Beijing experienced more than 200 days of air pollution categorized as “unhealthy” or worse in 2014, including 21 days that were “hazardous.”
In wealthier nations, women are more likely than men to consider climate change a serious problem, be concerned it will harm them personally and say that major lifestyle changes are needed to solve the problem.
But the degree of concern about climate change varies markedly from country to country.
Two-thirds of Americans say people will have to make major changes in the way they live to reduce the effects of climate change, but data on how much people have actually adopted several recommended lifestyle changes paints a very mixed picture.
U.S. homes are more energy-efficient per square foot than they used to be. But they're also bigger, and their increased size offsets most of the efficiency gains.
64% of Americans perceive scientists as neither liberal nor conservative.
Australia, Canada, Germany and the UK are among the other countries where there are partisan clashes on climate change issues.
A global median of 54% consider climate change a very serious problem. But there are regional differences on the issue, with the U.S. and China among the least concerned.
The U.S. Virgin Islands is the most "energy intensive" place on Earth -- meaning it uses the most energy per unit of GDP -- while gambling hub Macau is one of the least.
A majority of the public says science and religion often conflict, but fewer say science conflicts with their own beliefs. And highly religious Americans are less likely than others to see conflict between faith and science.