Climate and Ocean research: The World Climate Research Programme (WCRP)

Ocean issues are gaining visibility due to various organizational and political developments at the international level. These include:

• The growing Blue Economy
• The Sendai Framework for Disaster Risk Reduction, which motivates the development of multi-hazard impact-based services for decision-making support
• An increasing awareness of the importance of the ocean for understanding, predicting and responding to climate variability and change and sustainable development, as highlighted by publications such as the Intergovernmental Panel on Climate Change's (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate
• The United Nations Ocean Conferences, Sustainable Development Goals and Decade of Ocean Science for Sustainable Development (2021-2030). An opportunity to drive innovation, advance ocean science.

International ocean research is largely coordinated through the International Oceanographic Commission (IOC) of UNESCO, International Science Council (ISC) and WMO and their partnerships. WMO has significant interests in the development and delivery of ocean information to underpin the breadth of research, applications and services delivered by its Members, thus the Organization is involved in a range of ocean activities. The World Climate Research Programme, co-sponsored by WMO, IOC-UNESCO and International Science Council (ISC), offers a prime example of this coordination and partnership in climate research.

IOC ocean science efforts are organized under a collection of activities. In addition to WCRP, these are coordinated through a number of small projects and teams on themes such as ocean carbon and acidification, nutrients, eutrophication and deoxygenation, climate science (WCRP), climate change and ecosystem impacts, and marine plastics. The IOC, in partnership with WMO and other UN agencies, led the development of the UN Decade of Ocean Science for Sustainable Development, which has the potential to strengthen the international ocean research effort. The Joint WMO-IOC Collaborative Board (JCB), coordinates joint ocean related activities between the two Organizations.

ISC connects its two UN partners to a very broad global scientific constituency not usually directly connected to intergovernmental agencies. For example, there is the International Union of Geophysics and Geodesy that includes the International Association of Physical Sciences of the Ocean, which convenes regular international scientific conferences and fora. There is also the Scientific Committee on Oceanic Research (SCOR) that focuses on promoting international cooperation in planning and conducting oceanographic research and solving methodological and conceptual problems that hinder research. SCOR includes capacity building in a number of its research programmes and working groups, mainly targeting the development of observational methodologies and best practices. A recently signed cooperation agreement between ISC’s Future Earth and WCRP will more closely link their science activities, particularly in what is often referred to as ‘Actionable Science.”

WMO climate-ocean research activities are coordinated through the WCRP. One of the core WCRP projects is the Climate and Ocean: Variability, Predictability and Change (CLIVAR), which launched in 1995. The WCRP “Grand Challenges” includes the Regional Sea Level Rise and Coastal Impacts and Near Term Prediction (www.wcrp-climate.org/grand-challenges/ grand-challenges-overview). It also has a number of new “Lighthouse” activities that cover different aspects of the climate system, of which the ocean component is critical. One example is My Climate Risk, which aims to develop a new framework for assessing and explaining regional climate risk to deliver climate information that is meaningful at the local scale, and which will include regional sea level aspects (www.wcrp-climate.org/wcrp-ip-la).

Climate and Ocean – Variability, Predictability and Change

CLIVAR focuses on international scientific research coordination in the ocean. CLIVAR’s mission is to understand the dynamics, the interaction and the predictability of the coupled ocean-atmosphere system. To this end it facilitates observations, analysis and predictions of changes in the Earth’s climate system, enabling better understanding of climate variability and dynamics, predictability, and change, to the benefit of society and the environment in which we live. It aims to improve:

• Ocean system models
• Ocean-observing systems
• Ocean data, synthesis and information systems
• Knowledge transfer and stakeholder feedback
• Education, capacity building and outreach.

CLIVAR builds on the success of the Tropical Ocean Global Atmosphere (TOGA) project and the World Ocean Circulation Experiment (WOCE), both advanced the scientific understanding of ocean circulation and atmosphere-ocean interactions.

Science Directions in a Post COP21 World of Transient Climate Change: Enabling Regional to Local Predictions in Support of Reliable Climate Information Stammer, D., Bracco, A., Braconnot, P., Brasseur, G. P., Griffies, S. M., & Hawkins, E. (2018). Science directions in a post COP21 world of transient climate change: Enabling regional to local predictions in support of reliable climate information. Earth’s Future, 6, 1498–1507. https://doi.org/10.1029/2018EF000979

CLIVAR research has provided fundamental knowledge about the drivers of variability and predictability in the coupled climate system with emphasis on the ocean, the key subsystem that regulates the Earth climate. For instance, CLIVAR initiatives have been instrumental in the development of El Niño Southern Oscillation (ENSO) seasonal prediction systems and pioneered decadal predictions. The development of coupled models as part of CLIVAR contributed significantly – through the development of coupled climate modelling capabilities and of climate model intercomparison projects – to understanding the response of the climate system to anthropogenic increases in radiatively active gases and changes in aerosols.

CLIVAR – through the advancement of climate observing systems, process studies and coupled climate models – has greatly advanced our understanding of the processes driving ocean circulation and its role in the coupled climate system. We now have unique, new observing, modelling and reanalysis capabilities that support scientific investigations into ocean dynamics and variability and this is due in large part to CLIVAR. In addition, CLIVAR embraces and often formally endorses many new activities and projects that develop outside its framework but that demonstrate clear relevance to its goals and objectives. CLIVAR organizes topical scientific workshops aimed at communication, collaboration education, and furthering the careers of young scientists. WCRP, through CLIVAR, makes fundamental contributions to the knowledge and understanding of the climate system and which underpin the provision of operational climate services.

