What is a Healthy Climate and How do we Get There From Here?
Bruce Melton PE
Climate Change Now Initiative (Nonprofit 501c3)

1.      Clean Power Plan and US Paris Climate Talks Commitment are less stringent than the Kyoto Protocol… Kyoto Protocol Era emissions reductions were born of the 1992 Rio Earth Summit. The Clean Power Plan is 32 percent below 2005 levels by 2030 (1969 levels of 4007 Gt C) vs. Kyoto at 7 percent below 1990 levels by 2012 (1984 levels of 4559 Gt C). CPP is 12 percent more stringent but 18 years behind. Kyoto commitments for Phase II were generally at 80 percent below 1990 by 2020. (The United States, South Sudan and Afghanistan were the only countries to not ratify Kyoto). The current UNFCCC commitment by the United States is 80 percent below 2005 levels by 2050, 30 years behind.  2015 Paris Climate Conference emissions reduction commitments of 80 percent by 2050 are literally 30 years later than Kyoto Protocol commitments of 80 percent by 2020.
Historical Emissions 1850 to present, World Resource Institute: (download full data)
Clean Power Plan Fact Sheet:
Kyoto Protocol Reference Manual:
Phase II Kyoto Protocol:
United States 2050 UNFCCC commitment:

2.      Emissions since the Kyoto Era… Since 1978 the U.S. has emitted as much CO2 as was emitted in the previous 228 years. Globally, since 1984 we have emitted as much CO2 as in the previous 236 years. These numbers do not include offshored emissions, or emissions made in countries other than the U.S. where the products or services created in those other countries are consumed in the U.S.
Historical Emissions 1850 to present, World Resource Institute: (download full data)

Offshored emissions WRI/CAIT:

From -

Link to World Resource Institute Climate Analysis Tool (CAIT), Click on “Type of Emissions”, then “transfer.” in 2013 the US transferred 442 Mt CO2. 

Consumptive based estimates of offshored emissions – 520 Mt CO2 in 2008:

Davis and Caldiera, Consumptive-based accounting of CO2 emissions, PNAS, March 3 2010. Figure 2 shows 520 Megatons (0.53 Gigatons) outsourced by the U.S. in 2008.

3.      Current Climate Policy Allows Continued Warming…  The IPCC’s new Representative Concentration Pathway (RCP) scenario of RCP2.6, is basically the same thing as 80 percent emissions reductions by 2050 and is described by the IPCC as a “strong mitigation scenario.” RCP2.6 has CO2 peaking at about 440 ppm between 2050 and 2060 and temperature at 1.5 degree C 30 to 40 years later. The increase of 1.6 degrees C is double the current warming since the 1700s. This increase however is the average increase. The worst-case RCP2.6 warming is 2.7 degrees C or more than triple current warming. Considering the understating nature of the IPCC consensus (See Reference 7), the upper limits should be strongly considered as a distinctly plausible. Under the average RCP2.6 modeling and 1.6 degrees of warming with aggressive emissions reductions, the concentration of CO2 in our atmosphere does not fall below today’s level until after 2150, and does not return to preindustrial era temperature until long after the year 3000. Under the most extreme RCP2.6 limits with 2.7 degrees of warming above preindustrial times, Earth’s temperature does not fall below our current temperature for well over a 1,000 years.
Meinshausen et al., The RCP greenhouse gas concentrations and their extensions from 1765 to 2300, Climatic Change, November 2011, figure 6.

4.      Two Degrees C… The 1990 work that defined 2 degrees was done for the IPCC in their efforts to put real numbers to "dangerous climate change" so that limits could be defined. Basically their task was, "How do we know when climate change becomes dangerous?" Dangerous being a relative term of course. In their efforts to be as analytical as possible and leave nothing to doubt, they developed a couple of sentences that spell out the definition of climate change with a certain temperature response (warming):

“Beyond 1.0 °C may elicit rapid, unpredictable, and non-linear responses that could lead to extensive ecosystem damage.”

"An absolute temperature limit of 2.0 °C can be viewed as an upper limit beyond which the risks of grave damage to ecosystems, and of non-linear responses, are expected to increase rapidly."

The nonlinear responses referred to are abrupt changes that are ten to 100 times greater than projected and can be associated with temperature, the rate of sea level rise, and the occurrence and intensity of extreme weather events.
Rijsberman and Swart, Targets and Indicators of Climate Change, The Stockholm Environmental Institute, 1990, page viii, last paragraph and page is first paragraph.

