For all the blustering and doubt from the seemingly pro-business right over climate change, something doesn’t add up: Businesses themselves are investing plenty of money to brace for its impact, understandably wary of the effect on their bottom lines. That might be due in part to a recent report by Standard & Poor’s, which suggests that without action, climate change could impact the credit rating of entire countries.

In the overview, they state that “Climate change is likely to be one of the global mega-trends impacting sovereign creditworthiness, in most cases negatively.” Sure, some previously inhospitable locations might see some welcome warming and/or wetness, but in general: Warm places will get warmer, already wet places will get wetter and already dry places will get dryer. That spells drought for some, flooding for others, and billions of dollars in losses for the planet.

The report acknowledges that the “science is complex,” and that it’s a “global, collective action problem.” What’s perhaps most disheartening is that the report finds that low-income and third-world countries will be most affected by the change (that is, those who can least afford it will be hit the hardest). Established nations, on the other hand, will be hit harder by an aging, mostly older population:

“Our aging simulations suggest that in a no-action scenario, the net general government debt ratio of the advanced economies will rise by 150 percentage points between 2010 and 2050 to reach 216% of GDP. Emerging market sovereigns will experience an average increase of just under 120% points to reach a net general government debt ratio of 149%. In other words, the sovereigns that should be best able to address the aging challenge are hit by it more than proportionately,” they write.

They cite three factors linked to creditworthiness: Economic, fiscal, and external performance. How exactly climate change will affect sovereigns GDP is as yet unclear, but concerning global warming, they note that “consumption loss in 2100 as a fraction of global GDP would be around 2%, but jump to well over 5% should the annual global temperature rise twice as fast as in the current scientific baseline scenario.”

They note that, again, sovereigns with already low credit ratings are also the most vulnerable to climate change.