The decisive decade for humanity's future
We have “entered the decisive decade for humanity’s future, because this is the turnaround point”. That’s the stark conclusion of Professor Johan Rockström, Scientific Director of the Potsdam Institute for Climate Impact Research.
He has been speaking with Nik Gowing in Nature’s Newsroom at COP-26 in Glasgow on 6th November, the halfway point of COP-26. Johan Rockström says that “the direction of travel is not debated anymore” at COP 26. “It’s rather the pace of change” that is the question being discussed. He hopes that urgent message from science are at the forefront of leaders’ thinking at COP as a “constructive stress factor”.
NG: Central to everything that’s happening here in Glasgow at COP-26 is the science. For once, almost no voices are questioning it. What we’re seeing now is science which is more or less saying, ‘we don’t know everything, but we think it’s getting worse than even we were predicting maybe a year or two ago’.
And I’m joined by Johan Rockström who is Director of the Potsdam Institute for Climate Impact Research. Now Johan, you can make us all feel dreadful with some of the science, but the science is really quite gloomy. What are you saying now about what you call planetary boundaries?
JR: Yes, the science provides just the latest knowledge. So we have to have that right diagnostic. The latest science shows that we’re transgressing four of the nine planetary boundaries; we have unequivocal scientific evidence that they regulate the state of the entire planet, and thereby also the climate system. So it’s not only that we’ve gone too far on climate, we’ve also gone too far on degrading biodiversity, land system change, which is deforestation, overuse of nitrogen and phosphorus, which is also a very important greenhouse gas.
Also we are fundamentally overusing the whole land system changes across all big biomes in the Earth system. And this puts at risk the stability of your system, because the setting scientifically the planet boundaries, is to avoid crossing tipping points. We know today that the 15 to 20, big biophysical systems; that if they stay in the right state, (they) support us by cooling and dampening warming.
NG: So nature helps us?
JR: Yes, nature helps us. In fact we can quantify this, the IPCC (International Panel on Climate Change Assessment) confirms this; that 56% of the emission of greenhouse gases caused by fossil fuel burning are taken up in ocean and land-based ecosystems.
So far, the Earth’s system has been so resilient that it’s been able to stay in a Holocene. This is the period (in the 10,000 years) since we left the last Ice Age, that has been the prerequisite for civilizational development as we know it. And the planetary boundaries are the scientific guardrails or targets that give us the safe space to remain in a stable state. Now that we’ve passed four of them, we start seeing the invoices coming back to the economy.
So that’s why we see larger frequency and severity of extreme events, we see tipping points actually very likely being crossed already in, in the Arctic, in parts of tropical coral reef systems, and in western Arctic ice shelves. They very likely have already started to irreversibly move in a direction that gets just less and less able to provide life support for us humans, and also stability for the planet. So we’re really in a danger zone.
In fact, it’s what we today define as a planetary emergency. Because if we continue pushing these systems further, we are at risk of unleashing even further tipping points, which would lead from dampening and cooling to self-amplifying and warming. And that’s the exactly what we have to put all our efforts to avoid. That’s the kind of the ultimate risk analysis to avoid crossing tipping points that would lead to irreversible change.
NG: So just to be clear, what you’re saying is: tipping points, you thought were somewhere in the future, we’re now beginning to pass them much quicker than we expected.
JR: That’s correct scientifically, when we know in the order of 15 big tipping point systems, we published a report just one and a half year ago, our analysis showing that 9 out of these 15 are showing signs of instability, not that they’ve crossed tipping points, but that they are approaching tipping points.
Among those nine, you have the Arctic sea ice, the ice sheet, the overturning of heat in the North Atlantic, the Amazon rainforest, the West Antarctic ice shelf, tropical coral reefs, permafrost systems, large biophysical systems. And among those nine, we can unfortunately, scientifically, you know, declare the first ‘victims’ already, in terms of very likely having crossed tipping points, already 1.1 degrees Celsius. That is the Arctic sea ice. That is tropical coral reef systems. And that’s the West Antarctic ice shelf.
So I would argue that we have not only the science that unequivocally gives us the support for action, we have also from observations in the real world, very, very strong evidence that now is the time to rapidly turn away from continued global warming.
NG: Is it accepted that this is now the direction of travel? Are you still fighting an uphill battle to get people to understand this?
JR: Well, scientifically, there’s no uphill battle at all. I would argue that the last 10 years quite interestingly, there’s been opinion polls, led particularly from Yale University, but increasingly, also here in Europe. We find that 70% of citizens across the world are deeply concerned about climate change, they trust climate science and they want climate action. So among citizens, there’s since quite some time, then much, much higher level of concern and awareness than we normally see in media and politics.