5.      Hansen Target Atmosphere CO2: Where Should Humanity Aim? (350 ppm)… Hansen and his team from Columbia, Yale, the French Science Institute, Versailles, Boston U, U of California, and Wesleyan, base their thinking on the relative stability of the last few thousand years where mankind evolved into a sophisticated society.  Ice sheets and sea level were relatively stable during this period, and the weather that created our agricultural bread baskets, forests, grasslands, wetlands, rivers, aquifers, deserts, and barrier islands was stable as well. A warmer climate in prehistory had radically higher (200 feet plus) sea level, and much less water in the interior of continents – conditions that would decimate our society today because of how much humanity and industry are along our coastal areas and how much of our food comes from the interior of continents.  The authors’ study of prehistoric evidence and afterwards the modeling they developed to recreate our ancient climate showed them there was as “sweet spot” in our climate that varied in temperature about 1.5 degrees C. This is the sweet spot where our civilization matured from hunter gatherers to agrarian/urban smart phone users. Above this range sea levels were hundreds of feet higher, below, we fall into an ice age. Our global temperature is currently at the upper end of this range and if we ceased all emissions today temperature would continue to rise an additional 2 degrees C. In other words, our CO2 concentration is way out ahead of temperature at 400 ppm and warming in the pipeline will slowly manifest itself over the next several decades. Hansen and his team say CO2 needs to be at 300 to 350 or somewhere around 0.5 to 1.0 degree C of warming once our climate catches up to the CO2 level, to allow it to remain in the “sweet spot.”

Hansen et al., Target Atmosphere CO2: Where should humanity aim?, Open Atmospheric Science, March 15, 2008.

6.      IPCC and Paris Climate Talks Reduce Dangerous Climate Change Threshold to 1.5 degrees C… The Paris talks saw global leaders commit to efforts to keep warming below 1.5 degrees C. A new report evaluating the risks of 1.5 degrees C warming will be prepared by the IPCC.
Guardian report in Member commitments to 1.5 degrees C:
Scoping meeting the IPCC 1.5 degree report:

7.      Conservative IPCC – (Scientific American)… “Across two decades and thousands of pages of reports, the world's most authoritative voice on climate science {the Intergovernmental Panel on Climate change (IPCC)] has consistently understated the rate and intensity of climate change and the danger those impacts represent, say a growing number of studies on the topic."
“Climate Science Predictions Prove Too Conservative,” Scientific American, December 6, 2012, first sentence.

Conservative IPCC (University of California, Santa Barbara)… Top of the abstract: “Mass media in the U.S. continue to suggest that scientific consensus estimates of global climate disruption, such as those from the Intergovernmental Panel on Climate Change (IPCC), are ‘exaggerated’ and overly pessimistic. By contrast, work on the Asymmetry of Scientific Challenge (ASC) suggests that such consensus assessments are likely to understate climate disruptions.”

Last part of the abstract: “…new scientific findings were more than twenty times as likely to support the ASC perspective than the usual framing of the issue in the U.S. mass media. The findings indicate that supposed challenges to the scientific consensus on global warming need to be subjected to greater scrutiny, as well as showing that, if reporters wish to discuss ‘‘both sides’’ of the climate issue, the scientifically legitimate ‘‘other side’’ is that, if anything, global climate disruption may prove to be significantly worse than has been suggested in scientific consensus estimates to date.”

From the bottom of the second paragraph of the Introduction on page 1: “Precisely because of the ongoing pattern of criticisms toward climate science in general, and the IPCC in particular, work on the Asymmetry of Scientific Challenge (ASC) predicts that the overall effect on science will be precisely the opposite of the usual charges in the U.S. mass media—that is, that scientific consensus estimates such as those from the IPCC should be expected to underestimate the severity of climate disruption taking place.”
Freudenburg and Muselli, Global Warming estimates, media expectations and the asymmetry of scientific challenge,  Global Environmental Change, August 2010. (This paper is backed up with 75 references.)

