Today, the world is facing more frequent and severe heat waves. By 2100, metropolitan temperatures may increase by up to 4°C, doubling those of neighbouring rural areas, as cities grow. Vulnerable urban populations, especially the 800 million urban poor people—61% of which are women—who live in 77 high-impact nations and regions, are at high risk because of the little access to sustainable cooling. At the same time, the building sector is by far the biggest producer of greenhouse gases (37%) and space cooling is the fastest-growing source of building energy demand and emissions worldwide, contributing by 20% to global building sector energy emissions. Based on existing policies, the installed capacity of cooling equipment worldwide would triple by 2050, more than doubling power usage, according to UNEP's most recent research, Global Cooling Watch 2023.
Trees, vegetation, wetlands, and bodies of water are examples of nature-based solutions (NbS) that provide cooling through evapotranspiration, shade, and heat sinks. Depending on the climate, these natural solutions can lower temperatures by up to 12°C. As such, they are crucial resources for cities looking to lessen the effects of urban heat and increase people's resistance to it.
With co-benefits including lower emissions, energy savings, improved health outcomes, less urban heat effect, and improved water management and savings, nature-based urban cooling solutions have been recognized as important climate change adaptation methods. By providing building shade and insulation in the form of green walls and roofs, NbS for cooling also serve to lower the energy demand for space cooling, hence reducing related greenhouse gas emissions.
Through its many initiatives, and most notably the Cool Coalition, UNEP is at the forefront of change when it comes to helping developing countries to address their cooling challenges in an over-heated world. The GEF Mitigation Unit supports the countries in developing tailored approaches to tackling their cooling needs while keeping abreast with biodiversity and nature demands. Innovation is at the heart of design, making sure institutional and financial barriers are minimized in order to enhance resilience and sustainability.
