Climate change as a risk multiplier

November 2021

Adaptation, resilience and its relevance to national security


The surge in the intensity and frequency of extreme weather events increasingly reveals the need for profound changes in economic and productive activities. A recent study published by the Nature journal [1], highlighted the climate urgency: analyzing more than 100,000 studies through machine learning, researchers identified that 80% of the planet’s area, where 85% of the global population resides, has already experienced physical impacts attributable to climate change, such as changes in rainfall patterns, temperature, droughts and floods.

In 2020, the occurrence of floods, hurricanes and storms increased. In the United States, for example, ¼ of the population was exposed to extreme heat waves in the summer of 2020 [2], and there was a record of extreme weather events, with an approximated cost of around US$95 billion. These costs are estimated to have totaled more than US$1.8 trillion in the last 40 years in the country.

Also, recent research released by the UK’s national weather service during COP26 estimates that a billion people could be exposed to extreme heat if the global average temperature rises by 2°C, reaching half of the global population in a scenario of a 4°C rise [3].

Such data help explain why climate change and its impacts on international peace and security are currently part of the UN Security Council’s agenda. Climate change is a risk multiplier. A Chatham House report [4] points out that changes in rainfall patterns, increase in average temperature, droughts, heat waves, fires and floods can bring serious impacts such as the emergence of new diseases, water scarcity, food insecurity, reduced productivity at work due to extreme heat, loss of life and biodiversity.

From such impacts, possible consequences with implications for the national peace and security agenda can be highlighted. First, there could be an increase in forced migration, causing rural exodus and a potential refugee crises. Furthermore, armed conflicts can be exacerbated through regional struggles for scarcer natural resources, rise of extremist groups, organized crime and violence, and even civil wars. Finally, as the Task Force on Climate-related Financial Disclosure has repeatedly highlighted, climate change can cause market destabilization through spikes in commodity prices, loss of assets value, mass sale of assets, and collapse of financial markets.

Some governments already recognize such threats and are seeking to identify their vulnerabilities and define plans for adaptation and resilience. An executive order from US president Joe Biden in early 2021 called for all US government ministries and agencies to review and report their exposure to climate change risks, reports which were released in late October. The Defense Department, for example, estimates that its Florida-based Southern Command may face increasing instability in South America, as well as demand for humanitarian assistance as a result of drought and heat in the region.

The data and analysis above demonstrate the relevance of the adaptation, resilience agenda and its relevance to countries’ national security. In parallel with the mitigation efforts, which aim to reduce greenhouse gas emissions in order to limit the increase in the global average temperature, it is imperative that leaders, both governments and companies, incorporate the theme of climate resilience in their decision making.

These themes were discussed at an event promoted by Centro Soberania e Clima , a Brazilian think-tank dedicated to the study on how sovereignty and climate matters are intertwined, on November 11, under the theme “Oil, Sovereignty and Sustainability”. Panelists included Clarissa Lins, Admiral Eduardo Leal Ferreira and Luiz Barroso (PSR), with comments by Sergio Etchegoyen and moderation by Felipe Sampaio.

[1] Machine-learning-based evidence and attribution mapping of 100,000 climate impact studies | Nature Climate Change

[2] Heat-related symptoms affected one-quarter of Americans in summer 2020 | NSF – National Science Foundation

[3] One billion face heat-stress risk from 2°C rise – Met Office

[4] 2021_Chatham House_Climate change risk assessment 2021

Foto: Kelly Sikkema via



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