Climate change assessments

Given the increasingly urgent need to manage the impacts of climate change, it is not surprising that frameworks for climate change impact assessments have evolved.

Typically, changes to the climate and their consequences for real-world systems are investigated from two perspectives commonly referred to as “top-down” or “bottom-up” approaches. Top-down methods involve studies that obtain information on (i) the representation of different emissions scenarios, (ii) global model simulations, (iii) possible downscaling steps, and (iv) an assessment of the range of outputs from a particular impact model, such as a rainfall-runoff model.

On the other hand, a bottom-up approach starts with an attempt to identify the nature of climate risks that a socio-ecological system is exposed to under the current climate. These analyses also evaluate other aspects that influence the socio-ecological system and its performance. As such, climate risks are assessed in conjunction with other demands and impacts on the system. These types of assessments can help identify expected climate changes, assess the vulnerability of socio-ecological systems to those changes, and establish the level of confidence in the occurrence of those changes. Based on these findings, users can determine how to adapt or implement measures to reduce climate risks and impacts.

There are various ways in which climate assessments can occur. For example, the Cheltenham Borough Council in the UK has used a Climate Impact Assessment tool within its internal decision-making process, aligning all Council policies with its commitment to climate action. This means that even before a development or action is proposed, the Climate assessment must precede the Environmental Impact Assessment (EIA).

In other cases, climate impact assessments are incorporated as a tool or approach within broader EIAs.

Some interesting examples of climate impact assessments and how they are conducted include:

_{The Akosombo Hydroelectric Power Station on the Volta River supplies with energy almost whole Ghana and half of Togo, West Africa.}

Africa Hydropower: Africa is expected to face multiple hazards resulting from climate change, and hydropower is seen as a potential solution to minimize the adverse effects of climate change and help Africa achieve its Sustainable Development Goals (SDGs) while transitioning to clean energy. To determine the best approach and establish a range of hydropower developments, a climate risk and impact assessment was conducted by comparing two different climate scenarios. This assessment helped identify measures to enhance climate resilience and provided policy recommendations.

_{Damage caused by hurricane Sandy in the Rockaways, Queens, New York.}

New York: The City of New York launched a detailed climate impact assessment in 2021. It is a comprehensive analysis of how climate change is currently affecting and will continue to affect New York State, and how these impacts are likely to change in the decades ahead. The assessment also provides ideas and suggestions for building adaptation programs to increase the city’s resilience in coping with climate change in the long term. The findings of this overarching assessment will inform all future developments within the city, as well as the accompanying Environmental Impact Assessments (EIAs).

_{Aerial View of Solar Park Seßlach, Germany.}

Germany: In 2021, Germany conducted a nationwide climate impact and risk assessment, which revealed that the country will face droughts, heatwaves, and heavy rainfall that will affect the entire population if no action is taken. In response to this assessment, the German government has established support mechanisms, including financial support, for climate adaptation and action at all levels of governance. Cities, districts, and municipalities (local governments) will be supported in implementing measures such as urban greening, energy transitions, and on-ground climate adaptation. Germany recognizes the need for more trees in cities, increased greenery on roofs, more space for rivers, and urgent action to implement these measures. All ongoing and future developments and EIAs will be informed by this climate impact and risk analysis, and decisions will take into account its findings.

Optional further reading that summaries elements or examples of climate impact assessments:

_{1. Chang, I. Shin, and Jing Wu. “Integration of Climate Change Considerations into Environmental Impact Assessment- Implementation, Problems and Recommendations for China.” Frontiers of Environmental Science & Engineering, vol. 7, no. 4, 2013, pp. 598–607, https://doi.org/10.1007/s11783-013-0496-1.}

_{2. Jönsson, Anna Maria, et al. “Enhanced Science–stakeholder Communication to Improve Ecosystem Model Performances for Climate Change Impact Assessments.” Ambio, vol. 44, no. 3, 2015, pp. 249–55, https://doi.org/10.1007/s13280-014-0553-4.}

_{3. Larsen, Sanne Vammen. “Is Environmental Impact Assessment Fulfilling Its Potential? The Case of Climate Change in Renewable Energy Projects.” Impact Assessment and Project Appraisal, vol. 32, no. 3, 2014, pp. 234–40, https://doi.org/10.1080/14615517.2014.898386.}

_{4. Warnatzsch, Erika A., and David S. Reay. “Temperature and Precipitation Change in Malawi: Evaluation of CORDEX-Africa Climate Simulations for Climate Change Impact Assessments and Adaptation Planning.” The Science of the Total Environment, vol. 654, 2019, pp. 378–92, https://doi.org/10.1016/j.scitotenv.2018.11.098.}