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Carbon dioxide – the main atmospheric greenhouse gas – reached 410 parts per million in April, for the first time in recorded history. The connection to global warming is undeniable, but emissions have plateaued, which means that we can still reverse this trend, says climate scientist Michael Mann

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GREG WILPERT: It’s the Real News Network. I’m Greg Wilpert, coming to you from Quito, Ecuador.

This week, the National Oceanic and Atmospheric Administration announced that for the first time in recorded history, the average monthly level of carbon dioxide in the atmosphere reached 410 parts per million. For 800000 years carbon dioxide concentrations fluctuated between 170-280 parts per million. The last time CO2 concentration was as high as it is now was at least two to four million years ago during the Pliocene era. During that time, sea levels were 60-80 feet higher than they are now.

Does reaching this new record of 410 parts per million mean that we can expect sea levels to rise as high as they were during the Pliocene again? Well, joining me to discuss the meaning of this new record is Professor Michael Mann. Professor Mann is director of the Earth Science Systems Center at Penn State University. His latest book, co-authored with Tom Toles, is titled “The Madhouse Effect: How Climate Change Is Now Threatening Our Planet, Destroying Our Politics, And Driving Us Crazy.” Thank you for joining us again, Professor Mann.

MICHAEL MANN: Thank you. Good to be with you.

GREG WILPERT: So we always hear that greater concentration of carbon dioxide in the atmosphere is linked to global warming. Indeed, according to the National Oceanic and Atmospheric Administration, the average global temperature last March was the fifth highest ever recorded. But just how closely is CO2 concentration correlated with global average temperatures, and what does 410 parts per million mean for global temperatures in the next 30 or so years?

MICHAEL MANN: Yeah, on pretty much all time scales that we can resolve in the climate record, whether we’re talking about the past geological periods like the Cretaceous period where CO2 levels were very high and the planet was very warm, there was no ice on the planet, or the the cooling that occurred subsequent to that period, over subsequent tens of millions of years, or the dramatic warming that we are seeing today, on pretty much all time scales that we look at, CO2 is the main driver of climate change.

And that’s because it’s simple physics, simple radiative physics and chemistry. Greenhouse gases, of which CO2 is among the most prominent, carbon dioxide, which is produced by the burning of fossil fuels and other human activities, these gases absorb some of the heat that is attempting to escape from Earth’s surface out to space. It basically blocks the earth’s effort to cool off and send some of that heat back down towards the surface. That’s what’s known as the greenhouse effect. We’ve basically known of its existence for nearly two centuries. This isn’t new, controversial science. It’s very basic science. And it tells us that when you increase the concentrations of these gases like carbon dioxide, the planet will warm up. We know that we have increased the concentration of carbon dioxide in the atmosphere now, through fossil fuel burning and other activities, to levels not seen, as you alluded to, in literally millions of years. And what we would not be able to explain scientifically would be if the earth were not warming up. But of course, it is warming up.

And in fact, 2014, 2015, 2016, three consecutive record-breaking years. We’ve never seen that before. Temperatures, we broke record for global temperatures in each of those years. The good news is that 2017 didn’t set a new record. It was only the second-warmest year on record. So we are seeing this parade of record-breaking years in the global temperature record. We’re seeing unprecedented temperatures around the planet. Pakistan just saw the warmest temperature ever recorded in April. The impacts of climate change are no longer subtle. We’re seeing them play out in real time, now.

GREG WILPERT: So considering that there has been no slowing of CO2 concentration in the atmosphere since the signing of the Paris climate agreement last year, is there any chance, would you say, that the agreement’s target of not exceeding 2 degrees Celsius by 2100 can be maintained?

MICHAEL MANN: Yeah. Actually, there’s a little bit of good news here. In 2014, 2015, 2016 we actually saw global carbon emissions plateau, they didn’t increase, for the first time in modern history. Even as the world economy continued to grow, our carbon emissions didn’t. And that is an indication that we are beginning to move away from a carbon-based global economy.

Now, in 2017 the numbers did creep up a little bit. And that’s a reason for a little bit of concern. But really what it tells us is we have to double down in our efforts. We have to work even harder to maintain our obligations under the Paris accord. Ironically, right now the United States is the only country it’s a renegade nation where the only country in the world that, under Donald Trump, is not committed to the Paris agreement. And so we obviously need more leadership here in the United States. Fortunately, we are seeing that in the form of governors like Jerry Brown, the West Coast states, the New England states. States and municipalities and companies saying that whether or not Trump remains committed to the Paris agreement, we are. And we’re going to do everything we can to meet our obligations. And so there’s a little bit of room for cautious optimism, but we have to try even harder if we are going to avoid truly dangerous levels of carbon dioxide in the atmosphere.

