Sea level rise trajectories by 2200 with warmings of 1.5 to 2 degree C

Holding the increase in the global average temperature to below 2 degree C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 degree has been agreed by the representatives of the 196 parties of United Nations as an appropriate threshold beyond which climate change risks become unacceptably high. Sea level rise is one of the most damaging aspects of a warming climate for the more than 600 million people living in the low elevation coastal areas less than 10 meters above sea level. Sea level rise concerns both public and policymakers, because the impact, risk, adaptation policies and long-term decision making in coastal areas depend on future sea level rise projections. Sea level rise impact is expected to increase for centuries to come and thus it is a matter of the greatest urgency to accurately project future sea level rise and its uncertainties. However, currently there are no sea level projections for specific warmings of 1.5 and 2 degree C.

Our project will explore the pace and long-term consequences for sea level rise with restricted warming of 1.5 degree and 2 degree, providing global and regional sea level projections by 2200. Outputs from this project will contribute to the research assessed by the Intergovernmental Panel on Climate Change (IPCC) for the new Special Report scheduled to be produced in 2018.

The main questions in proposed research are:
1. How will global sea level respond to the warming of 1.5 and 2 degree C?
2. What are the regional differences in sea level projections with these warmings?

Proposed work will provide valuable information about global and coastal sea level rise with warming of 1.5 and 2 degree C. Our work will benefit research in coastal engineering, coastal planning (adaptation and mitigation), glaciology, and climatology. Sea level projections in coastal areas (including projections for 136 large coastal cities) are potentially of large societal and economic benefit; for example, planning decisions need to be made concerning coastal infrastructure, such as the Thames Barrier, that may last for decades and cost billions of pounds.

Fragile coastal ecosystems and increasing concentrations of population and economic activity in maritime cities are reasons why future sea level rise is likely to be one of the most damaging aspects of the warming climate. As temperature rises, so does sea level, but the pattern of sea level rise is complex. Our project will explore the pace and long-term consequences for sea level rise with restricted warming of 1.5 degree C and 2 degree C, and contribute to the research assessed by the Intergovernmental Panel on Climate Change (IPCC) for the new special report scheduled to be produced in 2018.

As well as providing fundamental advances in scientific knowledge, sea level rise quantification effects UK adaptation and mitigation policy. This is an area of significant public interest, and so the project is an opportunity for increased public engagement with marine and climate research. The academic beneficiaries of this project are described separately.

Three specific groups will benefit from outputs of this project : Policy makers, industry and the general public. Policy makers, including: UK government departments: particularly the Department for Environment, Food and Rural Affairs (DEFRA) and the Department for Business, Energy and Industrial Strategy (BEIS), potentially also the Ministry of Defence (MoD); UK governmental agencies such as Environmental Agency (EA) and the Met Office, and intergovernmental bodies, notably the Intergovernmental Panel on Climate Change (IPCC). Industry, including: insurance; offshore oil and gas; marine renewable energy; maritime operations, coastal engineers and transport. General public, including: National Trust, Natural Coastal Resources; National Coastal Heritage; Coastal and Marine Resources.

This project will contribute to the development of adaptation and mitigation strategies in the local, national, regional and global arenas, by reducing uncertainties in future climate projections with warming of 1.5 and 2 degree C. In coastal areas the impact assessment, risk management, adaptation strategy and long-term decision making will crucially depend on understanding of future sea level projections, improvement of which is the main goal of our project. This in turn benefits those using this information for a wide range of environmental policy issues, e.g. relating to Living Marine Resources, achieving/maintaining Good Environmental Status, and the regionalisation of global sea level rise, on a global scale.

A particular link between this work and policy on a global scale is through the IPCC and contribution to the IPCC Special Report on 1.5 degree C, scheduled to be produced in 2018. The PI was a lead author of the relevant chapter in the last Assessment Report. Whether or not she plays this role in the next, we will specifically target outputs from this work at the next report, by aiming for publication on a time frame that fits the preparation of that report and by tailoring the information and approaches to be accessible to that process.

Links with policy on a national scale will be made at a government departmental level and relevant agencies, for example through the Marine Climate Change Impacts Partnership, which provides a mechanism for synthesising the information into a readily digestible summary, and by providing evidence to future DEFRA National Climate Change Risk Assessments and the National Adaptation Programme. We will work the relevant NERC and NOC offices to facilitate this engagement with policy.