How can Nature-based Solutions (NbS) contribute to air quality

Published in 2017

Excerpts from: EKLIPSE report: An impact evaluation framework to support planning and evaluation of nature-based solutions projects

POTENTIAL ACTIONS AND EXPECTED IMPACTS
(p.23-24 of the report)

Air quality is a major concern worldwide, particularly in urban areas, due to its direct consequences on human health. In the political agenda, air quality issues can be coupled with climate change mitigation policies since many actions aimed at air quality improvement (such as reducing fossil fuel combustion) involve a concurrent reduction of GHG emissions. NBS based on the creation, enhancement, or restoration of ecosystems in human‐dominated environments also exploit the synergy between ecosystem processes that regulate pollutants and CO2 in the atmosphere. Vegetation affects air quality mainly through the removal of air pollutants (PM10, NO2, O3, CO, SO2) through dry deposition, although certain species can also emit biogenic volatile organic compounds (BVOC), which are ozone precursors. However, vegetation can also reduce the air temperature, which reduces the emission of BVOCs and slows down the creation of secondary pollutants such as ozone (Wang et al., 2015b; Calfapietra et al. 2013). Despite their limited contribution compared to the overall production of pollutants and GHG emissions at the city level, measures to tackle air quality by enhancing green infrastructure can be considered a good investment due to the number of co‐benefits that they produce and their contribution to amenity value over time (Baró et al., 2015).

 

 

Potential actions for AIR QUALITY and expected impacts

Potential actions

Expected impacts

  • Planting trees: in private domestic gardens (Davies et al., 2011), along the streets (Baró et al., 2014; McDonald et al., 2007; Mullaney et al., 2015), and in urban parks (Yin et al., 2011).
  • Reduction of air pollutants through increased deposition (Baró et al., 2014; Bealey et al., 2007; Grote et al. 2017; Tallis et al., 2011).
  • A number of co‐benefits including stormwater run‐off mitigation, microclimate regulation through shading, habitat and food provision for biodiversity, noise shielding, and recreational and cultural services (Mullaney et al., 2015).
  • Building green roofs (Li and Babcock, 2014) and green walls (Joshi and Ghosh, 2014).
 

 

  • Capture of air pollutants through deposition (Speak et al., 2012). 
  • A number of co‐benefits both for the outdoor (e.g. stormwater retention) and for the indoor environment (i.e., reduced energy needs and a more pleasant environment due to the higher thermal and noise insulation) (Wang et al., 2016).
  • Maintaining existing green infrastructure (Davies et al., 2011).
  • A wide range of co‐benefits including shading,  water retention, dry precipitation, infiltration.

Examples of indicators for assessing the impact of the above mentioned actions are listed on p.24 of the report

 


Access the full report online at: http://www.eklipse-mechanism.eu/apps/Eklipse_data/website/EKLIPSE_Report1-NBS_FINAL_Complete-08022017_LowRes_4Web.pdf

(Raymond, C.M., Berry, P., Breil, M., Nita, M.R., Kabisch, N., de Bel, M., Enzi, V., Frantzeskaki, N., Geneletti, D., Cardinaletti, M., Lovinger, L., Basnou, C., Monteiro, A., Robrecht, H., Sgrigna, G., Munari, L. and Calfapietra, C. (2017) An Impact Evaluation Framework to Support Planning and Evaluation of Nature-based Solutions Projects. Report prepared by the EKLIPSE Expert Working Group on Nature-based Solutions to Promote Climate Resilience in Urban Areas. Centre for Ecology & Hydrology, Wallingford, United Kingdom)