Chapter 01 · Climate & transitionClimate & Greenhouse Gas Emissions
Climate change impact assessment
Definition
The systematic assessment of interactions between a proposed project, plan, policy or asset and a changing climate, in both directions: how the intervention affects the climate (emissions) and how current and future climate conditions affect the intervention's performance, impacts and justification. It extends environmental impact assessment (EIA) with climate scenario analysis, forward-looking baselines and vulnerability assessment.
References
Two-direction assessment (project effects worsened by climate; project vulnerability); redefined future baselines; adaptation option evaluation; uncertainty characterisation.
Adaptation-specific assessment challenges; shifted-baseline problem; attribution and evaluation methods.
Overview
What it means
Traditional EIA assumes a stationary climate; climate change impact assessment drops that assumption.
Practice guidance requires assessors to redefine baseline environmental conditions under climate projections, evaluate how climate change may worsen a project's effects, assess the vulnerability of project components themselves (infrastructure lifetime, water availability, extreme events), and select adaptation options — each estimate carrying explicit uncertainty and confidence characterisation.
The same discipline appears in development cooperation (climate-risk screening of investments), finance (physical-risk assessment of portfolios and assets) and disclosure regimes (scenario analysis under TCFD/IFRS S2). Its methodological frontier is shifted baselines: designing for the climate of the asset's operating life, not the climate of the planning documents.
How it is used
EIA regulators integrate climate considerations into assessment directives; development banks screen portfolios for climate risk; engineers and planners apply climate-infrastructure design standards; adaptation plans use impact and vulnerability assessments as their analytical core.
Why it matters
Every long-lived asset approved today will operate in a changed climate; impact assessment is the gate where that reality either enters decisions or is ignored.