Climate Change Impacts 'No Longer Subtle,' Scientist Says Amid Extreme Weather

Aug 2, 2018
Originally published on August 2, 2018 1:10 pm

More then a dozen large wildfires are burning in California and a heat wave continues to grip much of Europe, where temperatures are expected to reach 118 degrees Fahrenheit in parts of southern Spain by the end of the week.

How much of this summer’s extreme weather can be attributed to climate change, and what role do news outlets play in drawing that connection?

Here & Now‘s Jeremy Hobson talks with Michael Mann (@MichaelEMann), distinguished professor of atmospheric science and director of the Earth System Science Center at Penn State University.

Interview Highlights

On the science of climate change and its direct link to extreme weather events

“What we’re seeing right now across the Northern Hemisphere is extreme weather in the form of unprecedented heat waves, droughts, floods, wildfires. In isolation, it might seem like any one of these things could be dismissed as an anomaly, but it’s the interconnectedness of all these events and their extreme nature that tells us that we are now seeing the face of climate change. The impacts of climate change are no longer subtle.

“When we frame the issue in terms of, was this event caused by climate change, that’s not the right question. The question is, was this event made more extreme by climate change? And that we can conclude with some certainty, because there’s basic physics that’s operating here. A warmer atmosphere holds more moisture. That means when you get rainfall, you get more of it in short bursts.

“As you bake the ground with sun and heat, you’re going to get worse drought. As you warm up the planet, obviously, heat extremes become more common.

“Part of what has made this July so unusual is not just the extreme nature of these events, but their persistence, the fact that the same weather system sticks around day after day so you continue to get dumped on by rain, like we are here in Central Pennsylvania, or you continue to be baked by heat, like California right now.

“Our own work has shown that, believe it or not, the melting of ice in the Arctic is changing temperature patterns in a way that is impacting the Northern Hemisphere jet stream, slowing it down, causing larger waves, larger meanders, which gives you more extremes. Where you see the jet stream sort of bend upwards, bend northward, we call that a ridge that’s associated with high pressure, warm conditions, sunny conditions. Where you see the jet stream then crash down southward, we call that a trough, and that’s a low-pressure system and you get lots of rainfall. When those wiggles are very large and when they stay fixed in place, that’s when you get these unprecedented weather events, and that’s what we’re seeing, and it’s actually driven by large-scale changes in the climate.”

On media outlets not mentioning climate change when discussing extreme weather events

“There are media outlets and there are journalists who are helping us connect the dots, but too often in our mainstream media and network news coverage, cable news, they’re not connecting the dots. There is some talk about the extreme nature of these weather events, but there’s a real teaching opportunity, there’s a real learning opportunity for the public in connecting the dots and explaining that this isn’t just a random event; it’s part of [a] coherent larger pattern, which is being impacted, which is being influenced, which is being made more frequent and more intense by climate change.

“That’s a huge lost opportunity when the media does not connect those dots for the people, because this is the face of climate change, and we have to understand it’s not just about polar bears up in the Arctic. It’s about extreme damaging weather events that we’re experiencing now in real time.”

On whether we have passed the point of being able to combat climate change

“It’s certainly much more of a challenge now. If we had acted on the problem when we knew about it for the first time decades ago … it would have been so much easier to keep the warming below truly dangerous, arguably catastrophic, levels. And what two decades of inaction — in part due to a public relations campaign by fossil fuel interests to pollute the public discourse over climate change, to fool the public and policymakers — what that has bought us is now …

“If you think about how we have to bend our carbon emissions down towards zero, we would have been dealing with a bunny slope if we had acted on this problem back in the ‘70s. Now, we’ve got a black double diamond slope to follow. We’ve got to bring our carbon emissions down by several percent a year if we are going to avoid warming the planet beyond about two degrees Celsius or 3.5 [degrees] Fahrenheit — the level of warming, where we see, where we think that some of the worst impacts will play out … that will be beyond our adaptive capacity frankly.”

On the Trump administration’s recent decision to reduce emission standards and its overall refusal to actively fight climate change alongside much of the rest of the world

“We need to reduce our emissions, not reduce our emissions standards, which is what the Trump administration wants to do. And sure, the rest of the world is moving forward, and states — the West Coast states, the New England states — cities, companies in the U.S., pretty much everybody else across the planet is on board. And that’s why we had this monumental agreement a few years ago, the Paris Accord, which commits the countries of the world to carbon emissions that will help us avoid catastrophic warming of the planet.

“So the world is moving on, and the question now is, simply, is the United States going to join the rest of the world in what is the great economic revolution of this century, the green energy revolution, or are we going to fall behind the rest of the world? That’s the decision that we have to make, and if we don’t like the path that we’re on right now with the Trump administration and Republican leadership in Congress, we’ve got a midterm election in less than 100 days, where we can speak out and say, ‘We want a different path. We want to join the rest of the world, rather than be the last holdout towards progress.’ ”

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