Even small concentrations of smoke pollution from wildfires can be harmful to human health.
As the climate changes, the number and cost of weather disasters is increasing in the U.S.
Warming temperatures combined with drought conditions are major factors for the increase in wildfires.
While Harvey was the most damaging weather event this summer, there were other extremes in the U.S.
See how the summer temperatures and rainfall compared to normal this year in these cities.
Climate change is one reason the area burned by western wildfires is increasing.
The number of large wildfires in the West is rising and climate change is playing a role.
We look at the general climate of Brazil and some of the potential climate change impacts there ahead of the Rio Olympics.