IPCC Conservative (University of Alberta, University of California, San Diego, College of St. Benedict/St. John's University, Princeton)… From the abstract: “Over the past two decades, skeptics of the reality and significance of anthropogenic climate change have frequently accused climate scientists of “alarmism” …  However, the available evidence suggests that scientists have in fact been conservative in their projections of the impacts of climate change.  … We suggest, therefore, that scientists are biased not toward alarmism but rather the reverse: toward cautious estimates, where we define caution as erring on the side of less rather than more alarming predictions.”

Another quote from the paper definitively spells out the authors findings on page 330, section 3.0, first sentence: “Our analysis of the available studies suggests that if a bias is operative in the work of climate scientists, it is in the direction of under-predicting, rather than over-predicting, the rate and extent of anthropogenic climate change.”

Sea level rise underestimated… From page 328, section 2.1, first paragraph: “In a 2007 article, Rahmstorf and colleagues compared projections of global mean temperature change, sea level rise, and atmospheric carbon dioxide concentration from IPCC’s Third Assessment Report (TAR) with observations made since 1973 and concluded: ‘‘Overall, these observational data underscore the concerns about global climate change. Previous projections, as summarized by IPCC, have not exaggerated but may in some respects even have underestimated the change, in particular for sea level’’ (p. 709). In the TAR, released in 2001, the IPCC predicted an average sea level rise of less than 2 mm/yr, but from 1993 to 2006, sea level actually rose 3.3 mm/yr—more than 50% above the IPCC prediction.”

Brysse et al., Climate change prediction: Erring on the side of least drama?, Global Environmental Change, February 2013. (This paper is backed up by 113 references.)  

IPCC Conservative, The Copenhagen Diagnosis… From page 328, section 2.4: “[The Copenhagen Diagnosis] reviewed ‘‘hundreds of papers . . . on a suite of topics related to human-induced climate change’’ since the drafting of AR4, and, like the NRC report, found that key changes were happening either at the same rate as, or more quickly than, anticipated. Among their key findings were that global temperature increases over the past 25 years have been consistent with model predictions of 0.19 C per decade, virtually the same rate as for the 16 years mentioned in Rahmstorf et al., 2007, while other important impacts are proceeding faster than expected, including CO2 emissions, increased rainfall in already rainy areas, continental ice-sheet melting, arctic sea-ice decline, and sea level rise. The data examined here overlap substantially with those analyzed by the Rahmstorf team, and it is noteworthy that an independent analysis by a different group of scientists comes to much the same judgment.”

Key findings of the Copenhagen Diagnosis:

i.             Rainfall has become more intense in already rainy areas, and ‘‘recent changes have occurred faster than predicted’’ (Allison et al., 2009, p. 15; see also Wentz et al., 2007; Allan and Soden, 2008; Liu et al., 2009).

ii.            Sea level rise has far exceeded predictions: ‘‘satellites show recent global average sea level rise (3.4 mm/yr over the past 15 years)—to be "80% above past IPCC predictions’’ (Allison et al., 2009, p. 7).

iii.           Surface ocean heat uptake between 1963 and 2003 was 50% higher than expected based on previous calculations. This difference helps explain why sea level rise (from thermal expansion) is also greater than expected (Allison et al., 2009, p. 35; see also Domingues et al., 2008; Bindoff et al., 2007).

iv.           Studies also show that deep ocean warming is more widespread than previously thought (Allison et al., 2009, p. 35; see also Johnson et al., 2008a,b).

v.            Summertime melting of Arctic sea-ice has ‘‘accelerated far beyond the expectations of climate models’’ (Allison et al., 2009, p. 7; see also Stroeve et al., 2007). Indeed, using unusually vivid language, the authors note that the record for previous Arctic sea ice summer minimum extent was ‘‘shattered’’ in 2007, ‘‘something not predicted by climate models . . . This dramatic retreat has been much faster than simulated by any of the climate models assessed in the IPCC AR4’’—with summer sea ice now well below the IPCC worst case scenario (Allison et al., 2009, pp. 29–30). Summer minimum sea ice was higher in subsequent years, but still fell near or below the long-term observed downward trend (which, as just noted, declines faster than the model predictions). Then, in 2012, another record minimum was set (Stroeve et al., 2007).

