More than 99% of the world’s 7.7 billion people have one or more of their environmental rights threatened, according to new research.

In the most comprehensive analysis of inequality in environmental conditions to date, CU Boulder researchers revealed that nearly half of the global population lives in regions facing three or more environmental problems. Those include polluted air, unsafe water, extreme heat, food insecurity and biodiversity loss.

The analysis was published September 25 in Environmental Research Communications.

It provides strong evidence for urgent climate action, as representatives from nearly 200 countries prepare to convene for the 30th Conference of the Parties (COP30), the United Nations’ annual climate meeting, in Brazil beginning November 10.

“Over the years, communities around the world have been fighting for local environmental justice,” said first author Naia Ormaza-Zulueta, a doctoral student in the Department of Environmental Studies. “We want to stitch their stories into a single, undeniable global tapestry so that they can’t be dismissed as isolated problems.”

In 2022, the UN formally recognized that everyone on Earth has the right to a healthy environment. The landmark resolution, while urging countries to take action to protect that right for their people, is not legally binding.

The resolution also failed to account for environmental harm caused by activities in other countries, said Ormaza-Zulueta. Extensive research has shown that large, industrialized nations, such as the United States, emit the most greenhouse gases, but lower-income countries experience the greatest impacts.

Pollution without borders

Ormaza-Zulueta and Zia Mehrabi, a data scientist in the Department of Environmental Studies and founder of the Better Planet Lab, wanted to put a number on how many people have had their environmental rights threatened.

They collected large datasets on environmental problems to calculate whether an individual in a given location around the world is experiencing, or has recently experienced, conditions that violated their rights in five core areas defined by the UN: clean air, clean water, a safe climate, healthy and sustainably produced food, and thriving biodiversity and ecosystems.

The team found that almost everyone on Earth lived in places that have recently experienced at least one environmental risk that failed to meet the UN conditions. Over 45%, or 3.4 billion people, had at least three rights threatened, and 1.25%, or 95 million experienced all five conditions.

“The numbers are heartbreaking,” said Ormaza-Zulueta.

Having access to clean air, defined as an annual average outdoor particulate matter concentration below the World Health Organization guideline, was the most common threat, followed by access to healthy and sustainably produced food.

In Colorado, a study has revealed that ozone pollution, mainly from cars and oil and gas operations, causes more than 800 deaths each year.

“A lot of people think Boulder has great air quality for being so close to the mountains,” said Mehrabi. “But the reality is that our ozone level is high for multiple months during the summer. There are days when the air quality is so bad that our children can’t play outside.”

Hotspots of injustice

While most people are at risk of poor environmental conditions, not everyone feels the same impact. Consistent with previous research, disadvantaged populations, such as those with lower incomes, those who are displaced and those living on Indigenous lands, are far more likely to experience poor air quality, limited access to clean water and excessive heat than the rest of the population.

Those living in wealthier areas usually experience the best environmental conditions and are more likely to escape the worst impact as climate change progresses.

Internationally, several environmental impact hotspots stood out in the study: South Asia, for example, contains 41% of all people living with all five threats to environmental rights, despite making up only one-fifth of the world’s population.

Much of the poor environmental conditions around the globe result from the activities of wealthy nations, the study found. For instance, pollution from the United States is responsible for 12,000 deaths from poor air quality in India each year and 38,000 deaths in China. Meanwhile, emissions from the 27 countries in the European Union have made extreme weather events 1.8 times more likely in Southeast Africa and the Amazon rainforest.

“No matter where we live, our rights are inherently connected to those of people in other parts of the world,” Ormaza-Zulueta said. She added that the large demand for products in the United States and Europe has caused biodiversity loss and deforestation in the Amazon rainforest. The resulting global warming and increased frequency of extreme weather events are felt around the world.

“An unstable environment destabilizes our society,” Mehrabi said. “There is already a lot of fear in the United States and elsewhere about conflict, immigration, and other signs of instability. Environmental issues are only going to make them worse.”

Even though the statistics are bleak, Mehrabi said they don’t tell the whole story. In addition to the five core categories, many people are at risk of other poor conditions that were not measured, such as exposure to toxins released from mining and plastic waste.

“There are many solutions to these environmental problems we’re facing now, from responsible clean energy to a more sustainable and just supply chain. We need strong policies that encourage businesses to adopt these solutions,” Mehrabi said.

Mehrabi pointed to due diligence laws in countries such as the Netherlands, France, and Germany, which require domestic companies to uphold human rights across their global operations. He said other nations need to follow suit.

The team hopes this study can empower communities and lawyers working on environmental rights issues.

“By showing how these injustices are happening across the world, deniers can no longer dismiss the polluted river here or dirty air there as anecdotes. This can be a critical tool for pushing for policy changes,” Ormaza-Zulueta said.