Developing the climate science basis for climate action

Manual and Guideline
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Anthropogenic climate change is a critical issue that must be addressed to ensure sustainable development. Climate impacts on human activities and nature are far-reaching. Extreme weather and climate events – such as heavy rainfall, floods, droughts, heatwaves, and tropical cyclones – are major contributors to loss of life and damage to infrastructure and the environment. Changes in the magnitude and frequency of these events and slow onset phenomena associated with climate change – like glacial retreat, sea-level rise, and ocean acidification – affect the balance in ecosystems otherwise needed to sustain human and natural life, and threaten to turn back the advances made over the past decades in socioeconomic development.

By analysing and making clear the relationships among the Earth system’s components and their disturbances and perturbations, climate science contributes to a better understanding of the susceptibility of socio-ecological systems to climate change. When acted upon, climate science can help to safeguard economic and human development and the environment from adverse climate impacts. Such information can be used to plan and design investments that increase the adaptive capacity and resilience of vulnerable populations.

The value of climate science for decision-making depends on the use of the best available data for characterizing the climate system and dealing with uncertainties. Reliable, high resolution and timely climate information is, therefore, a crucial input for decisions intended to promote adaptation to climate change and minimize impacts associated with climate-related hazards.

As the steps of the methodology presented in this guide will show, past, present, and projected future climate information is necessary in order to understand how the climate affects a region or sector. The conclusions drawn from implementing the methodology can support the identification of science-based climate actions and the design of climate services that respond to the local context, address potential vulnerabilities, and promote resilience to future climatic conditions.

Climate Science for Decision-Making

The Paris Agreement (2015) calls for “strengthening scientific knowledge on climate, including research, systematic observation of the climate system and early warning systems, in a manner that informs climate services and supports decision-making”. The Paris Agreement also calls on Parties to undertake rapid reductions in greenhouse gas (GHG) emissions in accordance with and to pursue, adaptation actions based on and guided by the best available science.

The Intergovernmental Panel on Climate Change (IPCC) similarly calls for solutions intended to address climate variability and change that are effective under current and expected future climate conditions. This underscores the need for climate science to be part of decision-making in policy, investment, and other societal applications. At the same time, climate science continuously evolves based on new research and findings. To be relevant for policymaking and decision-support, the scientific process must be informed by local knowledge and context and continually updated as lessons are learned.

In doing so, climate science strengthens countries’ capacities in responding to the agendas they may be seeking to address. Meanwhile, the data and information generated from science-based processes enrich local and global data sets and assessments in a virtuous cycle for better decision-making.

Strengthening Country Capacity

A climate science-based approach strengthens the country capacity for climate analysis and delivery of climate services through institutions such as National Meteorological and Hydrological Services (NMHSs) – as well as strengthens the capacity to identify and select climate action priorities. Monitoring the past, present, and projected future status of climate enriches countries’ abilities to track climate conditions in their local contexts. This provides evidence for country-level contributions to the Paris Agreement Global Stocktake (GST), including the preparation of national communications and future reports under the Paris Agreement transparency framework. A climate science basis also contributes to formulating and implementing other climate-related national policies, including the climate-sensitive objectives of the United Nations Sustainable Development Goals (SDGs) and the Sendai Framework for DRR.

Enriching Local and Global Assessments

Adoption of climate science as an essential element of the framework for climate action facilitates aggregation of scientific findings concerning national and local conditions into WMO and IPCC global processes. This can enrich national, regional, and global data sets and assessments. Such data are a crucial input for climate research, on which the IPCC process, as well as forecast systems for managing climate variability and change, depend. As better data and information are made available through globally aggregated data sets and models, they can enhance local decision-making processes; and as local data and processes improve they can feedback into global initiatives, thereby generating a virtuous cycle of both local and global benefits for decision-making.