vi.           CO2 emissions were also tracking the high-end scenarios developed in 1999 and applied in AR4, showing that scientists’ ‘‘worst-case scenario’’ has in fact been realized (Allison et al., 2009, p. 9; see also Nakicenovic et al., 2000), for the decade before the global financial disruption. Some people have pointed out that the emissions projections were not meant to be reliable in the short term, but it is interesting to note that, so far as these data may be relevant, they fit the pattern of underestimation. Bryssa and colleagues conclude with one more very important point about the lack of inclusion of feedbacks from greenhouse gases emitted by melting permafrost on page 329, section 2.6: “One more topic will help to underscore the point. It is well accepted that certain feedbacks in the climate system, such as increased cloud cover or the Arctic ice-albedo feedback, could work to accelerate or decelerate global warming. One potentially large, positive feedback involves permafrost melting, which could release increasing amounts of greenhouse gases. The total carbon contained in permafrost has been estimated at 1672 gigatons, more than twice the amount of carbon in the atmosphere (Tarnocai et al., 2009). This means that the potential amplifying effect of greenhouse gas release from permafrost melting is enormous. Yet this feedback ‘‘has not been accounted for in any of the IPCC projections’’ (Allison et al., 2009, p. 21). This omission introduces a potentially profound bias in the climate projections—not toward overestimation of climate change, but toward its underestimation.”
Allison, et al., The Copenhagen Diagnosis, 2009: Updating the world on the Latest Climate Science, The University of New South Wales Climate Change Research Centre (CCRC), Sydney, Australia.

8.      Antarctica has begun to lose ice 100 years or more ahead of IPCC predictions… Antarctic surface mass balance (SMB) in the 2007 IPCC Report was supposed to increase, not decrease, for all scenarios, through 2100. This means that snow accumulation was supposed to be more than melt, evaporation and iceberg discharge combined: “All studies for the 21st century project that Antarctic SMB changes will contribute negatively to sea level, owing to increasing accumulation exceeding any ablation increase (see Table 10.6).”
Intergovernmental Panel on Climate Change, Fourth Assessment Report, Climate Change 2007: Working Group I: The Physical Science Basis,, Surface Mass Balance, fifth paragraph. 

The 2013 IPCC report tells us that Antarctic ice loss has almost caught up with Greenland. Summary for Policy Makers, E.3 Cryosphere, page 9, third bullet. “The average rate of ice loss from the Antarctic ice sheet has likely increased from 30 [–37 to 97] Gt yr–1 over the period 1992–2001 to 147 [72 to 221] Gt yr–1 over the period 2002 to 2011.” Greenland, second bullet: “The average rate of ice loss from the Greenland ice sheet has very likely substantially increased from 34 [–6 to 74] Gt yr–1 over the period 1992 to 2001 to 215 [157 to 274] Gt yr–1 over the period 2002 to 2011.”  

Negative Antarctic Ice mass balance since at least 1994…

Stanley et al., Antarctic ice sheet melting in the Southeast Pacific , Geophysical Research Letters, May 1, 1996, last sentence of abstract.

9.      West Antarctic Ice Sheet Collapse Warning 2015… This work out of the German National Science Institute describes marine ice sheet collapse mechanisms, and how there is a very distinct tipping point with the West Antarctic Ice Sheet where collapse becomes irreversible in about 50 years. The very important take-away from this work is that to prevent ice sheet collapse the “perturbation” that creates the warming that is responsible for ice sheet collapse, which is mostly ocean warming, must end by at the latest 2050. This means that we must return ocean temperature to its preindustrial stable temperature by 2050. The challenge here is that it is much more difficult to cool the oceans than it is the atmosphere. Figure 3 shows the model runs that define the stable state in blue.
Feldmann and Levermann, Collapse of the West Antarctic Ice Sheet after local destabilization of the Amundsen Basin, PNAS, November 17, 2015.

West Antarctic Ice Sheet collapse began shortly after 2000… Vaughan summarized the science around West Antarctic Ice Sheet Collapse beginning in 1981. While the mechanisms for ocean melt were present in publication from the early 1990s, it was not until the early 2000s that work first showed definitive evidence of thinning, grounding line retreat, and ice stream acceleration in one of the most sensitive area of West Antarctica, the Amundsen Sea Embayment. Vaughan concludes that if these symptoms are indeed precursors to collapse, then collapse has begun. From what we know today, he was absolutely correct.
Vaughan, West Antarctic Ice Sheet collapse – the fall and rise of a paradigm, Climatic Change, 2008, see the abstract.

