Changing a binary climate argument into understanding the issues

Last month Geoff Chambers posted “Who’s Binary, Us or Them? Being at cliscep the question was naturally about whether sceptics or alarmists were binary in their thinking. It reminded me about something that went viral on youtube a few year’s ago. Greg Craven’s The Most Terrifying Video You’ll Ever See.

To his credit, Greg Craven in introducing both that human-caused climate change can have a trivial impact recognize that mitigating climate (taking action) is costly. But for the purposes of his decision grid he side-steps these issues to have binary positions on both. The decision is thus based on the belief that the likely consequences (costs) of catastrophic anthropogenic global warming then the likely consequences (costs) of taking action. A more sophisticated statement of this was from a report commissioned in the UK to justify the draconian climate action of the type Greg Craven is advocating. Sir Nicholas (now Lord) Stern’s report of 2006 (In the Executive Summary) had the two concepts of the warming and policy costs separated when it claimed

Using the results from formal economic models, the Review estimates that if we don’t act, the overall costs and risks of climate change will be equivalent to losing at least 5% of global GDP each year, now and forever. If a wider range of risks and impacts is taken into account, the estimates of damage could rise to 20% of GDP or more. In contrast, the costs of action – reducing greenhouse gas emissions to avoid the worst impacts of climate change – can be limited to around 1% of global GDP each year.

Craven has merely simplified the issue and made it more binary. But Stern has the same binary choice. It is a choice between taking costly action, or suffering the much greater possible consequences.  I will look at the policy issue first.

Action on Climate Change

The alleged cause of catastrophic anthropogenic global warming is (CAGW) is human greenhouse gas emissions. It is not just some people’s emissions that must be reduced, but the aggregate emissions of all 7.6 billion people on the planet. Action on climate change (i.e. reducing GHG emissions to near zero) must therefore include all of the countries in which those people live. The UNFCCC, in the run-up to COP21 Paris 2015, invited countries to submit Intended Nationally Determined Contributions (INDCs). Most did so before COP21, and as at June 2018, 165 INDCs have been submitted, representing 192 countries and 96.4% of global emissions. The UNFCCC has made them available to read. So these intentions will be sufficient “action” to remove the risk of CAGW? Prior to COP21, the UNFCCC produced a Synthesis report on the aggregate effect of INDCs. (The link no longer works, but the main document is here.) They produced a graphic that I have shown on multiple occasions of the gap between policy intentions on the desired policy goals. A more recent graphic is from the UNEP Emissions Gap Report 2017, published last October and

Figure 3 : Emissions GAP estimates from the UNEP Emissions GAP Report 2017

In either policy scenario, emissions are likely to be slightly higher in 2030 than now and increasing, whilst the policy objective is for emissions to be substantially lower than today and and decreasing rapidly. Even with policy proposals fully implemented global emissions will be at least 25% more, and possibly greater than 50%, above the desired policy objectives. Thus, even if proposed policies achieve their objective, in Greg Craven’s terms we are left with pretty much all the possible risks of CAGW, whilst incurring some costs. But the “we” is for 7.6 billion people in nearly 200 countries. But the real costs are being incurred by very few countries. For the United Kingdom, with the Climate Change Act 2018 is placing huge costs on the British people, but future generations of Britain’s will achieve very little or zero benefits.

Most people in the world live in poorer countries that will do nothing significant to constrain emissions growth if it that conflicts with economic growth or other more immediate policy objectives. In terms of the some of the most populous developing countries, it is quite clear that achieving the policy objectives will leave emissions considerably higher than today. For instance, China‘s main aims of peaking CO2 emissions around 2030 and lowering carbon emissions per unit of GDP in 2030 by 60-65% compared to 2005 by 2020 could be achieved with emissions in 2030 20-50% higher than in 2017. India has a lesser but similar target of reducing emissions per unit of GDP in 2030 by 30-35% compared to 2005 by 2020. If the ambitious economic growth targets are achieve, emissions could double in 15 years, and still be increasing past the middle of the century. Emissions in Bangladesh and Pakistan could both more than double by 2030, and continue increasing for decades after.

Within these four countries are over 40% of the global population. Many other countries are also likely to have emissions increasing for decades to come, particularly in Asia and Africa. Yet without them changing course global emissions will not fall.

There is another group of countries that are have vested interests in obstructing emission reduction policies. That is those who are major suppliers of fossil fuels. In a letter to Nature in 2015, McGlade and Ekins (The geographical distribution of fossil fuels unused when limiting global warming to 2°C) estimate that the proven global reserves of oil, gas and coal would produce about 2900 GtCO2e. They further estimate that the “non-reserve resources” of fossil fuels represent a further 8000 GtCO2e of emissions. The estimated that to constrain warming to 2C, 75% of proven reserves, and any future proven reserves would need to be left in the ground. Using figures from the BP Statistical Review of World Energy 2016 I produced a rough split by major country.

Figure 4 : Fossil fuel Reserves by country, expressed in terms of potential CO2 Emissions

Activists point to the reserves in the rich countries having to be left in the ground. But in the USA, Australia, Canada and Germany production of fossil fuels is not a major part of the economy. Ceasing production would be harmful but not devastating. One major comparison is between the USA and Russia. Gas and crude oil production are similar volumes in both countries. But, the nominal GDP of the US is more than ten times that of Russia. The production of both countries in 2016 was about 550 million tonnes or 3900 million barrels. At $70 a barrel that is around $275bn, equivalent to 1.3% of America’s GDP and 16% of Russia’s. In gas, prices vary, being very low in the highly competitive USA, and highly variable for Russian supply, with major supplier Gazprom acting as a discriminating monopolist. But America’s revenue is likely to be less than 1% of GDP and Russia’s equivalent to 10-15%. There is even greater dependency in the countries of the Middle East. In terms of achieve emissions targets, what is trying to be achieved is the elimination of the major source of the countries economic prosperity in a generation, with year-on-year contractions in fossil fuel sales volumes.

I propose that there are two distinct groups of countries that appear to have a lot lose from a global contraction in GHG emissions to near zero. There are the developing countries who would have to reduce long-term economic growth and the major fossil fuel-dependent countries, who would lose the very foundation of their economic output in a generation. From the evidence of the INDC submissions, there is now no possibility of these countries being convinced to embrace major economic self-harm in the time scales required. The emissions targets are not going to be met. The emissions gap will not be closed to any appreciable degree.

