Tipping Points, Part 2: Skiing Over The Cornice!

Pull up a chair and let’s talk climate! We’ll kick things off with my embarrassing ski wipeout story (turns out "slowly creeping toward cornices" is terrible advice) before getting real about what happens when Earth heats up past 1.5°C. No jargon, just straight talk about melting ice caps, rising seas, and collapsing ecosystems that our kids will actually face in their lifetimes.

Sure, it gets heavy—we're heading toward 2.3-3.1°C warming unless we change course—but I'm not here to leave you hopeless. We've got roughly 20-30 years to make choices that matter. The difference between 1.5°C and 3°C isn't just numbers; it's the difference between challenge and catastrophe. Next week I'll explore China's surprising climate moves (not all bad news!). Until then, keep paying attention—because this stuff? It actually matters.

Transcript

Good morning, afternoon or evening, whatever it is wherever you find yourself today. I hope you’re doing amazing. 

A little story to start off today. 

I used to ski a lot. I was a waiter during my late teens and early 20’s and instead of being responsible and going to college, I chose to ski and play a lot of soccer. So, was able to get up to the mountains and ski about 30-40 days a year, and I got pretty good. 

One day, I went out with a few friends of mine, and one of them saw a cornice as we were heading towards the first lift. And, in his opinion at least, we just had to conquer that. I had never skied off of a cornice and, it’s important to know that I’m absolutely terrified of heights and hate negative G’s — things like roller coasters for me are, they’re just right out. You know that feeling when you feel like your stomach wants to come out of your mouth when you’re on a roller coaster? Ya, I just hate that.

Well, we continued on and made it to the top of the mountain on the lift and we hiked and ski’d to where the cornice was, and once we got there I remember looking out and thinking, what the heck did I just sign myself up for? I had no idea how far this drop was. I was freaked out, but bravado, which is always a perfect reason to do things, told me that I had to go over it. 

The first guy pushed off aggressively and went over, and I quickly saw him come into view as he ski’d down once he cleared the cornice. Didn’t seem that intimidating of a drop? Then it was my turn. 

I remember standing on top of this cornice, and I almost not being able to move because I was so freaked out. So, instead of aggressively pushing off, like the first guy did and like I should’ve, I crept forward little by little and, turns out, that was a huge mistake. And, at some point, creeping forward little by little, I hit a point where I just couldn’t stop myself from going forward. I was committed. Slippery snow, my skis, everything just took over and I was going for that ride whether I wanted to or not. And I really didn’t want to.

Rookie mistakes though? I leaned way too far back on my skis, because I didn’t do that aggressive push off. And on the way down, my brain being completely taking over, it was absorbed by all of these negative G’s that my stomach was feeling. 

Well, I hit the snow, both skis came flying off, a pole went somewhere else, and well I got laughed at. I survived uninjured, and ya, that was the only cornice that I only went over. 

I regained some cool later when we got to moguls and I earned some respect back, but it took me a while to live that one down. 

But what does this have to do with climate change? Hang on for a minute and I will explain. 

I’m Dave and thank you so much for joining me today on Running my Mouth off About Climate Change, where, when I started this thing, I had initially intended to talk about the lesser discussed issues that surround climate change, lately it hasn’t been that way though and today is no exception, we’re talking about tipping points, part 2.

Last week we looked at the basics of tipping points and discussed a little bit about what happens when we hit that 1.5°C  threshold above preindustrial levels. And today. we’re going to look at 2° and beyond, what happens when we hit that 2° point and we go beyond that. 

And if you think that you were filled with hope and inspiration last week, but wait, there’s more. As I was organizing my notes, I was like, “wow, this is a, this is a huge downer. Kinda don’t wanna do this but ya know…” Let’s do this! 

First we’ll do a quick refresher of a few things that we discussed last week, a few terms that we’ll need to know. 

First off, tipping points. I hit a point on that cornice where I was committed, where there was just no turning back. No matter how hard I tried to stop, I was moving forward and I was going over. Tipping points are like that, once they’re hit, reversing them is incredibly hard, if not impossible. 

