The climate science behind this year's wildfires and powerful storms
At least 31 have died in the largest wildfires in California history. The east is defending itself against twice the usual number of tropical cyclones. And what may be the highest temperature ever recorded on Earth came in August in the United States. It's a torrid 2020 and it was forecast 32 years ago. In the 1980's, a NASA scientist named James Hansen discovered that climate change, driven by carbon emissions, was upon us. His graphs, of three decades ago, accurately traced the global rise in temperature to the year 2020. Last week, we had a lot of questions for Hansen. Are these disasters climate change? Do things get worse? Is it too late to do anything? But before we get to the causes, let us show you the effects.
Butte County, California, Volunteer Fire Station 61.
Scott Pelley: How long has the fire station been here?
Reed Rankin: About 35 years.
Scott Pelley: And how long have you been here?
Reed Rankin: 28 and a half years.
Reed Rankin is chief of what was Station 61. He's spent his life in the community of Berry Creek. He's on the school board and built his home with his own hands.
Scott Pelley: Tell me what your home looks like right now.
Reed Rankin: Nothin' but a foundation with a metal roof on top of it. It's completely burned down.
Scott Pelley: School burned down.
Reed Rankin: Yeah. Completely. All the buildings on it burned down. Nothin'-- nothin' left.
Fifteen people died in that inferno, the second week in September, north of Sacramento, where the central valley folds into the Sierra Nevada.
Thom Porter: These are fires that nobody, when I started in this business, ever even dreamed of happening in California. Not even close.
California State Fire Chief Thom Porter 'started in this business' in 1999. That year just over one million acres burned. By 2007, it was a million and a half. In 2018, two million. This season, nearly four million acres have burned so far.
Climate isn't the only reason. Decades of aggressively putting out every forest fire allowed brush to pile up like kindling. But the warming climate has intensified heat and drought. Chief Porter showed us the length of the fire lines he's defending right now would stretch from LA to New York.
Thom Porter: They talk about career fires. And a career fire was sometimes on the order of 10,000 to 50,000 acres. 50,000, that was crazy.
Scott Pelley: The kind of thing a firefighter would see once in his career.
Thom Porter: Correct. Once in a career. it dawned on me at one point that career fires are happening every single year, right now, today, there are ten fires in California that are 100,000 acres plus, and one that's 850,000 acres plus.
Four percent of the state has burned in total. The largest fires were ignited by storms, but because the air is so dry the rain evaporated before it reached the ground, leaving chief porter fighting dry lightning.
Thom Porter: I'm afraid, without significant change in the moisture that we get from the atmosphere we're gonna continue to see this getting worse and worse and worse.
Scott Pelley: How much of California can burn?
Thom Porter: Every acre in California can and will burn someday.
California smoke blew more than 2,000 miles to the east and drifted over the Pennsylvania farm of retired NASA scientist James Hansen. His 1988 paper on carbon and climate accurately predicted temperatures up to the far-off year of 2020.
James Hansen: Yeah, we're seeing exactly what we expected. But I expected that governments would be wise enough that they would begin to adopt policies to preserve the future for young people. But they haven't done that yet.
Hansen is the father of climate change science. For 32 years he was director of NASA's Goddard Institute for Space Studies. Today, at 79, he runs the program on climate science at Columbia University.
Scott Pelley: What is your forecast for the next 30 years?
James Hansen: Well, if we don't change anything, then we're going to continue to see more and more of these extreme regional events because the physics is quite simple. As you add more greenhouse gases to the atmosphere, you increase the heating of the surface. So, at the times and places where it's dry you get more extreme droughts. The fire seasons become longer. The fires burn hotter. But at the times and places where it's wet, you get more evaporation of the water. And you get warmer, moist air, which provides greater rainfall. And it's the fuel for storms.
This summer, the Atlantic Basin has soaked beneath 23 tropical storms or hurricanes, double the usual number. Death Valley, California, hit 130 degrees -- now being evaluated as a world record. And Los Angeles reached 120.
Michael Mann: People ask, are we dealing with a new normal? And the sobering answer is, that's the best-case scenario. A new normal is the best-case scenario 'cause that sorta means, well, we've got a new situation and we just have to learn how to deal with it. But it's much worse than that. So, there are surprises in store and we're seeing some of those surprises play out now.
Michael Mann is a geophysicist whose work on past climate showed today's rate of warming began with the Industrial Revolution. Mann is a lightning rod for deniers, but his research has been verified again and again. Mann is director of the Earth System Science Center at Penn State and a member of the National Academy of Sciences.
Scott Pelley: But there've always been fires in the west. There've always been hurricanes in the east. How do we know that climate change is involved in this?
