Why 400 parts per million is an opportunity

It might be too late to reverse climate change. But hopefully not.

I learned the news last Thursday, on light rail, just as the Meadowview-bound train veered from K Street onto Seventh: For the first time ever, the amount of carbon dioxide in the atmosphere had reached 400 parts per million.

The landmark measurement—taken from atop the Mauna Loa volcano on Hawaii's big island—was later corrected to 399.89. But anyone who gives a damn about the planet heard the message: Residents of Earth just can't quit. Cars, planes, plastic, coal, oil, fossil fuels—we're junkies.

Time for an intervention.

When it comes to CO2 atmospheric levels, the number 400 is an opportunity. Environmental activists want to drop down to 350 (there's a website, www.350.org), but that's absolutely not the trend, according to the National Oceanic and Atmospheric Administration, which measured the big 400 last Thursday, May 9. It says CO2 levels are up by nearly 6 percent in the last decade; other scientists cite greater digits.

I realize it's hard to see or understand the number 400 in our everyday lives. We can't sit down, crack open a cold beer and discern changes in plant photosynthesis.

And, of course, there are so many other things—the Sacramento Kings arena, your Facebook feed, Mom's brunch, Dad's Giants game—that preoccupy.

But if we continue to torch the planet's coal and tar sands, climatologists predict frightful real-world scenarios. Now. Unpredictable, extreme, dangerous weather. Food and water scarcity. Uninhabitable regions. Rising tides. All that stuff.

And then, perhaps in your childrens' childrens' lifetime, a possible “runaway greenhouse effect.” Google it, it's scary stuff.

So, 400—it's about legacy. Ours. On this planet.

Sometimes, I fear it's too late. Hopefully, I'm wrong.