Question

While classic Milankovitch climate theory posits that Northern Hemisphere summer insolation variations, driven by celestial orbital mechanics, serve as the primary pacemaker of Quaternary glacial-interglacial cycles, recent high-resolution paleoceanographic core analyses reveal inexplicable phase lags between orbital forcing peaks and Antarctic thermal maxima during the Eemian interglacial. To resolve this chronological discrepancy, some paleoclimatologists suggest that northern ice-sheet retreat initially triggered deep-ocean thermohaline circulation disruptions, which subsequently altered global oceanic carbon sink dynamics and amplified atmospheric carbon dioxide levels prior to southern polar warming. However, this oceanic feedback hypothesis relies on speculative proxies for deep-water ventilation rates, prompting alternative models that emphasize atmospheric teleconnections driven by equatorial sea-surface temperature anomalies. Rather than viewing orbital insolation as a direct thermodynamic cause of global ice melt, these counter-models characterize insolation as a mere catalyst that trips volatile, non-linear atmospheric feedback loops already nearing instability. Thus, the debate has shifted from quantifying orbital energy inputs to mapping the intrinsic sensitivities of terrestrial carbon and hydrological reservoirs.

Consider each of the choices separately and select all that apply.

Which of the following statements accurately describe the rhetorical function of specific sentences within the passage?