Increase or improve urban vegetation cover to help reduce outdoor temperature

The construction of a new main bus station inaugurated in 2014, is part of a desire to reduce greenhouse gas emissions and to encourage users to favor bus routes (Ref. 1). Part of this construction project, a vegetal wall of 210 meters long and 8 meters high has been implemented in order to act on noise (-20 decibels) and visual pollution, and improve air quality. It will be the largest public vegetal wall in France. (Ref. 4, page 26)

In 2008, a green wall of more than 500 m^2 using a hydroponic watering system was developed on the side of the Max Juvenal bridge. Designed by Patrick Blanc, french botanist and pioneer in the development of green walls, it is considered an "authentic work of art, which evolves over time and the seasons and contributes to "renaturing" the urban space" (Ref. 4, page 7). The wall is intended to illustrate the benefits that green walls can bring to the environment, such as the reduction of heat islands in urban areas and their contribution to cleaner air due to the production of oxygen and the reduction of CO2 rate by photosynthesis (Ref. 1).

It is the most extensive green roof in Lublin, designed to cover 16,700 square meters rooftop area of the shopping mall 'Castle Terraces' (Tarasy Zamkowe). Its purpose is to serve as a green recreational area for relaxation and public events, as well as an ecological solution for heat mitigation and water retention. The roof is divided into two parts: 1) an area accessible to the public with flower meadows, walking paths, viewing points from which the visitors can see Lublin’s old town 2) ‘intensive cultivation area’ with endemic trees, bushes and succulents which are not directly accessible to the public [1,2,3,8].

Due to the challenges caused by climate change, Hamburg decided to become greener and developed a comprehensive, pioneering green roof strategy. The strategy aims at creating 100 hectares of new green walls by 2019 by providing grants for building owners for greening roofs and offering them rain water fee reduction owing to the rain water retention of the green roofs. (Reference 1) The financial support offered until the end of 2019 is 3 million EUR. (Reference 2) The services offered by the city in this plan consist of four pillars: promotion (financial incentive), dialogue, regulation, and scientific support. (Reference 7)

Manchester’s Stevenson Square was given a green makeover. In addition to securing funds from Manchester City Council, the project underwent a substantial crowd fundraising campaign to transform the square into an ‘urban oasis’ and provide street trees, permeable pavements and planters.The pavement was extended on one side of Stevenson Square which enabled street trees to be planted. More tree planting undertook on the central reservation and a green roof was designed to collect and store rainwater. Self-irrigating hanging baskets were installed on lamp posts (ref 4).

The project aimed to test the potential to use existing surface water drainage charge mechanisms to incentivize increased implementation of Sustainable Urban Drainage Schemes (SuDS) to improve flood resilience and improve water quality in the city of Manchester (ref 1). Working with partners from The Water Taskforce, and funded by the DEFRA (Department for Environment, Food & Rural Affairs, UK Env agency), BITC (Business in the Community) and CLASP, these partners have been testing the concept that implementing SuDS on a school site could generate savings for a school, by reducing their hard-standing area and so their charges from their water supplier. Working with two schools in Manchester, the project team carried out detailed audits and SuDS interventions were identified that could divert or slow the flow of water into the sewer system, or reduce the amount of chargeable hard-standing area. Using this information, a trial version of a simple, user-friendly tool has been developed to help schools identify if there may be a cost-effective way to drop a chargeable surface water band (ref. 2).

The Revealing the Roch project uncovered two sections of the River Roch to expose a historic bridge which had been hidden for over 100 years (ref 1). Re-opening and deculverting the River Roch and bridge has a tangible benefit by reducing flood risk for the town (ref 4). The scheme, which is a key part of Rochdale town centre’s ongoing regeneration programme will help reduce flood risk in the town center and create educational opportunities. The project also includes enhancing the natural heritage of the river by introducing features that encourage river vegetation and creatures to re-establish themselves (ref 5). The project has since led to a wildlife boost, with brown trout, bullhead fish, heron and kingfishers all being seen since construction work to open the river began. (Ref 3). As the River Roch connects to River Mersey which empties into the North Atlantic ocean, this intervention addresses marine ecosystem restoration as well.

As part of the restoration of park Denis Gardens, an innovative water element was built consisting of water flowing down the stairs, circulated and cleaned by a pump and filters. This helps regulate the local microclimate by reducing temperatures in hot days and creating humidity in the air (Ref. 1; Ref. 5). Also, the element allows people to walk bare-footed and cool off. In addition, the water reduces air pollution by extracting dust from the air, and the structure has an aesthetic and recreational function, with a restaurant underneath. (Ref. 1; Ref. 2; Ref. 6).

Warwickshire Wildlife Trust has completed an urban river restoration on the Guphill Brook that aims to restore the brook's natural features and enhance the surrounding habitat. "The project [is expected to] bring multiple benefits to diminishing wildlife and deprived local communities but also importantly to flood risk reduction, which is becoming ever more important with the increased negative effects of climate change." (Ref. 1)

The city district Japigia in 2013 has proposed a project of a new park that links the necessity of housing, open spaces, urban sustainability. The park is centre of green spaces with a high level of accessibility, in a part of the city which was previously abandoned. The presence of hedges and trees guarantees the liveability of the area, while at the same time providing important ecosystem services such as mitigation of urban pollution and mediation of visual impact. The same can be said for the vertical gardens which will characterise the entrance of the park. (Ref.1.)