To determine if climate change influences extreme weather, scientists use supercomputers to build virtual models of the planet to see how storms might differ as the world grows warmer. Final reports conclude that storms like Harvey are three times more likely due to climate change.
Did Climate Change Cause Hurricane Harvey?
Published: February 26, 2019
Heidi Cullen: We can actually find the human finger print in individual extreme weather events. And that changes everything. Fundamentally, on our planet everything is interconnected. Crank up the temperature, more water evaporates from the oceans, our atmosphere is now moisture, and that means when it rains there is more moisture with which you can rain out during any given storm.
Onscreen: To determine if climate change influences extreme weather, scientists use supercomputers to build virtual models.
Cullen: So when we look at an extreme weather event, we basically create the world with global warming and the world without it. And then you re-create the conditions for a storm like Harvey.
Onscreen: Climate scientists look at conditions like temperature and rainfall.
Cullen: You run that model. You run that simulation of our planet many, many, many times so you have good statistics. And then you essentially count up how many times an event like that happens in each of these two different worlds. A lot of times what we see is that in this planet that we’ve essentially help create, those extreme events happen more and more frequently. And so our rainfall like Harvey happens far more often in the world that we’ve created.
Onscreen: Final reports conclude that storms like Harvey are three times more likely due to climate change. But it’s not just rain, these models can look at all kinds of weather.
Cullen: And what we’ve seen when we’ve done analyses is that the coral bleaching event that hit the great barrier reef, at least 175 times more likely in the world with global warming. The Louisiana flooding event, at least twice as likely in the world with global warming. The heat wave that hit Europe in 2017, 10x more likely as a result of global warming. So what we’re seeing is that these extreme events, really are being impacted by the things that we do. It’s a relatively young science but over the last 10 years has come a really long way and it’s fundamentally changed the conversation. As a society we have to ask ourselves, how are we going to manage this new normal?
Decoding the Weather Machine
Produced and Directed by: Doug Hamilton
Co-Produced by: Caitlin Saks
Director of Photography: Daniel Traub
Digital Producer: Brian Kantor
Additional Footage: ANU TV
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