This leaves Greg Craven’s binary decision option of taking action, or not, as irrelevant. As taking action by a country will not eliminate the risk of CAGW, pursuing aggressive climate mitigation policies will impose net harms wherever they implemented. Further, it is not the climate activists who are making the decisions, but policy-makers countries themselves. If the activists believe that others should follow another path, it is them that must make the case. To win over the policy-makers they should have sought to understand their perspectives of those countries, then persuade them to accept their more enlightened outlook. The INDCs show that the climate activists gave failed in this mission. Until such time, when activists talk about the what “we” are doing to change the climate, or what “we” ought to be doing, they are not speaking about

But the activists have won over the United Nations, those who work for many Governments and they dominate academia. For most countries, this puts political leaders in a quandary. To maintain good diplomatic relations with other countries, and to appear as movers on a world stage they create the appearance of taking significant action on climate change for the outside world. On the other hand they are serving their countries through minimizing the real harms that imposing the policies would create. Any “realities” of climate change have become largely irrelevant to climate mitigation policies.

The Risks of Climate Apocalypse

Greg Craven recognized a major issue with his original video. In the shouting match over global warming who should you believe? In How it all Ends (which was followed up by further videos and a book) Craven believes he has the answer.

Figure 5 : Greg Craven’s “How it all Ends”

It was pointed out that the logic behind the grid is bogus. As in Devil’s advocate guise Craven says at 3:50

Wouldn’t that grid argue for action against any possible threat, no matter how costly the action or how ridiculous the threat? Even giant mutant space hamsters? It is better to go broke building a load of rodent traps than risk the possibility of being hamster chow. So this grid is useless.

His answer is to get a sense of how likely the possibility of global warming being TRUE or FALSE is. Given that science is always uncertain, and there are divided opinions.

The trick is not to look at what individual scientists are saying, but instead to look at what the professional organisations are saying. The more prestigious they are, the more weight you can give their statements, because they have got huge reputations to uphold and they don’t want to say something that later makes them look foolish. 

Craven points to the “two most respected in the world“. The National Academy of Sciences (NAS) and the American Association for the Advancement of Science (AAAS). Back in 2007 they had “both issued big statements calling for action, now, on global warming“.  The crucial question from scientists (that is people will a demonstrable expert understanding of the natural world) is not for political advocacy, but whether their statements say their is a risk of climate apocalypse. These two bodies still have statements on climate change.

National Academy of Sciences (NAS) says

There are well-understood physical mechanisms by which changes in the amounts of greenhouse gases cause climate changes. The US National Academy of Sciences and The Royal Society produced a booklet, Climate Change: Evidence and Causes (download here), intended to be a brief, readable reference document for decision makers, policy makers, educators, and other individuals seeking authoritative information on the some of the questions that continue to be asked. The booklet discusses the evidence that the concentrations of greenhouse gases in the atmosphere have increased and are still increasing rapidly, that climate change is occurring, and that most of the recent change is almost certainly due to emissions of greenhouse gases caused by human activities.

Further climate change is inevitable; if emissions of greenhouse gases continue unabated, future changes will substantially exceed those that have occurred so far. There remains a range of estimates of the magnitude and regional expression of future change, but increases in the extremes of climate that can adversely affect natural ecosystems and human activities and infrastructure are expected.

Note, this is conjunction with the Royal Society, which is arguably is (or was) the most prestigious  scientific organisation of them all. It is what not said that is as important as what is actually said. They are saying that there is a an expectation that extremes of climate could get worse. There is nothing that solely backs up the climate apocalypse, but a range of possibilities, including changes somewhat trivial on a global scale. The statement endorses a spectrum of possible positions that undermines the binary TRUE /FALSE position on decision-making.

The RS/NAS booklet has no estimates of the scale of possible climate catastrophism to be avoided. Point 19 is the closest.

Are disaster scenarios about tipping points like ‘turning off the Gulf Stream’ and release of methane from the Arctic a cause for concern?

The summary answer is

Such high-risk changes are considered unlikely in this century, but are by definition hard to predict. Scientists are therefore continuing to study the possibility of such tipping points beyond which we risk large and abrupt changes.

This appears not to support Stern’s contention that unmitigated climate change will costs at least 5% of global GDP by 2100. Another context of the back-tracking on potential catastrophism is to to compare with  Lenton et al 2008 – Tipping elements in the Earth’s climate system. Below is a map showing the the various elements considered.

Figure 6 : Fig 1 of Lenton et al 2008, with explanatory note.

Of the 14 possible tipping elements discussed, only one makes it into the booklet six years later. Surely if the other 13 were still credible more would have been included in booklet, and less on documenting trivial historical changes.

American Association for the Advancement of Science (AAAS) has a video

Figure 7 : AAAS “What We Know – Consensus Sense” video


It starts with the 97% Consensus claims. After asking the listener on how many,  Marshall Sheppard, Prof of Geography at Univ of Georgia states.

The reality is that 97% of scientists are pretty darn certain that humans are contributing to the climate change that we are seeing right now and we better do something about it to soon.

There are two key papers that claimed a 97% consensus. Doran and Zimmerman 2009 asked two questions,

1. When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?

2. Do you think human activity is a significant contributing factor in changing mean global temperatures?

The second of these two responses was answered in the affirmative by 77 of 79 climate scientists. This was reduced from 3146 responses received. Read the original to find out why it was reduced.

Dave Burton has links to a number of sources on these studies. A relevant quote on Doran and Zimmerman is from the late Bob Carter

Both the questions that you report from Doran’s study are (scientifically) meaningless because they ask what people “think”. Science is not about opinion but about factual or experimental testing of hypotheses – in this case the hypothesis that dangerous global warming is caused by human carbon dioxide emissions.

The abstract to Cook et al. 2013 begins

We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics ‘global climate change’ or ‘global warming’. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming. 

Expressing a position does not mean a belief. It could be an assumption. The papers were not necessarily by scientists, but merely authors of academic papers that involved the topics ‘global climate change’ or ‘global warming’. Jose Duarte listed some of the papers that were included in the survey, along with looking at some that were left out.

Neither paper asked a question concerning belief in future climate catastrophism. Sheppard does not make clear the scale of climate change trends from the norm, so the human-caused element could be insignificant. The 97% consensus does not include the policy claims.

The booklet is also misleading as well in the scale of changes. For instance on sea-level rise it states.

Over the past two decades, sea levels have risen almost twice as fast as the average during the twentieth century.

You will get that if you compare the tide gauge data with the two decades of satellite data. The question is whether those two sets of data are accurate. As individual tide gauges do not tend to show acceleration, and others cannot find statistically significant acceleration, the claim seems not to be supported.