West Antarctic Ice Sheet deteriorating rapidly (University of Texas, Austin) – physical evidence of ice shelf failure… The Amundsen Sea Embayment is a massive critical area of the West Antarctic Ice Sheet (WASI) that likely acts like a cork in a barrel. It is now thinning and retreating rapidly in a similar way as major outlet glacier in Greenland and this area is the key to fifteen to twenty feet of sea level rise. Once it is gone, the WAIS will collapse rapidly. This article documents the retreat and thinning of this “plug” in the WAIS. of particular interest are landsat images of massive rifting of the surface of the Crosson Ice Shelf in the Eastern portion of the Amundsen Sea Embayment that the authors say is evidence that this area is very unstable.
MacGregor et al., Widespread rifting and retreat of ice-shelf margins in the eastern Amundsen Sea Embayment between 1972 and 2011, Journal of Glaciology, No. 209, 2012. (Press Release)

West Antarctic Ice Sheet deteriorating rapidly (Victoria University of Wellington,  Worcester State University, University of New South Wales, University of Massachusetts) Discussion of the irreversible collapse beyond the 2 degree C warming threshold…    This work modelled disintegration of the WAIS based on IPCC scenarios and found that only RCP2.6 with something similar to 80 percent emission reductions by 2020 was capable of stopping collapse.  A compilation of quotes from the press release is enlightening: “The stakes are obviously very high—10 percent of the world’s population lives within 10 metres of present sea level. Missing the 2°C target will result in an Antarctic contribution to sea-level rise that could be up to 10 metres (33 feet) higher than today… The striking thing about these findings is that we have taken the most conservative estimates possible… In all IPCC global warming scenarios, only RCP2.6 saw Antarctic ice shelves avoid ongoing collapse. In every other case we saw significant collapse and rising sea levels continue for hundreds to thousands of years… The results suggest Antarctic ice shelf stability has a tipping point dependent on a critical temperature threshold that can lead to substantial sea level rise even if we reduce emissions after that threshold has been reached.”
Golledge et al., The multi millennial Antarctic commitment to sea level rise, Nature, October 15, 2015.

press release :

West Antarctic Ice Sheet deteriorating rapidly (University of California Jet Propulsion Lab and the California Institute of Technology)… This work looked in more detail at the thinning and retreat in the major glacier basins in the Amundsen Sea Embayment where two of the five biggest glaciers in Antarctica discharge. Of major interest was discussion of the ungrounding of the pinning points and retrograde beds of these glaciers. The pinning point is a high ridge beneath a glaciers path that slows its discharge and these glaciers have retreated behind their pinning points allowing much faster ice discharge. A retrograde bed is one that gets deeper farther inland. This characteristic creates a large zone of instability as compared to a normally sloping bed that gets higher towards the interior where and has a very small area of instability at its calving front. Most notable in the article is the final sentence of the abstract: “Upstream of the 2011 grounding line positions, we find no major bed obstacle that would prevent the glaciers from further retreat and draw down the entire basin.”

Rignot et al., Widespread, Rapid Grounding Line Retreat of Pine Island, Thwaites, Smith and Kohler Glaciers, West Antarctica From 1992 to 2011, Geophysical Research Letters, May 27, 2014.

West Antarctic Ice Sheet Deteriorating Rapidly (Scripps Institution of Oceanography, University of California, San Diego) – Ice shelf volume decline from zero to 300 cubic kilometers in 20 years… Ice shelves buttressing land ice in Antarctica have seen a dramatic decline in volume due to thinning and retreat. Between 1994 and 2013 ice loss went from almost zero to 310 cubic kilometers annually. Ice loss was led by West Antarctica which increased by 70 percent in the last ten years of the study. The loss is caused by thinning, mostly from melt below the surface. As the shelves thin, their ability to cling to surrounding land and grounded ice diminishes and ice flows faster from the interior. Part of the increase in ocean temperatures doing the melting is actually caused by increased sea ice coverage in Antarctica in recent decades. The increased sea ice itself is part of a melt water feedback where less salty (less dense) melt water floats on the surface of the ocean instead of mixing with saltier denser water below. The fresh water freezes faster and is responsible for more sea ice. The combination of increased sea ice and the fresh water cap decreases wind mixing of deep ocean waters into surface waters. This wind mixing is responsible or upwelling cold deep waters so less upwelling means that more heat is trapped in upper ocean waters. It is this upper ocean water that circulates beneath the ice shelves and causes the melt that destabilizes them and increase ice discharge. The way the water circulates is that the freshwater melt, floating on top of the denser salt water, piles up beneath a glacier on top of the salt water and flows outward. This water is replaced by warmer water that is actually sucked in by the fresh water draining out on top of the saltier water.
Paolo et al., Volume loss from Antarctic ice shelves is accelerating, Science Express, March 25, 2016.

