It's something of an abstract concept, but with real world implications, and the universality of such physical models, based on things
like radiative balance, atmospheric composition and density, distance from the local Sun, etc., is a very strong argument in favor of general acceptance of the results of climate models and observations on Earth.
Not exact matches
I think a better definition of climate change would be a recognizable
radiative balance state change that appears immune to short term cycles
like ENSO and seasonal cycles.
Because short - term projections depend on unforeseeable factors
like volcanoes, solar intensity changes, ENSOs etc., and long - term projections depend on
radiative balance and conservation of energy.
Yes, the change is incremental, and yes it's difficult to foresee sufficient incremental change to reach a carbon neutral future, but it's a bigger impact than I think your colleague anticipates (disclosure: I didn't read his entire report carefully, but I didn't see anything that looks
like a carbon
balance or net
radiative forcing calculation).
Heat melts Rock
like ice and this thuderhead of magma rises high in the geo - sky to bring heat to sea level, thus
balancing the core «s heat output when it's
radiative rate is slowed by the R - value of the gas atmosphere.
Recall that Teh Modulz are not only tuned to GMST, but to things
like cloud, snow and ice coverage as well as ocean heat content — all of which have an impact on
radiative balance and hence energy budget of the system, not to mention energy redistribution internally.