Next term: positive feedback loops. I addressed this last week but, again, feedback loops are basically systems that have an input, and an output, and the output, influences the input, and it forms an input-output-input loop. And there are two types of feedback loops, positive and negative. Negative is the one that we want when it comes to our climate — they keep things nice and stable and calm. 

Again, and I used this example last week, think of a negative feedback loop like the thermostat in your home; you’ll set it to a certain temperature and the thermostat is constantly receiving input, i.e., the temperature of the room. When it detects that the temperature dropping, it gives an output, and that output is the heater that gets turned on. The thermostat then receives input detecting the rising temperature and it shuts the heater off when that desired temperature is reached, everything is nice and stable. We like this in nature. 

Positive feedback loops? Imagine road rage. One person accidentally cuts another person off as they’re driving along, the second person reacts in a less than ideal manner, starts driving incredibly aggressively until the two cars finally pull over and punches start being thrown. Ideally, a simple “I’m sorry” wave followed up with, “Hey, it’s cool..”, I mean, that would probably be the better option but, these two chose not to go that route. They escalated things, all that bravado kicks in and bad stuff happens.

Positive feedback loops overwhelm nature’s ability to maintain that state of homeostasis, things escalate and, like our road rage fight, bad stuff is pretty much gonna to happen. 

It’s also important to know that these changes don’t happen over night. Things like glaciers, some of these things are just enormous, they’re huge, and it’s going to take a long, long time for some of these to melt. That said though, glacier’s are melting faster than we’ve anticipated.  

Ok, that intro out of the way, let’s get into it. Let's talk about what happens if we go beyond 1.5°C – into that territory of 2 or 3°C or even 4°C of warming. 

And again, these aren't just abstract numbers on a thermometer, or randomly selected as Bjorn Lumborg, who I mentioned last week. claims. They represent fundamentally different worlds from the one in which we’ve built our civilizations.

What's troubling though, is that with current policies – not pledges or promises that came across in the Paris Accords, but actual government and corporate policies in place, we’re conservatively on track for somewhere between 2.3 to 2.8° degrees of warming by the end of this century. In fact, some studies are now putting that number closer to 2.7 to 3.1°C. So, when we talk about this 2° and beyond, this is something that is likely going to happen sooner rather than later if we keep doing what we’re doing. 

And if we see significant failures in climate policy, like, what’s going on in the US right now, or these positive feedback loops just start going crazy earlier than we’ve anticipated like those glaciers, 4°C becomes increasingly possible. And at these temperatures, large-scale Earth system changes don't just become likely – they become unavoidable.

Again, we talked about 1.5°C last week, let’s look at some fundamental differences in what happens when we ratchet up the temperature to 2°C. 

I mentioned glaciers melting faster than we’ve been anticipating. So what happens to the water coming off of these glaciers? Obviously it finds its way into the oceans. 

At 1.5°, which is something that we’re dangerously close to already, we can expect about 48cm, or 1.6ft, of sea level rise above year 2000 levels. We’re not talking about pre-industrial levels, we’re talking about year 2000 levels. It’s 2025 right now, so we’re talking about 75 years from now. Translation, this is what the children that we’re having right now will experience in their lifetimes, over a foot and a half of sea level rise.

At 2°C, that amount of sea level rise increases to about 56cm, or 1.8ft, which doesn’t sound like a huge difference? But that represents a difference of over 8”, which, in the real world, translates into millions more people being impacted by floods and oceans creeping into the places that they call home. 

Longer term, by 2300, and this is the timeframe that our grandkids and great grandkids will live through. These sea level rises at 1.5°C are at about 1.5 meters, again that's above 2000 levels. And at 2°C, that increases to 2.7 meters. Notice how this gap is starting to widen? This only gets worse as time goes on. And we’re talking about 2°, which we’ll likely eclipse in not too long if things continue as they are. Again, recall those temperature projections, the more conservative one being 2.3-2.8°C of temperature rise. We’re talking about the displacement of somewhere around 5 million people before the year 2300.

Let’s move on from sea level rise. Let’s check out a more realistic situation though, if we eclipse 3°C, and we’re moving into the Arctic now. 

The Arctic would essentially become ice-free, not just in summer but for much longer periods each year. And this creates a massive change in how our planet absorbs and reflects heat. 