At around 4.15 in the consensus video AAAS CEO Alan I. Leshner says

America’s leaders should stop debating the reality of climate change and start deciding the best solutions. Our What we Know report makes clear that climate change threatens us at every level. We can reduce the risk of global warming to protect out people, businesses and communities from harm. At every level from our personal and community health, our economy and our future as a global leader.  Understanding and managing climate change risks is an urgent problem. 

The statement is about combating the potential risks from CAGW. The global part of global warming is significant for policy. The United States share of global emissions is around 13% of global emissions. That share has been falling as America’s emissions have been falling why the global aggregate emissions have been rising. The INDC submission for the United States aimed as getting US emissions in 2025 at 26-28% of 2005 levels, with a large part of that reduction already “achieved” when the report was published. The actual policy difference is likely to be less than 1% of global emissions. So any reduction in risks with respect to climate change seems to be tenuous. A consensus of the best scientific minds should have been able to work this out for themselves.

The NAAS does not give a collective expert opinion on climate catastrophism. This is shown by the inability to distinguish between banal opinions and empirical evidence for a big problem. This is carried over into policy advocacy, where they fail to distinguish between the United States and the world as a whole.


Greg Laden’s decision-making grid is inapplicable to real world decision-making. The decision whether to take action or not is not a unitary one, but needs to be taken at country level. Different countries will have different perspectives on the importance of taking action on climate change relative to other issues. In the real world, the proposals for action are available. In aggregate they will not “solve” the potential risk of climate apocalypse. Whatever the actual scale of CAGW, countries who pursue expensive climate mitigation policies are likely to make their own people worse off than if they did nothing at all.

Laden’s grid assumes that the costs of the climate apocalypse are potentially far greater than the costs of action, no matter how huge. He tries to cut through the arguments by getting the opinions from the leading scientific societies. To put it mildly, they do not currently provide strong scientific evidence for a potentially catastrophic problem. The NAS / Royal Society suggest a range of possible climate change outcomes, with only vague evidence for potentially catastrophic scenarios. It does not seem to back the huge potential costs of unmitigated climate change in the Stern Review. The NAAAS seems to provide vague banal opinions to support political advocacy rather than rigorous analysis based on empirical evidence that one would expect from the scientific community.

It would appear that the binary thinking on both the “science” and on “policy” leads to a dead end, and is leading to net harmful public policy.

What are the alternatives to binary thinking on climate change?

My purpose in looking at Greg Laden’s decision grid is not to destroy an alternative perspective, but to understand where the flaws are for better alternatives. As a former, slightly manic, beancounter, I would (like the Stern Review  and William Nordhaus) look at translating potential CAGW into costs. But then weight it according to a discount rate, and the strength of the evidence. In terms of policy I would similarly look at the likely expected costs of the implemented policies, against the actual expected harms foregone. As I have tried to lay out above, the costs of policy and indeed the potential costs of climate change are largely subjective. Further, those implementing policies might be boxed in by other priorities and various interest groups jostling for position.

But what of the expert scientist who can see the impending on-coming catastrophes to which I am blind and to which climate mitigation will be useless? It is to endeavor to pin down the where, when, type and magnitude of potential changes to climate. With this information ordinary people can adjust their plans. The challenge for those who believe there are real problems is to focus on the data from the natural world and away from inbuilt biases of the climate community. But the most difficult part is from such methods they may lose their beliefs, status and friends.

First is to obtain some perspective. In terms of the science, it is worth looking at the broad range of  different perspectives on the Philosophy of Science. The Stanford Encyclopedia of Philosophy article on the subject is long, but very up to date. In the conclusions, the references to Paul Hoyningen-Huene’s views on what sets science apart seems to be a way out of consensus studies.

Second, is to develop strategies to move away from partisan positions with simple principles, or contrasts, that other areas use. In Fundamentals that Climate Science Ignores I list some of these.

Third, in terms of policy, it is worthwhile having a theoretical framework in which to analyze the problems. After looking at Greg Craven’s video’s in 2010, I developed a graphical analysis that will be familiar to people who have studied Marshallian Supply and Demand curves of Hicksian IS-LM. It is very rough at the edges, but armed with it you will not fall in the trap of thinking like the AAAS that US policy will stop US-based climate change.

Fourth, is to look from other perspectives. Appreciate that other people might have other perspectives that you can learn from. Or alternatively they may have entrenched positions which, although you might disagree with, are powerless to overturn. It should then be possible to orientate yourself, whether as an individual or as part of a group, towards aims that are achievable.

Kevin Marshall

Sea Level Rise Acceleration as a sign of Impending Climate Apoclaypse

Global warming alarmism first emerged in the late 1980s, three decades ago. Put very simply, the claim is that climate change, resulting from human-caused increases in trace gases, is a BIG potential problem. The BIG solution is to control reduce global greenhouse gas emissions through a co-ordinated global action. The actual evidence shows a curious symmetry. The proponents of alarmism have failed to show that rises in greenhouse gas levels are making non-trivial difference on a global scale, and the aggregate impact of the policy proposals on global emissions, if fully implemented, will make a trivial difference to global emissions pathways. The Adoption of the Paris Agreement communique paragraph 17 clearly states the failure. My previous post puts forward reasons why the impact of mitigation policies will remain trivial.

In terms of an emerging large problem, the easiest to visualize, and the most direct impact from rising average temperatures is rising sea levels. Rising temperatures will lead to sea level rise principally through meltwater from the polar ice-caps and thermal expansion of the oceans. Given that sea levels have been rising since the last ice age, if a BIG climate problem is emerging then it should be detectable in accelerating sea level rise. If the alarmism is credible, then after 30 years of failure to implement the BIG solution, the unrelenting increases in global emissions and the accelerating rise in CO2 levels for decades, then there should be a clear response in terms of acceleration in the rate of sea level rise.

There is a strong debate as to whether sea-level rise is accelerating or not. Dr. Roy Spencer at WUWT makes a case for there being mild acceleration since about 1950. Based on the graph below (from Church and White 2013) he concludes:-

The bottom line is that, even if (1) we assume the Church & White tide gauge data are correct, and (2) 100% of the recent acceleration is due to humans, it leads to only 0.3 inches per decade that is our fault, a total of 2 inches since 1950.

