This chapter describes how the combination of societal progress and medical expertise has given rise to new health challenges that result from the 21st-century lifestyles to which we have become accustomed and take for granted. It points to the inconsistency of our behaviour in terms of how we deal with health issues in our daily lives and the relationship between human health and the health of the planet. Access to good quality green space is beneficial in guarding against cardiovascular disease and type 2 diabetes and several forms of cancer. This is due to the benefits of exercise outdoors in clean air and the enjoyment of contact with nature and social interaction. Humankind’s rapid consumption of natural resources causes pollution that harms delicate global ecosystems. The human inventiveness that gave rise to growing crops and rearing animals was, as a lifestyle, less energetic than hunter-gathering and was primary influence on the development of communal settlements and the specialisation of skills.