Rising Temperatures, Falling Ratings: The Effect of Climate Change on Sovereign Creditworthiness

Enthusiasm for ‘greening the financial system’ is welcome, but a fundamental challenge remains: financial decision makers lack the necessary information. It is not enough to know that climate change is bad. Markets need credible, digestible information on how climate change translates into material risks.

To bridge the gap between climate science and real-world financial indicators, we simulate the effect of climate change on sovereign credit ratings for 108 countries, creating the world’s first climate-adjusted sovereign credit rating. Under various warming scenarios, we find evidence of climate-induced sovereign downgrades as early as 2030, increasing in intensity and across more countries over the century. We find strong evidence that stringent climate policy consistent with limiting warming to below 2°C, honouring the Paris Climate Agreement, and following RCP 2.6 could nearly eliminate the effect of climate change on ratings. In contrast, under higher emissions scenarios (i.e., RCP 8.5), 63 sovereigns experience climate-induced downgrades by 2030, with an average reduction of 1.02 notches, rising to 80 sovereigns facing an average downgrade of 2.48 notches by 2100.

We calculate the effect of climate-induced sovereign downgrades on the cost of corporate and sovereign debt. Across the sample, climate change could increase the annual interest payments on sovereign debt by US$ 22–33 billion under RCP 2.6, rising to US$ 137–205 billion under RCP 8.5. The additional cost to corporates is US$ 7.2–12.6 billion under RCP 2.6, and US$ 35.8–62.6 billion under RCP 8.5.

Bracing for the Typhoon: Climate Change and Sovereign Risk in Southeast Asia

Southeast Asian countries are among those most heavily affected by climate change. The number and intensity of extreme weather events in the region have been increasing markedly, causing severe social and economic damage. Southeast Asian economies are also exposed to gradual effects of global warming as well as transition risks stemming from policies aimed at mitigating climate change. To empirically examine the effect of climate change on the sovereign risk of Southeast Asian countries, we employ indices for vulnerability and resilience to climate change and estimate country-specific OLS models for six countries and a fixed-effects panel using monthly data for the period 2002–2018. Both the country-specific and the panel results show that greater climate vulnerability appears to have a sizable positive effect on sovereign bond yields, while greater resilience to climate change has an offsetting effect, albeit to a lesser extent. A higher cost of debt holds back much-needed investment in public infrastructure and climate adaptation, increases the risk of debt sustainability problems, and diminishes the development prospects of Southeast Asian countries.

Climate Change and Sovereign risk

Climate Change and Sovereign Risk provides a comprehensive analysis of the ways in which climate risks affect sovereign risk. New empirical evidence demonstrates how climate risk and resilience influence the cost of sovereign borrowing, with econometric analysis showing that higher climate risk vulnerability leads to significant rises in sovereign bond yields. The report provides a closer look at Southeast Asia, a region with significant exposure to climate hazards such as storms, floods, sea level rise, heat waves, and water stress. It explains that the implications of climate change for macrofinancial stability and sovereign risk are likely to be material for most, if not all, countries in Southeast Asia.

The report also stresses the need for governments to climate-proof their economies and public finances or potentially face an ever-worsening spiral of climate vulnerability and unsustainable debt burdens. It urges financial authorities to integrate climate risk into their risk management processes. It also encourages governments to prioritize comprehensive climate vulnerability assessments and work with the financial sector to promote investment in climate adaptation.

The report was co-published by SOAS University of London, ADBI, the World Wide Fund for Nature, and Four Twenty Seven.

Feeling the Heat: Climate Risks and the Cost of Sovereign Borrowing

This paper empirically examines the link between the cost of sovereign borrowing and climate risk for 40 advanced and emerging economies. Controlling for a large set of domestic and global factors, the paper shows that both vulnerability and resilience to climate risk are important factors driving the cost of sovereign borrowing at the global level. Overall, we find that vulnerability to the direct effects of climate change matter substantially more than climate risk resilience in terms of the implications for sovereign borrowing costs. Moreover, the magnitude of the effect on bond yields is progressively higher for countries deemed highly vulnerable to climate change. Impulse response analysis from a set of panel structural VAR models indicates that the reaction of bond yields to shocks imposed on climate vulnerability and resilience become permanent after around 12 quarters, with high risk economies experiencing larger permanent effects on yields than other country groups.