As Judith Curry mentioned in her continuing series of posts on sea level rise, we should heed the words of the famous oceanographer, Carl Wunsch, who said,

“At best, the determination and attribution of global-mean sea-level change lies at the very edge of knowledge and technology. Both systematic and random errors are of concern, the former particularly, because of the changes in technology and sampling methods over the many decades, the latter from the very great spatial and temporal variability. It remains possible that the database is insufficient to compute mean sea-level trends with the accuracy necessary to discuss the impact of global warming, as disappointing as this conclusion may be.”

In metric, the so-called human element of 2 inches since 1950 is 5 centimetres. The total in over 60 years is less than 15 centimetres. The time period for improving sea defences to cope with this is way beyond normal human planning horizons. Go to any coastal strip with sea defences, such as the dykes protecting much of the Netherlands, with a measure and imagine increasing those defences by 15 centimetres.

However, a far more thorough piece is from Dave Burton (of in three comments. Below is his a repost of his comments.

Agreed. On Twitter, or when sloppy and in a hurry, I say “no acceleration.” That’s shorthand for, “There’s been no significant, sustained acceleration in the rate of sea-level rise, over the last nine or more decades, detectable in the measurement data from any of the longest, highest-quality, coastal sea-level records.” Which is right.

That is true at every site with a very long, high-quality measurement record. If you do a quadratic regression over the MSL data, depending on the exact date interval you analyze, you may find either a slight acceleration or deceleration, but unless you choose a starting date prior to the late 1920s, you’ll find no practically-significant difference from perfect linearity. In fact, for the great majority of cases, the acceleration or deceleration doesn’t even manage statistical significance.

What do I mean by “practically-significant,” you might wonder? I mean that, if the acceleration or deceleration continued for a century, it wouldn’t affect sea-level by more than a few inches. That means it’s likely dwarfed by common coastal processes like vertical land motion, sedimentation, and erosion, so it is of no practical significance.

For instance, here’s one of the very best Pacific tide gauges. It is at a nearly ideal location (mid-ocean, which minimizes ENSO effects), on a very tectonically stable island, with very little vertical land motion, and a very trustworthy, 100% continuous, >113-year measurement record (1905/1 through 2018/3):

As you can see, there have been many five-year to ten-year “sloshes-up” and “sloshes-down,” but there’s been no sustained acceleration, and no apparent effect from rising CO2 levels.

The linear trend is +1.482 ±0.212 mm/year (which is perfectly typical).

Quadratic regression calculates an acceleration of -0.00539 ±0.01450 mm/yr².

The minus sign means deceleration, but it is nowhere near statistically significant.

To calculate the effect of a century of sustained acceleration on sea-level, you divide the acceleration by two, and multiply it by the number of years squared, 100² = 10,000. In this case, -0.00539/2 × 10,000 = -27 mm (about one inch).

That illustrates a rule-of-thumb that’s worth memorizing: if you see claimed sea-level acceleration or deceleration numbers on the order of 0.01 mm/yr² or less, you can stop calculating and immediately pronounce it practically insignificant, regardless of whether it is statistically significant.

However, the calculation above actually understates the effect of projecting the quadratic curve out another 100 years, compared to a linear projection, because the starting rate of SLR is wrong. On the quadratic curve, the point of “average” (linear) trend is the midpoint, not the endpoint. So to see the difference at 100 years out, between the linear and quadratic projections, we should calculate from that mid-date, rather than the current date. In this case, that adds 56.6 years, so we should multiply half the acceleration by 156.6² = 24,524.

-0.00539/2 × 24,524 = -66 mm = -2.6 inches (still of no practical significance).

Church & White have been down this “acceleration” road before. Twelve years ago they published the most famous sea-level paper of all, A 20th Century Acceleration in Global Sea-Level Rise, known everywhere as “Church & White (2006).”

It was the first study anywhere which claimed to have detected an acceleration in sea-level rise over the 20th century. Midway through the paper they finally tell us what that 20th century acceleration was:

“For the 20th century alone, the acceleration is smaller at 0.008 ± 0.008 mm/yr² (95%).”

(The paper failed to mention that all of the “20th century acceleration” which their quadratic regression detected had actually occurred prior to the 1930s, but never mind that.)

So, applying the rule-of-thumb above, the first thing you should notice is that 0.008 mm/yr² of acceleration, even if correct, is practically insignificant. It is so tiny that it just plain doesn’t matter.

In 2009 they posted on their web site a new set of averaged sea-level data, from a different set of tide gauges. But they published no paper about it, and I wondered why not. So I duplicated their 2006 paper’s analysis, using their new data, and not only did it, too, show slight deceleration after 1925, all the 20th century acceleration had gone away, too. Even for the full 20th century their data showed a slight (statistically insignificant) deceleration.

My guess is that the reason they wrote no paper about it was that the title would have had to have been something like this:

Church and White (2009), Never mind: no 20th century acceleration in global sea-level rise, after all.

There is no real disagreement between the too accounts. Roy Spencer is saying that if the Church and White paper is correct there is trivial acceleration, Dave Burton is making a more general point about there being no statistically significant acceleration or deceleration in any data set.                                                At Key West in low-lying Florida, the pattern of near constant of sea level rise over the past century is similar to Honolulu. The rate of rise is about 50% more at 9 inches per century but more in line with the long-term global average from tide gauges. Given that Hawaii is a growing volcanic island, this should not come as a surprise.

I choose Key West from Florida, as supposedly from projecting from this real data, and climate models, the Miami-Dade Sea Level Rise Task Force produced the following Unified Sea Level Rise Projection.

The projections of significant acceleration in the rate of sea level rise are at odds with the historical data, but should be discernible as the projection includes over two decades of actual data. Further, as the IPCC AR5 RCP8.5 scenario is the projection without climate mitigation policy, the implied assumption for this report for adapting to a type of climate change is that climate mitigation policies will be completely useless. As this graphic is central to the report, it would appear it is the usage of the most biased projections that appears to be influencing public policy. Basic validation of theory against modelled trends in the peer-reviewed literature (Dr Roy Spencer) or against actual measured data (Dave Burton) appears to be rejected in favour of beliefs in the mainstream climate consensus.

The curious symmetry of climate alarmism between evidence for BIG potential climate problem and the lack of an agreed BIG mitigation policy solution is evident is sea level rise projections. Unfortunately, given that policy is based on the ridiculous projections, it is people outside of the consensus that will suffer. Expensive and unnecessary flood defences will be built and low-lying areas will be blighted by alarmist reports.


Kevin Marshall


Sea Level Rise Projections and Policy

One blog I follow is TrustYetVerify. The latest post – Projecting sea level 300, nah, 1000 years in the future – is straightforward and highlights some significant issues for climate policy.

