United Nations Decade on Biodiversity - INTERNATIONAL DAY OF FORESTS (21 March 2018) “Forests and sustainable cities”
MESSAGE OF THE EXECUTIVE SECRETARY OF THE CONVENTION ON BIOLOGICAL DIVERSITY
DR. CRISTIANA PAŞCA PALMER on the occasion of the
INTERNATIONAL DAY OF FORESTS
21 March 2018
“Forests and sustainable cities”
Forests are essential for cities around the world. Forest ecosystems provide water and other critical services on which cities depend.
This is especially true for developing countries. Two-thirds of all major cities in developing countries depend on protected areas, mostly forested watersheds that catch rainfall and other precipitation for their water supply. In fact, three-quarters of the world’s accessible fresh water comes from forested watersheds.
At the same time, as noted in the Cities and Biodiversity Outlook report[1], the projected urban expansion will require us to double urban spaces within 30 years and could have serious impacts on the surrounding ecosystems.
Furthermore, investing in nature is cost-effective. Filtering freshwater through forests and wetlands, for example, costs one-tenth of the amount than depurating through a chemical water treatment plant. A recent article published in The Guardian newspaper noted that New York City had spent $2 billion over the last 20 years protecting the city’s natural watershed that provides it with water. This has worked so well that 90 percent of the water needs no further filtering. Building a water treatment plant would have cost $10 billion.
Forests also help secure against disaster risks. By helping to stabilize slopes, forests help reduce the risk of landslides precisely in the urban expansion areas forecasted to house up to 400 million new citizens in developing countries. Wetlands can help regulate floods, by providing coastal vegetation and natural features such as sand dunes, while mangroves can provide protection from storm surges and strong winds. Compared to hard infrastructures, such as seawalls and levees, restoring mangroves is often more affordable for protecting large coastal areas.
Forests are also important for our health. Tropical forests, undisturbed or even well-restored, can help moderate the effects of infectious diseases. In deforested or heavily degraded areas in the tropics, for example, the risk of malaria infection has been found to be as much as 300 times higher compared to areas of healthy forest. Degraded forests have more shallow water pools, which act as breeding grounds for mosquitoes and other disease vectors, and because natural predators of insects, such as birds, are less frequent than in forests in better condition.
Forests also form a key part of the solution for one of our biggest and most pressing challenges, climate change, by providing one of the most cost-effective and efficient carbon capture and storage systems. Forests can also act as temperature regulators and provide resilience against climate change impacts.
As the global population becomes increasingly urban, it will be all the more important to connect city dwellers with the natural environment. Simply put, the more you know about nature, the more likely you are to engage, on some level, in the conservation and sustainable use of our natural resources.
Well-managed forests and cities go hand in hand. Let us work together to protect our precious forest.
