A simple solution to climate problems faced by cities: soil and plants

Game Changers: In the era of extremes, healthy soil and diverse communities of healthy plants become critical infrastructure

The urgency of action is inescapable. European cities have baked and burned this summer not long after icy hailstorms wiped out field crops. Around the world we’ve seen rivers of mud sweep buildings, roads and cars away. In one horror clip, a woman sits stranded on top of a car as torrents of mud water threaten to take her. Elsewhere, exhausted fire fighters tackle forest fires too big to fight.

Extreme deluges are being called rain bombs. Last night I watched as water fell with a ferocity that is beginning to feel normal. Lisa Hannigan was singing Song of the Sea and it felt like a good soundtrack. Water was general all over Ireland, pummelling hard surfaces in towns and cities, powerhosing pollutants, heavy metals, microplastics, pollution from cars, heating and cooling systems straight into our rivers and out into the sea. Drainage systems designed to flush water quickly exacerbate this first flush of pollution.

In my small forest garden the water pings down through the leaves of trees. It doesn’t pound or splash off the ground. The soil is able to take it because the roots of the trees have turned our small patch into a sponge.

We need daylighted soil at scale across urban areas to slow down flood waters, to clean pollutants and capture the water for times of drought.


Earlier in the summer, Dublin City Council’s senior executive water engineer John Stack gave a presentation in the Mansion House at an event hosted by the then lord mayor Green Party Councillor Caroline Conroy. Nature-based solutions can fix so many of the challenges we have ahead of us, Stack explained.

Daylighting hard surfaces and using trees, Dublin City Council is starting work on a three-year Santry river landscaping project to clean it, slow the flow and create a riverside greenway. Another vital fix will be designing native plants into this newly daylighted soil.

Talking to architects recently, Dr Úna Fitzpatrick, senior ecologist at the National Biodiversity Data Centre, explained how vital native trees and shrubs are to our urban landscapes. Decorative planting can be “the icing on the cake”, she said. But our wildlife, birds, insects and soil life need the native plants with which they have evolved. In the era of extremes, this healthy soil and with diverse communities of healthy plants become critical infrastructure, the only kind that grows more effective and stronger the older it gets. It could be two fixes in one. And we need as many of those as we can get.

Catherine Cleary

Catherine Cleary

Catherine Cleary, a contributor to The Irish Times, is a founder of Pocket Forests