A Note on the occasion of passing 400 ppmv atmospheric CO2 and a possible new approach

   Recently it was in the environmental and climate change news that the concentration of CO2 in the atmosphere surpassed 400 parts per million volume (ppmv).  Great that the mainstream media covered this unhappy milestone, but to hear some of the news anchors talking about it, you would think that it came as surprise, like an especially intense heat wave that will stick around and then go away again.  Actually, it was entirely predictable, based on the amount of CO2 we are emitting and the way the atmosphere responds.
   The countries of the world emit a lot of CO2 each year.  Not all of it gets reabsorbed, so the ppmv figure goes up.  It used to be rising at around 3 ppmv per year back when we crossed the 350 ppmv threshold, but  the amount of CO2 emitted each year has been going up (and not down as we would like in order to protect the climate).  So now the rate of rise is about 4 ppmv per year.  In 2010 we were at 388; 3 years go by and it rises by 3 x 4 = 12, so hey presto we get to 400.  If we don't start curbing the global emissions rate -- not just for a subset of countries, but for the entire world community -- at the rate of 4 per year we'd surpass 450 ppmv 12 or 13 years from now, in 2025 or 2026.  Average global temperature bounces around more, but the general trend is up there too.
   Obviously this news is disheartening, but so that I don't go out on a gloomy note, maybe there is a possible solution hidden in these numbers, a new way to attack the problem.  President Obama talks about 80% reduction by 2050, and Bill McKibben talks about returning the level to 350 ppmv, but what if we start with a stepping stone toward those more distant goals: In the last 20 years, all of the years but two have had MORE emissions than in the previous year, and both of those coincided with worldwide economic recessions.  So what if we pick a year very soon in the future, and make sure the WORLD emissions in that year are LESS than they were the year before.  If we succeed with that one year in lowering emissions, we go for lower emissions in the next year, and the year after that...maybe we need to learn how to walk before we can learn how to run?