A new report from the World Meteorological Organization shows that concentrations of carbon dioxide in the atmosphere surged at an unprecedented speed in 2016 to the highest level in 800,000 years
D. LASCARIS: This is Dimitri Lascaris for the Real News Network. On October 30th, the World Meteorological Association issued a greenhouse gas bulletin reporting that concentrations of carbon dioxide in the atmosphere surged at record-breaking speed in 2016 to 403.3 parts per million. According to the bulletin, the rate of increase of atmospheric carbon dioxide over the past 70 years, is nearly 100 times larger than that at the end of the last ice age. Such abrupt changes in the atmospheric levels of CO2 have never been seen before. Rapidly increasing atmospheric levels of CO2 and other greenhouse gases have the potential to initiate unprecedented changes in climate systems, leading to, “severe ecological and economic disruptions,” said the report. Scientists say that recent devastating hurricanes in the US and the Caribbean are examples of major disasters that may have been made much more destructive by human-caused climate change. With us to discuss the World Meteorological Association’s report, and what these record levels of CO2 in Earth’s atmosphere mean, we are joined by Dr. Kevin Trenberth. Dr. Trenberth is a distinguished senior scientist at the National Center for Atmospheric Research, climate and global dynamics laboratory. He joins us today from Boulder, Colorado. Thank you for joining us again today, Kevin. KEVIN TRENBERTH: Good to be here. Thank you. D. LASCARIS: In the new report, Kevin, it says that globally average concentrations of CO2 reached 403.3 parts per million in 2016, up from 400 parts per million in 2015 because of a combination of human activities and a strong El Niño event. Concentrations of CO2 are now 145% above pre-industrial levels, according to the greenhouse gas bulletin. What did the Earth and its climate look like the last time the CO2 levels were this high? KEVIN TRENBERTH: Oh. That’s going back probably something like three million years or more. It’s a very long time ago. The pre-industrial value was around 280 parts per million by volume, and that was fairly stable from about 9,000 years ago up until 200 years ago. And about 45% of the increase has occurred since that time, but half of that increase has occurred since about 1980. We can go back reasonably well to about 900,000 years ago, using ice cores in Antarctica and Greenland, with bubbles of air trapped in the ice. But going back further is much more difficult, and the information is much more fuzzy and hazy, but the estimate is that you have to go back three million years, or something like that, when even the communal drift comes into play, and other factors have led to changes, but certainly the atmospheric concentrations prior to then was quite different. It was much higher if you go back 50 million years ago, back to times when the dinosaurs were running around, and things like that. It was a much warmer period at that time. D. LASCARIS: You indicated that we can go back 800,000 years or so and try to reconstruct what the world looked like. What was the concentration of CO2 in the atmosphere at that time? Do we have that figure? KEVIN TRENBERTH: The last 800,000 years. Well, there’s a series of so-called glacials and inter-glacials. You know, we call the glacials ‘ice ages’ and the last major ice age was about 20,000 years ago, something like that. At that time, there was a major ice sheet over North America and also over Europe. Values are about 100 parts per million by volume lower during the ice ages. Then as we came out of the ice age, there was an increase that occurred in a number of surges, and got us to the level that we’ve been relatively stable at in the last 9,000 years. D. LASCARIS: What I’m trying to get at is, in particular, at a point in time where we had comparable levels of a CO2 concentration in the atmosphere as we have today, what did the ice sheets look like, and what did sea levels look like? KEVIN TRENBERTH: The last major inter-glacial was 120,000 years ago, or something like that. Temperatures were maybe a bit warmer than they are now, but the Greenland ice sheet was much lower and sea levels were estimated maybe four meters higher, or something like that. So conditions were very different than today. These evolved over thousands of years, in order to get to that point. The key point of this report, really, is that the changes we’re making today are occurring in 100 years, whereas in nature they occur in 10,000 years. D. LASCARIS: Right. In interest of CO2 from human activity, there’s some indication that they’ve plateaued in the very recent past. And yet in 2016, we saw the surprisingly large increase in the CO2 concentration in the atmosphere. If in fact CO2 emissions are plateauing, how could we have seen such an unusually large increase in CO2 concentrations? What would account for that? KEVIN TRENBERTH: Well, you’re talking about emissions versus concentrations. Emissions are what we’re putting into the atmosphere, and the rate at which we’re doing that. And the concentrations are the cumulative result. And so as long as you’re putting anything into the atmosphere, the concentrations will continue to go up. Although we have stabilized emissions in the last few years, in particular in the US, the emissions have stabilized. They’ve even gone down a little bit. But the concentrations continue to rise. The fact that it’s risen at the record rate in the last year, well part of that might be related to the El Niño and the conditions that have arisen, but it’s an indication that we’re really not getting this problem under control at all. D. LASCARIS: Might it be an indication that we’ve actually achieved a tipping point around the verge of doing so? KEVIN TRENBERTH: Well, a tipping point relates to irreversible changes. And indeed, some of these changes may ultimately be that way. The warming of the ocean that’s going on, we’re at a point where the ocean heat content this year is the highest on record. It’s probably contributed to all of the hurricane activity, and so on, that we’ve seen. And it’s very hard to cool off the oceans. It’s very hard to put back major ice sheets, so if Greenland were to melt, and it’s in the process of certainly melting, it’s very hard to put that back. So there are changes in the ocean, which are going on, that we worry about. They may not really be reversible. At some point, it may become obvious that that’s the case. It’s less obvious at the moment. D. LASCARIS: Does this finding perhaps suggest that we have, the scientific community has underestimated the rapidity with which we have to move to a zero carbon world? KEVIN TRENBERTH: I don’t think the scientific community has underestimated that, but I think the politicians and the economists have greatly underestimated that. This is reflected in the national plans, like the clean power plan, or also in the Paris agreement. You know, the Paris agreement was a major achievement, international approach to reducing the emissions and trying to slow down and prevent the problem from happening. But if you look at it really hard, it’ll make a dent, but it really won’t solve the problem. That doesn’t go far enough. None of these changes that have been put in place, including the US national changes are going anything like far enough because we really have to move to a carbon-free economy really quite quickly, on a timescale of, say, 20 years, which might be do-able. It’s not something we can turn the switch on. D. LASCARIS: Lastly, the magnitude of the increase we saw in CO2 concentration in 2015, does that suggest that, or add force to the argument that staying within the aspirational goal of 1.5 degrees Celsius, states in the Paris Climate Accord that you referred to, is unrealistic at this stage? Do we think [crosstalk 00:09:29] to feel optimistic about that? KEVIN TRENBERTH: I don’t think there’s any chance we’ll stay within 1.5 degrees. In some ways, they’re talking about not really staying within 1.5 degrees, but maybe going up to three degrees Celsius and then coming back down to 1.5 degrees. But if you go up to three degrees Celsius warming globally, there will be major changes, including major melting of Greenland and various other changes that … These things are not linear. They’re not reversible in reality, so I think that’s quite unrealistic. We’re gonna blow through 1.5 degrees Celsius very easily, I think, and it’ll be a major challenge to stay within two degrees Celsius warming overall. What we’re seeing in this report is an indication that all of the changes that have been made, in terms of moving more to solar power and non-renewable sources, it’s still only a small dent so far, and it’s not going anywhere near far enough quickly enough. D. LASCARIS: This has been Dimitri Lascaris for the Real News, speaking to Dr. Kevin Trenberth about a new report showing a record concentration of CO2 in the atmosphere at 403.3 parts per million. Thank you very much for joining us today, Dr. Trenberth. KEVIN TRENBERTH: You’re most welcome. D. LASCARIS: And this is Dimitri Lascaris for the Real News.