Melbourne city to double its canopy cover by 2040 to confront global warming

11 / 09 / 2019

By Marwa Nassar - -

The city of Melbourne, Australia, is aiming to almost double canopy cover – from 22 percent to 40 percent – by 2040 to tackle heatwaves. Around 3,000 new trees will be planted each year.

On a sunny day, from evaporation alone, a single healthy tree can have the cooling power of more than 10 air-conditioning units. That’s not including the shade they provide for buildings, which in the United States can reduce air-conditioning costs of detached houses by 20 percent to 30 percent. And instead of emitting more carbon, trees absorb it. Not to mention, trees have the ability to filter air pollution, improving our health and that of the planet.

This way of using nature to adapt to climate change, known as “ecosystem-based adaptation” or “nature-based solutions”, is, quite literally, a breath of fresh air.

It’s part of a much larger paradigm of environmental problem-solving called nature-based solutions. The United Nations Secretary-General’s Climate Action Summit this month will provide an opportune moment to catapult nature-based solutions to the forefront of climate action.

Moving from cities to coasts, forests are again a major defense against extreme weather.

One of the more ominous prospects of climate breakdown is rising seas that threaten to sink cities or slowly drag them into the ocean. The evidence is overwhelming that mangrove forests are effective and cheap natural barriers against coastal floods and shoreline erosion. They reduce both wave height and wave force. In fact, if all of today’s mangroves were lost, the global damage from flooding would be an extra $82 billion a year.

Drought is another worldwide crisis – already here for many, looming ominously for others. Even as early as 2025, half the world’s population will be living in “water-stressed areas”. When people fell trees, the problem deepens because roots act like sponges that absorb rain and recharge groundwater supplies. Without them, water flushes straight through the soil and isn’t stored for times of need.

It’s this realization that led to the ambitious “Great Green Wall” in Africa. The Sahara Desert has expanded by 10 percent since 1920, eliminating grazing land and waterholes in its way, and imposing financial ruin for nearby villages.

To halt the process of desertification, 21 African countries are collaborating to restore an “8,000km natural wonder” of trees and shrubs across the width of Africa to lock in soil moisture and to keep the lands productive. The UN Convention to Combat Desertification says the endeavor can create 10 million green jobs by 2030.

This month in India, the convention is bringing 197 countries together to explore how these types of restoration efforts can thwart desertification.

The Global Adaptation Commission seeks to accelerate adaptation action and increase political support for building climate resilience. A new report by the commission is making a pitch for scaled-up investment in nature-based solutions for climate adaptation.

Heatwaves, droughts and coastal storms are just three examples in which forests defend us from extreme weather, but there are far more. Carefully planted tree species can act as firebreaks, keeping trees next to farmland can protect crops from the erosive forces of intense rain, and forests can alleviate inland floods due to the sponge-like way they absorb water.

The latest UN Intergovernmental Panel on Climate Change report on land and climate change notes that land surface air temperature has risen nearly twice as much as the global average. Forests therefore play a critical role on the front lines of our efforts to guarantee resilience in a climate changing world.

Using ecosystems and nature-based solutions to adapt to climate change means we’re keeping biodiversity safe. The zero sum between development and environment vanishes. This is not nature or people; this is nature for people.