Research project

Understanding Pathways to and Impact of a 1.5 degrees rise in Global Temperature

Project overview

There is considerable uncertainty in the emissions pathway required to achieve the 1.5 degrees C warming target from the COP21 climate agreement. For example, the latest United Nations Intergovernmental Panel on Climate Change report indicated that 1.5 degrees C is compatible with cumulative carbon emissions of somewhere between 500 and 1500 Gigatonnes of carbon. To restrict warming to 1.5 degrees C, should we aim for net cumulative emissions of 500 GtC or of 1500 GtC? We do not yet have the required knowledge of the climate and carbon systems to decide. In fact, if a warming target of 1.5 degrees C is to be achieved, there has to be scope to adjust our future emissions plans over the 21st century and beyond in response to our evolving knowledge of the climate and carbon systems.

This project will define and evaluate Adjustable Pathways to 1.5 degrees C, in which the emissions pathway responds to climate observations over the 21st century to maximise the likelihood of delivering the final warming target. The Adjustable Pathways will be tested using millions of climate simulations from an innovative fast climate model whose ensemble members mimic the warming response range of the state-of-the-art CMIP5 models. We will assess how best to formulate the Adjustable Pathway to 1.5 degrees C warming, considering: (1) The initial rate of emissions reductions; (2) The time-interval between observational re-assessment of the emissions pathway; (3) The maximum rate of change of emissions reductions due to observational re-assessment; and (4) The existence of observational triggers that cause immediate re-assessment of the emissions pathway regardless of the time-interval.

We will then assess how the feasibility of Adjustable Pathways to 1.5 degrees C depends on the eventual value of the Transient Climate Response to Emission (TCRE) at 2100, and the future potential evolution of carbon capture and storage technology. We will assess the relative physical consequences of 1.5, 2.0 degrees C and 2.4 degrees C warming for sea level rise and the frequency of extreme sea level events. We will also assess impacts and costs of sea level rise 1.5 degrees C, 2.0 degrees C and 2.4 degrees C warming over the 21st century and beyond to year 2500, focusing on vulnerable, low-lying regions.

The unique aspect of this project that enables Adjustable Pathways to be evaluated is the ability to perform millions of climate simulations that reach the specific policy-driven warming targets. Conventional climate simulations use identical emissions pathways, but simulate a wide range of warming responses due to the uncertainty in the climate response. Here, we utilise a fast climate model that has recently developed by the research team, and mimics the range of climate responses shown by conventional models. This fast climate model can be configured to generate climate simulations that all lead to the same warming target, but cover a wide range of emissions pathways due to the uncertainty in the climate response.

Staff

Lead researchers

Dr Philip Goodwin

Associate Professor

Research interests

  • Philip has a number of research interests spanning climate and the carbon cycle:
  • (1) Earth’s coupled physical climate and biogeochemical system;
  • (2) The Anthropocene (including surface warming, sea level rise and ocean acidification);
Connect with Philip
Other researchers

Professor Ivan Haigh

Professor

Research interests

  • I currently have 8 active research grants (4 as principle investigator (PI)) worth £4.8M. 
  • I am the PI on two international grants that started in 2019, both looking at compound flooding. Compound flooding (when the combination, or successive occurrence of, two or more hazard events leads to an extreme impact e.g., coastal and fluvial flooding), can greatly exacerbate the adverse consequences associated with flooding in coastal regions and yet it remains under-appreciated and poorly understood. In the £788k NERC- and NSF- (US National Science Foundation) funded CHANCE project, I am leading a team (working alongside researchers from the University of Central Florida), to deliver a new integrated approach to make a step-change in our understanding, and prediction of, the source mechanisms driving compound flood events in coastal areas around the North Atlantic basin. In the £575k NERC- and NAFOSTED- (Vietnam’s National Foundation for Science and Technology Development) funded project, I am leading a team that is working with colleagues in Vietnam to map and characterise present, and predict future, flood risk from coastal, fluvial, and surface sources and, uniquely, to assess the risk of compound flooding across the Mekong delta; one of the three most vulnerable deltas in the world. I am also the PI on a grant, which started in 2021. In this 41k project, funded by the Dutch Ministry of Infrastructure and Water Management (Rijkswaterstaat), we are assessing past and future closures of the six storm surge barriers in the Netherlands.
  • In 2021, I was awarded a 3-year (50% of my time) prestigious Knowledge Exchange Fellowship funded by NERC (UK’s Natural Environmental Research Council) and worth £154k. This fellowship builds strongly on my prior research and the overall goal is to provide guidance and tools that will help storm surge barrier operators better prepare for the impacts of climate change across every area of their operation now and into the future. Within the fellowship I am working primary with the UK Environment Agency (EA) and the Dutch Ministry of Infrastructure and Water Management (Rijkswaterstaat). However, to ensure the work undertaken can benefit all the existing (and planned) surge barriers around the world, I am also working closely with I-STORM. I-STORM is an international knowledge sharing network for professionals relating to the management, operation and maintenance of storm surge barriers, and has representation from all the surge barriers worldwide.
Connect with Ivan

Professor Juerg Matter

Professor of Geoengineering&Carbon Manag
Connect with Juerg

Collaborating research institutes, centres and groups

Research outputs

Philip Goodwin, Martin Leduc, Antti-Ilari Partanen, H. Damon Matthews & Alex Rogers, 2020, Geoscientific Model Development, 13(11), 5389–5399
Type: article
Robert J. Nicholls, Sally Brown, Philip Goodwin, Thomas Wahl, Jason Lowe, Martin Solan, Jasmin A. Godbold, Ivan D. Haigh, Daniel Lincke, Jochen Hinkel, Claudia Wolff & Jan-Ludolf Merkens, 2018, Philosophical Transactions of The Royal Society A, 376(2119), 1-20
Type: article
Sally Brown, Robert Nicholls, Philip Goodwin, Ivan Haigh, Daniel Lincke, Athanasios Vafeidis & Jochen Hinkel, 2018, Earth's Future
Type: article