A new study has found that the amount of green space (such as parks, gardens, and riversides) that a city has impacts the happiness of the people living there. Analysis of the populations of 90 global cities found that citizen happiness increases with the amount of green space they can access, although the relationship was stronger in richer countries. The researchers suggests that the results may reflect the fact that green spaces provide aesthetic pleasure and also positively impact health through promoting physical activity and social interaction.