The Impacts of Climate Change on Human Societies

Introduction: What diagram are we talking about?

Presented in the Executive Summary for Policymakers of the IPCC Working Group II report^[1], this diagram^[2] provides an overview of the consequences of climate change for three major areas, namely:

1. Access to water and food production;
2. The health and well-being of populations;
3. Cities, institutions, and infrastructure.

It summarizes the findings of a large number of scientific studies on the impacts of climate change on human systems, both globally and in different regions of the world. To provide a clearer understanding, the diagram indicates the level of confidence regarding climate change’s role in disrupting human systems. The blue circles thus indicate a high to very high level of confidence, the purple ones a medium level, and so on. The “plus” and “minus” symbols also provide some clarification regarding the nature of this impact: negative only (-) or negative and positive depending on the context (±).

Access to Water and Food Production

Water Resources and Food Production (via (agriculture, livestock farming, fishing, and aquaculture) are feeling the impacts of climate change:

• The impacts are exclusively negative in three regions of the world: Africa, small islands, and the Mediterranean region.
• Positive and negative impacts in other regions and globally. More specifically, with regard to agricultural productivity, the negative impacts of climate change are primarily observed in mid- and low-latitude regions, while the positive impacts are observed in high-latitude regions.

Globally, while agricultural productivity continues to rise, climate change has been responsible for slowing that growth over the past 50 years. Better predicting the local impacts of climate change on water resources and food production is therefore a major challenge for nearly every country in the world. It is also an economic challenge for many companies:

• First and foremost, for those in the agriculture, agri-food, fisheries, and aquaculture sectors, who see their source of income directly threatened. For example, in nearly every region of the world, climate change is expected to negatively impact fishing yields and aquaculture production—a risk for all those who harvest or depend on marine resources. For these stakeholders, analyzing their vulnerability to climate change today means building their resilience for the years ahead—and that of the society in which they operate.
• Next, with regard to the global economy: when there is a shortage of water or food, society as a whole is affected, because these resources are one of the cornerstones of a nation’s stability. In the 1980s, Morocco was rocked by a popular uprising that particularly affected Casablanca, known as the “Bread Revolt.” Several factors explain this crisis, which centered on the cost of food: a deteriorating economic situation and a reduction in government subsidies for basic necessities, compounded by severe droughts that had been affecting the country since 1979.^[3]. Climate change can thus be an aggravating factor leading to social and economic instability in countries.

Public Health and Well-Being

The second area, concerning the health and well-being of populations, focuses on four major categories of risks: 1. The spread or emergence of infectious diseases, 2. Suffering caused by heat and malnutrition, 3. The deterioration of populations’ mental health, and 4. Population displacement caused by climate change. These are four areas in which climate change is expected to have only negative impacts!

More specifically, with regard to the physical health of populations, climate change is responsible, on a global scale, for: an increase in the incidence of food- and waterborne diseases, the expansion of the range of vector-borne diseases, and the emergence of zoonoses in new regions of the world.

The issues of public health and well-being are a matter of social justice that governments must address—but not only them: they also concern all stakeholders in the business world. The COVID-19 crisis has clearly demonstrated this: ensuring the physical and mental well-being of populations also means ensuring the smooth operation of businesses. Building climate resilience while taking into account the impacts of climate change on people’s well-being and health is therefore a dual social and economic challenge for all civil society actors.

Cities, infrastructure, facilities, and key economic sectors

This last area of impact is perhaps the one in which the consequences of climate change are easiest to visualize: on a global scale and in virtually every region of the world, climate change threatens the proper functioning and integrity of cities, infrastructure, and facilities, as well as key economic sectors.

This damage or destruction, which is primarily linked to extreme weather events, is often quite localized and poses a significant challenge for economic stakeholders who may be directly affected.

Exposure to extreme weather events varies between companies, or between different sites within the same company. Such disruptions may not affect the company itself, but rather a player in its value chain, infrastructure used for transporting goods, or the networks on which it depends (such as the electricity and natural gas grids). For a business, simply assessing the vulnerability of its own sites to extreme weather events is not enough; it must adopt a true value chain perspective.

Conclusion

What conclusions can we draw from this diagram? First, that it is possible to gain a much deeper understanding of how climate change affects human societies. The exercise we’ve conducted here was intended only to highlight a few of the many conclusions that can be drawn from this diagram; it was not meant to be exhaustive.

Second, climate risk is multidimensional: it does not affect just one aspect of human societies, but the entire world in which we live. In the context of globalization, no actor—whether public or private—can consider itself unaffected by the consequences of climate change.

The framework also highlights the interdependent nature of climate resilience: For a company, assessing its own vulnerability to physical risks by taking into account its entire value chain and encouraging the stakeholders on which it depends to do the same means equipping itself with the means to adapt and fostering its own resilience, as well as that of the society in which it operates.

The value chain perspective is one of the principles on which the OCARA method, developed by Carbone 4 in partnership with ADEME, HDI Global France, Bureau Veritas, and the Grand Est Chamber of Commerce and Industry (CCI). OCARA provides a methodology for conducting a climate resilience assessment and launching an adaptation strategy.