Read More: Urban Resilience

With so many of our urban built environments located close to rivers and/or the sea, Irish cities are particularly vulnerable to sea level rises and increased rainfall which are inevitable in the years ahead. As per the tree canopy section, the current levels of tree canopy, particularly in low income areas, leave us even more exposed to these changes to our biosphere.

We know that sewage and draining systems are already stretched given the frequent overflow and raw spillages into the Irish Sea and associated E Coli risk. Inadequate infrastructure will be put under increased strain owing to extreme and unpredictable weather patterns, in particular heavier, more frequent rainfall and ‘flash flooding’. Though it is obvious that significant investment is needed to our water processing plants, a simple, inexpensive means of mitigating against the increased rain fall and flooding is through ambitious, strategic urban tree planting; these trees can intercept rainfall and delay its delivery to watercourses.

We will also encounter more sustained and frequent heatwaves in the coming years. Urban trees provide a cooling mechanism to protect against hot weather events and provide shade to residents. Remarkably urban forests can reduce temperatures by up to 25 degrees through shading and evaporative cooling effects. More detailed information is provided in the benefits section. However, these benefits will only be realised if concerted efforts are made now to expand and diversify urban canopy cover, particularly in the most vulnerable and exposed areas.

Hard surfaces continue to dominate Irish urban environments. These tarred or concreted surfaces increase flood risk and trap and radiate heat. These surfaces must be replaced and regenerated with soil, shrubs, and trees so excess water can be regulated and absorbed - this takes time and careful planning led by subject experts.

Efforts to make progressive, decisive changes however are painfully slow moving and often stymied by small but powerful vested interest groups despite widespread public support. There needs to be a shift in mindset and if necessary legislation to ensure central government and local councils can make quick, decisive improvements to urban settings for the betterment of society at large.

Further Reading:

Using Trees and Vegetation to Reduce Heat Islands: https://www.epa.gov/heatislands/using-trees-and-vegetation-reduce-heat-islands

Potential for reducing urban air temperatures and energy consumption through vegetative cooling: https://www.osti.gov/biblio/10180633

Hard surfaces, hidden costs: https://www.greenblue.com/wp-content/uploads/2016/05/Tree-Planting-in-Paved-Surrounds.pdf

Irish addresses at risk of coastal flooding by 2050: https://www.irishtimes.com/news/environment/over-70-000-irish-addresses-at-risk-of-coastal-flooding-by-2050-1.4258531

Over one-fifth of Dublin Bay water users become ill, pressure group claims: https://www.irishtimes.com/news/environment/over-one-fifth-of-dublin-bay-water-users-become-ill-pressure-group-claims-1.4536227