Nature in the city, weapons against global warming

Cities cover only 3% of the earth’s surface. But they are home to 60% of the population and emit more than 70% of the planet’s greenhouse gases. This extreme concentration multiplies the effects of global warming: In the urban areas of South Asia, the unusual heat waves of 2019 and 2022, the floods of 2020 caused thousands of deaths, and according to the UN, the number of these deaths could increase by 60% in the coming decades.

The associated financial losses and costs are enormous and are expected to increase in the same proportions. Most of the major cities in our developed countries with a temperate climate do not yet experience such shocks, but in Australia or on the west and south coasts of the United States, severe and costly climatic “events” are multiplying.

Europe became aware very early on of the problems associated with the impact of natural phenomena on cities. This was one of the driving forces behind the creation of environmental service companies such as Suez or the Compagnie Générale des Eaux, the ancestor of Veolia, from the end of the 19th century.e century. Today, large cities are beginning to adapt to climate change, for example by radically changing mobility tools or energy sources in line with the priorities of all developed countries.

Quality of life. A special feature of urban policies, however, is the attention they place on better management and development of their green spaces: in Europe, their surface area in big cities has increased by 38% in twenty years. This phenomenon is certainly not universal: in the United States, a city in rapid growth like Houston lost ten million trees between 1990 and 2000. Nevertheless, this interest so far is primarily a result of residents’ request and the contribution of green spaces to their quality of life.

However, these spaces are a real tool in the fight against global warming and its effects. Trees in US cities absorb almost 90 Mt CO2 per year and store more than 2.5 billion. That equates to the CO2 footprint of 5 million Americans … or 10 million French people. Cities are just beginning to realize this. A significant part of their decarbonisation will have to be provided by a new management of their natural resources.

In Medellin, Colombia, the revision of the city plan accompanied by a comprehensive planting plan has reduced the average temperature by 2 ° C

Globally, it is estimated that solutions based on the latter can produce one third of the decarbonization required to stay below the 2 ° C heating limit. These solutions offer three unique benefits. First, they are cheap: the average price for a tonne of CO2 removed is between 10 and 20 dollars, against more than 50 minimum for carbon capture (which will nevertheless be necessary).

Then they offer free and important additional benefits, such as protection of biodiversity, regulation of humidity and the effects of heavy rain. Finally, they are available immediately. Occasional successes confirm this diagnosis. In Medellin, Colombia, the revision of the city plan accompanied by a comprehensive planting plan has reduced the average temperature by 2 ° C.

Sophisticated tools

Nevertheless, the implementation of these solutions in the service of decarbonisation and, on the necessary scale, requires a different view of the nature of the city. It is now a matter of designing it as a complex, integrated asset capable of financial and technical management similar to large infrastructures. Like them, urban green spaces are, from a technical point of view, sophisticated tools whose efficiency requires the implementation of several advanced technologies.

This involves, for example, the creation of exhaustive and continuous databases of plant resources, monitoring of their state of health and their risks, measurement of the associated biodiversity and its development, etc. This presupposes the use of sensors, software and artificial intelligence tools specific to these complex measurements of life in all its forms. For its part, plant biotechnology is beginning to offer new ways of protecting, adapting and developing plants. And of course, intelligent flow or maintenance management tools will enable the transformation of jobs in the field, facilitating and enriching the work of often young and “digitally native” teams.

Cities thus face the same problem as companies: how to transform the management of a complex and valuable asset by integrating a myriad of technological tools? Experience shows that it is disappointing to acquire and install tools here or there. These tools are only effective with an overall audit of management and organization. Conversely, mastering these tools is not enough: Gafam’s attempts to control neighborhoods, such as Google’s in Toronto, fail because these global giants do not know the special conditions and social or political complexities of cities.

If they share common problems with businesses, cities are not businesses. It is by connecting their own expertise with companies dedicated to the management of green spaces and mastering all the tools and technologies now needed that cities will be able to mobilize their natural resources.

Expertise. If they share common problems with businesses, cities are not businesses. It is by connecting their own expertise with companies dedicated to the management of green spaces and mastering all the tools and technologies now needed that cities will be able to mobilize their natural resources and be able to fight against global warming. This is the decision already made by big cities like Manchester: It has been decided to plant 3 million trees, which poses an industrial and technological challenge.

From an economic point of view, very few cities have assessed the value of their natural heritage. Manchester has just done this work and estimates that the replacement value of their trees was over 5 billion euros. Similarly, very few assess the profitability of investing in green spaces, which US studies place between 1.5 and 4. The way we look at these natural assets must evolve to take into account this very enormous value and profitability of to invest in it. This will result in new ways of financing the mobilization and increase of urban natural resources, which no longer come exclusively from the municipal budget, which is necessarily very limited, but from financial instruments used to develop infrastructures.

Affected companies

And what applies to cities will also apply to the businesses that are located there. For example, the initiators must now integrate the respect and even the increase of biodiversity, plantations or land into their projects. Large-scale distribution is also involved, with particular limitations because it is one of the main causes of soil artificialization. And it is one of the sectors that controls their carbon bill at least: 85% or more of the distribution’s emissions are due to its supplies (agriculture, livestock, transport, etc.) and the consumption of its products (packaging, waste…).

The logistics profession encounters a similar problem. Here, too, it is through collaboration with the few specialized actors that these large activity sectors will be able to develop solutions based on nature. This is no longer an option. The time is over for cosmetic solutions.

Lawsuits are rising against very large companies accused of greenwashing, misleading statements or even for not doing enough. Nearly 40 criminal complaints were lodged against this issue against companies in 2021, ie double that by 2020. The rationale will multiply as policies to combat climate change are tightened and legislation becomes more precise. .

Yesterday, the management of urban green areas was a collection of valuable craft knowledge intended for convenience and quality of life in the city. From now on, it is an essential tool in the fight against global warming, an expertise based on science. Its ultimate effectiveness is nonetheless based on craftsmanship, which is often difficult to assess, but also on understanding and respecting these irreducible peculiarities that make up a city’s unique magic.

Byrevolution

Olivier Brousse is the CEO ofIdverde. For him, urban green spaces must now be designed as a complex, integrated asset capable of financial and technical management similar to major infrastructures.

Leave a Comment