Dnarever wrote on May 8
th, 2015 at 7:21am:
BatteriesNotIncluded wrote on May 8
th, 2015 at 12:37am:
gizmo_2655 wrote on May 8
th, 2015 at 12:04am:
Since the Co2 levels were above 400 ppm 100,000 years, without human industry or action (and during a Glaciation) why are you so sure that 400 ppm of Co2 has anything to do with the recent warming or was even mostly caused by human industry??
Correlation
Correct, every time in the past that one of the greenhouse gasses were measured to be high the event correlated to a warm period.
Co2 has anything to do with the recent warming or was even mostly caused by human industry?
CO2 levels were fairly constant for many centuries, From the industrial revolution till today we have been pumping billions of tons of CO2 into the atmosphere.
Do you really think that increasing levels of CO2 in the atmosphere coinciding with us pumping billions of tons of CO2 into the atmosphere is just a crazy coincidence.
C-14 is produced from C-12 in the biosphere by cosmic radiation. Fossil fuels have been buried shielded from cosmic radiation long enough to have all their C-14 decayed to C-12
if you look at a graph of change in C-14 over time, you will see that there is a decrease in the fraction of C-14 (relative to C-12) and this means that much of the CO2 added to the earths atmosphere is made up of Carbon which is depleted of the C-14 isotope
So, this is very strong evidence that the increase in atmospheric CO2 concentration is due to the combustion of fossil fuels.
This coincidence that you speak of, has left a very distinct isotopic marker which can be measured
there is no doubt that the increase in atmospheric CO2 levels are human generated (fossil fuel combustion and deforestation)
(in any case, a simple mass balance will tell you how much CO2 has been produced by human activities over the past century or so, and this CO2 has gone somewhere hasnt it folks)
https://tallbloke.files.wordpress.com/2013/08/14cratio.png Just sayin... do you have anything younger for a graph. Anybody do any papers after the 1950's