Friday, August 31, 2012

14 October 2011 – The eyes have it


About two weeks ago, the European Space Agency’s Envisat this week completed its 50,000th orbit of Earth since its launch in 2003.  The satellite, which is the size of a truck, is the most sophisticated Earth environment monitoring satellite currently circling the planet.  You can read about it here.

One of the instrument packages carried by the satellite uses precise radar measurements to monitor sea level (avoiding the problems of isostatic lift and subsidence that plague ground-based depth gauges) in order to build a database to verify the impact of climate change on average global sea levels.  That human-produced CO2 is causing sea levels to increase is a common assumption both in the climate science community and in government organizations that accept and reiterate that community’s pronouncements and prognostications.  As just a few examples:

·         “Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level.” (IPCC 4th Assessment Report, Summary for Policymakers, page 2)

·         “…temperatures and sea level will continue to rise regardless of global efforts to limit greenhouse gas emissions.” (From Impacts to Adaptation: Canada in a Changing Climate, page 22)

·         “ has been suggested that environmental changes, particularly the rising sea level, could eventually result in the migration of wildlife, insects, and fish stocks that have sustained the population in the region for generations.” (Arctic Integrating Concept, page 11)

·         “...climate change will have severe consequences, including melting polar ice, rising sea levelsRising sea levels and melting glaciers are expected to increase the possibility of land loss…” (Future Security Environment: Part 1 - Current and Emerging Trends, page 36)

Thanks to Envisat, we have a little more data to validate these sorts of assertions.  This is what the data look like when you graph them:
Between Envisat’s launch in 2003 and a few years ago, sea level rose on average about half a millimetre a year.  That equates to 50 mm, or 5 cm, per century.  To put that in context, according to conventional depth measurement gauges, the rate of sea level rise since the mid-1800s has been approximately 20 cm per century.  So the rate for the last decade or so has been one quarter the average rate for the last century or so.  This demonstrates that although atmospheric CO2 concentrations have continued to climb, the rate of sea level rise has been slowing. 
In case that’s not obvious from the above chart, let me break it into two charts for you, with the corresponding linear trendlines.  The first shows sea level change from 2003-2009...
...and the second, from 2009-2011:

This is the opposite of what the climate models and the IPCC said would happen.  The IPCC predicted both an acceleration in the rate of sea level increase, and an overall increase in average sea level of 18-56 cm by 2100 due to melting ice alone; and a further increase in sea level over the period 2000-2015 of 40 to 140 cm due to thermal expansion alone (see the SPM, table SPM.6, page 20).  Observed data, by contrast, show that the rate of sea level rise is decelerating instead of accelerating; and that average sea levels are in fact declining.

That latter point is key.  For the last two years, despite continually increasing anthropogenic CO2 emissions and steadily rising atmospheric CO2 concentrations, the average global sea level has been plummeting at a rate of 7.5 mm per year.  The word “plummeting” is justified because the rate of sea level decrease is at present about 75 cm per century.  This is roughly 15 times greater than the rate of sea level increase over the past decade.  As of right now, the average sea level is lower than it was when Envisat was launched nearly a decade ago.  In other words, over the past decade, sea levels have fallen rather than rising as the IPCC models predicted they would.

Is this a new trend?  Is it evidence that climatic behaviour is cyclical, as sceptics argue, instead of linear, as the IPCC would have us believe?  Is it, in point of fact, empirical refutation of the model-based assumption that sea level will inexorably rise in response to “CO2 forcing”?  Could be.  One thing is certain, though: it’s observed data, and it’s diametrically opposed to the assumptions and outputs of climate models and the pronouncements of the IPCC.  And unlike the model assumptions and outputs, you can check the satellite data for yourself.  It’s all right here; all you need is cursory familiarity with MS Excel:]

Incidentally, seeing as how the IPCC said that sea level rise was inevitable as a result of melting land ice (glaciers and what-not; as Archimedes kindly demonstrated, floating sea ice can’t affect sea level whether it melts or not), and the proponents of catastrophic anthropogenic global warming still claim that land ice is melting at a ferocious rate, one has to ask: if sea level is demonstrably declining and there’s no accumulation of snow or land ice...then where’s the water going?  Just wondering.
Is this issue relevant to strategic analysis?  Well, take another look at the above-cited assumptions and the documents they come from.  Governments are conducting policy and force planning and development activities on the basis of assumptions, repeated over and over again in key strategic-level documents, that are in fact contradicted by observed evidence.  All of those documents were published before the current precipitous decline in sea level – but the slow-down in sea-level rise was already evident before they came out.  As the last few years demonstrate, contrarian evidence is important, and even if you’re confident in your data, you have to keep going back to them.  Observation is a continuous process, and when the facts change, we need to figure out why - and if necessary, change our arguments.
It all boils down to whether we understand and accept that argumentum ad verecundiam is not an argument at all, but a fallacy of reasoning.  Arguments from authority carry no weight; science obliges us to check the data for ourselves. 
Or as Groucho Marx might have put it, who are you gonna believe: the gold-plated experts and their unimpeachable, infallible computer models...or your lyin’ eyes?



P.S.  Groucho Marx also said, “Outside of a dog, a book is man’s best friend.  Inside of a dog, it’s too dark to read.”  Hard to argue with that.