The authors discuss their findings at the Natural Hazards annual Researchers Meeting in Denver, Colorado, USA. Credit: Amer Abukhalaf

Have you ever looked at a photograph of a raging wildfire, a flooded neighborhood or a starving polar bear and immediately felt something before you even had time to think? Most of us have.

That emotional reaction happens almost instantly. We do not first calculate sea-level rise or remember a scientific report. Instead, we experience sadness, fear, frustration, helplessness or even guilt within seconds.

As researchers studying climate change and mental health, we became interested in a simple question:

How do we actually measure those emotions?