Understanding and Attributing Composition-Climate Feedbacks in the Earth System

Lead Research Organisation: University of Leeds
Department Name: School of Earth and Environment

Abstract

The Earth's surface has warmed by ~0.8 degrees Celsius over the past 130 years. A large body of scientific evidence indicates that the majority of this warming has been driven by mankind's activities: principally the emission of greenhouse gases, like carbon dioxide, into the atmosphere. If greenhouse gas emissions continue unabated, it is considered likely that dangerous climate change will occur in many parts of the globe by the end of the century or earlier. It is therefore crucial that the scientific community is able to provide quantitative, reliable information about climate in the coming decades to enable governments to implement appropriate adaptation and mitigation strategies in good time.

Whilst the fundamental physics that links increases in greenhouse gases to global warming is very robust and well understood, the exact magnitude of surface temperature change depends upon a complex array of feedback loops that amplify or damp the response, much like in an electronic circuit. For example, the melting of Arctic sea ice and glaciers is a positive feedback that enhances surface warming because the Earth's surface can absorb more incoming energy from the Sun leading to further warming. A comprehensive understanding of these feedbacks is required if we are to be able to provide quantitative information about future climate.

Climate projections are strongly reliant upon complex climate 'simulators' that capture a wide range of physical processes. These large computer programs are run of the world's most powerful supercomputers and have developed in leaps and bounds over the past few decades. They now include sophisticated representations of the atmosphere, ocean, sea ice, vegetation, land surface, ocean biogeochemistry and atmospheric chemical processes: so-called Earth System Models. This wide array of processes means that new interactions and feedback loops will be captured that could be important for our understanding of climate; many of these loops may have been previously ignored or not well represented in less comprehensive climate models and therefore scientific research is required to understand them in detail.

An important candidate for 'new' interactions in the Earth system is atmospheric chemical processes. Both chemical and transport processes are sensitive to climatic conditions. This means that the distribution of other gases in the atmosphere, such as ozone, will also change as levels of carbon dioxide increase. Ozone is also a greenhouse gas, so changes in its abundance will have further effects on our climate. This coupling between carbon dioxide, ozone levels and climate is one example of a chemistry-climate feedback loop. These feedbacks are complex to understand because they involve sequences of processes that are intimately coupled. The main goal of this research is to investigate the two-way interactions between climate and the composition of Earth's atmosphere, and to determine which feedback loops are important for our understanding of climate change.

Such studies are only now possible because of the recent rapid progress in our capabilities to simulate the Earth system. The project will track the cutting edge developments in this area by using a state-of-the-art Earth System Model currently being built by the UK scientific community. This research will improve our fundamental understanding of how chemical processes affect Earth's climate and will shed light on their role in determining how climate may evolve in the coming decades.

Planned Impact

The main users of the research and strategies for dissemination to these groups are described below.

The UK Met Office

The outcomes of the project will contribute to the future development of the Met Office Unified Model. The UM has been adopted by more than 42 end-users around the globe, including the Centre for Australian Weather and Climate Research, the Korea Meteorological Administration and the National Institute of Water and Atmospheric Research (New Zealand), and many of these external partners will also benefit from the research.

The research will make a substantial contribution to the joint Met Office/NERC programme to develop the UK Earth System Model 1 as part of the Joint Weather and Climate Research Programme (JWCRP). Met Office scientists will be closely engaged with the research, both via existing collaborations established by development of UKCA and new links with the 'Understanding Climate Change' group (see letter of support). Regular visits to Exeter are planned.

Other users could benefit from the implementation of new diagnostic tools into UK-ESM1, and efforts will be made to get these lodged in the model code so that they are available to the wider community.

Other international modelling centres

Many international centres are currently developing Earth System Models. The research will directly impact on these centres and their activities through increases in fundamental understanding of Earth System processes. The research will be disseminated to these users through publications in peer-reviewed journals and through talks at international conferences and meetings. The extended visit to NOAA will also enable links to be made with the modelling group at the National Center for Atmospheric Research (NCAR) who are developing the CESM-WACCM Earth System Model.

Other researchers working on radiative forcing and climate feedbacks

There is a large international community working on topics related to radiative forcing and climate feedbacks who will be interested in the research. It will be disseminated to these users through my involvement with the Radiative Forcing Model Intercomparison Project (RFMIP), which is planned as part of CMIP6 (see attached letter of support from RFMIP co-lead Prof Piers Forster). This will strengthen links to international scientific assessments such as future IPCC reports.

Other researchers working on chemistry-climate processes and air quality

The research will make substantial steps forward in the role of understanding of chemical processes in the climate system and will therefore impact on the wider atmospheric chemistry community. Cambridge is closely involved in the Chemistry-Climate Model Initiative (CCMI), which will provide a channel for disseminating the research through meetings and workshops. There is a close symbiosis between air quality and climate for topics related to composition. Whilst the research will focus on climate, it is also anticipated that the air quality community will be interested in the work, and efforts will be made to engage with them where possible.