10.   Heat extremes are happening 10 to 100 times more frequently…  Abstract: “This hot extreme, which covered much less than 1% of Earth’s surface during the base period, now typically covers about 10% of the land area.” Discussion, page 6 of 9, third paragraph: “These extreme temperatures were practically absent in the period of climatology, covering only a few tenths of one percent of the land area, but they are occurring over about 10% of global land area in recent years…. It follows that we can state, with a  high degree of confidence, that extreme anomalies such as those in Texas and Oklahoma in 2011 and Moscow in 2010 were a consequence of global warming because their likelihood in the absence of global warming was exceedingly small.”

Hansen, Sato, Ruedy, Perception of Climate Change, Proceedings of the National Academy of Science of the United States of America (PNAS), August 2012.

11.   Xcaret Reef, Yucatan Peninsula: 6.5 to 10 feet of sea level rise in possibly 10 to 24 years… During the short warm period before our last 100,000 year-long ice age that is very similar to what we are experiencing today, a reef called Xcaret on the Yucatan Peninsula was suddenly drowned. Corals are very picky about the depth of water that they grow in and the Elkhorn coral in particular was devastated by a sea level jump of 6.5 to 10 feet about 120,000 years ago. The jump came in several pulses, the largest of which was 6.5 to 10 feet. The time frame could not be determined exactly because dating materials this old is just not that accurate. The “backstepping,” literally, the reef moving back as the authors describe the drowning event, was very evident in their work as the normal coral skeletons were replaced dramatically by algal remains, indicating that suddenly, the water became too deep for the corals to survive. Even though chemical dating is not accurate enough to determine the time period of the sea level jump, the authors say that that it took place in a time frame that was one to two life spans of elkhorn coral. Because elkhorn lives 10 to 12 years, this time period could be as short as 10 to 24 years.

Blanchon, et al., Rapid sea level rise and reef back stepping at the close of the last interglacial highstand, Nature, April 2009.  First Paragraph, page 884: “During those jumps, direct measurement of rise rates shows that they exceeded 36 mm per year.” (1.2 feet per decade)

12.   Ice sheet collapse approaches prehistoric evidence…  The abstract from DeConto and Pollard states: “model coupling ice sheet and climate dynamics—including previously underappreciated processes linking atmospheric warming with hydrofracturing of buttressing ice shelves, structural collapse of marine-terminating ice cliffs, and feedback effects of a retrograde bed that gets deeper towards the interior—that is calibrated against Pliocene and Last Interglacial sea-level estimates and applied to future greenhouse gas emission scenarios. Antarctica has the potential to contribute more than three meters (10 feet) of sea-level rise by 2100 and more than 13 meter (fifty feet) by 2500, if emissions continue unabated.”
DeConto and Pollard, Contribution of Antarctica to past and future sea level rise, Nature, March 31, 2016.

13.   NOAA (RIMS) 10 feet of sea level rise by 2050 to 2060… Margaret Davidson, NOAA’s senior advisor for coastal inundation and resilience science and services, and Michael Angelina, executive director of the Academy of Risk Management and Insurance, in a conference session titled ‘Environmental Intelligence: Quantifying the Risks of Climate Change,” stated that sea level could rise by roughly 3 meters by 2050 to 2060 and that “These new findings will likely be released in the latest sets of reports on climate change due out in the next few years.” Neither addressed the cause of the change saying it was not the purpose of their talk. Further explanation is found on a self-identified blog called, that debunks climate denial propaganda. Climate Crocks posted a text obtained from Margaret Davidson of NOAA to Eric Holthaus of Slate, of which the following quote summarizes the pertinent information: “i explained the timelag between observations/data in the field and published approved scientific consensus of peer reviewed literature can be as much as 10 years. and as before, the next approved consensus will likely see a notable uptick in slr [sea level rise] guidance (based upon field work in the period ’05-13) as it will need to have been published by 2017 when the synthesis process begins anew. I am not a scientist, but hang with them a lot. referenced recent paper by Hansen et al (which suggested 3 to 5 meters by 2100 tho Hansen has been saying 5 meters for nearly 15 years.) current work re cryosphere and mass water balance which more recent area of science work. and reports regarding current field observations as mentioned and discussed by experts at various scientific mtgs on presentation rooms an corridors within past 6 months. WA [West Antarctic Ice Sheet] deteriorating rapidly… portions of shelf are now ungrounded with a lens of water underneath like Greenland but different. actually said my personal opinion was 2 to 3 meters in the next 50 years (that 2100 was not a useful frame for most people.)”