He compares claims of an activist in a Belgium newspaper that unmitigated climate change will result in sea level rise of 5 metres in 300 years, with a graphic from UNIPCC AR5 WG1 Chapter 13 on sea level rise that showed a at most around a 3 metre rise.

There was a good spot by Michel in relation to a graphic from a December 2017 presentation on the impacts of an 8 metre rise in sea levels by the year 3000. In was originally from a 2004 Greenpeace document. Only the earlier document also had the impacts of current sea inundation and a 1 metre sea level rise.

There are some lessons that can be learnt.

Marginal Difference of policy

The current sea coverage is of large areas of the Netherlands that are not currently covered by sea water. To create the graphic, they have removed the dykes that have enabled the Netherlands to vastly increase its land area. This not only vastly exaggerates the impact of sea level rise, but contains the assumption that people are too dumb to counter the impact of sea level rise by building dykes higher. Given that even the exaggerated claims are 5 metres in 300 years, that means an average rate of rising of 17mm per annum and a maximum rate of maybe 30mm. What is more, any rise is predictable over maybe decades. Decisions can be made over 20-50 year timescales, which are far less onerous than taking the long-term perspective. Even if a 5 metre rise over 300 years was accurate, either building dykes now assuming sea levels are 5 metres higher, or abandoning areas that will be inundated will cause needless costs for this generation and the next few generations.
The is an even greater policy assumption, that I repeatedly point out. Climate mitigation through reducing greenhouse gas emissions requires that global emissions are reduced.  It does not matter whether Belgium, and the Netherlands make massive cuts their emissions, if most other countries do not follow similar policies. As a graphic 3.1 from the UNEP Emissions Gap Report 2017 clearly demonstrates, the net impact of all proposed policies is very little compared to doing nothing, and a long way from the 1.5°C or the 2°C targets. This is after over 20 years of annual COP meetings to obtain much bigger reductions.

The marginal impact of sea-level rise is therefore exaggerated by

  • Assuming that the existing flood defences vanish.
  • Assuming people do not build any more defences.
  • Exaggerating the projected rise.
  • Looking at a far greater timescale than rational planning ought to take place.
  • Falsely promoting emissions reductions to combat sea level rise impacts, knowing that whatever a few countries do will not make a difference to overall emissions. If significant warming is caused by human GHG emissions, and this leads to significant sea level rise, then current emissions policies are largely a waste of time.


Checking and Interpreting Forecasts / Projections

Consider the sea level rise graphic from UNIPCC AR5 WG1 Chapter 13 .

Consider the projections for the year 2500.

The High Scenarios shows sea level rise of 1.5 to 6.5m in 2500 for >700ppm CO2.
Medium scenarios show sea level rise of 0.2 to 2.3m in 2500 for 500-700ppm CO2.
Low scenarios show sea level rise of 0.5 to 1.0m in 2500 for <500ppm CO2.

How can the medium scenarios project a lower bottom end than the low scenarios?

The explanation probably lies in different modelling assumptions. After all the greater the scenario from the current state of affairs, the greater the uncertainty range, unless you assume that the structure of the model contains truths not revealing from any observations.

Further note the High scenarios lower limit is only 30cm a century, and the top end is 1.3m a century, whilst the medium scenarios bottom end over five centuries is roughly the rate of sea level rise per century for the last few centuries. That is, well within the medium scenario uncertainty range is the possibility that some global warming will make no difference to the rate of sea level rise.

What I also find interesting is that under the medium scenarios, Antarctica is gaining ice, hence reducing sea levels, but under the low scenarios has no impact whatsoever. Again, this shows the different modelling assumptions used.

Concluding note

Suppose a pharmaceutical company promoted a product with clearly exaggerated claims of its effectiveness, false alarm for the need for the product, and deliberately played down the harms that the product could cause to the patient? There would be an outcry, and the company being sued in a world without regulations. In most countries, strict regulations mean that to market a new product, the onus is on that company to demonstrate the product works, and that side effects are known. But it is alright to promote such falsehoods to “save the plant for future generations“. Indeed, to shout down critics as deniers of climate change. 

Kevin Marshall

Joe Romm eco-fanaticism shown in Sea-Level Rise claims

The previous post was quite long and involved. But to see why Jo Romm is so out of order in criticizing President Trump’s withdrawal from the Paris Climate Agreement, one only has to examine the sub-heading of his rant  Trump falsely claims Paris deal has a minimal impact on warming. –

It may be time to sell your coastal property.

This follows with a graphic of Florida.

This implies that people in Southern Florida should take in account a 6 metre (236 inch) rise in sea levels as a result of President Trump’s decision. Does this implied claim stack up. As in the previous post, let us take a look at Climate Interactive’s data.

Without policy, Climate Interactive forecast that US emissions without policy will be 14.44 GtCO2e, just over 10% of global GHG emissions, and up from 6.8 GtCO2e in 2010. At most, even on CIs flawed reasoning, global emissions will be just 7% lower in 2100 with US policy. In the real world, the expensive job-destroying policy of the US will make global emissions around 1% lower even under the implausible assumption that the country were to extend the policy through to the end of the century. That would be a tiny fraction of one degree lower, even making a further assumption that a doubling of CO2 levels causes 3C of warming (an assumption contradicted by recent evidence). Now it could be that every other country will follow suit, and abandon all climate mitigation policies. This would be a unlikely scenario, given that I have not sensed a great enthusiasm for other countries to follow the lead of the current Leader of the Free World. But even if that did happen, the previous post showed that current policies do not amount to very much difference in emissions. Yet let us engage on a flight of fancy and assume for the moment that President Trump abandoning the Paris Climate Agreement will (a) make the difference between 1.5C of warming, with negligable sea-level rise and 4.2C of warming with the full impact of sea-level rise being felt (b) 5% of that rise. What difference will this make to sea-level rise?

The Miami-Dade Climate Change website has a report from The Sea Level Rise Task Force that I examined last November. Figure 1 of that report gives projections of sea-level rise assuming the no global climate policy.

Taking the most extreme NOAA projection it will be around the end of next century before sea-levels rose by 6 metres. Under the IPCC AR5 median estimates – and this is meant to be the Climate Bible for policy-makers – it would be hundreds of years before that sea-level rise would be achieved. Let us assume that the time horizon of any adult thinking of buying a property, is through to 2060, 42 years from now. The NOAA projection is 30 inches (0.76 metres) for the full difference in sea-level rise, or 1.5 inches (0.04 metres) for the slightly more realistic estimate. Using the mainstream IPCC AR5 median estimate, sea-level rise is 11 inches (0.28 metres) for the full difference in sea-level rise, or 0.6 inches (0.01 metres) for the slightly more realistic estimate. The real world evidence suggests that even these tiny projected sea level rises are exaggerated. Sea tide gauges around Florida have failed to show an acceleration in the rate of sea level rise. For example this from NOAA for Key West.

