Natural infrastructure saves costs, builds climate change resilience, research finds

Planting trees and preserving mangrove swamps and wetlands are cheap and effective but overlooked, report says. Photo by Vishwasa Navada K on Unsplash.

Tree-planting, wetland restoration, mangrove swamps and other natural ways of protecting the environment from the impacts of the climate crisis could save hundreds of billions of dollars a year and replace high-carbon infrastructure, a global research has found.

Research published on Monday by the International Institute for Sustainable Development (IISD) found that using natural infrastructure to protect against climate breakdown could save up to $US248 billion ($330 billion) a year globally, costing only about half as much as equivalent built infrastructure and delivering the same protection.

The research further shows that swapping just over 11 per cent of the current global infrastructure needs with nature-based infrastructure (NBI) could create additional benefits worth up to $US489 billion ($650 billion) every year – a figure that rivals the annual GDP of countries such as Austria, Ireland, or Nigeria.

The argument in favour of NBI gets even stronger when looking at what other benefits come from using nature instead of a built solution. Nature-based infrastructure is up to 50 per cent cheaper than traditional “grey” infrastructure providing the same infrastructure service. In addition, NBI provides 28 per cent better value for money than grey infrastructure. These numbers are based on the IISD’s Sustainable Asset Valuation assessments of various NBI projects.

Governments and infrastructure investors normally default to grey infrastructure to meet infrastructure needs for coastal protection, water supply, energy, and transport, as well as to increase the resilience of existing infrastructure. This happens because the cost savings and added benefits of NBI options are neither well understood nor integrated into traditional assessments of infrastructure projects. This means that grey infrastructure often appears as the more attractive option on paper, though it is less so on the ground. The result is a missed opportunity to tackle our climate and biodiversity crises, which places both our natural environment and societal health at risk.

Over the next 20 years, the level of infrastructure needed to support development needs would cost $US4.29 trillion ($5.7 trillion) annually if only grey infrastructure is used. In practice, some of this infrastructure could instead be built using nature. The IISD’s research found that 11.4 per cent of this infrastructure need could be met effectively using NBI.

Rising temperatures, more intense heat waves, and the resulting urban heat island effect are driving demand for cooling, and thus more energy. Trees and green spaces can naturally cool down their surroundings and prevent the need for investments in energy-intensive air conditioning. NBI can also improve building insulation and thus improve energy efficiency. Bioenergy and micro-scale hydropower are two examples of how NBI can provide renewable energy and contribute to energy supply.

Nature-based solutions also tend to be cheaper to maintain, while creating local jobs, and additional benefits such as helping to clean up air and water pollution, improving habitats for wildlife and restoring natural ecosystems. Mangrove swamps, for example, are used as nurseries by fish, to the benefit of local fishing, and attract other wildlife, but about a third of them have been torn up or damaged around the world in recent decades in the quest for development.

Historically, governments and private investors tend to support traditionally engineered infrastructure, also known as grey infrastructure. Common examples include wastewater treatment plants, dikes, and seawalls. In recent years, evidence has clearly shown that we should instead rely on nature for solving some of these infrastructure needs, given that nature-based infrastructure saves money and provides greater benefits.

The Nature-Based Infrastructure Global Resource Centre was created to address this evidence gap. Over the next few years, IISD will develop more than 40 assessments comparing NBI with built infrastructure for a variety of assets. A database will collect and share data on the economic performance of NBI for use by policy-makers, investors, and infrastructure planners.