Jerger, RIMS 2016: Sea Level Rise Will Be Worse and Come Sooner, Insurance Journal, April 12, 2016., Peter Sinclair, Caution: New Sea Level Story May be a Step too Far, April 21, 2016.

14.   One meter sea level rise adaptation limit… “only a limited number of adaptation options are available for specific coastal areas if sea level exceeds a certain threshold (1 m) at the end of the century.”

IPCC 2013, Physical Science Basis, Chapter 5, Coastal Systems and Low-lying Areas, Adaptation opportunities, Constraints and Limits, Page 393, paragraph 10.

15.   Two meters of sea level rise (6.5 feet) displaces 187 million people… Though this work looks at impacts on a much warmer world, without the benefit of the new ice sheet collapse projections and without consideration of prehistoric evidence of abrupt sea level rise from ice sheet collapse (See Reference 11). This work nonetheless provides insight into impacts that are now projected to happen with much less warming. The authors also caveat heavily in the abstract that the future rate of sea level rise is largely dependent on ice sheet collapse and much better knowledge of this subject area is needed. The total population affected (187 million) will be less because the 2 meter sea level rise was projected in 2100 with a global population higher than today.
Nichols et al., Sea-level rise and its possible impacts given a beyond 4C world in the twenty-first century, Royal Society, 2011, fourth sentence, abstract.

16.   100-year storm and 1.2 meters (4 feet) of sea level rise… In 2100 with 1.2 meters (4 feet) of sea level rise, cumulative impacts from the 100-year storm around the globe will impact 310 million people and cost $210 trillion dollars. This is up to 9.3 percent of global GDP, and 4.6 percent of global population. An average person has a 60 percent chance of encountering a 100-year storm in their lifetime. From the German National Academy of science.
Hinkel et al., Coastal flood damage and adaptation costs under 21st century sea-level rise, PNAS, March 4, 2014.

17.   Direct Air Capture (DAC) of Carbon Dioxide—Whose Science is Correct?... Reports of new DAC technologies in the 2000s gave hope for a silver bullet for climate pollution. Estimates of costs on the order $20 per ton were made based on lab experiments and small scale projects. In 2011, two reports surfaced, one from the American Physical Society (APS) and the other from Massachusetts Institute of Technology (MIT). Both declared the physics behind the promising research was impossible and that costs would be $600 to $1,000 per ton or more. Because of the plausibility of a simple solution to climate pollution, these reports were widely repeated in the media. What did not make the media however, were subsequent rebuttals that showed the two negative reports only evaluated mature, WWII Era carbon capture techniques and both made fundamental errors in physics. The rebuttals used the incorrect APS and MIT work to show that the former promising research was valid.

Global Thermostat Full Scale Pilot Project: $10 per ton with waste heat… The important aspect to understand about the Global Thermostat project is that energy is the largest component of DAC and these studies used $0.07 to $0.20 per kWh, whereas today solar power is at $0.03 per kWh and continuing to fall rapidly.
Global Thermostat Graciela Chichilnisky Presentation, slide 7, $10 per ton. 

Direct air capture (DAC) costs… Goeppert et al., produced a literature summary of current DAC findings in 2012. It is important to note that considerable false propaganda has been circulated in the media about the infeasibility of DAC based on a report by the American Physical Society. Discussion of this apparent controversy is given below highlights of Geoppert 2012.

Goeppert et al., Air as the renewable carbon source of the future - CO2 Capture from the atmosphere, Energy and Environmental Science, May 1, 2012.
Abstract only:!divAbstract 

$20 per ton (just over) capture and storage… Section 5.1 paragraph 2, “using the K2CO3/KHCO3 cycle is described as being able to capture CO2 from air for less than $20 per ton. The total cost including sub-surface injection was estimated to be slightly above $20 per ton.”

