NEW YORK – Americans and Russians have grown more dissatisfied with the way their governments address environmental issues in recent years, according to research released on Wednesday of the world's biggest carbon dioxide emitters.

Residents of China and Saudi Arabia, meanwhile, have become more proud of their countries' environmental efforts, said the research by Gallup, a prominent US-based polling group.

To mark the 50th anniversary of Earth Day, Gallup surveyed attitudes about efforts to fight climate change and preserve the environment in 145 countries.

Overall satisfaction was bolstered by rising levels in Asia and in sub-Saharan Africa, said Julie Ray, Gallup's managing editor for world news.

"Satisfaction levels in the European Union, Latin America and Northern America, however, continued to falter and move in the opposite direction," she said.

Among the top emitters of global-warming gases, 56% of Americans said they were dissatisfied with their country's environmental preservation in 2019, up from 52% in 2017.

"Throughout Donald Trump's Presidency, and even in the last year of President Barack Obama's second term, Americans have given U.S. efforts in this arena a relatively poor grade," said Ray.

The U.S. president has made it a priority since taking office in 2017 to roll back environmental regulations he believes are an obstacle to economic development.

The Trump administration filed paperwork in November to withdraw the United States from the Paris Agreement, the 2015 global pact to fight climate change.

In Russia, 59% of respondents said they were dissatisfied, up from 56% in 2017.

Russia pledged in March to cut planet-warming emissions by a third by 2030 from 1990 levels, when the heavily industrial Soviet Union collapsed, although that represents an increase in Russia's greenhouse gas pollution from today.

In China, 85% of respondents said they were satisfied with their country's preservation efforts, up from 68% in 2017.

China has said it would raise the share of non-fossil fuels in its total energy mix to 20% by the end of the next decade, up from 15% in 2020.

In Saudi Arabia, 79% of respondents were satisfied with their country's job preserving the environment as opposed to 71% in 2017, it said.

Saudi Arabia, the world's largest exporter of oil, said in October of last year it was planning to launch a carbon-trading scheme to diversify its energy supplies and reduce carbon emissions.