Here at COP 26. in Glasgow, I think we’ve really turned a corner. Because over 25 COP meetings, we’ve always had this debate on the direction of travel, there’s been groups of countries that have completely dug in; we’ve had basically trench wars, we’ve had complete stalled periods of days where all the negotiations have been postponed because of inability to even agree on whether or not we have a problem.
Now at COP 26, the direction of travel is not debated anymore. It’s rather the pace of change, that we still have laggards versus alliances of more rapidly acting countries. So I think that’s a really significant shift that, now we are sustained not questioning the science and the need to transition towards a fossil fuel free world economy.
We have as we’ve seen, just the last few days, remarkable acts, remarkable pledges on halting deforestation, the recognition that carbon sinks in nature are fundamental to deliver the Paris Agreement. Still, it’s going too slow. Nations are not ramping up in line with science entirely. But it’s rather the speed of change, rather than debating the direction.
NG: Let me put to your hand what has happened in the northern hemisphere summer period, whether it be in Siberia (Russia), in Maharashtra (India), in Central Europe, in Germany, what you saw in Lytton in British Columbia (Canada). What about what do you deducing now those who are not reading your scientific papers about the Jetstream and the Gulf Stream? And what is there for happening, which is different to everything we’ve taken for granted up to now?
JR: So this is science frontier, it is, if anything, what makes me and many of my colleagues most nervous of all, because it’s not only that we have identified the tipping point systems in the Earth system, not only that we have identified that nine out of 15 are moving in the wrong direction. It’s also that we are learning more and more that these tipping element-systems are connected in what we call cascades.
So what happened in the northern hemisphere, in summer 2021 was not a series of extremes. These were super extremes. And the question is, how could it be that Lytton got 49.6 degrees Celsius of warming, and then two weeks later burnt down? When that is so far out of the normal that you can talk of super extremes that are difficult to explain just as a freak event.
And we have scientifically a candidate for this, which is; when the Arctic melts so fast. In fact, the Arctic is warming to three times faster than the global mean average, melting very fast warming up the atmosphere and slowing down the Jetstream. When the Jetstream slows down, which is the high wind system that leads to the travel of high/low pressure weather system across the North Atlantic, it starts meandering and these meanders (by the Jetstream) lead to locked in blockages of high low-pressure systems.
So we cannot exclude that would happen and Lytton that would happen the devastating floods in Germany this summer. It could be blockages of high low-pressure systems; extreme rainfall in Germany, extreme heat in Canada, because of a meandering Jetstream because of the Arctic warming.
NG: A year ago, would you have warned about that?
JR: One year ago, there were a handful of scientific papers warning about this. In fact, there was a paper following the heatwave in 2018, in Europe, warning that this could be the case. We’ve had an extreme; you remember the winter in the US 2017, the highest electricity bills ever. There was a scientific paper warning about this. So that’s how science advances. You get scientific groups starting to find evidence. But it takes some time before we can say in settings like this that yes, we now have enough confidence to say that, yes, this is very likely the explanation.
So no, two years back, I wouldn’t be able to say with confidence that this is the explanation. We cannot even say today this is exactly for certain. But we’ve come long enough far enough to see that we have interconnections between tipping elements.
The other one, which is even more dramatic is that when the Greenland ice sheet melts so fast, it releases cold freshwater into North Atlantic, that is slowing down the whole overturning of heat in the North Atlantic, the so-called AMOC (Atlantic Meridional Overturning Circulation), which in turn, pushes the monsoon systems further South, which can explain why we get more droughts and forest fires over the Amazon rainforest, which of course pushes that system closer to a tipping point. So you have cascades.
NG: So I need to ask you, sadly, we’re going to have to bring this to a close. But when it comes to talking to the politicians who’ve got to take policy decisions and convince their public within electoral cycles, that this is an urgency. It’s not for 2070- 2060 It’s actually for a few years down the track and they’ve got to change What’s your feeling about whether they’re taking seriously the science that you are analysing?
JR: Hmm, you’re absolutely right. I mean, that’s why I talk about this as having entered the decisive decade for humanity’s future, because this is the turnaround point. And it’s a turnaround point to avoid that we drift off in this irreversible direction. What I’m seeing here at COP with the political leadership is that this is starting to sink in, but not beyond the incremental leadership. That this is now a transformative moment. And it has to scale at the entire global level. I mean, that’s the big drama now that if it had been 20 years ago, we could have accepted 4,5,6 economies lagging behind but now everyone has to sing the same tune at scale. So of course, there’s a drama here and I really hope that the science is at the forefront as a constructive stress factor for that political leadership.
NG: Johan Rockström, thank you very much indeed.
This interview has been lightly edited for clarity and brevity.
Natures Newsroom was produced in association with the Global Commons Alliance.
Photo of Johan Rockström courtesy of PIK.