There are a few topics out there that I know are really important, but one that I don’t feel I can write abut with any authority probably because as important as I know that it is, the subject makes me a little cross-eyed at time. So, instead of me attempting to slog through it, John Knox White has shared this letter that he sent to the City Council on the issue of sea level rise and Alameda Point. So here it, it should be very informative as to the discussion around how to plan for sea level rise at Alameda Point. The letter is directed at the City Council, just in time for tonight’s meeting:
At Tuesday night’s meeting (11/19), your agenda presents a discussion on sea level rise that came to the Planning Board last week. At our meeting, members of the Board praised the science and data the city staff has chosen to determine predictions for future impacts at Alameda Point. The presentation does a great job of showing that the planning for Alameda Point is relying on solid climate science that is in line with current assumptions.
At that same meeting, a majority of the Board, 2/3 of the members in attendance, also questioned whether the city was using the right timeframe for mitigations from sea level rise. Staff is currently proposing to use a 37-year time horizon for initial sea level rise mitigation. As such, it is likely that some amount of Alameda Point will be built with less than 30 years before the next round of sea level protection must be built. New homeowners will not have paid off their first mortgage before the shoreline around the entire area will need to be dug up and replaced with a higher wall at immense cost and disruption.
As was mentioned the last time the Master Infrastructure Plan was presented to the council, to date our city has not discussed what the right sea level rise timeframe is for planning at Alameda Point. There are significant moral issues involved in this determination, including: if a new community is to be built at the Point, is less than 35 years enough of a buffer for protecting it?
It was unclear at the Planning Board whether this determination is just going to move forward without discussion. Unfortunately, the presentation you are receiving does not include the information that would allow Alamedans, our council or city staff to make such a determination.
But it does not mention that the most recent IPCC report, released in Sept 2013, found that sea levels were projected to rise 50% faster than 2007’s version of the report did. Additionally, that sea level rise projections are greater than they were expected to be six years ago.
It is clear that the climate science and modeling is still catching up with this issue, there are significant inputs that are still not included in the models. Every revision that has been made has been in the direction of greater impacts. In fact, climate scientists expect this to continue as new externalities are integrated into the modeling.
In this discussion, there are many trade-offs. Raising the initial mitigation height will increase upfront costs for development. But it will also lower costs for ongoing fees needed to build subsequent mitigations by spreading them over a longer turn. This will reduce the risk to the city’s finances as the city is more able to develop enough of the base to cover these additional fees.
What’s the worst that could happen? Building six inches higher on day one may be unnecessary in 50 years, but it will still likely be needed in 100. These are considerations that should be vetted and discussed, not brushed off as inconvenient to moving forward.
These trade-offs are important, they will have large impacts on the community that is built at Alameda Point, and could have significant repercussions for existing residents and businesses. At the very least, it is a discussion that deserves to be had publicly and openly, with a final determination made intentionally. Not because the year 2050 was an actual 50 year time horizon back when the first versions of these projections were made. In fact, staff reports earlier this year referred to 2050 as a 50 year time horizon.
As our elected policy-makers, you should determine the best time-horizon based on analysis that allows you to protect new residents and businesses appropriately, supports reasonable development and can be financed in a way that does not risk the city’s general fund. To do this, data and analysis is needed.
It’s my hope that Tuesday night, you will give direction to staff to bring a discussion on sea level time and time-horizons to you and any boards/commissions you feel are appropriate. In doing so, we can ensure that our development plans moving forward based on policies that have been made mindfully after a meaningful discussion of the key issues and tradeoffs.
And a few resources from the footnote of the letter:
“This is perhaps the biggest change over the 4th IPCC report: a much more rapid sea-level rise is now projected (28-97 cm by 2100). This is more than 50% higher than the old projections (18-59 cm) when comparing the same emission scenarios and time periods.”
“Many developments are now considered to be more urgent than in the fourth IPCC report, released in 2007. That the IPCC often needs to correct itself “upward” is an illustration of the fact that it tends to produce very cautious and conservative statements, due to its consensus structure – the IPCC statements form a kind of lowest common denominator on which many researchers can agree. TheNew York Times has given some examples for the IPCC “bending over backward to be scientifically conservative”. Despite or perhaps even because of this conservatism, IPCC reports are extremely valuable – as long as one is aware of it.” [JKW editorial: “cautious” and “conservative” mean “downplaying” impacts, not choosing greater ones]
“The range up to 98 cm is the IPCC’s “likely” range, i.e. the risk of exceeding 98 cm is considered to be 17%, and IPCC adds in the SPM that “several tenths of a meter of sea level rise during the 21st century” could be added to this if a collapse of marine-based sectors of the Antarctic ice sheet is initiated. It is thus clear that a meter is not the upper limit.
It is one of the fundamental philosophical problems with IPCC (causing much debate already in conjunction with the 4th report) that it refuses to provide an upper limit for sea-level rise, unlike other assessments (e.g. the sea-level rise scenarios of NOAA (which we discussed here) or the guidelines of the US Army Corps of Engineers). This would be an important part of assessing the risk of climate change, which is the IPCC’s role (**). Anders Levermann (one of the lead authors of the IPCC sea level chapter) describes it thus:
In the latest assessment report of the IPCC we did not provide such an upper limit, but we allow the creative reader to construct it. The likely range of sea level rise in 2100 for the highest climate change scenario is 52 to 98 centimeters (20 to 38 inches.). However, the report notes that should sectors of the marine-based ice sheets of Antarctic collapse, sea level could rise by an additional several tenths of a meter during the 21st century. Thus, looking at the upper value of the likely range, you end up with an estimate for the upper limit between 1.2 meters and, say, 1.5 meters. That is the upper limit of global mean sea-level that coastal protection might need for the coming century.”