Two phenomena that both can cause large numbers of premature human deaths have been gained attention in the last years: Heat waves and air pollution. These two effects have two things in common: They are closely related to climate change and they are particularly intense in urban areas. Climate warming will act directly by causing heat shock and desiccation – and indirectly by decreasing pollution transport out of the city and favoring ozone formation. Urban areas are particular susceptible to these impacts because of their large heat storage capacity and little opportunity for evaporative cooling (also known as the urban heat island effect). In order to mitigate these impacts and to establish an environment that protect human health and improve well-being, implementation of green infrastructure – trees, green walls, and green roofs – is commonly proposed as a recipe. More trees, hedges and lawns are intuitively welcome by people living in cities that didn't look very attractive in many other ways, but to which degree can such greening actually counterbalance the expected effects of climate change? In this review I would like to investigate what science can offer to answer this question.