Comments to the CRC April 29, 2015.

By Dave Burton

This is one of those glass half-empty or half-full situations. This draft report is much, much better than the 2010 Report. That Report showed no actual tide gauge graphs; this one does. That Report ignored the differences between local rates of sea-level change in different parts of the State; this one analyzes them. That Report made an erroneous central claim that SLR has accelerated in response to global warming; this one does not make that error. That Report relied heavily on a discredited paper by Stefan Rahmstorf; this one does not.

However, I still have concerns.

One is that this draft report does not acknowledge any of the errors in the previous report, not even the mistaken claim that SLR accelerated due to global warming. I think we have a responsibility to do our best to undo the confusion which was caused by that error.

Another concern is the Report's exclusive reliance on sources from one end of the scientific opinion spectrum, primarily global sea level rise predictions from the most recent U.N. Intergovernmental Panel on Climate Change's 5th Assessment Report (AR5).

I was an Expert Reviewer of that IPCC Report, and I'm here to tell you that it's not a firm foundation. Their so-called expert review process was a sham. Their accelerated SLR scenarios are not credible. Even their low emission scenario projects over twice the current global rate of sea-level rise, 5.3" vs 2.2" for 30 years. That's ridiculous.

The next 30 years will probably see only about 70 additional ppmv CO2, which, because of its logarithmically decreasing effect, will have much less effect than the last 100 ppmv – and that hasn't caused any acceleration in SLR at all. It is absurd for the IPCC to predict that global SLR will double in response to a small forcing, when it didn't increase at all in response to a much larger forcing.

This draft report praises the IPCC and notes the 50,000 comments they received on their Report. But those comments were often ignored, and that praise is misplaced.

To balance the IPCC, I recommended that our Science Panel use the relevant sections of the reports from the Nongovernmental International Panel on Climate Change (NIPCC) and the U.S. Senate's Environment and Public Works Committee's Republican staff reports on climate change, but they did not.

The most important fact that everyone needs to understand about sea-level rise is that it has not accelerated at all in response to human greenhouse gas emissions.

The vast majority of human GHG emissions have been since the 1940s. Since then, we've driven up CO2 from about 300 ppm to 400 ppm – yet the rate of sea-level rise hasn't increased at all.

This fact is a huge problem for the models that the IPCC relies on. Dr. Steven Koonin was undersecretary for science in the Energy Department during President Obama's first term. After he left that position, he finally felt at liberty to tell the inconvenient truth. He said, “Even though the human influence on climate was much smaller in the past, the models do not account for the fact that the rate of global sea-level rise 70 years ago was as large as what we observe today.”

And yet, the IPCC still relies on those models. They just can't accept the empirical fact that anthropogenic CO2 has very little effect on sea-level rise. They still base their sea-level projections on hypothetical extreme acceleration scenarios, which they claim will be caused by CO2 emissions.

This Report is much better than the last one, but the Science Panel erred by basing so much of their work on the flawed projections of the UN IPCC's 5th Assessment Report, and by not examining more credible sources, like the Nongovernmental International Panel on Climate Change.

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