Standard & Poors, the international credit rating company, released a report outlining the next two global “mega-trends” that threaten the global economy: aging populations, and climate change. The S&P report noted that the poorest countries of the world were likely to be disproportionately affected by the effects of unpredictable weather systems and disasters.

“While most sovereigns will feel the negative effects of climate change to some degree, we expect the poorest and lowest rated sovereigns will bear the brunt of the impact,” the report noted. “This is in part due to their reliance on agricultural production and employment, which can be vulnerable to shifting climate patterns and extreme weather events, but also due to their weaker capacity to absorb the financial cost.”

The report, titled “Climate Change Is A Global Mega-Trend For Sovereign Risk”, concludes the impact on creditworthiness will probably be felt through various channels, including economic growth, external performance, and public finances. Sovereign nations will be unevenly affected by climate change, with poorer and lower rated sovereigns typically hit hardest, which could contribute to rising global rating inequality.

The report also performed a vulnerability assessment on 116 countries throughout the world based on three variables. The percentage of population living 5 meters below sea level was used to calculate the potential severe economic impacts and loss due to rising sea levels, flooding, groundwater salinity contaminations.

Another factor was the portion of national GDP that came from agriculture; agriculture is an important industry in many small and growing economies, yet is also highly susceptible to minute changes in temperature, precipitation, and weather patterns. Therefore, the larger share of agriculture a country depended on to survive, the more vulnerable that nation is to economic crises due to climate change.

Finally, the S&P used the Notre Dame University Global Adaptation Index (GAIN), which measures the degree to which a system is susceptible to, and unable to cope with, adverse effects of climate change. The index includes three components: exposure, sensitivity and adaptive capacity.

The S&P concluded that Cambodia was the most vulnerable country in the world, followed by Vietnam and Bangladesh. Although the credit ratings agency has never downgraded a nation’s credit rating due to a national disaster, the S&P warned that ultimately, the continued negative impacts felt from either natural disasters or could curb the ability of a small nation to borrow the funding necessary to get through a time of economic instability.