A new report sets out a clearer case for investment in multi-functional green space or Green Infrastructure (GI) by considering its contribution to economic growth. The authors based their conclusions after reviewing a range of UK and international case studies. These include the canal-side redevelopment in Birmingham City Center, the Green Renewal Programme in Glasgow and the development of the Merseyside Forest in the UK. Other projects include the High Line Linear Park, the highly successful development of the a former overhead railway line in New York, the Philadelphia Land Care Programme in Pennsylvania which focused on greening neglected land. Another case study was the Cheonggyecheon Stream Restoration Project in Seoul, South Korea which removed a congested overhead roadway and restored the river that had been directed into an underground culvert. The case studies were investigated in relationship to six characteristics or ‘logic chains’ which considered the impact of GI on; inward financial investment to the area; on visitor attraction and spending; on environmental cost savings; health benefits; market sales and finally on employment generation. The report concludes that GI has positive impacts on all six of the characteristics considered.

The Highline New York, before and after
The creation of the High Line Linear park over 34th street from the disused overhead railway that runs through the former meat-packing district of New York has dramatically changed its fortune. It has resulted in a destination visitor attraction for tourists while dramatically improving property prices for the adjacent blocks stimulating economic development and regeneration of the previously neglected area.
The report highlights the difficulty in identifying if economic activity could be regarded as new economic activity or merely displaced from another location. While displaced activity may be attractive for local regional investment only new activity can be considered as adding to a country’s Gross Domestic Product (GDP). Nonetheless the study was able to point to significant cases of new investment, particularity where the developments attracted either international tourism or business investment and relocation. The High Line Linear Park for example has had as significant impact on inward investment in this area of New York, massively influencing adjacent property prices and helping drive regeneration of the surrounding area. It has also become a significant tourist destination and as a consequence significantly raised the tourist spend in the local area.
The river restoration project in Seoul is demonstrably helping provide environmental benefits, in particular reducing flood risk, improving air quality and reducing local temperatures. In a very densely built city it is also creating a relative haven of calm which is fostering reduced stress while also reducing local heat island effects; both of which bring consequent health benefits. These projects demonstrate limited impact on market sales but the report does point to the growing interest in locally produced food which could be achieved in other GI initiatives. These sort of developments could bring a range of benefits, such as reduced emissions and local organic waste recycling, though not necessarily making significant contributions to GDP. All the projects have had significant impacts on employment generation and the report highlights that within England UK up to 5% of jobs could be support by the GI sector. The economic value of GI is also being increasingly recognized with the report noting that some 95% of real estate developers across Europe believing that GI adds value to commercial property so that on average being prepared to pay a premium of at least 3% and up to 15-20% for land close to multi-functional green space.

Cheonggyecheon Stream Restoration Project in Seoul, before and after
Provides flood protection for up to a 200-year flood event. Increased biodiversity by 639% [plant species from 62 to 308, fish species from 4 to 25, bird species from 6 to 36, aquatic invertebrate species from 5 to 53, insect species from 15 to 192]. Urban heat island effect reduced by 3.3° to 5.9°C compared to parallel roads 4-7 blocks away. Reduced small-particle air pollution by 35% halving the number of residents likely to suffer respiratory disease. Increased price of land by 30-50% within 50 meters. Increased number of businesses by 3.5% in area during 2002-2003,double the rate in downtown Seoul. Increased the number of working people in area by 0.8%, v decrease in downtown Seoul of 2.6%. Attracts average of 64,000 visitors daily inc. more than 1,000 foreign tourists who contribute up to $1.9 million USD to the Seoul economy