The CLIVAR legacy includes the implementation and development of multinational and multi-platform observing networks in all ocean basins, the development of climate models with realistic ocean components and the development of ocean reanalyses. These bridge observations and modelling through data assimilation. In-situ elements of established observing systems include global deployment of surface drifters and profiling Argo floats, ocean gliders, arrays of moorings in both tropical and extra-tropical locations, full-depth sampling of the water column from ships of the repeat hydrography program, etc. Since the late 1970s, satellite observations of the ocean have become a crucial part of the global observing system. CLIVAR works closely with the Global Climate Observing System (GCOS) and Global Ocean Observing System (GOOS), using the “Framework for Ocean Observing” to guide its implementation of an integrated and sustained ocean observing system.

As WCRP moves into a new strategic planning and implementation phase, CLIVAR’s new objective is to describe, understand and model the dynamics of the coupled climate system, emphasizing ocean-atmosphere interactions and identifying the processes responsible for climate variability, change and predictability on subseasonal-to-seasonal, interannual, decadal and centennial time scales. In detail, CLIVAR will critically contribute to the new WCRP strategy by covering the following topics:

• Understanding the ocean’s role in climate variability, change, and transient sensitivity
• Understanding the ocean’s role in shaping the hydrological cycle and distribution of precipitation at global and regional scales
• Understanding the drivers of regional climate phenomena that provide predictability on different time scales
• Provision of coordinated observations, analyses and predictions of variability and change in the Earth’s climate system
• Detection, attribution and quantification of climate variability and change
• Development and evaluation of climate simulations and predictive capabilities.

To this end, CLIVAR coordinates the international research in climate and ocean science, facilitating cooperation amongst national and multinational efforts, thereby enabling global climate research beyond the regional and institutional capabilities of any individual nation. It facilitates observations, analysis, predictions and projections of variability and changes in the Earth’s climate system, enabling better understanding of climate variability and dynamics, predictability, and change, to the benefit of society and the environment in which we live. Through its Panels, Research Foci, workshops, summer schools and conferences, CLIVAR continues to bring together researchers from all over the world (see e.g. Stammer et al., 2018). In doing so, CLIVAR develops a strong, multidisciplinary international community of scientists at all stages of their career to coordinate the efforts required to measure, simulate and understand coupled ocean-atmosphere dynamics, and to identify processes responsible for climate variability, change and predictability.

The development of reliable regional climate change information that can be provided on time scales from seasonal to centuries and beyond, to the benefit of humanity and life on Earth, is central to future climate science strategies. CLIVAR through its work contributes directly to reaching those goals. It is anticipated that in a 5- to 10-year timeframe much progress will be achieved in expanding theoretical process understanding, in improving climate models through better representation of important climate processes in numerical models and in improving regional climate predictions and associated climate information on time scales from seasonal to decadal. This will build firmly on efforts required to improve and sustain the Global Climate Observing System (GCOS).

CLIVAR, like many WCRP activities, relies on national support, provided through annual voluntary contributions and crucially on the hosting of International Project Offices. CLIVAR has two such offices: The International CLIVAR Global Project Office, hosted by the Ministry of Natural Resources First Institute of Oceanography in Qingdao, China, and the International CLIVAR Monsoon Project Office, hosted by the Indian Institute of Tropical Meteorology in Pune, India.

Regional Sea-level Change and Coastal Impacts

A roadmap to sustained observations of the Indian Ocean for 2020-2030

Recognizing that coastal sea level rise is among the most severe societal consequences of anthropogenic climate change, WCRP formed a Grand Science Challenge on Regional Sea-level Change and Coastal Impacts.

Contemporary global mean sea level rise will continue over many centuries as a consequence of anthropogenic climate warming, with the detailed pace and final amount of rise depending substantially on future greenhouse gas emissions.

Over the coming decades, regional sea level changes and variability will significantly deviate from global mean values. The detailed sea level change along coastlines can therefore potentially be far more substantial than the global mean rise and will depend on many processes involving the ocean, the atmosphere, the geosphere and the cryosphere. Societal concerns about sea level rise originate from the potential impact of regional and coastal sea level change and associated changes in extremes on coastlines around the world, including potential shoreline recession, loss of coastal infrastructure, natural resources and biodiversity, and in the worst case, displacement of communities and migration of environmental refugees.

Local sea level rise and extreme events can have significant impacts on coastal zones. On subsiding coasts, the impacts of resulting sea level rise are already demonstrable in some coastal cities and deltas. It is very likely that a large fraction of the world’s coasts will be affected by climate-induced sea level rise. Detailed impacts, however, will vary strongly from region to region and coast to coast. They cannot be easily generalized, as changing mean and extreme coastal water levels depend on a combination of near shore and offshore processes, related to climatic but also non-climatic anthropogenic factors. These include natural land movement arising from tectonics, volcanism or compaction; land subsidence due to anthropogenic extraction of underground resources; and changes in coastal morphology resulting from sediment transport induced by natural and/or anthropogenic factors.

The overarching goal of the Sea Level Grand Challenge has been to:

• establish a quantitative understanding of the natural and anthropogenic mechanisms of regional to local sea level variability 
• to promote advances in observing systems required for an integrated sea level monitoring
• to foster the development of sea level predictions and projections that are of increasing benefit for coastal zone management.