The H₂ energy reservoir. Energy required to isobarically heat a mass of gas equivalent to 0.45% of TRAPPIST-1’s atmosphere (typical of strong flares, see text for details) from 2000 K. The two dashed horizontal lines indicate bolometric energies of the two strongest TRAPPIST-1 flares analyzed by W. S. Howard et al. (2023). The figure demonstrates that the dissociation energy stored in H₂ is sufficient to account for the flare’s total bolometric emission.