end of this century as a warming planet produces massive melt-offs in the polar regions.

The project builds on the work of Chip Fletcher, who chairs the Department of Geology & Geophysics at the University of Hawaii at Manoa.

“Three years ago, I began to pay a lot closer attention to global warming issue,” Fletcher says. “I realized that the scientific community–or many, or myself I should say–while not ignoring the issue, had not really embraced it.”

Around that time, satellite evidence documented an acceleration of sea level rise that roughly doubled 20th century levels.

“I’d been aware of global warming since the ’70s,” Fletcher says, “but I hadn’t seen any truly dramatic change. This knocked me over the head. I realized as a coastal geologist, I needed to get involved.”

Using laser mapping technology, Fletcher and his students marked the 1-meter mark and began showing it around. Fletcher’s line is the one that 1,500 Hawaii students will be coloring in blue chalk on Oct. 24.

“The thinking is that Hawaii’s youth have a historic opportunity to send a message that their future is in jeopardy,” Mikulina says.
“I know it’s an overused expression, but it is truly a historic year for this critical issue that faces the earth. We thought [the blue line] was a good metaphor, but also a science-based statement that we need to draw the line on carbon.

What’s at stake

Both Fletcher and Mikulina point to the Islands’ unique vulnerability to climate change.

“We take a lot for granted, and often don’t realize how exposed we are to this threat,” Mikulina says. “The reef runway, a lot of our infrastructure, our sewage treatment, and then obviously our beaches and recreational spots. Even our fresh water supply is directly affected.

Fletcher is quick to point out that the 1-meter line does not represent the projected shoreline. Instead, it marks a new zone of coastal inundation, prone to severe and ongoing flooding problems.

“We’ll be building large seawalls to prevent the direct flooding by waves,” Fletcher says. “We’d see dramatic beach loss, we’ll see fresh water ecosystems turn into estuaries, increased exposure to coastal hazards such as tsunami and storm surge from hurricanes.”

“Groundwater sits on top of sea water, so as the sea level rises, there will places where ground waters comes out on the land,” Fletcher says. “We’ll see some dry areas [Moiliili could be one, Haleiwa another] turn into wetlands. We’ll see other areas where heavy rains will mean standing water in the streets, and where it won’t drain for a week.”

If you visit the airport industrial district of Mapunapuna at high tide, Fletcher says, you can get a clear picture of what this looks like. “Mapunapuna is an area of fill, and it’s beginning to settle. They get knee deep pools of water at high tide.”

He’s got the photos to prove it–the sea water outflow from storm drains is so voluminous that Mapunapuna locals regularly report seeing reef fish and even baby hammerhead sharks in the streets of the industrial district.

“That’s a modern laboratory of what most of our coastal communities are going to be experiencing by mid- and certainly late-century,” Fletcher says.

Why so soon? Because the rate of sea-level rise is now at 3 to 3.5 millimeters per year. That’s about double what it was during the 20th century and the rate of rising only increases as the atmospheric carbon count goes up.

Fletcher says widespread flooding is already probably in Honolulu’s future, and that the question now is how much. Some island communities may have to be abandoned altogether.

“The flooding can only be mitigated spot by spot,” he says. “Downtown or in Waikiki, it’s obviously worth the money to pump the water out and engineer solutions, but Haleiwa, Kaa‘awa, even Lahaina, we won’t be able to afford.”

The most immediate effects will likely be an exaggeration of current problems in low-lying communities. While hurricane strikes have been relatively uncommon in recent Hawaiian history, seasonal wave inundation is a constant menace, with north-facing shores particularly at risk of wintertime washouts.

“That problem is going to grow worse and worse,” says Fletcher. “Let’s say that Laniakea gets overwashed with sand a gravel in a big swell: Today, the City clears it in a couple of hours. That’s going to become four hours, and then six and 12. The people who live at Sunset won’t be able to get through–neither will emergency vehicles. Areas that don’t currently flood will begin to.”

Fletcher says now is the time to act to mitigate the changes that are already taking place. But he worries that the incremental nature of things like sea-level rise will lead to continued complacency.

“Little things like this are already part of daily life. We’ll manage our way around them for a while, until they become untenable. It’ll all happen very slowly, over a couple of generations. It’s easy to ignore.”

A chance for change

And so far, with the Copenhagen meeting just two months away, most of the world’s major industrial nations are doing just that. While, President Barack Obama has a group of 13 Cabinet secretaries and White House advisors meeting regularly to help craft energy reform legislation, he has shown no hint that he will commit the United States to anything like the 350ppm goal–and prospects for the U.S. Senate, which must ratify any treaty, are even grimmer.

Still, McKibben is hopeful.

“We’re not going to get the agreement we need out of Copenhagen,” he says, “But if we can get this number out there, we’ll help set the agenda. The problem is that the debate so far has been about how much change can coal companies bear, how much support is there in the Senate, etc. We need the debate to be about chemistry and physics because those are the controlling factors. It’s all been about the political reality. We need to introduce reality-reality into the discussion.”
The good news is, people are stepping up all over the world, and we’re definitely looking forward to all the things coming out of the Aloha State.”