Carbon Virgin

Background to the Sea Level Videos. Also useful are the pages: Paleoclimate and Ice & sea level and Key Element.

The videos show the equilibrium sea level rise in the centuries to come for A] a 2^oC average global warming since 1880, and B] for the average global warming from business as usual or flat volumes over the next 30 and 40 years followed by declining annual emissions to levels consistent with 5% of current CO₂ emission volumes by the year 2100 and held at this level^L []. C] The 350ppm scenario in the videos assumes near zero CO₂ emissions within 30 or 40 years.

The calculations are based on paleoclimate research into the relationship between the atmospheric life of CO₂ , CO₂ concentrations, average , the of Antarctica and Greenland, and . [Spread sheet] and are the drivers of change^L.

Global Average Surface Temperature Change [surface waters 71% & land air 29%] from 1880 to ..... to historic comparable	Percentage Change in Earth’s Global Average Surface Temperature Base: 13.8^oC [+/-0.1^oC] in 1880	Equilibrium Sea Level Adjustment in Meters relative to 1880 + Atmospheric CO2	Size of Ice Sheets in meters of sea level rise potential once equilibrium reached	% change in global average temp of air over land surface Base: 8.5^oC in 1880. Use 1.5x uplift factor
- 4.8^oC to Last Glacial Maximum 20,000 years ago	- 29% to a global average of 9.7^oC	120 meters lower CO2 170ppm	190 meters	- 84.7% to land average of 1.3^oC
0.8^oC to 2010 link occurred already	+ 5.7% to 14.5^oC occurred already	3 meters higher CO2 393 ppm in 2012	67 meters	+14% to 9.7^oC occurred already
+1.5^oC to Eemian 125,000 years ago	+10.9% to 15.3^oC	4 to 6 m higher (perhaps 9m) link CO2 300ppm	61 to 66 meters	+26.5% to 10.75^oC
+2 to 3^oC to Pliocene 3 to 5m years ago	+ 14.5% to 15.8^oC +22% to 16.8^oC	15 to 25 meters CO2 340 - 390ppm	50 to 55 meters	+35.3% to 11.5^oC +53% to 13^oC
+4^oC to Miocene 14 to 16m yrs ago	+28.9% to 17.8^oC	30 to 45 meters CO2 450ppm	25 to 40 meters	+70.5% to 14.5^oC
+6^oC to Eocene 35 to 40m yrs ago	43.5% to 19.8^oC	60 meters+ higher CO2 550 to 650ppm	less than 10 m	+106% to 17.5^oC

The Greenland ice sheet and the seabed grounded Antarctic ice sheets, containing 25m in sea level rise potential, have never in the last 65 million years of Earth's history fully formed or even remained 50% intact when CO₂ has been 350ppm or more [Link]. Atmospheric CO₂ is 394 ppm in 2012. Atmospheric CO₂eq is approaching 500ppm. After netting out for human aerosols the CO₂eq level is just under 400ppm CO₂eq [eq=equivalent].

Sea levels have been higher for average global temperatures warmer than present climate [] for atmospheric CO₂ of 450ppm+. They were 15 to 25 meters higher for climates just 1^oC to 1.5^oC warmer than present climate for CO₂ of 340 to 380ppm. 125,000 years ago, during the Eemian period, sea levels were 4 to 6 meters [perhaps even 9m, link] higher for a global average climate just than present for CO₂ of 280ppm [Orbit change had caused this warming].

The projected rate of warming [4^oC+ CO₂ 600ppm+] for the 21^st Century under business as usual is easily 60 times faster than the rate of the 4^oC to at most 5^oC global average warming during the 8,000 year emergence from the last ice age [or 160 times faster than the PETM 55.6m years ago]. That's a 1^oC rise in global average temperatures every 26 years in the 21^st Century. In the exit from the last ice age it was a gradual 1^oC rate every 1,600 to 2,000 years, cumulating to a 4^oC to 5^oC from a 100ppm CO₂ rise in 8,000 years, and 120 meter sea level adjustment over 11.000 years.

