steve pyne: we've mismanaged fire. now we get fires that are really off the scale, shouldn't be here, shouldn't be behaving in this way. and now we're left with these monsters. and it is remaking the world. police officer: (voice breaking) it's all bad up here, brother. it's all bad. oh, my god. [thunder crackling] welcome to violent earth. i'm liev schreiber. scientists say wildfires are more frequent and burning bigger. in the past, a 50,000 or 60,000 acre fire was considered big. these days, firefighters are often dealing with fires well above 100,000 acres. according to government statistics, during the 1990s, an average of 3 million acres a year burned in the united states. since 2000, that number has more than doubled. in 2020 alone, over 10 million acres were consumed. the experts say 85% to 90% of wildfires are caused by human activity. tonight, violent earth takes a look at this roaring force of nature, starting with the mega fire that burned through paradise, california, in 2018. [police radio chatter] kory h