As oceans warm, great white sharks are overheating
Warming oceans may be pushing large “warm-bodied” fish like great white sharks toward an energetic and thermal dead end, as new research suggests their heat production now outpaces their ability to shed heat, especially in already overfished waters. Commenters weigh how this fits into past climate variability, questioning whether ancient shark lineages can adapt to today’s unusually rapid, human-driven changes. The conversation broadens into climate pessimism, personal versus systemic responsibility for emissions (including diet and corporate behavior), and controversial proposals such as geoengineering, alongside outright skepticism of the climate crisis framing.
Shark physiology & warming oceans
- Commenters highlight the paper’s claim that large “mesothermic” fish (e.g., great whites, tuna) generate internal heat and have high metabolic demands, creating an overheating risk as oceans warm.
- A key point is a scaling mismatch: heat production rises faster with body size than heat loss, so very large warm-bodied fish are especially vulnerable in warm water.
- Warmer water also holds less oxygen, pushing many fish closer to the surface for sufficient O₂, which can worsen heat stress.
Migration, adaptation & extinction risk
- Some argue sharks are ancient, highly resilient, and have survived much warmer oceans over hundreds of millions of years, so current changes are not existential.
- Others counter that “sharks” as a group may endure, but particular species like great whites—large, specialized predators—can still go extinct, especially amid rapid change and other stressors.
- There is discussion that great whites do dive deeper and migrate long distances; however, moving to cooler waters may mean less prey, so they face a “starve vs. overheat” trade-off.
- Overfishing and food-web disruption are repeatedly cited as at least as important as temperature.
Climate change, food systems & emissions
- Long subthread debates whether a sudden global shift to veganism would cut emissions ~60%.
- Views range from “maybe large reductions in food-related emissions” to “more like ~20% of total,” to skepticism about underlying estimates and feasibility.
- Points raised: livestock inefficiency, land use, methane, fertilizer, fossil-fuel inputs, and the role of a small number of major (often fossil-fuel) companies.
Geoengineering & mitigation
- Some see stratospheric aerosol injection as the only realistic path to near-term cooling.
- Others condemn it as reckless pollution with unknown second-order effects, arguing present air-pollution deaths already outweigh hypothetical marginal cooling benefits.
Emotional, ethical & political reactions
- Many express grief, pessimism, and “doom” about biodiversity loss, mass extinction, and political inaction.
- There is debate over individual responsibility vs. systemic/elite power, guilt vs. acceptance, and whether small-scale activism (diet change, restoration, local volunteering) is meaningful or merely symbolic.
- A minority dismisses the broader climate narrative as exaggerated or “alarmist.”