Kuala Lampur, Oct. 19 -- We are living longer. This, one of humanity's greatest triumphs, is increasingly being framed as one of its greatest threats. As birth rates plummet and life expectancies extend, a profound demographic shift is reshaping nations from Tokyo to Turin. The question now echoing through economic forums and policy circles is a startling one: is the ageing of our societies an even more imminent and intractable danger than climate change?

The comparison is provocative, but flawed. Climate change is an existential, planetary crisis; its unchecked progression threatens the very habitability of the Earth. Ageing, by contrast, is a structural, predictable, and human crisis. The real question isn't about ranking these colossa...