As oceans warm, great white sharks are overheating

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.”