Climate Science for Climate Finance

Climate science is relevant to climate finance in at least three ways: a) it supports the selection of transformative climate actions; b) it promotes effective implementation of climate actions, and: c) it facilitates countries’ access to finance.

Selecting Transformative Climate Actions

Climate science provides a basis for identifying and selecting investments necessary for adapting to a changing climate situation. Climate science is an essential aspect that ensures that the proposed intervention will generate climate-adaptive benefits for vulnerable populations, communities, and sectors.

Since climate finance seeks to support climate actions that address climate variability and change at local, national or transnational levels, results obtained through climate actions are strengthened when investments draw upon scientific evidence concerning climate risks and opportunities that need to be understood, identified, assessed, and addressed.

A climate science basis also ensures that funding dedicated to supporting climate action addresses climate impacts as opposed to other non-climate related development needs or priorities. It is expected that climate actions will likely enhance countries’ development agendas that can and should be supported, but as a co-benefit of climate finance. This leverages climate finance in a targeted way that uses climate science to select actions that will indeed address countries’ climate change issues.

Furthermore, a climate science basis contributes to selecting and designing actions that address climate variability and change, and in a manner envisaged to lead to transformational impacts. A scientific basis provides the foundation on which actions can be selected. These actions can be more transformative when the science demonstrates the need for investment and can show where impacts will be greatest. This information can equip project planners and designers to think more innovatively and address future climate impacts in a more transformative way.

Using climate science to identify how climate variability and change contribute to climate impacts and selecting effective actions based on that knowledge, can also prevent actors from selecting actions that may inadvertently lead to maladaptation. Avoiding maladaptation requires paying attention to multiple climatic and non-climatic contributing factors and to future impacts of proposed interventions to ensure that their selection and implementation do not somehow erode sustainable development.

Promoting Effective Implementation

Context-specific climate information can generate more effective results at the local level, increasing the effectiveness of climate actions. By clearly establishing relationships between climatic and non-climatic contributing factors and their impacts, and between climate actions and their outcomes, the use of climate information in the planning and design of projects results in more effective implementation. It also increases the likelihood of actions achieving their intended results.

By building and improving on national, regional, and global data sets, observations and analyses, climate science provides a more comprehensive understanding of what is happening locally in terms of climate trends, variability and change, informing appropriate response actions. Evidence about climate drivers and impacts at a high resolution allows decision-makers to size, plan, and design solutions that respond more effectively to local circumstances and needs. This should ultimately lead to a smoother implementation of the selected actions.

Facilitating Access to Finance

Climate science enables public and private actors, including development financing institutions, governments, and private sector investors (such as financiers and project developers) to take an evidence-based approach to addressing risks arising from climate variability and change. An evidence-based approach: a) provides greater certainty that an intervention is more likely to address impacts in any given area of focus; b) accommodates for better upfront planning and design of investments; and c) mitigates potential risks. This makes science-based investments more attractive to climate financiers. The increased certainty, as well as opportunities for better planning and risk mitigation, in turn, facilitates countries’ access to climate finance.

A Methodology for Developing the Climate Science Basis of Climate Actions

A climate science basis is the scientific underpinning for determining that an action may be needed as a result of a country’s changing climate situation. It is the scientific foundation upon which climate action can be selected. WMO and Green Climate Fund (GCF) have prepared this guide to support countries in developing a climate science basis for climate actions. It provides guidance for ensuring that climate actions are supported by the best available science.

Specifically, the methodology described in this guide provides steps for developing a climate science basis for activities seeking climate finance. It addresses climate-sensitive sectors and is particularly relevant for adaptation investments. The methodology’s utility can be extended to support interventions that climate-proof mitigation actions by improving their resilience to climate variability and change. However, the thrust of the methodology is on selecting adaptation actions.

The methodology helps users identify past, present, and future climate conditions affecting society and the environment and select effective actions under current and anticipated climate conditions. To do this, the methodology involves a four-step process:

Step 1 – Identify the Area of Focus
Step 2 – Identify Relevant Climatic Contributing Factors and Data
Step 3 – Identify Relevant Non-Climatic Contributing Factors
Step 4 – Select Effective Climate Actions.

