Researchers at King’s College London, landscape architects J & L Gibbons and art foundation Nomad Projects have used smartphone-based technology to assess the relationship between nature in cities and momentary mental wellbeing in real time. They found that (i) being outdoors, seeing trees, hearing birdsong, seeing the sky, and feeling in contact with nature were associated with higher levels of mental wellbeing, and that (ii) the beneficial effects of nature were especially evident in those individuals with greater levels of impulsivity who are at greater risk of mental health issues.