The warming since 1970 to 2010 has been 15 times faster, and the increase in atmospheric CO₂ 120 times faster than the exit from the last ice age. The 21^st Century projected rate of CO₂ increase is 300 times faster for business as usual, and 60 times faster under the 450ppm overshoot 2^oC scenario. These abrupt changes mean accelerated change in the cryosphere, and sea levels. NASA Ice Viewer

Multi-meter sea level rise per century has often happened in paleoclimate for global average warmings 60 times slower than that forecast in the 21^st Century. [Diagrams: Antarctic Ice sheet formation, Global surface temp 65m years, 35m year sea level record]

Quotes of NASAs Head of GISS: "A CO₂ amount of order 450 ppm or larger, if long maintained, would push Earth toward the ice-free state." .... "Thus goals to limit human-made warming to 2°C are not sufficient — they are prescriptions for disaster. Link".... "The important point is that the uncertainty is not about whether continued rapid CO₂ emissions would cause large sea level rise – it is about how soon the large changes would begin. Link" [NASA GISS] J. Hansen NASA GISS Director @ TEDX 18 mins

Sea level did rise at rates of , even 4m, during the exit from the last ice age: Link. Given the speed of the heat shock we are subjecting the planet to, and the atmospheric life of CO₂, one can only accept that huge sea level rise will be compressed into narrower time frames of centuries. [Revised 21^stC Sea Level Rise forecasts].

The (ocean, permafrost, soils, forests) easily contain 50 times the sum of all carbon in the atmosphere. 100ppm of atmospheric CO₂ is equal to less than 0.5% of the surface reservoirs stores of carbon. They must only release 2% to 7% of their carbon stores to create a net 100ppm increase in CO₂by the year 3100when comparedto that in the 21st Century. It is warming which triggers the release of carbon from the biosphere. Given the pace of change, regrowth will not be able to compensate and these calculations may be overly optimistic. It could be much worse and it will certainly be no better. 1000 years of sustained warming 50 times faster than ever before on Earth is plenty of time for the ice sheets to melt.

* Incremental temperature & CO₂ change 2020 - 2098 from the UK Committee on Climate Change median A1B representation of the IPCC scenario

** Model equilibrium temperatures are dependent upon CH₄& N₂0 tracking CO₂ as in the past and sulphate aerosols declining to natural levels over time

*** Solomon et al 2009, Archer et al 2009, 40% of airborne fraction remains in air in 1,000 years for no feedbacks. Permafrost and Ocean feedbacks are 80%. Together these two sources contain 47 times the carbon that is in the atmosphere. Only some must be released as feedbacks. Mac Dougall et al 2012, Schaefer et al 2011. 100ppm = 213bn tons of carbon or just 0.5% of carbon in the land and ocean sinks.

**** If we decide to artificially reduce atmospheric CO₂ the ocean will, irrespective of temperature, release CO₂ as atmospheric CO₂ falls to maintain the partial pressure [Revelle Factor]. As a consequence and when combined with the earlier start date the true level of CO₂ that would have to be sequestered by humans from the atmosphere to return to 280 ppm is likely to be 100% larger than shown above. Once large amounts of fossil carbon are introduced to the surface reservoirs [atmosphere, ocean, surface soil & vegetation] it must be pumped back under ground to get rid of it, otherwise it is part of the main carbon cycle.

For a full explanation of above table read the end notes on this page link.

One can see in these 3 diagrams of the last 2,000 years that sea level has responded to increased temperature which was caused by increased GhGs: GHG levels, Global Temperature & Sea Level. We are on track for atmospheric CO₂ concentrations greater than 650ppm later this century which is consistent with average global temperatures being more than .

Less than 5% of global energy comes from non CO₂ producing sources. But if we want to avoid flooding our cities, we must rapidly reducing atmospheric CO₂ to 350ppm and lower, to limit global average warming to less than 1.1^oC since 1880. This means reducing our CO₂ emissions to near zero levels, within 30 to 40 years, to both prevent atmospheric CO₂ from increasing further, and to give Nature a chance to draw down the excess CO₂_. Levels are at 393ppm in 2012 - a with temperatures 1.5^oC higher than present and sea levels higher. [7 mins on 21^stC sea level ]

*UK Committee on Climate Change analysis: Emission Budget Spreadsheet, Technical appendices. IPCC Table on CO₂ & Emissions. Climate Science history & why the message does not get through: 1hr

An excellent 30m lecture on some aspects of the technicalities of SLR past and future:

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