Michael Mann: Well, there are a number of independent sort of sources of information, lines of evidence that tell us that this isn't natural, that this is human-caused. Let's look at the big picture, the warming of the planet a little less than 2 degrees Fahrenheit warming of the planet since pre-industrial time. Now, people ask, well, couldn't that happen naturally? Well, it turns out that if you look at the factors that are driving natural changes right now -- small but measurable fluctuations in the brightness of the sun, Volcanic eruptions -- they tell us that earth should've cooled slightly over the past half-century.
Here's what he means. In that yellow line at bottom, NASA has measured a steady decline in heat from the sun since the 1950's. But the red line, the temperature of the Earth, has only increased.
Michael Mann: We can only explain that warming when we include the human factor of increased greenhouse gas concentrations; in particular, carbon dioxide from the burning of fossil fuels.
Scott Pelley: Well, the president says about climate change, science doesn't know.
Michael Mann: The president doesn't know. And he should know better. He should know that the world's leading scientific organizations, our own U.S. National Academy of Sciences, and national academies of every major industrial nation, every scientific society in the United States that's weighed in on the matter. This is a scientific consensus. There's about as much scientific consensus about human-caused climate change as there is about gravity.
That's what President Trump heard last month from Wade Crowfoot, head of California's Natural Resources Agency, which includes fire fighting.
Wade Crowfoot to President Trump on 9/14/20: Because if we ignore that science and sort of put our head in the sand and think it's all about vegetation management, we're not going to succeed together protecting Californians.
President Trump: Okay. It'll start getting cooler. You just watch.
Crowfoot: I wish science agreed with you.
President Trump: Well, I don't think science knows, actually.
Wade Crowfoot: Well, with respect, I think he's wrong and he's on the wrong side of history.
This is the unmasked Wade Crowfoot, who reminded us California emerged from a five-year drought in 2016.
Wade Crowfoot: In that drought, which we called a mega-drought-- hasn't happened at that level in a thousand years. We experienced communities in California literally running out of water.
And where California dried out is now the site of the largest single fire in state history, called the Creek Fire.
Wade Crowfoot: So that's an existential challenge. We lost over 160 million trees in the Sierra Nevada mountain range as a result of that drought. The fire that burned the hottest and most dangerous, the Creek Fire, was in the epicenter of that tree mortality. It ran so hot that it created a smoke cloud 50,000 feet in the sky.
Scott Pelley: What was the impact of all the smoke
Wade Crowfoot: So consider this. Fifty million Americans on the West Coast suffered through weeks of the worst air quality on the planet.
Scott Pelley: You didn't have to live anywhere near the fires to be affected by them.
Wade Crowfoot: Not at all. Throughout California the smoke was so bad that our kids couldn't play outside. And folks were discouraged from even spending any time outdoors.
Scott Pelley: I did my first climate story more than 20 years ago and I remember, at the time, being told that there would be terrible fires and terrible hurricanes in 100 years; that this was a problem for our great-grandchildren. What changed?
Michael Mann: what we're finding is that many of these changes can happen faster than we thought they could. We didn't really expect to see substantial loss of ice from the two major continental ice sheets, the Greenland Ice Sheet and the Antarctic Ice Sheet. But now, the satellite measurements and in situ measurements tell us that they're already losing ice. They're already beginning that process of collapse. It's already contributing to sea level rise, decades ahead of schedule.
Still, geophysicist Michael Mann told us warming can be stopped. Oceans and forests would begin to absorb excess carbon in a matter of years if emissions, principally from coal-fired power plants, are reduced close to zero. Former NASA scientist James Hansen believes the way to do that is for governments to tax cheap fossil fuels to make them more expensive than clean alternatives.
James Hansen: They have these wishful thinking agreements like Kyoto Protocol and the Paris Agreement. Every country says, "We'll try to do better." That won't work. What we need is to have an increasing price on the fossil fuels and do it in a way that the public will accept.
Scott Pelley: At what point does it become too late?
James Hansen: It becomes too late if you get to the point that you cannot stop the ice sheet disintegration. That's the biggest point of no return. We can get to a point where we're going to get several meters of sea level rise out of our control. That's too late. We would lose our coastal cities. And more than half of the large cities in the world are on coastlines.
Scott Pelley: If we don't start to reduce the CO2 in the atmosphere, 50 years from now, someone doing research on this time might look at this interview and I wonder what you would like to say to them.
Michael Mann: That-- that's a tough question. I would say we did everything we could and we're sorry. We're sorry that we failed. But I don't think that's our future. I don't want that to be our future. That's a possible future. We have to recognize that. The worst visions that Hollywood has given us of dystopian futures are real possible futures if we don't act on this problem; the greatest crisis that we face as a civilization.
Produced by Maria Gavrilovic and Alex Ortiz. Broadcast associate, Ian Flickinger. Edited by April Wilson.