2.37mm/year is 9 inches a century. Even this might be an exaggeration, as in Miami itself, where the recorded increase is 2.45mm/year, the land is estimated to be sinking at 0.53mm/year.

Concluding Comments

If people based their evidence on the real world, President Trump pulling out of the Paris Climate Agreement will make somewhere between zero and an imperceptible difference to sea-level rise. If they base their assumptions on mainstream climate models, the difference is still imperceptible. But those with the biggest influence on policy are more influenced by the crazy alarmists like Joe Romm. The real worry should be that many policy-makers State level will be encouraged to waste even more money on unnecessary flood defenses, and could effectively make low-lying properties near worthless by planning blight when there is no real risk.

Kevin Marshall


Rignot et al 2011 on ice sheet melt acceleration – reconciling with sea level rise

In this posting I will look at Rignot et al 2011 and compare with the University of Colorado “official” level figures.

The basic conclusions are

  1. Rignot et al 2011 estimate that over an 18 year period the acceleration in polar ice melt contribution around 1.8mm extra to annual sea level rise that either stayed constant at 3.2mm, or showed a slight decline. Examination of the Rignot figures suggests this result is a bit too neat.
  2. Although that acceleration in ice melt are not reflected in average long-term rise, large short-term variations ice-melt in the rate of ice melt do show up in swings in the rate of sea level rise two or three years later. In fact using an 11 month moving average sea level rise, the fit on some of those changes in sea levels are almost a mirror image of that rise.
  3. The mirrored similarities between the graphs would be improved by removing the acceleration trend in the ice-melt.
  4. When I measure the magnitude of the swings in the sea levels they are six to eight times greater than the expected 1mm rise from 365 billion tonnes of water. Considering possible errors makes the problem worse and would reduce the similarities between the two graphs.

This is where I need people to critically review the figures. Point 1 I believe is beyond doubt. Points 2 and 3 are easy to replicate if you have something like Excel 2010 where you can ghost one graph over another. But on point 4 I have been scratching my head over for a couple of days now, and cannot see any way that will correct the figures in the right direction.

The Rignot Paper Abstract

Rignot et al 2011 et al says the following.

Ice sheet mass balance estimates have improved substantially in recent years using a variety of techniques, over different time periods, and at various levels of spatial detail. Considerable disparity remains between these estimates due to the inherent uncertainties of each method, the lack of detailed comparison between independent estimates, and the effect of temporal modulations in ice sheet surface mass balance. Here, we present a consistent record of mass balance for the Greenland and Antarctic ice sheets over the past two decades, validated by the comparison of two independent techniques over the last 8 years: one differencing perimeter loss from net accumulation, and one using a dense time series of time variable gravity. We find excellent agreement between the two techniques for absolute mass loss and acceleration of mass loss. In 2006, the Greenland and Antarctic ice sheets experienced a combined mass loss of 475 ± 158 Gt/yr, equivalent to 1.3 ± 0.4 mm/yr sea level rise. Notably, the acceleration in ice sheet loss over the last 18 years was 21.9 ± 1 Gt/yr2 for Greenland and 14.5 ± 2 Gt/yr2 for Antarctica, for a combined total of 36.3 ± 2 Gt/yr2. This acceleration is 3 times larger than for mountain glaciers and ice caps (12 ± 6 Gt/yr2). If this trend continues, ice sheets will be the dominant contributor to sea level rise in the 21st century.

In 2006 combined mass loss was 475 billion tonnes, sufficient to raise sea levels 1.3mm. This gives 365 billion tonnes to raise sea levels by 1mm, something that I have verified in other studies. So the paper estimates the sea level rise from Greenland and Antarctic ice sheets mass loss is accelerating by 0.1mm per annum. The authors also claim that from mountain glaciers and ice caps there is a further 0.033mm of acceleration. Multiply that by 18 years means melting ice must be raising sea levels in 2011 by around 2.4mm more than in 1993. We can also backtrack to when the start point of net ice melt by deducting 36.3 from yearly figure. In 1993, the first year of the study, ice melt comes to 3.1 billion tonnes. That is effectively zero.

Further, the 2006 ice mass loss has a calculated uncertainty figure at 158 is quite large. To the nearest whole number it is exactly one-third of 475 central ice-mass loss figure. From this we can then calculate the upper and lower uncertainty bands on the contribution to sea level rise in 1993. The upper band is to assume the highest figure for 2006 (+475+158) and the lowest acceleration (+36.3-2). The lower band is to assume the lowest figure for 2006 (+475-158) and the highest acceleration (+36.3+2).

I have put the results in giga tonnes, and equivalent sea level rise into a couple of tables below.

Rignot2011 implied polar ice melt

The whole structure of figures seems somewhat contrived. However, it does not mean that the figures are outside of the bounds of what could be actually happening. To assess that we must look to the seasonally adjusted sea level rise figures from the University of Colorado.

At this stage, the point to note is the trend line. Since the first satellite data in 1993, sea levels have been rising at about 3.2 mm per year. This I have plotted against the modelled contribution from Rignot.

If you add in the contribution from mountain glaciers and ice caps, in 18 years ice melt is alleged to have increased from 0% to 75% of the sea level rise trend in that period. That does not stack up. A model that fits so conveniently into the study period and nicely rounds to sea level rise equivalents, shows a trend that is completely out of line with the sea level rise.

To probe further, I downloaded the sea level data figures from the University of Colorado.

Replicating the Colorado Sea Level Rise graph

From the website I downloaded the seasonally adjusted figures, as that is what Rignot had used for ice melt.

I only use Excel, not the R statistical package like proper statisticians use. So I had to simplify the data. Please bear with me, as my “dumb” analysis still yields some very interesting results in the next section.

There are currently 710 lines of data, of which the first is “1992.9595 -5.800“. Each data point has a date and a value. The four places of decimals enable not only the actual day, but even the hour do be identified. As such, if readings are irregularly spaced, it will not bias the analysis, despite there only being about three readings a month, or one every ten days. I split the data into calendar months by first multiplying the decimal by days in the year and doing a lookup from here. I then took the average value per month. I know that February is likely to be under represented, by with 245 months of data, it will not make much of a difference to the general picture.