Policy makers and the general public

The research will be highly relevant to future international scientific assessments, such as Intergovernmental Panel on Climate Change reports and the World Meteorological Organisation (WMO) Ozone Assessments. I was invited to participate in the final review process for the 2014 WMO Ozone Assessment Report and therefore have contacts within this community that I will maintain during the research.

The research planned as part of this project is aimed at increasing our understanding of our environment and its sensitivity to mankind's actions. This will contribute to the large body of climate research that enables scientists to provide information to policy makers and the general public, and is therefore of indirect benefit to the wider society.

Publications

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Banerjee A (2015) Drivers of changes in stratospheric and tropospheric ozone between year 2000 and 2100 in Atmospheric Chemistry and Physics Discussions

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Bednarz E (2016) Future Arctic ozone recovery: the importance of chemistry and dynamics in Atmospheric Chemistry and Physics

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Bednarz E (2016) Future Arctic ozone recovery: the importance of chemistry and dynamics in Atmospheric Chemistry and Physics Discussions

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Chrysanthou A (2019) The effect of atmospheric nudging on the stratospheric residual circulation in chemistry-climate models in Atmospheric Chemistry and Physics Discussions

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Collins W (2017) AerChemMIP: quantifying the effects of chemistry and aerosols in CMIP6 in Geoscientific Model Development

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Iglesias-Suarez F (2018) Key drivers of ozone change and its radiative forcing over the 21st century in Atmospheric Chemistry and Physics

 
Description Lead Author of Intergovernmental Panel on Climate Change Sixth Assessment Report
Geographic Reach Multiple continents/international 
Policy Influence Type Participation in a advisory committee
 
Description Lead Author of World Meteorological Organization Ozone Assessment Report 2018
Geographic Reach Multiple continents/international 
Policy Influence Type Participation in a advisory committee
URL https://www.esrl.noaa.gov/csd/assessments/ozone/2018/
 
Description Constraining uncertainty of multi decadal climate projections (CONSTRAIN)
Amount € 8,000,000 (EUR)
Funding ID 820829 
Organisation European Commission H2020 
Sector Public
Country Belgium
Start 07/2019 
End 06/2023
 
Description Joint project with Met Office UKCP18 Demonstrator and National Environment Research Council Yorkshire Integrated Catchment Solutions Programme (ICASP)
Amount £90,000 (GBP)
Funding ID NE/P011160/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 06/2017 
End 09/2017
 
Description NERC Highlight Topics 1st round
Amount £3,000,000 (GBP)
Funding ID NE/N006038/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 12/2015 
End 11/2019
 
Description NERC Industrial CASE PhD awards
Amount £90,000 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 10/2017 
End 09/2021
 
Description NERC Research Experience Placement
Amount £2,000 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 06/2017 
End 08/2017
 
Description Philip Leverhulme Prize 2018
Amount £100,000 (GBP)
Organisation The Leverhulme Trust 
Sector Academic/University
Country United Kingdom
Start 10/2019 
End 09/2022
 
Description Member of International Space Science Institute team on Tropical Width Diagnostics Intercomparison Project 
Organisation International Space Science Institute (ISSI)
Country Switzerland 
Sector Academic/University 
PI Contribution International group of scientists funded by the International Space Science Institute to hold two joint meetings to address the challenge of measuring changes in the width of the tropical belt. PI attended meetings and contributed to remote meetings and joint journal paper.
Collaborator Contribution International group of scientists funded by the International Space Science Institute to hold two joint meetings to address the challenge of measuring changes in the width of the tropical belt. Collaborators attended meetings and contributed to remote meetings and joint journal paper.
Impact Journal paper submitted: Waugh, D., Grise K., Seviour W., Davis S., Davis N., Adam O., Son S-W, Simpson I, Staten P., Maycock A., Ummenhofer C., Birner T., Ming A., Revisiting the Relationship among Metrics of Tropical Expansion, 2018, submitted to J. Climate.
Start Year 2017
 
Description Member of US Clivar Working Group on the Changing Width of the Tropical Belt 
Organisation US Climate Variability and Predictability
PI Contribution Member of international scientific Working Group researching evidence for recent changes in the width of the tropical belt. Remotely attended team meetings.
Collaborator Contribution Members attended two working group meetings in Bloomington, IN (October 2016) and Boulder, CO (October 2017).
Impact Submitted joint journal paper: Waugh, D., Grise K., Seviour W., Davis S., Davis N., Adam O., Son S-W, Simpson I, Staten P., Maycock A., Ummenhofer C., Birner T., Ming A., Revisiting the Relationship among Metrics of Tropical Expansion, 2018, submitted to J. Climate.
Start Year 2017
 
Description Met Office CASE PhD project - Dow 
Organisation Meteorological Office UK
Country United Kingdom 
Sector Public 
PI Contribution Supervisor to a PhD project funded by the NERC SPHERES Doctoral Training Partnership
Collaborator Contribution CASE supervisor to a PhD project funded by the NERC SPHERES Doctoral Training Partnership
Impact Not known
Start Year 2018
 
