Introduction

The consideration of climate in environmental and social impact assessments has gradually become established. It existed peripherally in frameworks prior to 2018, often addressed only from the angle of direct greenhouse gas emissions, without systemic analysis. Recent revisions to the main DFI frameworks have changed this logic.

The Equator Principles in their version 4 (October 2020) require, for Category A projects and certain Category B projects, a climate risk assessment aligned with the recommendations of the Task Force on Climate-related Financial Disclosures (TCFD). For high-emission projects (beyond 100,000 tonnes of CO2 equivalent per year), an analysis of lower-emission alternatives and a scenario exercise are required.

The World Bank's Environmental and Social Framework (2018) includes climate risks in ESS1 and treats them as a full dimension of the prior assessment. The 2023 revision of the AfDB's ISS strengthens this dimension by adding explicit climate analysis requirements to OS4.

This article presents the two areas of climate analysis, their methodology for integration into a standard ESIA, the scenario requirements, and the most frequent pitfalls in early ESIAs that integrate this dimension.

The mitigation component: quantifying and reducing emissions

The first component of climate analysis concerns the project's contribution to climate change itself, that is to say its greenhouse gas emissions.

The reference methodology is the GHG Protocol, an international standard that distinguishes three scopes.

Scope 1 covers direct emissions, produced by sources owned or controlled by the project: combustion of fuels by site equipment, generators, any industrial processes, flares for gas projects, direct releases of methane or fluorinated gases.

Scope 2 covers indirect emissions related to purchased energy, primarily electricity consumed, attributed according to the supplier's mix or the national grid.

Scope 3 covers other indirect emissions from the value chain: manufacture of input materials (cement, steel, construction materials), upstream and downstream transport, end-of-life treatment, in some cases emissions related to use of the product delivered (road traffic for a motorway, energy consumption of buildings delivered).

For an infrastructure project, scope 3 is often dominant. The manufacture of cement and steel represents a major share of the carbon footprint of a bridge or a dam. Ignoring this scope, as many older ESIAs did, gives a very partial picture of the real climate contribution.

The assessment of emissions must be accompanied by an analysis of lower-emission alternatives. This analysis is at the heart of the mitigation hierarchy applied to climate: can we avoid the project, minimise it in emissions through technical choices or routing, compensate it with quality carbon credits? This analysis must be documented, not simply asserted.

The adaptation component: assessing climate vulnerability

The second component concerns the effects of climate change on the project, the counterpart to the first. The infrastructure will be exposed, over its lifespan, to climatic conditions that will differ from those observed historically. The analysis aims to anticipate these changes to prevent the project from becoming inoperative or dangerous mid-way.

Physical exposure is characterised by the climate phenomena to which the project will be subjected: average and extreme temperatures, precipitation (quantity, intensity), cyclones and storms for coastal projects, droughts for water-dependent infrastructure, sea-level rise, bush fires, river floods.

The sensitivity of the infrastructure describes the characteristics that make it more or less vulnerable: composition of materials, design of drainage systems, dimensioning of hydraulic structures, location in the flood plain, altitude relative to anticipated submersion.

Adaptive capacity combines planned or foreseeable measures to reduce vulnerability: reinforcement of structures, over-dimensioning of structures, redundancy of critical systems, flood protection zones.

The result of this analysis takes the form of a vulnerability matrix that identifies, by hazard and by project component, the level of residual risk and the adaptation measures integrated into the design.

Climate scenarios

The difficulty of the exercise lies in the prospective nature of the analysis. An infrastructure project built in 2026 will be operated until 2056 or beyond. The climatic conditions of that period are not those of the present.

The TCFD recommends the use of multiple scenarios to frame uncertainty, in particular a scenario compatible with warming limited to 1.5 or 2°C and a so-called "business as usual" scenario with higher warming. The two scenarios produce different risk trajectories that the project must be able to absorb.

Scenario data come from the work of the Intergovernmental Panel on Climate Change (IPCC), broken down by region via the Shared Socioeconomic Pathways (SSP) scenarios and the regional projections of the Coupled Model Intercomparison Project (CMIP). These public resources are available to qualified consultancies.

The exercise does not consist of precisely predicting the future climate, which would be illusory, but of building a robust understanding of the envelope of probable conditions and verifying that the project holds within that envelope. A project that holds only in the most favourable scenario is not a resilient project, it is a project at risk.

Integration into the standard ESIA

Climate analysis does not come as an annex; it permeates the entire ESIA.

At the scoping stage, climate issues are identified from the outset: is the project high-emission? Is it exposed to climate hazards? These questions guide the depth of the work to come.

At the baseline stage, the physical baselines integrate a climate characterisation of the area: historical data, observed trends, reference projections. This characterisation serves as the basis for the vulnerability analysis.

At the impact assessment stage, the project's emissions are quantified over the lifespan, alternatives are analysed, vulnerability is assessed according to the selected scenarios.

At the mitigation stage, the ESMP integrates climate mitigation measures (reduction of the project's emissions) and adaptation measures (strengthening of resilience). These measures often have their own costs and timelines that must be integrated into the project schedule and budget.

At the monitoring stage, climate indicators feed regular reporting: annual emissions, carbon intensity per unit produced or transported, monitoring of extreme climate events experienced by the project, adjustments to adaptation measures.

The pitfalls of early climate ESIAs

Five pitfalls recur in ESIAs that integrate climate for the first time.

Emissions calculation limited to scope 1. Many ESIAs limit themselves to direct emissions, which are easier to quantify, and ignore scopes 2 and 3. For an infrastructure project, this limitation produces a picture of the carbon footprint that may be three to ten times lower than reality.

Absence of alternatives analysis. Emissions are quantified but no lower-emission alternative is seriously compared. Lenders, particularly under EP4, examine this analysis and require it before acceptance.

Adaptation analysis based on historical data only. Some ESIAs characterise climate by means observed over recent decades, without integrating projections. This approach is now explicitly insufficient for lenders.

Selection of a single scenario. An analysis conducted on a single climate scenario, even if well documented, does not satisfy the TCFD requirements adopted by EP4. Scenario plurality is required for eligible projects.

Dissociation between quantification and action. Emission figures and vulnerability scenarios are produced but do not lead to concrete measures integrated into the design and the ESMP. This passivity transforms climate analysis into a sterile documentary exercise.

Conclusion

Climate analysis in an ESIA is not a marginal topic; it is a dimension that has become established in a few years as a structural component. Lenders who did not speak of it ten years ago require it today. Those who integrate it today into their review grids will do so with greater rigour in five years.

For a project owner, the right strategy is to anticipate this rise in requirements rather than endure it. Climate analysis, conducted seriously from the studies stage, produces design decisions that withstand climate change over the project's lifespan, and it builds the credibility of the file with all lenders who will progressively integrate these requirements into their standards.

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