YOU ARE HERE ~ 400 ppm

As reported in the NYTtimes and numerous other sources yesterday, the concentration of carbon dioxide (CO2), the most important heat-trapping gas in the atmosphere, reached an average daily level of 400 parts per million (ppm).

"The best available evidence suggests the amount of the gas in the air has not been this high for at least three million years, before humans evolved, and scientists believe the rise portends large changes in the climate and the level of the sea.

" .... Virtually every automobile ride, every plane trip and, in most places, every flip of a light switch adds carbon dioxide to the air, and relatively little money is being spent to find and deploy alternative technologies.  China is now the biggest emitter, but Americans have been consuming fossil fuels for far longer, and experts say the United States is more responsible than any other nation for the high level.

" The new measurement came from analyzers atop Mauna Loa, the volcano on the big island of Hawaii that has been ground zero for monitoring the worldwide trend on carbon dioxide.  Devices there sample clean, crisp air that has blown thousands of miles across the Pacific Ocean, producing a record of rising carbon dioxide levels that has been closely tracked for half a century.

" .... From studying air bubbles trapped in Antarctic ice, scientists know that going back 800,000 years, the carbon dioxide level oscillated in a tight band, from about 180 ppm in the depths of the ice ages to about 280 ppm during the warm periods between.  The evidence shows that global temperature and CO2 levels are tightly linked.

"For the entire period of human civilization, roughly 8,000 years, the carbon dioxide level was roughly stable near that upper bound.  But the burning of fossil fuels has caused a 41 percent increase in the heat-trapping gas since the Industrial Revolution, a mere geological instant, and scientists say the climate is beginning to react, though they expect far greater changes in the future.  (See graph below, click to enlarge)

"Indirect measurements suggest that the last time the carbon dioxide level was this high was at least three million years ago, during an epoch called the Pliocene.  Geologic research shows that the climate then was far warmer than today, the world's ice caps were smaller, and the sea level might have been as much as 60 or 80 feet higher."

Here is an interactive map on which you can choose location and sea level rise, then observe the effect.

The Times report is conservative in implying that reaching the 400 ppm threshold is a moment of sudden illumination.  In fact, we have been steadily approaching that threshold for decades, and since at least the early 1980s climate scientists have issued warnings about the rising global temperatures, melting glaciers and ice caps, rising sea levels, and unpredictable severe weather events which we are already witnessing.

Further, other sources reveal that according to research reported in the journal Science, "Unchecked burning of fossil fuels has driven carbon dioxide to levels [at which] temperatures were 14.4 degrees Farenheit higher than today, lush forests covered the tundra, and sea levels were up to 40 meters [131 feet] higher than today."

It is a regrettable trait of our species (and of American culture in particular) to react to crisis, rather than thinking ahead or behaving proactively.  A prime example ~ the United States failure to ratify the 1997 Kyoto Protocol which set binding obligations on industrialized nations to reduce emissions of greenhouse gases.  191 nations and the European Union are members of the protocol.  Had we done so, American industries would have had a head start in developing the technology needed to operate cleanly.  Further, we have lagged behind other nations in deploying alternative, renewable energy sources (solar, wind, geothermal), and in reducing or eliminating our heavy reliance on polluting fossil fuels (coal, oil, natural gas).

So what is to be done, now that we face the monster we've created?  A climate research website called Climate Nexus published a timely graph which portrays four alternatives ~

1.  No action

• Catastrophic and unpredictable impacts on entire human population.
• Emissions continue indefinitely.  Temperatures rise more than 6 degrees Celsius (more than 16 degrees Farenheit).

2.  Delayed action

• Mass migrations from areas that are now uninhabitable.
• Very worst heat waves now widespread.
• Mass extinctions.
• Carbon dioxide concentrations rise past 700 ppm, with a warming impact of 4.5 degrees Celsius (12 degrees Farenheit).  Global emissions do not peak until 2080.

3.  Some action

• Extreme heat waves and high summer temperatures become much more common.
• Oceans acidify, harming corals and shellfish.
• More extreme weather, with damages costing much more than mitigation.
• Carbon dioxide concentration stabilizes at 550 ppm, with a warming impact of 3.6 degrees Celsius (10 degrees Farenheit).  Global emissions peak in 2040.  This could happen if all country pledges are met.

4.  Decisive action

• Extreme weather events increase in frequency and intensity.
• Sea level rise threatens some coastal cities.
• Carbon dioxide concentration eventually stabilizes around 350 ppm (considered a safe level by many) and temperature rises less than 2 degrees Celsius (3-4 degrees Farenheit).  Global emissions peak in 2020.  This would require most new energy investments to go to clean energy, and fossil fuels to be phased out.

So.  Here we are, at 400 ppm carbon dioxide in our atmosphere.  Should we continue merrily in denial, playing Russian roulette with the planet and all its life forms?  Or should we get serious in our role as stewards of the planet, and take decisive action?  I'm for the latter.  If you are too, it's time to become a militant activist.   Start by using this link to contact your elected state and federal officials, explain the urgency of the problem (the Climate Nexus graph makes a good reference), and demand that addressing climate change be placed at the top of every legislative and executive priority list.

If you wish to engage in civil protest to call attention to the damage being done by existing and proposed coal, oil, and natural gas projects, that is your right.