GREG WILPERT: Let me just ask a slight clarification question about, you mentioned carbon emissions have not, or have plateaued. But the statistic I was mentioning about the concentration of carbon seems to have increased, that is by two parts per million per year, relatively steadily. Is that correct? In other words, that even though there’s a plateauing of emissions, the concentration could still be increasing. Is that possible?

MICHAEL MANN: Yes, because this is the difference between stocks and flows. If you like, you know, a bathtub with the drain closed will continue to see rising water levels as long as the faucet is turned on. So even if you keep the faucet fixed at the same rate, think of that as our carbon emissions, the water level will continue to rise. The water level won’t, it won’t stop rising until you turn the faucet off. You bring the emissions down to zero. So bringing our emissions to a plateau is an important first step, because they were rising. Our emissions were rising year after year, escalating the problem.

But bringing them to a plateau isn’t enough to stop the rise in CO2. We have to actually bring those emissions down towards zero over the next several decades if we are going to keep those levels from rising above what most scientists would consider dangerous levels of carbon dioxide in the atmosphere; 450 parts per million CO2 in the atmosphere probably locks in dangerous planetary warming of more than three and a half degrees Fahrenheit. We have to bring our emissions down dramatically if we are going to avoid crossing that threshold.

Now, as you mentioned, we’ve crossed 410 parts per million now for the first time in millions of years. And 450, we’ll hit that number pretty soon at the rate that we’re adding CO2 to the atmosphere if we don’t bring those emissions down. So bringing them to a plateau, important first step, but it’s not enough. We’ve got to ramp them down. We’ve got to bend that curve downward now.

GREG WILPERT: I see. So just returning to the policy aspect, President Trump’s EPA is currently re-evaluating the Obama administration’s declaration that carbon dioxide is a pollutant. What impact would such a decision, if they were to reverse that, what, what impact would such a decision have on CO2 emissions in the United States?

MICHAEL MANN: Well, you know, right now what we’re seeing under the Trump administration and under Scott Pruitt, who is the current head of the EPA, is literally an effort to dismantle all of the environmental protections put in place, including policies to deal with climate change under the Obama administration. But in fact they are literally trying to dismantle all of the environmental policies passed over the past half century. The Clean Air Act, Clean Water Act. Basically all of these regulations that were put in place by both Democratic and Republican administrations to deal with problems like ozone depletion, acid rain, and of course, climate change.

Now, the, you know, the fact is that the last administration, the Obama administration put in place policies, the Clean Power Plan to reduce carbon emissions from power generation. They tightened the EPA transportation, car, gas efficiency standards to bring down the carbon emissions from the transportation sector. And so what we’re seeing now is an effort to undo all of those policies. Obviously that makes it more difficult for us to meet our obligations under Paris, if we have an active effort on the part of the administration to roll back the very policies that were put in place to help us meet our obligations under Paris.

Here’s the good news. Even if that happens at the federal level, even if Trump and his administration undoes the policies that were put in place by the Obama administration, there’s enough progress now being made at the local level, at the state level, groups of states banding together to enforce policies, to incentivize renewable energy, to move away from carbon emissions, to put a price on the burning of fossil fuels. Those efforts are likely to yield enough dividends that we may meet our obligations under Paris even if Trump formally pulls out, and even if he undoes the policies of the last administration to deal with climate change. There’s so much progress happening, you know, from the ground up, from the grassroots up, that we can still do it. Of course, we would like to go beyond our Paris commitments. The Paris commitments alone aren’t going to be enough to keep warming, planetary warming, below those dangerous levels of 3.5 degrees or more Fahrenheit warming of the planet. We have to actually ratchet up those commitments.

And so the problem is at a time when we need to be ratcheting up the commitments the current administration is making it very difficult for us to meet our obligations. That’s why, you know, we have an opportunity in a little over 200 days, if we don’t like the policies of the current administration and the current congressional leadership, or the lack thereof when it comes to the issue of climate change, we have an opportunity to show up at the voting booth in the midterm elections and send a message that we want to move in a different direction. We don’t want the United States to be the skunk at the garden party. We want to join the rest of the world in tackling this problem and moving into the 21st century.

GREG WILPERT: OK. Well, we’re going to have to leave it there for now, but we’ll definitely come back to you again. I was speaking to Professor Michael Mann, director of the Earth Science Systems Center at Penn State University. Thanks again for having joined us today, Professor Mann.

MICHAEL MANN: Thank you. Always good talking with you.

GREG WILPERT: And thank you for joining The Real News Network.

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Dr. Michael E. Mann is a Distinguished Professor of Meteorology at Penn State University, with joint appointments in the Department of Geosciences and the Earth and Environmental Systems Institute (EESI). He is also director of the Penn State Earth System Science Center (ESSC).