Re: [Phys-L] carbon wars

[John Denker <jsd@av8n.com>]

On 10/05/2014 05:10 PM, Folkerts, Timothy J asked:

> What specific "utter catastrophe" do you foresee happening after the
> next 500 GT of carbon is burned (on the order of 50 years at current
> rates = ~ 1-2 K if my estimates and sources are accurate) that could
> kill the human race?

I am not an expert in this area.  I do not know exactly
what will happen, much less the details of how it will
happen.

We can however play the odds.  The question arises, how
much risk of extinction are you willing to run?
 -- Is a 50% chance of extinction acceptable?
 -- Is a 20% chance of extinction acceptable?
 -- Is a  1% chance of extinction acceptable?

One has to watch out for positive feedback effects.  There
is a long list of possibilities:
 *) The #1 most powerful greenhouse gas is water vapor.
  Increasing the temperature increases the amount of H2O
  in the atmosphere.  This further increases temperature
  ... and also increases instability i.e. the prevalence
  of violent weather.
 *) There are already "dead zones" in the ocean.  If the
  oceans die, land species are in big trouble.
 *) Collapse of antarctic ice sheets may already have passed
  the tipping point.  This process will play out over many
  decades, but may already be unstoppable.
 *) There's a lot of frozen peat in the high latitudes.  If
  this thaws, it will release humongous amounts of CO2 into 
  the atmosphere.  Again, this won't happen overnight, but
  it could be very hard to stop.
 *) et cetera.

The last time there was a sudden warming, 75% of the large
animal species died out.  Do you really want to gamble that
humans are going to be in the lucky 25%?

  It's certainly possible than humans will pull through.
  For one thing, there are genes for dwarfism in humans.
  It may be that dwarf humans will survive.

On the other hand, the fact that humans evolve slowly compared
to (say) mice or sheep (not to mention viruses) puts them at 
a tremendous disadvantage in times of stress.

Furthermore, it may be that humans will do something uniquely 
human, like waging nuclear war to punish whomever is perceived 
as causing the disaster ... thereby accelerating the extinction. 
Or they might try some well-intentioned but bone-headed geo-
engineering project that backfires.

==================

As for the "hiatus":  When I look at the global temperature 
data, I don't see any discrepancies that need explaining.
There's noise in the data, but I've seen noise before, and 
I'm not going to get excited about it.  The last 20 years 
of data is systematically /above/ the 100-year trend line, 
which tells me the warming is most likely accelerating.

The global surface temperature for August 2014 was the highest
on record, exceeding (at long last) the record set by the 
infamous 1998 spike.  Similarly the June-July-August 2104 
three-month period was the warmest on record, exceeding the 
previous record set in 1998.

FURTHERMORE a physicist once told me that temperature is not
the same thing as energy.  Let's look at a plot the data for 
the heat content of the oceans, such as the first figure here:
  http://www.realclimate.org/index.php/archives/2013/09/what-ocean-heating-reveals-about-global-warming/

Do you see a "hiatus" there?  I sure don't.

The energy data is less noisy than the temperature data, but
it is telling us the same thing.  If you keep dumping energy 
into the system, "something" is going to go kerblooey.