Green roofs can make cities more climate resilient by improving local air, superior psychological benefits, and acts as a mitigating element for the urban heat island effect. The environmental benefits of green roofs include a reduction in the amount of external water runoff volume and a reduction in optimal overflow. Vegetated roofs for stormwater management are also effective as are extensive landscape roofs that are often drought-tolerant, low-maintenance, and self-seeding plant roof coverings that integrate colored. The Earth’s atmospheric temperature can decrease to -39 degrees without carbon emission, because the Earth needs greenhouse vapor to maintain its temperature. These plants are mainly succulents and can thrive in alpine environments under roofs throughout a period of time. In other words, there isn’t much soil, but the roof experiences frequent amounts of sun and wind coverage.
References: Alexandri, E. and P. Jones (2008). " Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates." Building and Environment 43(4):
Carter, T. and C. R. Jackson (2007). Vegetated roofs for stormwater management at multiple spatial scales. 80: 84-94.