Nature Is Overheating: Ocean Heat Records Are Breaking Again

0:13 The ocean is buffering climate change, but it's reaching its limits. This is the How to Protect the Ocean podcast, your weekday ocean update. If you care about staying informed on ocean every weekday, The ocean is buffering climate change, but it's reaching its limits. This is the How to Protect the Ocean podcast, your weekday ocean news update. If you care about staying informed on the ocean every weekday, hit that follow button right now so you don't miss tomorrow's episode. So here's the thing, global ocean heat content continues to reach record highs, intensifying marine heat waves and ecosystem stress.

0:56 So how much additional heat can marine ecosystems absorb? before functional collapse accelerates? This is the question that we are going to try and set. And I think what it's really interesting to set the difference is we look at air heat content and water heat content. Air heat content can fluctuate up and down, just like we see in the weather. And we can see that fluctuation. Over time, we have seen an increase in heat. But the heat content in the ocean warms slower, right? Because it takes a longer time to heat water. But we're starting to see that trend and it acts as a bit of a more of a tell about where we are within ocean heat, right? And so we are at a point where it's getting a little hot in there, right?

1:39 And we gotta get out and we gotta start cooling it. But the ocean has acted as the planet's primary buffer forever, right? That's its role, one of its major roles. And according to the Intergovernmental Panel on Climate Change, IPCC, the AR6 report, that working group report, the ocean has absorbed more than 90 % of the excess heat generated by greenhouse gas emissions. That's a big amount. That's a big amount of the ocean, which covers 71 % of the Earth's surface is taking on, right, is taking on 90 % of that extra heat. But it has come without, but it has not come without a loss. And so here's the thing is like the heat doesn't just disappear.

2:21 It accumulates underwater. So a lot of the times when we see, I actually don't really see or I don't really feel a difference. The ocean does and the ocean regulates our climate. And if the ocean stops being able to regulate our climate, we are in trouble as a species and as a planet. So let's just talk about the data. The data shows that according to the National Oceanic and Atmospheric Administration, NOAA, the National Center of Environmental Information. global ocean heat content data set shows a persistent upward trajectory in ocean heat. Ocean heat content has reached record highs in recent years. We even saw that where we saw 100 degrees Fahrenheit, the ocean reaching 100 degrees Fahrenheit within the summers and that led to, and that's off the coast of Florida, and that led to a summer of crazy storms, crazy intensifying storms where they would intensify rapidly before they hit land.

3:16 So we saw that happen a few years ago in Tampa where Tampa doesn't really get many big storms like that and it hit right dead on lots of damage and then another one came right after and there was a lot of worry in that. think Tampa and the surrounding areas got away with a lot more than they expected but it can be devastating to get that damage every year over and over again and if the storms are intensifying the damage is going to intensify as well with any kind of adaptation. When you look at the heat content, this is not just the surface temperature. A lot of times you see uh sea surface temperature radar satellite imagery. This is not just sea surface temperatures.

3:57 It's not just like the five meter of the surface, below the ocean surface. This is, you're looking at this measures heat stored through the upper 2,000 meters of the ocean. That's a big swath, that's a big water column swath of the ocean. So here the key point is the ocean is storing more energy than at any other time in recorded history. Now the independent scientific confirmation that we see is in a 2023 study by Cheng et al published in advanced and advances in atmospheric sciences reported that record breaking ocean heat content recorded record breaking ocean heat content.

4:37 And in these values, the authors concluded that the rate of ocean warming is actually accelerating. And the important framing around that, and this is not, let's take that out, and this is not a temporary spike, it is a long-term trend driven by energy imbalance. So the Earth system is retaining more heat than it actually releases. The ocean absorbs most of that imbalance. So research published in Nature Climate Change documents increasing frequency, duration, and intensity of marine heat waves. So we saw heat waves where uh Prolonged periods of unusually warm uh ocean temperatures.

5:18 can last weeks oh to months, disrupt food webs, trigger global warming, sorry, trigger global bleaching, shift species ranges, and heat waves are no longer rare anomalies. They are becoming structural features of a climate system. And so some of the ecological consequences of these heat waves is it? contributes to coral bleaching and reef mortality, kelp forest collapse, altered fish migration because they're going to different places because it's too hot in certain areas, reduced oxygen levels, and stratification that limits nutrient mixing, which limits fish production. Warmer water holds less dissolved oxygen.

5:59 Without dissolved oxygen, the fish can't breathe, right? The animals can't breathe underwater. So if you have less of it, it's gonna be start to get to a point where it can only handle a certain amount of species. Stronger stratification reduces nutrient upwelling. So in other words, when we see very productive sites, and a lot of these like upwelling, upwelling essentially if you don't know what that is, is a system where it starts from the bottom uh and it goes to the top of the surface. So it from the deep, deep sea, it takes all this production, so phytoplankton, zooplankton, that has maybe reached the bottom at some point, and it takes all that production and brings it back up to the surface. And a lot of times you'll be able to see this in satellite imagery. In fact, I used to look at for these upwelling areas and we're using satellite imagery and you can just see a temperature difference will go up because you'll see like a sea surface satellite image, like sea surface temperature detecting satellite image that will show it'll actually be colder in that one area than the surrounding areas.

6:56 And that's because it's coming from the deep and it's bringing all that production and all those animals up. And so you'll see a gathering, these are actually hotspots for biodiversity. You'll see a gathering of a lot of different species from marine mammals, sharks, tuna, salmon, sea birds, all these different types of species, and they'll come in and they'll start feeding on these areas. that upwelling, you won't see those migration areas, oh where species will migrate to those areas. And so once you see that, that's a really important area. But if there's stratification, meaning that there's layers of ocean where it's like deep, know, cold, salty water at the bottom, but it can't break through that stratification layer to get to the next part of the water column and then to the to the surface, then you're not going to see those production sites.

