The Trump administration's aggressive regulatory rollback on the environment has rapidly led to worsening air quality in the U.S., according to a new study.

Researchers at Carnegie Mellon University said Tuesday that after seven years of a 24 percent decline in air pollution, it took just two years for the number of pollutants in the air to rise by 5.5 percent, from 2016 to 2018.

The study linked declining air quality to three factors, all tied to the climate crisis and the U.S. government's refusal to reduce fossil fuel emissions that are warming the planet.

Since taking office in 2017, President Donald Trump has completed 10 regulatory rollbacks involving efforts to improve air quality and has slashed nine regulations on fossil fuel extraction industries.

Trump's repeal of a rule requiring state authorities to track vehicle emissions on highways, his decision to change how oil and gas refineries monitor pollution, and his rollback of a rule limiting industrial pollution are among the decisions that have led to worsened air quality, according to the report written by Karen Clay and Nicholas Muller and published by the National Bureau of Economic Research.

"This is happening at a time when the EPA has disbanded its scientific panel reviewing fine particle air pollution," tweeted Washington Post reporter Christopher Ingraham.

This is happening at a time when the EPA has disbanded its scientific panel reviewing fine particle air pollution. https://t.co/GYr3HvoOXo pic.twitter.com/EvCNHl02kw — Christopher Ingraham (@_cingraham) October 23, 2019

The increase in pollutants "was associated with 9,700 premature deaths in 2018," Clay and Muller wrote.

The authors also linked declining air quality to wildfires that tore through parts of California and other western states between 2016 and 2018 and increased economic growth in the United States.

Climate scientists say the wildfires, like those that have scorched 162,000 acres in California so far this year, are partially the result of global warming.

Along with economic growth have come more vehicles on the country's roads and increased emissions by manufacturers, contributing to the rise in air pollution.

At the U.N. in September, climate campaigner Greta Thunberg lambasted world leaders for supporting economic growth at any cost, including rising sea levels, increased populations of climate refugees, and the collapse of ecosystems.

"We are in the beginning of a mass extinction, and all you can talk about is money and fairy tales of eternal economic growth," Thunberg said.