Sea level set to rise for centuries: New York conference
July 11, 2017
The Regional Sea Level Changes and Coastal Impacts Conference organised by the World Climate Research Programme (WCRP), CLIVAR, and the UNESCO Intergovernmental Oceanographic Commission is being held this week in New York.
The opening day set the scene for the six conference sessions over the week-long conference.
Guy Brasseur, Chair of the WCRP called for the creation of “smart, end-to-end, climate information systems of basic research to climate services” to help decision makers and stakeholders better prepare for the impacts of sea level rise through adaptation and coastal management.
H. E. Peter Thomson, President of the 71st Session of the General Assembly warned that despite clear evidence of sea levels rising, desertification spreading, melting of the Arctic and submerging of islands, “we are confronted by powerful forces who deny that any of this is actually happening, or that if it is happening it is not for the anthropogenic reasons identified by scientific consensus” .
Sea level rise will not stop at the end of the 21st century but will continue for many centuries.
The Forty-Sixth session of the Intergovernmental Panel on Climate Change (IPCC) of the IPCC will take place in Montreal (Canada) from 6 to 10 September 2017. The IPCC assessment AR6 will give governments the scientific, technical, and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts, and options for adaptation and mitigation.
Specific to sea level rise, Valerie Masson-Delmotte, co-chair of the IPCC Working Group 1, shared how in the last decade over 4000 peer review papers were published with “sea level” in the title. She also presented the IPCC AR6 schedule, which includes a special report on 1.5°C of global warming (scheduled for release in 2018) and an oceans and cryosphere special report (schedule for release in 2019), both of which will discuss the latest science of sea level rise.
Other highlights of the opening session included:
Scientists are improving the closure of the sea level budget, but there is still significant uncertainty on all components. While modeled sea level changes are increasingly representing regional variability, some big challenges remain, such as accurately estimating ocean heat uptake in the deep ocean and under the ice. (John Church, University of New South Wales)
There is room for huge advancements in the rate and locations of understanding historical paleo records. For example, deformation of Orangeburg scarp (located in South Carolina) is not simply glacial isostatic adjustment. Dynamic topography causes non-horizontal shorelines – a few meters over 100,000 years. (Maureen Raymo, Lamont-Doherty Earth Observatory)
Ice sheets are responding to the ocean, and if we want to understand ice sheets, then we need to understand regional climate change. High-end projections of sea level change are harder than the ‘most likely’ outcomes because many processes that control mass loss are highly localized. Recent increases in ice flow are due to ocean circulation changes and may involve natural variability. (Tony Payne, University of Bristol)
Governments should take a metropolitan regional approach to city adaptation with a response structure across sectors and communities. New York was used as an example, which has its own panel for climate change that addresses resilience with a “portfolio approach” that combines policy, engineering, social action, and ecosystem based solutions. As with physical processes, there are tipping points in community response, such as lost homes. (Cynthia Rosenzweig, NASA GISS).