Constructing scenarios of regional sea level change using global temperature pathways

Hylke De Vries,Caroline Katsman,Sybren Drijfhout

doi:10.1088/1748-9326/9/11/115007

Hylke De Vries, Caroline Katsman + Show 1 more

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https://doi.org/10.1088/1748-9326/9/11/115007

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Abstract

The effects of sea level change become increasingly relevant for the Dutch coast. Therefore we construct two scenarios for regional sea-level change in the 21st century. They are designed to follow two temperature pathways, in which global mean temperature rises moderately (‘G’, +1.5 K in 2085) or more substantially (‘W’, +3.5 K in 2085). Contributions from all major processes leading to sea level rise are included (ocean expansion, glacier melt, ice-sheet changes, and landwater changes), except glacial isostatic adjustment and surface elevation changes. As input we use data from 42 coupled global climate models that contributed to CMIP5. The approach is consistent with the recent fifth assessment Report of IPCC, but provides an alternative viewpoint based on global temperature changes rather than RCPs. This makes them rather accessible and readily applicable to policy makers and the general public. We find a likely range for the G-scenario of +25–60 cm in 2085, and +45–80 cm for the W-scenario. These numbers have been rounded to 5 cm precision, to emphasise to any end-user of these scenarios that estimated lower and upper limits themselves are uncertain.

Highlights

Global and regional sea level rise are amongst the most important indicators and consequences of the fact that our planet gradually warms
Global sea level has risen by about 20 cm over the past century, and the recent fifth assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR5, hereinafter AR5) clearly shows that moderate to substantial further rises can be expected in the coming decades to centuries (Rignot et al 2011, Church et al 2013)
Observations are included as 5 year (+ sybols) and 30 year running averages of 6 tide-gauge stations along the Dutch coast

Summary

Introduction

Global and regional sea level rise are amongst the most important indicators and consequences of the fact that our planet gradually warms. While uncertainties in future projections are considerable, it is clear that vast coastal areas may potentially be under threat, even if the rate of sea level rise will not accelerate. Impacts of sea level rise are obviously most pronounced for low lying coastal areas.

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