Frankly the Triassic period doesn't sound so bad.
Much of the land was desert then but that was mostly the result of it all being one large supercontinent. I suspect it would mean less desert in the modern world. A warmer wetter world is something I can get behind.
Actually, from studying the rocks deposited in this region from the Cambrian up, there were relatively few times in geologic history where this would have been a pleasant place to be (defining now as "pleasant", YMMV) and not many more it would have been survivable for a human without even considering the flora and fauna. For instance, 300 ft. of salt not only implies a large body of marine water prior to evaporation, but conditions like the Utah salt flats--only over a much larger area and more consistent duration. Longer period of carbonate tidal flats bespeak even more hostile environments, eras of submergence, the red beds which indicate arid and oxidizing environments, punctuated by salt and anhydrite deposits from evaporation of slat water, and even the time period represented by the Bakken, indicating a vast basin with little or no oxygen and die-offs, or much later Quaternary sediments left by two mile thick ice sheets.
Nope. We live in a wonderful window of relatively nice weather. That, too will change. Which ever tack the climate takes, however we will not be able to survive by shedding the means to use energy which is certain (stored chemically in coal, natural gas, and petroleum) for the vagaries of methods which require constant wind within a specific velocity range or sunshine. That, too will change, and those fixed platforms that depend on the weather might not be in the right place any more to be of utility.
Despite all the ballyhoo, it is the warmer times in which humanity flourishes. We explore, find and develop resources, to the degree we have the surpluses which allow for specialization and advancements in something other than subsistence. It is here we make progress in the arts, science, and technology. Not when we are scratching for unblighted potatoes or trying to find grain not contaminated by mold in the cold and rain.
It is ironic that this is also the time which has spawned the greatest movements to stop doing the things which have made us successful as a species.
It isn't the warmest times which have come close to extinguishing the light of humanity, it is the coldest and darkest, brought about by major volcanic eruptions (Toba, for example) which have come closest, followed by the devastation of unusual cold, ineffective sunlight, and insufficient growing season, or cooler shifts in climate (the little ice age), with much the same sort of result, albeit not as drastic.
Beyond that, if you really want to look to the future our survival as a species may well depend on continuing to explore, not on this planet, but to spread through space to other planets and their moons, and perhaps someday, even other solar systems. Provided we can stay sane long enough.
