The Climate 100 List: John Clarke Mills and the battle against wildfires

John Clarke Mills, the founder of the Watch Duty app never planned to be a climate warrior. He just wanted to know what was happening one morning when he saw helicopters over his ranch in Sonoma, California but couldn't find anything on the news or internet about a wildfire.

Now Mills leads a team of two dozen staff and some 250 volunteers who tap into a host of firefighting communications and weather data in the American West to report on wildfires from the moment they break to the moment they are contained, saving countless lives with vital information when they need it most.

Most wildfires that make headlines are ones that blow up either close to major cities or become large enough – a few hundred acres or more – to attract attention.

But each day in California and across the Western US and Canada, hundreds of smaller wildfires break out, taxing authorities and causing emergencies only for those nearby.

Watch Duty currently has around five-million active monthly users, and during massive fires such as the ones in Los Angeles earlier this year, the former tech entrepreneur's app saw more than one million downloads in one day.

“We've really broken through to a bunch of people that don't normally use these things,” Mills said. “It's really started to pick up throughout the (rescue services) industry too.”

Most wildfires, floods and other disasters in the US are fought by authorities whose first priority is to stop the disaster and rescue people, not to communicate the rolling impact of these tragedies to people who may be in their path.

Watch Duty taps into disaster relief communications, which are public, and seeks to create an easy-to-use way for people to see where fires are, how fast they are growing, and most important, which direction they are moving.

Mills runs Watch Duty as a non-profit business, dependent on donations from readers and subscribers. But they are increasingly adopting a membership model that includes major companies such as Pacific Gas & Electric (PG&E), which is California's largest utility. He said the non-profit is pacing toward $5m (£3.7m) in revenue this year, which it is using to grow its services across the country.

“We can make money later; we're focused on outcomes,” Mills said. Watch Duty currently operates in 22 US states, all west of the Mississippi River. But Mills and his team are actively planning to expand east, and to begin monitoring floods as well.

He argues that the critical need for public information when sudden floods occur is similar to with wildfires, which makes Watch Duty perfect to address them.

“What happened in Kerrville (Texas flood), is exactly what happened in Lahaina (Hawaii fire),” Mills said. “People die and they don't understand what happened. That's why we're here.”

The Independent will be revealing its Climate100 List on 21 September