Comments 1 to 6:

1. Trevor_S at 10:17 AM on 4 June, 2017

   So where is all this CO2 coming from ? The IEA keeps reassuring us and folk like Stefan Rahmstorf use this data to suggest athrophogenic emisions have 'flatlined' for the last three years, for example here.. is it we're being misled about anthro emisions, as suggested here backed up by a real world example here ? or are sinks finally giving their CO2 up ie old anthro CO2 emissions coming back to haunt us, we have no El Nino to blame 

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2. Tom Curtis at 11:13 AM on 4 June, 2017

   Trevor_S @1, CO2 emissions from the combustion of fossil fuels have indeed flatlined:

   

   That does not include emissions from cement manufacture, and nor does it include emissions from LUC.  It is, therefore, quite possible that total anthropogenic emissions have continued to rise.  (Certainly emissions from cement manufacture are likely to have done so.)

   More importantly, a plateau in emissions still means anthropogenic CO2 in the atmosphere is increasing.  A plateau will only mean the increase is at a constant rate rather than at an accelerating rate as has been the case prior to 2014.

   Finally, the three years of the fossil fuel emissions plateau have also, each set a new Global Mean Surface Temperature record.  With higher temperatures comes a reduced rate of absorption of CO2 by the ocean, and consequently a rise in CO2 concentration.  This factor will average out with slower rises in concentration in likely neutral or La Nina years in the near future.

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3. Art Vandelay at 14:37 PM on 4 June, 2017

   Some good news in that data though. The annual increase is half that of the previous year, and a levelling off of global CO2 emissions means that the projected annual percentage increase will continue to decelerate. 

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4. longjohn119 at 15:13 PM on 4 June, 2017

   When you denude a forest you release tons of Carbon .... when you plow fields you release tons of Carbon .... However the largest increase is likely due to thawing tundra and the release of CO2 trapped in ice that's now gone. 

   It's a classic positive feedback mechanism only this time it run in reverse with CO2 leading and Temperature following whereas under natural conditions the Temperature leads and the CO2 levels follow as tundra thaws and releases Carbon. The Feedback mechanism works as such More CO2 = more warming which causes more CO2 to be released which causes even more warming which causes even more CO2 to be released .... Lather rinse repeat until you go into a runaway feedback condition AKA Tipping Point or something catastrophic happens such as a large meteor strike or a shift in the Earth's axis to make break the feedback loop and lower temperatures

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5. Daniel Bailey at 22:08 PM on 4 June, 2017

   Not quite:

   "With the more realistic physics in the Russell model the runaway water vapor feedback that exists with idealized concepts does not occur. However, the high climate sensitivity has implications for the habitability of the planet, should all fossil fuels actually be burned.

   Furthermore, we show that the calculated climate sensitivity is consistent with global temperature and CO2 amounts that are estimated to have existed at earlier times in Earth's history when the planet was ice-free.

   One implication is that if we should "succeed" in digging up and burning all fossil fuels, some parts of the planet would become literally uninhabitable, with some time in the year having wet bulb temperature exceeding 35°C.

   At such temperatures, for reasons of physiology and physics, humans cannot survive, because even under ideal conditions of rest and ventilation, it is physically impossible for the environment to carry away the 100 W of metabolic heat that a human body generates when it is at rest. Thus even a person lying quietly naked in hurricane force winds would be unable to survive.

   Temperatures even several degrees below this extreme limit would be sufficient to make a region practically uninhabitable for living and working.

   The picture that emerges for Earth sometime in the distant future, if we should dig up and burn every fossil fuel, is thus consistent with that depicted in "Storms" — an ice-free Antarctica and a desolate planet without human inhabitants"

   LINK

   So no runaway. But Hansen notes that it won't take a runaway to basically completely eradicate civilization as we know it.

   Further, unlike the simple example of positive feedback we learned in high school, the increase from every round of feedback gets smaller and smaller, in the case of the enhanced greenhouse effect. It is a significant factor in the overall warming, but it does NOT lead to a "runaway" trajectory for temperature.

   LINK

   LINK

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6. knaugle at 03:22 AM on 7 June, 2017

   #1
   There is a clear misconception among many that its the INCREASE in fossil fuel emissions that is causing CO2 to increase.  However, if tomorrow emissions were cut in half, it simply means the year over year increase in CO2 would decline to about 1 ppm/yr from 2 ppm/yr.  That's because, correct me if I'm wrong, burning coal and oil and nat'l gas is not part of the natural carbon cycle when viewed in human time frames.  So there is only a small connection to El Nino.  Test this by removing the El Nino and La Nina years from the data and noting that not much changes in the past 50 years.  The Keeling curve remains pretty steady.

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