There’s a term called the Albedo Effect, and that’s essentially all about how different surfaces reflect sunlight. Light surfaces reflect more light than do darker surfaces. And, when those darker surfaces don’t reflect light, they absorb the light energy, which we know as heat. 

White ice reflects sunlight back to space while things like darker ground and open water absorbs it. Once the Arctic ice goes, warming accelerates even further because of this albedo effect.

As the ice melts, more ground is revealed. The ground absorbs more heat and then radiates it back into the ice and atmosphere and everything warms up even more.

Again, these positive feedback loops are causing things, that, at these temperature points, are far, far beyond our ability to control, they’re taking on a life of their own. 

Coral reef ecosystems—we briefly touched on this briefly last week—which are already struggling at current temperatures, remember that half of these have disappeared since 1950 as of 2021. These coral reefs would face widespread collapse globally. We're not talking about just losing 90% of reefs like at 1.5°C – we're talking about the functional extinction of coral reef ecosystems as we know them. This isn't just an ecological tragedy; it's an absolute food security catastrophe for hundreds of millions of people who depend on these systems for survival.

Ya, this topic is kind of a downer, I almost want to stop right here. Ya, but why not. Go big or go home, right? Moving on…

Both the Greenland and Antarctic ice sheets would experience significant and well, irreversible ice loss at these temperatures, at 3 to 4°. Those rates of sea level rise that we mentioned, would accelerate well beyond what coastal communities could adapt to in most cases. We'd be looking at meters of sea level rise, yards, meters of sea level rice over the longer term, not just the centimeters or inches we've experienced so far or the roughly one meter projected for lower warming scenario by 2100.

The Atlantic Meridional Overturning Circulation, better known as and more easily pronounced as AMOC, which again is that ocean current system that keeps Northern Europe much warmer than it would otherwise be – faces potential collapse at these higher temperatures. Again, if that happens, we'd see dramatic regional climate shifts, with parts of Europe experiencing much colder winters while affecting rainfall patterns across the tropics. I guess the good news is that Greenland would get its ice back? Kind of like showing up to a party when it’s already over.

Last week we said that these weather patterns associated with the AMOC collapse would take place over about 800 years? Well, at 3-4°C we’re speeding that up a couple centuries at these temperatures. Which again, is more likely than 1.5°c or even 2°. 

Major monsoon systems that billions of people depend on for agriculture would shift in extremely unpredictable ways. Monsoons are already unpredictable, but these things won’t just be minor changes in rainfall timing. What we're talking about is a fundamental restructuring of precipitation patterns that have shaped civilizations for thousands of years, in places like India, Southeast Asia, and a lot of Africa

So now we’re kinda moving into how this impacts us humans. Well, more good news.  

Our current food systems are optimized for the climate we've had, not the one we're creating. At 3 to 4°C, breadbasket regions around the world, i.e., the places from which we get our food, face simultaneous crop failures at frequencies we've never had to deal with before. And I can’t stress this enough, this isn’t something that “might” happen this is something that’s simply unavoidable at this temperature thresholds. Things like physics and math, they, they don’t lie. 

Mass migrations becomes inevitable as parts of the world become effectively uninhabitable due to combinations of extreme heat, drought, and sea level rise. Hundreds of millions of people would be on the move, absolutely dwarfing any refugee crisis we've experienced in modern history.

The risk of conflict, i.e. wars, over increasingly scarce resources – especially water – rises dramatically at these temperature points. Nations that share river systems already have tensions over water rights. Imagine what happens when those river flows become, well, just a bit more iffy.

Also, the roads we drive on, our infrastructure wasn't built for these conditions either. Power grids will no doubt fail more frequently during extreme heat. Again, this is grandchildren and great grandchildren stuff. Roads and railways buckle because of that heat. Water and sewage systems get completely overwhelmed by floods in some regions while drought strains supply in others.

At these warming levels, it's not just about specific tipping points anymore – it's about the entire Earth system shifting into a state that we humans have never experienced. The last time that Earth was 4°C warmer than pre-industrial times was about 15 million years ago. And that’s a long before we as a species existed. At this point in time, what we’re essentially doing, is conducting a planetary experiment with ourselves inside the test tube.

