So for the past 12 years,
I've been obsessed with this idea
that climate change is an information issue
that computers will help us fight.
I went from data science to climate policy research,
from tech to public service,
in pursuit of better data
to avoid the wasted energy, resources, opportunities
that lead to runaway carbon emissions.
Until one day, running in the streets with a friend, it hit me:
the same cars, factories, power plants
whose emissions are wrecking our climate over time
also release harmful, local pollutants
that threaten our health right here and right now.
All this time I'd focused on the long-term environmental risk
when I should have been up in arms
about the immediate health impact of pollutants in the air.
Air pollution is a burning public health crisis.
It kills seven million people every year,
it costs five trillion dollars to the world economy
and, worst, it robs us of our most precious gift,
the years in our lives:
six months of life expectancy in my hometown of Paris
and up to three, four, five years in parts of India and China.
And in the US, more people die from car exhaust than from car accidents.
So how do we protect ourselves from pollution?
The reason it's difficult is an information gap.
We simply lack the data to understand our exposure.
And that's because the way we monitor air quality today
is designed not to help people breathe but to help governments govern.
Most major cities operate networks of air-quality monitoring stations
like this one in London,
to decide when to cut traffic or when to shut down factories.
And these machines are like the computers from the '60s
that filled entire rooms.
They're incredibly precise but incredibly large,
heavy, costly --
so much that you can only deploy just a few of them,
and they cannot move.
So to governments, air pollution looks like this.
But for the rest of us,
air quality looks like this.
It changes all the time:
hour by hour, street by street,
up to eight times within a single city block.
And even more from indoor to outdoor.
So unless you happen to be walking right next to one of those stations,
they just cannot tell you what you breathe.
So what would environmental protection look like
if it was designed for the age of the smartphone?
So for the past three years,
my team and I have been building a technology
that helps you know what you breathe
and fits in your hand.
Flow is a personal air-quality tracker that you can wear with you
on a backpack, a bike, a stroller.
It's packed with miniature sensors
that monitor the most important pollutants in the air around you,
like nitrogen oxides,
the exhaust gas from cars,
or particulate matter that gets into your bloodstream
and creates strokes and heart issues.
Or volatile organic compounds,
the thousands of chemicals in everyday products
that we end up breathing.
And that makes this data actionable
and helps you understand what you're breathing
by telling you where and when you've been exposed to poor air quality,
and that way you can make informed decisions
to take action against pollution.
You can change the products you use at home,
you can find the best route to cycle to work,
you can run when pollution is not peaking
and you can find the best park to bring your children out.
Over time you build better habits to decrease your exposure to pollution,
and by tracking air quality around them,
cyclists, commuters, parents
will also contribute to mapping air quality in their city.
So we're building more than a device,
but a community.
And last summer,
we sent early prototypes of our technology to 100 volunteers in London,
and together they mapped air quality
across 1,000 miles of sidewalk
and 20 percent of all of central London.
So our goal now is to scale this work around the world,
to crowdsource data so we can map air quality on every street,
to build an unprecedented database
so scientists can research pollution,
and to empower citizens, civic leaders, policy makers
to support clean-air policies for change.
Because this can and must change.
Remember cigarettes in bars?
It took decades of lung cancer research and second-hand smoking studies,
but eventually, we reached a tipping point and we passed smoking-ban laws.
We must reach the same tipping point for air quality and I believe we will.
In the past couple years alone,
governments have fined carmakers record amounts
for cheating on emission standards.
Cities have passed congestion charges or built bike lanes --
like Paris that turned this highway,
right next to my home, in the middle of the city,
into a waterfront park.
And now mayors around the world are thinking of banning diesel outright
by 2025, 2030, 2035.
But how much faster could we go, how many lives could we save?
Technology alone will not solve climate change,
nor will it make air pollution disappear overnight.
But it can make the quality of our air much more transparent,
and if we can empower people
to take action to improve their own health,
then together we can act to bring an end to our pollution.
Thank you very much.
(Applause)