To validate this, I created a simplified version of the cumulative sea level rise graph. It still shows a cumulative rise of 64mm in 20 years. It shows the data points and a 5 month centred moving average.

The problem with the graph is that it visually under represents significant short term fluctuations. The rise in the last twelve months is obtained by subtracting figure from 12 months previous from the current month. This generated some enormous fluctuations. I therefore created 11 month and 35 month centred moving averages.

Even though smoothed, there are some pretty large fluctuations in the rate of sea level rise, particularly in 1997 to 2000 and after the start of 2010.

The 35 month centred is much smoother and it is possible to see a distinct decline from 2001 to 2007 by more than 50%.

Rignot graph compared

The Rignot et al 2011 paper posts three nice graphs of estimated ice losses. There are separate ones for Greenland and Antarctica, then a combined graph. It is this graph C that I reproduce below.

The annualised rate takes each month reading and multiplies by 12. So change is exaggerated?

My graph smooth the peaks, as it is a moving average. However, the Rognot graph appears to be almost a mirror of the sea level rise 11-month centred, except ice mass balance has a slope. For instance

  • Rognot has a peak of ice loss around the end of 1994, with an opposite peak of ice gain by a low at the end of 1994. The rate of sea level rise peaked in early 1996, followed by sharp change to small decline in sea levels at the end of 1998.
  • Rognot has a peak of ice loss at the end of 2007, with an opposite low in ice loss in early 2009. The rate of sea level rise peaked in early in late 2009, followed by sharp change to significant decline in sea levels in early 2012.

The peaks and troughs are so similar I flipped over the Rignot graph and aligned it up with rate of sea level rise graph.

Not only do major turning points correspond, but whole sections as well. The delay in the ice sheet melt is reflected in sea rise about 20 to 36 months after, so it not that exact. Also, a much better fit would be obtained if Rignot had not built in a slope in the graph. It seems the acceleration is anomalous.

I have uploaded a file here that contains the images. In Excel try moving the upper image over the lower one, without releasing. I have also included another graph with a centred 13 month moving average. It obtains similar results. It seems that in Rignot et al polar ice melt model (modified for slope) would appear to be an excellent short-run predictive model of the rate sea level rise.

There is a slight snag with my numbers. Before doing the above comparison, I looked at various movements between high and low points.

I have had to estimate the sea ice changes and dates of changes from the graph. In light blue is the number of gigatonnes of ice/water that is apparently needed to raise see levels by 1mm. The figure in deeper blue is how many times more effective Rignot ice melt appears to be in raising sea levels. I cannot see where I have made an error in this table. Or, at least, everything I can think of makes the problem worse. Here are some possibilities.

  1. Annualised data on ice-melt. Each monthly figure is multiplied by twelve. But smoothing would not only make the movements less of a fit between graphs but would exaggerate the problem.
  2. Moving average figure for sea level rise. But de-smoothing would not only make the movements less of a fit between graphs but would exaggerate the problem. Further, I would expect a lagged response to smudge the sharpness of the initial impulse, not make it more acute.

Please look at the figures carefully, as there is bound to be an issue. After all, one (slightly) manic beancounter is more likely to be wrong that four leading experts in their field.

Kevin Marshall

NB. I have comment moderation set for anyone who has not previously commented. If you would like to contact, but do not wish publication, please use the comments, making this clear. I will respect any non-threatening request.

Rignot, E., I. Velicogna, M. R. van den Broeke, A. Monaghan, and J. Lenaerts (2011), Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise, Geophys. Res. Lett., 38, L05503, doi:10.1029/2011GL046583.,

Two Comments on Antarctic Ice Accumulation

Jo Nova blogs on a study that claims the Antarctic continent is accumulating ice mass at a rapid rate. I have made two comments. One is opposing someone who claims that Antarctica is actually losing ice. The other is that the claimed rate of ice accumulation does not make sense against known data on sea levels.


April 17, 2013 at 6:27 am · Reply

John Brooks says

I’m also interested that the mass of antarctic land ice follows solar irradiance. This makes perfect sense. However I can’t see why the effective of an increase in the greenhouse effect wouldn’t have exactly the same result.

Maybe you should look at the period covered by the graph John. There is an 800 year correlation of mass of antarctic land ice with solar irradiance, with the biggest movements in both prior to 1800. Insofar as the greenhouse effect is significant, it is nearly all after 1945.

And for some reason, I’ve got the idea in my head that antarctic land ice is decreasing.

Sure enough from the Carbon Brief link, this quote

Measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite since 2002 have shown that the mass of the Antarctic ice sheet is decreasing at an average rate of 100 cubic kilometres every year – the size of a small UK city.

(emphasis mine)
The size of a city is usually measured in area, not volume. The ancient City of York, for instance, has an area of 272 square kilometres (105 square miles) and a population of 125,000. Or maybe they mean the volume of the buildings in a city? A famous building in New York is the Empire State Building. Not only is it quite tall it also has quite a large volume. Around 1,040,000 cubic metres or 0.001 cubic kilometres in fact. So does the Carbon Brief claim that a small UK city have a volume of buildings equivalent to 100,000 Empire state buildings? Or each average person in a small UK city occupies a building volume greater than Buckingham Palace?
Alternatively, does John Brooks quote a source that does not have a clue about basic maths?


April 17, 2013 at 8:01 am · Reply

I think this paper does not stack up. I worked as a management accountant in industry for 25 years. One thing I learnt early on when estimating or forecasting was to sense-check the estimates. No matter how good your assumptions are, when estimating or extrapolating well beyond the data trend (where there is potential for error), the best check on the data is by reconciling with other data.
From the above

“The SMB of the grounded AIS is approximately 2100 Gt yr−1, with a large interannual variability. Those changes can be as large as 300 Gt yr−1 and represent approximately 6% of the 1989–2009 average (Van den Broeke et al., 2011).”

