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Accelerating Sea Level Rise: explained in plain language


sandy_mckibben_rect-460x307Carbon Talks
,
in partnership with ACT, recently hosted John Englander to speak about his new book, High Tide on Main Street
 that explains how Sea Level Rise (SLR) has started to, and will continue to, drastically alter coastal landscapes worldwide. 

John Englander is an oceanographer, geologist, and explorer who specializes in SLR. In his talk, he used non-scientific language to explain the long-term implications of SLR and the risks it poses to coastal communities. His main goal is to raise awareness of the phenomenon of SLR amongst the public, governments and the private sector, to examine the anticipated impacts this century and beyond, and to stress the need for strategic, smart adaptation. The enormous threat that SLR poses was communicated by breaking down the scientific evidence in a way that anyone can understand. The message was clear: sea levels have been relatively stable for the past 6-8,000 years and are now rising at an accelerating rate. This is largely due to current and projected greenhouse gas (GHG) emissions that have effectively locked us into rising sea levels for centuries to come. Once the scale of the situation is understood, it is obvious that there is no time to waste. Planning to protect vulnerable people and properties ought to be a priority for all governments and stakeholders alike.

In order to drive this point home, John Englander uses the historical record for the past 420,000 years to show the correlation between increased average global temperatures, increased atmospheric concentration of CO2, and rising sea levels. This vast historical evidence highlights that until recently, sea levels rose and fell according to natural cycles. For instance, 20,000 years ago, at the height of the last ice age, sea level was 120 meters lower than today. However, anthropogenic climate change is interfering with those cycles and committing us to unprecedented climatic changes. In fact, in the absence of human induced climate change, the planet would be slowly moving towards the next ice age. We have certainly solved that problem for the foreseeable future!

As additional background, the basics about the phenomenon of SLR are as follows. SLR is fundamentally interconnected to, and a direct result of global warming. Sea levels are rising mainly due to: thermal expansion (ocean water expands as it heats up) and melting of glaciers and icecaps (as ice on land melts, additional water flows into the ocean). Since 1870, global sea level has risen by approximately 20 cm. Satellite measurements show that sea level is rising at approximately 3.4 mm per year and that the rate of rise is closely tied to temperature. In other words, as the average global temperature continues to increase, ocean levels will continue to rise faster and faster.

antarctica-sea-level-riseSo what are the projections for how much and how fast sea levels will rise? Global climate models show that a rate of accelerated rise will continue for hundreds of years, even assuming global temperature is stabilized. A combination of modelling and observations indicate that this will translate into somewhere between 18 cm to 2 metres of global average SLR by 2100. This large range results from different assumptions about the rate of GHG emissions and sources of energy used over the course of this century. The lowest projection of 18 cm is from the last International Panel on Climate Change report, which did not include accelerating melt rates in Greenland or Antarctica. Forecasting and understanding of this complex issue is continually improving. 

To see videos of how quickly the conditions in the arctic are changing visit Paul Beckwith’s Actic News.

When considering global SLR projections, it is important to note that sea levels differ significantly from one region to the next. Therefore, locally specific studies are required to support appropriate adaptation planning. Of course, as planning begins to incorporate sea level rise projections, more attention is being paid to how much protecting coastal cities will cost. A report released last year estimtes the cost to be over $9.5 billion for the Lower Mainland alone. As the risks become better understood, the price tag will likely grow. In the climate change community, the hope is that the economics will cause decision-makers to pay more attention to the need for aggressive mitigation.

As local governments struggle to address the many challenges posed by SLR, ACT is involved with a number of initiatives to support effective coastal adaptation.

english bay storm surgeACT is a partner on the Coastal Cities at Risk: Building Adaptive Capacity for Managing Climate Change in Coastal Megacities Program that aims to develop the knowledge base and enhance the capacity of mega-cities to successfully adapt to and cope with risks posed by the effects of climate change, including sea level rise, in the context of urban growth and development. The mega-cities included are Metro Vancouver, Manila, Bangkok and Lagos. The Vancouver area was chosen because it is the coastal region in Canada most at risk from SLR combined with other climate related threats. In an OECD report, Vancouver was rated 15th for exposed assets, with USD $55 billion at risk, and 32nd in terms of population at risk, with 320,000 people exposed. 

The CCaR project takes an interdisciplinary approach involving natural, engineering, socio-political-economic and health scientists and builds upon leading programs, which are also partners in the research program. The project runs from March 2011 to March 2016 and is funded by the International Development Research Centre together with the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada, and the Social Sciences and Humanities Research Council of Canada. 

ACT has also partnered with West Coast Environmental Law to convene a committee of local government practitioners in the Lower Mainland. The aim is to facilitate collaboration around shared climate adaptation challenges. As SLR crosses jurisdictional boundaries, participants have decided to focus on how to overcome barriers to planning for SLR in a unified manner at a regional level. This group, now referred to as the SLR Collaborative, is working on common issues such as how to fill gaps in relevant local and regional scientific data on climate change impacts, and how to obtain additional resources to help plan and implement coastal adaptation actions. The CCaR program, the Real Estate Foundation, the Bullitt Foundation, and the Law Foundation fund this initiative.

Finally, in April 2013, ACT, the BC Water and Waste Association Climate Change Committee, and the Okanagan Basin Water Board held a daylong workshop in Kelowna on flood risk assessment entitled ‘Not Waiting for Noah’. Local and senior government representatives, and industry partners came together to share concerns about the social and economic costs of flooding related to climate and other forces of hydrological change. The main goals of the workshop were to discuss available models and tools for risk assessment, build a community of practitioners, and together discuss problems and solutions for flood management and mitigation in a changing climate. The workshop also aimed to highlight proactive strategies to address the changing risk landscape and the increasing number of vulnerable people and assets in flood prone areas. This initiative was sponsored by the BC Water and Waste Association, the Okanagan Basin Water Board, the Real Estate Foundation of BC, the BC Ministry of Community, Sport and Cultural Development, and the SFU Adaptation to Climate Change Team. A paper reviewing highlights and conclusions of the workshop can be found in the upcoming BC Water & Waste Association’s Watermark Magazine. Additionally, a full report including an appendix of resources will soon be available at act-adapt.org.

 

By Yaheli Klein, ACT Senior Researcher

 

 

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