David Suzuki is the host of the CBC’s The Nature of Things and author of more than 30 books on ecology (with files from senior editor and writer Ian Hanington).

Environmental racism or discrimination can take many forms. To find an urban example, look to the trees.

Research shows wealthier neighbourhoods usually have better tree and shrub cover than poorer, more diverse neighbourhoods. That’s important for a number of reasons. First, most of us live in cities — 80 per cent in Canada. Beyond the fact that they look nice and increase property values, trees and shrubs reduce pollution and noise, keep air cooler, decrease flooding and runoff, make cities more resilient, improve mental health and well-being and provide shelter and habitat for numerous animals.

Giving more people better access to treed green spaces is something everyone can get behind. David Suzuki Foundation studies in Montreal, Ottawa and Toronto found residents in all three cities are willing to invest in “an urban forest with a higher density of trees, a wider diversity of tree species, the presence of street shrubs.”

The studies — conducted by researchers at the University of Quebec in Outaouais and University of Montreal — noted that “the distribution of vegetation over a city’s territory is generally uneven: poorer or more multicultural neighbourhoods often have a thinner canopy than their richer or white neighbours. These well-documented inequalities can be seen in cities around the world.”

Dense urban canopies are especially important as research shows urban areas are heating faster than rural areas — on average about 29 per cent. A study by scientists at Nanjing and Yale universities found planting trees along streets, creating rain gardens and removing pavement can create a cooling effect and reduce the rate of urban warming. Increasing trees and green spaces in urban areas has already reduced heat in cities in Europe and the U.S.

A recent study in Nature found that “more than two-thirds of tree species across cities worldwide are facing severe climate risks, undermining their roles in climate adaptation and other ecosystem services they provide.” The researchers recommend cities everywhere take immediate measures such as planting more trees and shrubs, especially climate-resilient ones, and channelling rainfall into rain gardens or tanks.

Greening cities is a crucial part of resolving the climate crisis, but it also offers ways to address the many inequities that poor urban planning has created and climate disruption has exacerbated.