7:48 You're not going to get that feeding. Whales will you'll start to see whales, you know, become emaciated. They're not going to have that that production to eat feed off of. Right. A lot of whales, baleen whales especially, will eat, you know, uh plankton. If they don't have that plankton in those upwelling areas, during those long migrations, they're not going to be able to stand those long migrations and eventually lose enough energy where they can just drown. So that's not great. So having that stratification reduces those nutrient upwellings, reduces fitness of species like marine mammals, and it also doesn't bring fish around so sharks and things like that can get out of sea turtles and so forth.

8:29 So that's not good, obviously. That means also that less productivity at the base of the food web in many of the regions So you're not going to have any kind of base activity. It's going to be down deep Now the ocean is not just warming. It's actually changing functionally so with ocean heat uh It interacts with ocean acidification where you're gonna see less shells being made from calcification Less over fish or they'll be more over fishing because they're gonna they're gonna go for species that they know they can get and they're gonna over fish those species You're gonna see much more pollution You can see lot of habitat destruction. We're seeing habitat destruction in Florida a lot of the times because there's been such bad water quality, cumulative effects, bad water quality due to nutrient runoff and not control enough of nutrient, which is more the state government's fault.

9:14 But that nutrient is coming out with the added heat from climate change and the marine heat from climate change. That starts to rapidly increase in terms of phytoplankton, algae, all that kind of stuff. It will come to the shores along the the coastline, whether it be the Atlantic or even the Gulf of Mexico. And that could come with the right amount and the right levels of zooplankton or dinoflagellates could make a red tide with the nutrients and the winds and the temperature, which we've seen more and more each year. And that could destroy a lot of the animal life along the golf shores or even on the Atlantic where it sometimes happens. But what you also see is the breakdown of these seagrass habitats because algae will cover the seagrass habitats, seagrass habitats will go away.

10:00 Mantis go away, you don't see a lot of habitat. The seagrasses we've talked about or we talked about last episode, or yesterday's episode, we talked about seagrasses, how important they are for biodiversity as well as a carbon sink. And it's just, when you don't have that, because of all this algae coming in, because of climate change, because of marine heat waves, then you start to lose these critical climate habitats and that's not good. So the ocean can only absorb as much as it can, but it can't do it indefinitely without a systematic change. you know, as heat content increases, marine heat waves intensify, ice sheets melt faster, sea level rise accelerates through thermal expansion, weather extremes become more severe, as we mentioned a lot in this episode.

10:50 The ocean's buffering capacity protects us, but that protection definitely has boundaries. So if you like this kind of stuff, you know, learning about the ocean and what the boundaries are, you know, if you really like this idea and the grounded, like learning information grounded by real data, follow this show right now so you don't miss tomorrow's story because we'll be covering a lot of that, uh you know, in an interview with looking at how this is managed and how this is enforced tomorrow going off a book. It's going to be really great. Check in tomorrow's episode. But reducing greenhouse gas emissions is the only way to slow down this ocean heat accumulation. And even if we shut down all the greenhouse gases now, we're still going to see the effect of marine heating still happening, accelerating, but it will eventually stop.

11:36 Mitigation directly reduces energy imbalance. adaptation strategies in the meantime must include protecting intact ecosystems, reducing those local stresses. I talked about nutrient overload and other things. uh expanding high quality marine protected areas, restoring blue carbon habitats, which I talked about in seagrasses. A resilient ocean buys us time, but only emissions cuts change to the trajectory. Look, we are not in a good shape right now. None of the countries are moving fast enough to reduce climate change. We need people to run for office that are willing to make those sacrifices. And yes, it will be a sacrifice. need to fundamentally change the way we live, to fundamentally change and invest more into renewable energy and away from fossil fuels.

12:23 Whether you agree with fossil fuels or not, whether you are on different sides of the aisle politically, whether you're conservative or more of a liberal or Democrat, it doesn't matter. This is data. We're seeing the planet change. And if we don't do anything soon or now or yesterday or a decade ago, we are in big trouble. We're already starting to see that. So this is your call to action to be like, Hey, we need to vote for the people who are not going to take away protections on greenhouse gas emissions, right? Are not going to take away restrictions on greenhouse gas emissions, which was just done by Donald Trump's administration last week. Like this is, this can't happen. We cannot be in a situation where this is going to happen because the people in charge, in my opinion, don't care.

13:10 They care about what lines their pockets. They care about their money. This is not just a Donald Trump thing. This is every government. They just care about the people who put them into power because they like having that type of power. The ocean has absorbed the vast majority of excess heat. That's what we've defined today in this episode. That buffering has shielded the atmosphere from even faster warming. But the consequences are unfolding underwater. Record heat is no longer surprising and it becomes the new baseline. So the ocean has protected us from the full force of climate change. Now it is showing the cost and we are seeing that cost. So I'd love to hear what you think of this episode.

13:51 Go to speakupforblue.com forward slash feedback. Let me know what you think. If you love this type of content, follow the button, hit the follow button. I would love to hear your thoughts on this. You can go to speakupforblue.com forward slash feedback. Hit that follow button. Thank you so much for joining me on today's episode of the How to Protect the Ocean podcast. I'm your host, Andrew Luan. Have a great day. We'll talk to you next time and happy conservation.