What makes this especially sobering is that a lot of these changes would continue to unfold over centuries, even if we somehow managed to stop all emissions immediately after reaching these temperatures. The inertia, the momentum, in these large Earth systems means that we're setting in motion processes that again, our great and great-great-grandchildren would still be dealing with.

And then there are compounding effects of all of this. We tend to discuss these systems in isolation— like the Amazon, Arctic sea ice, permafrost—but in realistically, they don't exist in separate bubbles. They interact in ways that are far more complex than my brain can handle, but they amplify each other. For example, as Arctic ice melts, it changes atmospheric circulation patterns, which will affect rainfall over the Amazon, which has the potential to push that system closer to its own tipping point. It's like dominos, except each falling domino makes the next one more likely to fall.

The good news in all of this—if we can call it that—is that greater awareness of these tipping points seems to be driving more ambitious climate action. Understanding that we face not just gradual warming but potentially abrupt, irreversible shifts fundamentally changes the risk calculation. More and more science is coming out about this stuff and there are those who are starting to pay attention. It's no longer just about reducing future warming; it's about avoiding critical thresholds that would commit us to changes we just can't undo.

Now some may call me an alarmist, I don’t see myself that way. There are certain laws of nature, laws of physics and laws of math, that can’t be broken. For example, if you put ice on the kitchen counter when the temperature is 50°F, it’s going to melt, right? Raise that temperature to 60°F and it will melt faster. I’m typically pretty matter of fact about this stuff but I’d be lying if I said that I wasn’t just a bit concerned about this situation that we’ve found ourselves in. 

But yeah, we’re heading toward a cliff, or that cornice, if you will. And we’re creeping toward it inch by inch, like me, we’re still thinking we’ve still got a bit time because we’re seeing minor effects here and there but, things haven’t really kicked into gear so I think it’s easy to imagine that we’ve still got a little time, as Bjorn Lumborg would say. Some of us are ignoring this altogether and I will refrain from mentioning names..… But at some point, gravity is gonna take over. The system tips. And when it does, it doesn’t matter how good you are on your skis—you’re already airborne in a situation that you’ve never experienced.

And here’s the thing: like the cornice I went over, you don’t always know when the point of no return hits — there wasn’t a point that I looked at on the cornice that I could see that, once I went past, I was committed. It’s not marked on a map anywhere. It’s quiet, It’s kind of invisible. Until it’s not. And by the time we realize we’ve crossed it, it’s already too late.

Here’s the part I didn’t mention, and honestly, this feels a bit cheesy to me but, I’m gonna say it anyway. We’re not standing on that cornice alone. That’s the difference. This isn’t a solo drop. We’re in this together. Unlike my panicked 20-something year-old self, we’re at that point where we still do still have choices and this is not gonna last forever. But right now? This is the moment for course correction. 

Based on everything that I’ve read, everything that I’ve seen, it seems to me that we have maybe 20. 30 years, at most to make things right? We’re not gonna fix everything, but we still do have a little bit of control over what happens next. The difference between 1.5 and 3 degrees is the difference between a disruption and a disaster. It’s the difference between hardship and total collapse. And the more we collectively understand that, the more we can push for action that actually matters.

So keep learning. Keep paying attention. Talk about it. Act like it matters—because it absolutely does. And again, remember that these things that we’re talking about? The children that we’re having today, they’ll see that 48cm or that 1.6ft of sea level rise. Kids being born today, will absolutely experience that. And their kids, will have an entirely different existence. 

I don’t buy into the idea though that we’re hosed and that it’s too late. Again, we can’t fix everything and there are some things that we simply can’t turn around, but we can do something about what comes next. And that’s me officially trying to put a positive spin on things.

I think I’m gonna stop right here and end off of this doom and gloom. I feel the need to do something positive next week so I think we’re going to look at some of things that are happening in China. They’ve been the largest producer of greenhouse gasses for a while now, and we in the US seem to take a lot of joy into demonizing China. But it may surprise you to learn about some of the climate change stuff that’s happening inside of those walls though. That’s what’s coming up next week. 

Again though, thank you so much for joining me today on Running my mouth off about climate change, I’m Dave and I hope you have an amazing week.