From stronger heat waves to new vectors for disease transmission to worsening freshwater pollution, the health threats associated with environmental degradation are vast, according to the United Nations’ sixth Global Environment Outlook.
The report, released on March 4, says that millions of people are expected to die prematurely as the environment declines, and the world’s poorest populations will be the most negatively affected.
“The science is clear. The health and prosperity of humanity are directly tied to the state of our environment,” Joyce Msuya, acting executive director of the UN Environment Programme (UNEP), said in the report’s press release. “We are at a crossroads. Do we continue on our current path, which will lead to a bleak future for humankind, or pivot to sustainable development?”
The global environment is deteriorating in a number of ways. The UN notes that resource extraction has more than tripled over the past 50 years, which has driven more than 90% of the planet’s biodiversity loss. Various forms of pollution — from industrial plants dumping toxins into local environments to countries releasing plastic into bodies of water — are corroding the health of ecosystems, which leads to various health complications in humans.
And climate change is causing environmental shifts that can undermine public health.
The health risks associated with the worsening environment can be broken down into three categories, according to Jeffrey Shaman, director of the climate health program at Columbia University: direct consequences, indirect consequences, and complex health risks.
Direct consequences include rising deaths from heat waves, intensifying storms, and air and water pollutants.
“These are real easy and clear connections,” Shaman, who was not involved with the UN report, told Global Citizen. “You have a change in temperatures, a heatwave, and you see a big spike in deaths.”
The World Health Organization estimates that 38,000 additional people will die prematurely each year through 2050 because of heat stress. The number of people who will be exposed to deadly heat waves will nearly double by 2050, according to a University of Hawaii study.
Air pollution, meanwhile, is increasingly making it hard for people to breathe. A new study estimates that 8.8 million people die prematurely from contaminants in the air each year.
The UN report notes that the pollution of freshwater sources could lead to millions of more deaths each year. In Tennessee, a coal plant has been leaking highly toxic coal ash into groundwater drinking supplies, putting the health of millions of people at risk.
The indirect consequences, according to Shaman, include the health problems associated with forced migration from sea level rise and storms, and the spread of diseases in changing climates.
By 2100, more than 2 billion people could be displaced from their homes due to environmental changes.
Complex health risks are “things that have to do with conflict, food and water insecurity, and the inability to maintain the sort of sustainable resources that we have relied on for the past 10,000 years,” Shaman said.
“There has to be some continuity and constancy in the environment for us to feed ourselves, and in many places around the world things are changing at a really rapid rate, leading to agricultural failures, nutritional problems, and additional stresses,” he added.
Shaman said that the civil war in Syria, for example, has been partly linked to a terrible drought that began around a decade ago, and the drought consuming the Lake Chad region has destroyed local fishing and agricultural industries, driving widespread migration.
Whether its air pollution harming people with breathing problems, new pathogens infecting young children, prolonged heat waves hurting elderly people, or contaminated water supplies provoking regional fights for water, the UN says that the health of humans is inextricably linked to the health of the planet, and countries ignore environmental hazards at their own peril.
As is often the case, the world’s poorest populations are at the greatest risk of the cascading effects of ecological decline.
“Those who are living in resource-poor areas are going to be disproportionately affected by this,” Shaman said. “They will not have the resources to deal with the problems associated with climate change, they won’t have the capital to build safeguards for agriculture or desalination plants, and they won’t have the means to take care of their populations.”