Lahti, Finland, has invited five local residents to try a 'planetary health plan' to see if making greener choices could be good for your health. They received personalized regimes put together by Finland's first planetary health physician, Dr. Hanna Haveri. They followed her recommendations for two months with their carbon emissions and overall health tracked before and afterwards. Lahti, named European Green Capital in 2021, is the first city to offer this program in its healthcare services. The theory that human health is deeply intertwined with the health of nature and the environment was popularized in 2015 by The Rockefeller Foundation and The Lancet, which said that humanity's actions put Earth's key life support systems at risk. Experts in planetary health believe that by slowing climate change, we could also improve our own well-being. The World Health Organization says nearly one in four deaths worldwide are now linked to environmental conditions.