$49 to $80 per ton… Section 5.1 paragraph 3: “An air capture system designed by Keith et al. using a Na/Ca cycle was estimated to cost approximately $500 per ton C ($140 per ton CO2).81,98 The authors added that about a third of this cost was related to capital and maintenance cost. Further development and optimization of the system by Carbon Engineering Ltd.113 for the effective extraction of CO2 from air resulted in the decrease of the estimated cost to $49–80 per tonne CO2.”

$30 per ton long term… Section 5.1, paragraph 5: “Lackner and co-workers developed an anionic exchange resin able to release CO2 in a moisture swing process. The cost of only the energy required per ton of CO2 collected was around $15. The initial cost of air capture including manufacturing and maintenance can be estimated at about $200 per ton of CO2. However, this cost is expected to drop considerably as more collectors are built, possibly putting CO2 capture in the $30 per ton range in the long term.”

Conclusion, first paragraph... “Despite its very low concentration of only 390 ppm, the capture of CO2 directly from the air is technically feasible. Theoretically, CO2 capture from the atmosphere would only require about 2 to 4 times as much energy as capture from flue gases, which is relatively modest considering that at the same time the CO2 concentration is decreased by roughly a factor of 250–300.”

American Physical Society Study…

Socolow et al., Direct Air Capture of CO2 with Chemicals, The American Physical Society, June 2011.

APS research revealed as significantly incomplete by Nature… Socolow 2011 evaluated existing WWII Era atmospheric removal techniques and not surprisingly found them economically infeasible to address climate pollution. New technologies were not evaluated. The media widely circulated the APS study and even though the third most important scientific journal in the world refuted APS claims—because they did not evaluate current new technologies—the damage was done; the media cycle has run its course. Today DAC is almost completely discredited in climate pollution mitigation strategies considered by policy makers and advocates, regardless of academic findings counter to this understanding.

Evaluation of APS study by Nature:

Van Norden, Sucking carbon dioxide from air too costly, say physicists, Nature, May 11, 2011.

Evaluates only mature technologies … House et al., economic and energetic analysis of capturing CO2 from ambient air, PNAS, September 2011.

Further rebuttal of APS and MIT … Holmes and Keith identifies short fallings of MIT and APS work calling out different design choices, insufficient optimization and use of higher cost processes. When new DAC technologies are evaluated, costs are at or below those of mature DAC removal technology.
Holmes and Keith, An air-liquid contactor for large-scale capture of CO2 from air, Philosophical transactions of the Royal Society A, 370, 4380-4403, 2012.

Flawed analysis of the Basic physics of enthalpy … These researchers point out a fundamental flaw in the work of APS and MIT showing direct air capture takes more energy than flue capture because of CO2 concentration: “The notion of minimum work does not apply to the capture of CO2, because the capture process is exothermic.” When CO2 is reacted with something to remove it from air or flue gas, the reaction creates heat, “is exothermic.” So instead of 400 kJ or work per mole CO2 energy required the actual energy required involves moving air over whatever process is used to remove the CO2 from the air. This is 6 kJ per mole CO2. This relationship of the actual costs of removal of CO2 from the atmosphere being 1.5 percent of the costs suggested by APS and MIT corresponds very well to the costs assumed by research evaluating new technologies of +/- $20 per ton. It is important to note that the cost of regenerating the chemicals used to capture the CO2, whether for flue gas or atmospheric capture, is identical.

Realff and Eisenberger, Flawed analysis of the possibility of air capture, June 19, 2012.

18.   Carbon Nano Fibers… Carbon dioxide captured directly from the sky can be used to create carbon nanofibers, a very advanced material that could be used to build almost anything on Earth. Productions costs are similar to that of aluminum and the carbon fibers have a value 1,000 times that of aluminum.
Ren et al., One-Pot Synthesis of Carbon Nanofibers from CO2,American Chemical Society, August 3, 2015.       

19.   Positive energy generation with fuel cell flue gas carbon capture… Traditional flue gas capture technology requires energy to run. This new technology generates additional energy, it does not require that part of the generation of fossil fuel facility be used to clean up the carbon pollution it generates.