Scientific Framework

The methodology draws on three categories of climate indicators that constitute its scientific framework:

  1. State of the climate indicators;
  2. Context-specific climate indicators; and
  3. High-impact events indicators.

These categories of indicators can be used to describe the past and current state of the climate, as well as to project future climate conditions. The scientific framework, and a compendium of data, tools, and methods for applying it, are further elaborated in Annex I.

Climate Information Platform (CIP)

A key online tool ( for developing the climate science basis for climate action is the Climate Information Platform (CIP) hosted by the Swedish Meteorological and Hydrological Institute (SMHI). The WMO, GCF, and SMHI collaborated to develop the CIP for users to access site-specific climate data and information. The methods, tools, and procedures provided by the CIP ensure that the outputs from their application and use are based on state-of-the-art scientific evidence.

Target Audience

The target audience for this guide includes all stakeholders whose collaboration enables the climate science value chain that links climate information to climate actions. These actors span project developers to decision-makers engaged in climate-sensitive sectors – from climate forecasters working in NMHSs to urban management authorities and private sector entities.

  • Relevant national authority – national focal point who ensures that the methodology is implemented within a consultative framework; convenes relevant stakeholders; reviews key documents and interventions to ensure that climate actions are addressing Nationally Determined Contributions (NDCs), National Adaptation Plans (NAPs), and/or other national and sectoral strategies; and support identifying, prioritizing, and selecting climate actions.

  • NMHSs – national authoritative sources of observed historical weather, water and climate data, and associated products; provide data and information from hydroclimatic datasets and climate projections at local, national, and regional scales.

  • Other relevant national and sectoral experts – provide information on impacts of climate variability, change and extremes, exposure, vulnerabilities, and risks and opportunities in the climate-sensitive sectors prioritized; contribute to obtaining the data and elaborating the science needed to analyse and assess impacts – including documenting data, information, or knowledge gaps that impede the assessment of climate impacts. These experts should also support identifying, prioritizing, and selecting climate actions.

  • WMO Secretariat and experts – provides scientific guidance as well as supplementary climate and sector-specific data, internationally or regionally certified methods and toolkits, and products based on data on past and current climate and future climate projections for the country.

  • Project Proponents – includes international and national entities that assist in overall project development and implementation. These entities can include United Nations (UN) agencies, multilateral organizations, bilateral agencies, international or local financial institutions, national or regional development banks, and other public or private sector entities involved in the design, development, and/or financing of eventual climate actions.

Structure of this Guide

This guide is structured as follows:

  • Section 1 introduces the methodology and defines its purpose and target audience.

  • Section 2 explores what constitutes best available climate science and highlights the difference in the climate science basis for mitigation and adaptation actions.

  • Section 3 explains the four steps of the methodology to develop a climate science basis for climate action.

  • Section 4 provides an overview of the key technical resources through which stakeholders can access the climate data and products needed for developing the climate science basis.

  • Section 5 discusses options for developing a climate science basis in contexts with limited coverage of observation networks or limited data.

  • Section 6 focuses on enabling mechanisms for implementing the methodology. These mechanisms promote access to the expertise necessary for assembling the inputs needed to prepare a climate science basis and to correctly interpret the scientific results.

  • Section 7 offers some final reflections relevant for implementing the methodology at the country level and how capacity developed through its implementation reinforces the process.

  • Annex I provides a resource for accessing data, methods, and tools, structured in line with the scientific framework of the methodology. It also provides steps and criteria for assessing data requirements and data adequacy. It draws on guidance material developed over the past decades by WMO experts, consistent with internationally agreed standards.

  • Annex II provides examples of how the process described in this guide has been implemented in four countries to develop a climate science basis for a range of climate actions across a wide variety of sectors and geographies.