Seeing the environmental forest

Humanity is in trouble with climate change.  A recent article in Vox by David Roberts came to that conclusion.  It begins with "There has always been an odd tenor to discussions among climate scientists, policy wonks, and politicians, a passive-aggressive quality, and I think it can be traced to the fact that everyone involved has to dance around the obvious truth, at risk of losing their status and influence. The obvious truth about  global warming is this: barring miracles, humanity is in for some awful shit."  The basis for that conclusion?  Total carbon emissions to date, which are closely following the RCP 8.5 curve from the IPCC. That black curve is emissions to date.  We as a civilization are on track to take carbon dioxide levels to around 1000 ppm by 2100 AD.  The 12-month moving average of atmospheric CO 2 levels shows that we're already at 398.83 and still accelerating upward. That locks us into at least 1.53ºC of total...

This is a response to those who try to claim that global warming won't be so bad.  The gist of their argument is that since life thrived in the Mesozoic when CO 2 was ~2400 ppmv and temperatures 8ºC warmer, climate change today isn't anything to be worried about.  Unfortunately, this argument ignores some very basic facts about biology and physics.  Here is some of what they're ignoring. 1) First, thanks to those individuals for accidentally confirming the relationship between CO 2 and global temperature, as well as modern estimates of climate sensitivity.  At modern solar radiation levels and with climate sensitivity at 0.809 W/m 2 , the equilibrium climate model predicts that with CO 2 at 2400 ppmv, global temperatures would rise by 9.3ºC above pre-industrial temperatures.  Factor in a weaker sun back in the Mesozoic and you get the 8ºC rise experienced from 2400 ppmv CO 2 back then ( Royer 2006 ).  Got to love it when those who dismiss science scor...

President Obama in his State of the Union address praised his "all of the above" energy strategy.  What he left out is that "all of the above" is a recipe for disastrous climate change. The 12-month running mean for Mauna Loa CO 2 levels is currently at 396.18 ppmv. With a climate sensitivity of 0.809ºC/W/m 2 (3ºC per doubling CO 2 ), that translates to warming of ΔT = λΔF = λ*[5.35 W/m 2 * ln(C/C 0 )] ΔT = 0.809ºC/W/m 2 * [5.35 W/m 2 * ln(396.18 ppmv/280 ppmv)] ΔT = 1.50ºC above pre-industrial levels with just the CO 2 levels of today.  However, that climate sensitivity value is just the 100-year value.  At longer time spans (i.e. 1,000 years), sensitivity is actually closer 1.618ºC/W/m 2 .  That means that at today's CO 2 levels, we're already committed to 3ºC of warming over the next millennium.  The key phrase?  "At today's CO 2 levels."  And that's the main problem I have with how President Obama is approaching the...