Hello RDT1944 - from Calgary, where it is now snowing, at zero degrees C - so right on the edge of snow/rain.
I haven't seen The Revenant. I was a full-time mountaineer from 1998 thru 2003, and find many of these movies also unrealistic.
But let me ask you - who among us is reality based on the environment???
I am reading a truly fascinating book right now, being an oilpatch field geologist for eighteen years before my mountaineering avocation. It is titled "The Oracle of Oil", just out, and is about Marion King Hubbert, the United States Academy of Sciences geophysicist who famously called the end of peak production of conventional oil in the US.
What is most fascinating is the usual concerted opposition at the time of his prediction, ca 1956 and then afterwards - the same old business as usual interests up against real brains and integrity - in fact the oldest story that I know of - the struggle for survival - best depicted for a modern citizenry by Star Wars - our Dark Side vs the Jedi Knights, of whom I consider King Hubbert one, along with James Hansen, Carl Sagan, JFK, you get the picture...
Before I went into the oil business in 1979 I researched nuclear, as I then thought (university days), that looking for uranium might be an honorable way to spend my time earning a living. I encountered "Project Plowshare", and being - I fancied myself, a good scientist, I dismissed nuclear from my mind, as I considered these proponents of nuclear little better than crazy. I just read in the aforementioned book that King Hubbert did the same - and his thoughts on Project Plowshare coincided with mine in no uncertain terms, Hubbert's thoughts on Plowshare being: "Project Screwball".
My time as a wellsite geologist was honorable, to my way of thinking, I was in fact a Canadian Hunter, so to speak, bringing back the bacon.
At that time I didn't know about CO2, but should have I suppose, having read Gilbert Plass's landmark Scientific American paper "Carbon Dioxide and Climate" (1955 or 1956), as part of my McGill University course on Marine Geology.
Even Hubbert, when asked to head the committee on mineral resources for the National Academy of Science report to JFK in 1961, stated loudly that no one man could possibly be an expert in all the relevant fields of a complex world.
To return to your original criticism - DiCaprio is undoubtedly doing his best - given his background. As an artist, I am presuming he sees clearly that we are in deep trouble - totally accurate!
Governments exist to protect nations - a fact of life it would do well to remember.
All that is left, as I see it on this snowy morning - is to choose sides.
We are all warriors in the final analysis - some better than others - as it has always been.
But we can at the least respect those who fight on our side.