Description NOAA CIRES Visiting Fellowship 
Organisation National Oceanic And Atmospheric Administration
Department Earth System Research Laboratory (ESRL)
Country United States 
Sector Public 
PI Contribution From June to September 2016 I spent 3 months visiting the Chemical Sciences Division at the NOAA ESRL laboratory in Boulder, CO, USA. I worked on a joint project relating to changes in the width of the tropical belt which is linked to my involvement with an internationally coordinated activity run as a US CLIVAR Working Group. https://usclivar.org/working-groups/changing-width-tropical-belt-working-group
Collaborator Contribution CIRES funded my travel and accommodation during my stay.
Impact The work performed during my visiting fellowship is contributing to two international science activities: (1) US CLIVAR Working Group on the Changing Width of the Tropical Belt; (2) International Space Science Institute team on a Tropical Width Metrics Intercomparison Project.
Start Year 2016
 
Description Be Curious Science Festival, University of Leeds 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I coordinated a climate themed stand at the Be Curious Science Festival at the University of Leeds in March 2017 on the climate of Yorkshire in the past, present and future. The stand consisted of animations of climate model output, a model of the Yorkshire area during the last glacial maximum and information relating to climate change.
Year(s) Of Engagement Activity 2017
 
Description Gave research lecture to prospective undergraduate students at Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Gave taster lecture to prospective undergraduate students who are applying for Environmental Sciences and Meteorology and Climate Science programmes at Leeds University.
Year(s) Of Engagement Activity 2017
 
Description Interview for Tern productions for Channel 4 programme Britains Wildest Weather 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Interviewed by Tern TV production company for Britain's Wildest Weather TV show on Channel 4 in December 2017. Interview footage was not used in final cut.
Year(s) Of Engagement Activity 2017
 
Description Keynote talk at launch of Leeds Institute for Fluid Dynamics 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact I was invited to give a keynote talk at the launch of the Leeds Institute for Fluid Dynamics, a cross-department initiative for fluids research at the University of Leeds.
Year(s) Of Engagement Activity 2019
 
Description Lecturer at National Centre for Atmospheric Science Introduction to Atmospheric Science course 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Gave lecture on 'What is Climate?' as part of NCAS Introduction to Atmospheric Science training course in January 2019
Year(s) Of Engagement Activity 2019
 
Description Lecturer at National Centre for Atmospheric Science Introduction to Atmospheric Science course 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Gave lecture on 'What is Climate?' as part of NCAS Introduction to Atmospheric Science training course in January 2018
Year(s) Of Engagement Activity 2018
 
Description Met Office Academic Partnership Annual Poster Session (Exeter) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact I gave an "inspirational" presentation to PhD students from institutes engaged with the Met Office Academic Partnership (Exeter, Oxford, Reading and Leeds Universities).
Year(s) Of Engagement Activity 2016
 
Description Participation in Royal Academy of Engineering INGENIOUS project workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact The event brought together local schoolchildren, sustainable development practioners, academics and charitable organisations to share our ideas and visions for a sustainable future. A total of around 50 people attended the event.
Year(s) Of Engagement Activity 2018
 
Description Pint of Science Festival in Leeds 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I gave a public talk on climate change as part of the Pint of Science festival held in Leeds in March 2016. Around 40 members of the public attended the talk which was hosted in the local pub.
Year(s) Of Engagement Activity 2016
 
Description Presentation to the Parties of the Montreal Protocol at the 29th Meeting of the Parties to the Montreal Protocol 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Participated in expert Science Panel in the plenary session of the 29th Meeting of the Parties to the Montreal Protocol in October 2017. Presentation was received by the delegates of the Parties of the Montreal Protocol and was live streamed online.
Year(s) Of Engagement Activity 2017
 
Description Provided quote for Carbon Brief article 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Quote provided for online article by Carbon Brief relating to a new study in the journal Nature about changing climate variability.
Year(s) Of Engagement Activity 2018
URL https://www.carbonbrief.org/long-term-climate-variability-could-fall-world-warms
 
Description Quote for National Centre for Atmospheric Science on cold weather in February 2018 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Provided simple explanation for cause of cold weather in February 2018 which was tweeted by the National Centre for Atmospheric Science.
Year(s) Of Engagement Activity 2018
URL https://twitter.com/AtmosScience/status/968512458536181765
 
Description Royal Meteorological Society National Meeting on Recent climate changes in high Southern latitudes (London) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact I gave a talk entitled "An update on the ozone hole" at the Royal Meteorological Society National Meeting. The meeting was live streamed over the web.
Year(s) Of Engagement Activity 2016
 
Description Seminar at Karlsruhe Institute for Technology in Germany 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Gave invited seminar to group at Karlsruhe Institute for Technology.
Year(s) Of Engagement Activity 2018
URL http://www.imk.kit.edu/english/259.php/event/34617
 
Description Talk to Royal Meteorological Society Yorkshire Local Centre 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact 50-60 people attended the talk at the University of Leeds and a further 10-20 watched online remotely. The talk discussed the Beast from the East in February 2018.
Year(s) Of Engagement Activity 2018