A gigatonne of ice is equivalent to a cubic kilometre of water. If the land ice volume is increasing, the water must come from somewhere. Nearly all of that water needs to come from the oceans.
Now for some basic maths. A gigatonne is a billion tonnes. As water has a relative density of 1.0, a tonne of water (1,000 litres) is a cubic metre. Therefore a gigatonne of water is a cubic kilometre (1000^3 = 1,000,000,000 = one billion).
A further factor to consider is the area of the oceans. According to my Times Concise Atlas, the total area of the oceans and seas (excluding the enclosed waters like the Dead Sea and Lake Baykal) is 325,000,000km^2. A cubic kilometre of water added to an enclosed sea of one million square kilometres, would raise the sea level by just 1mm (1000mm x 1000m = 1,000,000mm in a kilometre). So 325km^3 = 325Gt-1 of new ice accumulation above sea level in Antarctica would reduce sea levels by 1mm, or 2100GT-1 by 6.5mm.
Some of the ice accumulation will be on ice shelves, so the impact of 2100GT-1 extra ice per annum extra ice might be to reduce sea levels by just 5mm per annum. Also sea levels might be rising by a little less than the 3.2mm a year that official figures claim, but there is no evidence that sea levels are falling. Further, any net ice melt elsewhere (mostly Greenland) is only adding 1mm to sea level rise. So the rest must be mostly due to thermal expansion of the oceans. I think that the evidence for the oceans heating is very weak and of insignificant amounts. Even Kevin Trenberth in his wildest flights of fantasy would not claim the missing heat (from the air surface temperatures) adds more than 1-2mm to sea level rise.
What this study does show is that by honestly looking at data in different ways, it is possible to reach widely different conclusions. It is only by fitting the data to predetermined conclusions (and suppressing anything outside the consensus) that consistency of results can be achieved.

My scepticism on global warming stems from a belief that scientific evidence is strengthened by being corroborated from independent sources. Honest and independent data analysis means that wildly different conclusions can be reached. Comparing and contrasting these independent sources leads me to believe that the public face of the global warming climate change consensus massively exaggerates the problem.

Kevin Marshall

Cold water on sea level rise alarmism

The new article in Nature on “Recent contributions of glaciers and ice caps to sea level rise” (Jacob et al. 2012) is in stark contrast to what has gone before. It is far from the previous claims.

The main estimates before Jacob et al. 2012 were:-

  • The Himalayan Glaciers will disappear by 2035. (UNIPCC AR4 2007) Changed to the Himalayan Glaciers may disappear by 2350. (UNIPCC 2010)
  • The Grace Satellite data shows that the polar ice caps are not only melting, but the melt rate is accelerating. Velicogna 2009 claimed that the acceleration in Greenland was −30 ± 11 bnt/yr2 to 286 bnt/yr-1 in 2007 to 2009, and in Antarctica was −26 ± 14 bnt/yr2 to 246 bnt/yr-1 in 2007 to 2009. Concentrating on the period from 2006 to early 2009 for Antarctica only , Chen et al. 2009 estimated that the continent was losing ice at the rate of 190 ± 77 bnt/yr-1, two-thirds is of which comes from West Antarctica, covering about a quarter of the total land surface area. By 2010, the loss from both polar caps would, by Veligona’s estimate be 600 to 650 bnt/yr-1.
  • The average of these two articles was that in 2010 there would be around 600 bnt/yr-1 loss per year.
  • One of the articles’ authors, Prof John Wahr of University of Colarado, Boulder, had previously stated that the Grace measurements indicate an accelerating trend in Greenland. The current graph at Wahr’s website for Greenland shows a distinct accelerating trend through to the start of 2010.

    Mass variability summed over the entire Greenland Ice Sheet, monthly Gravity Recovery and Climate Experiment (GRACE) results (black line; the orange line is a smoothed version) April 2002 and December 2009.

    Prof John Wahl’s graph of Greenland Ice sheet loss, indicating a doubling of the rate of loss over the period to around 150 bnt/yr-1 in 2009.

  • In Zwally and Giovinetto 2011, using three separate estimation techniques, and including the pre-satellite data from 1992 to 2002, estimated the range of +27 to -40 bnt/yr-1.

The new paper in Nature:-

  • Estimates no net loss from the Himalayas in the period 2003 to 2010. When the claim that the Himalayas would lose their glaciers by 2035, Rajendra Pauchari, head of the UNIPCC said the doubts were “voodoo science”. Now even the more moderate claim of melting over hundreds of years looks to be in doubt. Josh has penned a cartoon to illustrate this point.

  • Velicogna 2009, seems somewhat extreme. The Nature paper would estimates a loss of 50% to 75% Velicogna estimate for 2010.
  • Most importantly, there is no mention of acceleration of ice melt from the polar ice caps. This sudden turn-around might be to a sudden change in the data. The sea level rise appears to have stalled in the last 18-24 months, so the sea ice melt (which the Nature paper estimates accounts for 40% of the sea level rise) may have stalled as well. (See Appendix 2). It is necessary to re-run the Nature paper numbers for 2011 data to confirm if this is the case.

In conclusion, it looks that the new nature paper reaches a more moderate position than previous papers using the GRACE satellite data, as it uses a longer period, and subjects the data to a more detailed breakdown. However, in terms of the polar ice melt, it still more extreme than a paper that uses a longer timeframe and three distinct methods of calculation.

Appendix 1 – Leo Hickman in the Guardian has a breakdown of the figures, that nicely puts the issue in context.

Ignore Region Rate (Gt yr-1)
1 Iceland -11.±.2
2 Svalbard -3.±.2
3 Franz Josef Land 0.±.2
4 Novaya Zemlya -4.±.2
5 Severnaya Zemlya -1.±.2
6 Siberia and Kamchatka 2.±.10
7 Altai 3.±.6
8 High Mountain Asia -4.±.20
8a Tianshan -5.±.6
8b Pamirs and Kunlun Shan -1.±.5
8c Himalaya and Karakoram -5.±.6
8d Tibet and Qilian Shan 7.±.7
9 Caucasus 1.±.3
10 Alps -2.±.3
11 Scandinavia 3.±.5
12 Alaska -46.±.7
13 Northwest America excl. Alaska 5.±.8
14 Baffin Island -33.±.5
15 Ellesmere, Axel Heiberg and Devon Islands -34.±.6
16 South America excl. Patagonia -6.±.12
17 Patagonia -23.±.9
18 New Zealand 2.±.3
19 Greenland ice sheet.+.PGICs -222.±.9
20 Antarctica ice sheet.+.PGICs -165.±.72
  Total -536.±.93
  GICs excl. Greenland and Antarctica PGICs -148.±.30
  Antarctica.+.Greenland ice sheet and PGICs -384.±.71
  Total contribution to SLR -1.48.±.0.26
  SLR due to GICs excl. Greenland and Antarctica PGICs -0.41.±.0.08
  SLR due to Antarctica.+.Greenland ice sheet and PGICs -1.06.±.0.19


Appendix 2 – University of Colarado Sea level Rise Estimates