paper link: https://www.science.org/doi/10.1126/science.adt2981
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Editor Summary:
Body size and metabolic rate are intertwined, a factor that is especially important to understand with regard to animals that live in aquatic environments, where heat loss is related to water temperature. Payne et al. developed a method to estimate routine metabolic rate based on measures from tagged fish, and combined the estimates with published respirometry rates to create a dataset spanning the entire body size range of extant fishes. Using these data, the authors found a scaling imbalance between heat production and loss that affects especially large, mesothermic fishes in warm waters. This imbalance both explains the distribution of these fish in cooler waters and suggests a special sensitivity to warming waters. —Sacha Vignieri
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Abstract:
Body size and temperature set metabolic rates and the pace of life, yet our understanding of the energetics of large fishes is uncertain, especially of warm-bodied mesotherms, which can heavily influence marine food webs. We developed an approach to estimate metabolic heat production in fishes, revealing how routine energy expenditure scales with size and temperature from 1-milligram larvae up to 3-tonne megaplanktivorous sharks. We found that mesotherms use approximately four times more energy than ectotherms use and identified a scaling mismatch in which rates of heat production increase faster than heat loss as body size increases, with larger fish becoming increasingly warm bodied. This scaling imbalance creates an overheating predicament for large mesotherms, helping to explain their cooler biogeographies. Contemporary mesotherms face high fuel demands and overheating risks, which is a concern given their disproportionate demise during prior climate shifts.
- if everyone on the entire planet went 100% vegan from tomorrow, will carbon emissions really go down by 60%?
long term with a proper transition, probably not 60% but likely some lower double-digit percentage (maybe closer to 20?)
Sure, that stuff isn't of the same quality as food grown for human consumption, but putting livestock on a diet and diverting some of their food to human consumption would more than cover any shortfall from the missing meat
Food is responsible for about a quarter of greenhouse gas emissions[1]. I agree that it’s not realistic to assume this will be solved individually, more pressure needs to be put on these large corporations from governments, but the quickest way you or I can make our own (individually small, collectively large) impact is by cutting out meat from our diet (specifically beef[2]). We are end-consumers of those 100 largest corporations one way or another.
(Not a vegetarian/vegan btw. I’m not trying to shame, I’m certainly not perfect! I just wanted to share the info that it’s not someone else’s problem. We’re all in this together)
[1] https://ourworldindata.org/food-ghg-emissions [2] https://ourworldindata.org/explorers/food-footprints?Commodi...
We need to reduce our dependency on fossil fuels.
For full clarity, it's also not the 100 biggest corporations that produce most emissions, but the 100 biggest companies. A massive amount of the global emissions are done by state-owned companies.
On the other side, not all climates can produce all the plants required for a balanced vegan diet. Here in Canada, nothing grows for 6 months and what does grow is relatively limited.
The lowest energy system would likely include a reduction in animal products but not a complete elimination, while keeping transportation to a minimum.
Also, just like with energy generation, there's the game theory aspect. If you reduce emissions, will everyone cooperate? What if you suffer only to have someone else increase their emissions anyway? We see this here... We limit our fisheries to try preserve ocean fish, only for Chinese vessels to sit on the edge of our borders hoovering up all the aquatic life...
But this is the world now, there will only be more stories like this, and so I'm not turning away from it any further. The world becomes less beautiful, less rich, less full every year.
I do volunteer, donate, and advocate and I won't use my extreme pessimism as an excuse not to engage. But in private, I mourn what is coming with little hope for substantial reduction in harm. If anything, those with power seem upset that we're not doing more to fasttrack catastrophe - if it's going to happen, may as well be the one to profit from it as much as possible before you're dead, the thinking seems to go.
Natural world would be mostly fine one way or other, human beings might not survive though...
Can any legislature get away with dramatically increasing taxes on meat, fish, gas, and plane tickets, just at a level high enough to account for environmental externalities? Even dictatorships couldn't get away with it because it would cause too much unrest.
I sometimes think about a post-industrial fantasy world where technology still exists, though minimally, and carefully applied to solve real problems humanity faces instead of selling FOMO or millions of "shiny things" that wind up in land fills so you can sell the new FOMO/shinything so some numbers on a spread sheet goes up.
I simply cannot decide to avoid all the technology of my field because whoever designed the electrical infrastructure didn’t do it responsibly. Or because the handling of ewaste hasn’t been dealt with. Or because everyone sourced materials in unethical ways.
My responsibility for most of that kinda ends at my voting behavior or trying to make reasonable personal decisions that are well within my small sphere of influence. That’s a problem domain I can handle.
Anyone who watched The Good Place knows what I mean. It’s not absolution for my own behavior, it’s just not holding myself accountable for everything that everyone else does… badly.
None of this is to say don't mourn or long for any of this, but the show doesnt end, the charecters just change.
They are moving to cooler waters but the cooler waters won't have the food supplies they need. So it's either stay where the food is and overheat or go to cooler water and starve.
Is that sharks are an ancient species and they’ve survived way warmer oceans even relatively recently.
For example the Medieval Warm Period Sargasso Sea surface temperatures were 1°C warmer than 400 years ago, and Pacific Ocean water temperatures were 0.65°C warmer than the decades before.
There are ~500 living species of shark and likely tens of thousands extinct in their lineage.
We are perpetrating a mass extinction event that incorporates not just temperatures, but ocean acidification and trophic cascade for fisheries. In mass extinctions, enough things about the ecosystem change that specialists often go extinct. Great White Sharks are a specialist species in their extreme size; Most size specialists are in a precarious local maxima that disappears too quickly to adapt if conditions change drastically.
I don’t see a way out except for stratospheric aerosol injection.
For example, something is red, you touch it, get burned. You won’t touch it again.
Environmental harm unfortunately is precisely the opposite. Consequences arise on a very long arc, in some cases beyond even our lifetimes. We register problems like this only intellectually, and even that becomes clouded with politics.
So the problem is kind of inevitable unfortunately.
1234letshaveatw•1h ago
sailingparrot•1h ago