Yes, for any of it to be true there would have to be an obscene source of constant power bearing down on all the planetary bodies of our solar system, filling them with potentiality against the void.
^That is hilarious, since a key part of the greenhouse effect is the assumption that the skyfire isn't sufficient to explain temperatures by itself, though that is mostly a problem when you work out the average energy received by a planet and calculate the expected temperature rather than looking at the temperatures expected due to say, the instantaneous power integrated across the surface.
Edit: Is there any way to explain Venus's temperature without the GH effect?
Volcanic overturning events of the crust are the only way to explain the uniformly young surface given the lack of plate tectonics. These events would involve injections of heat and gas in massive amounts but without processes which remove CO2/SO2 from the atmosphere it wound up with an excess for a terrestrial planet. Roughly 90 times the atmosphere means roughly 90 times the pressure, there is no way to have that much atmosphere without it being extremely hot at the bottom, this is just what a column of gas suspended in a gravity well does. This is obvious for the atmosphere of Jupiter, Saturn, Uranus, Neptune, but for Venus the mere suggestion is absurd.
I remember being mocked the first time I suggested that idea, but it seems obvious due to how I'm looking at it. Take a long and thin cylinder of air floating in space away from a gravity well, the gas will equilibrate with the temperature of the walls, distributed evenly inside, right?
Now have an engine oriented along the long axis, with the "floor" nearest, and the "ceiling" furthest from it.
Start accelerating the tube, observe what happens. Does the gas remain evenly distributed, or does a pressure gradient develop at one end? If the volume remains constant but there is a pressure increase at one end, what happens to the temperature? What is the point? Gravity is accelerating gas suspended above the surface of a rotating rocky planet, in the absence of an input the gas will cool and settle down until it freezes, otherwise it will tend towards a state with the average temperature found at some point above the surface, the warmest temperatures at the surface below the input, coolest would be where the most indirect energy is received near the rotational poles on the night side.
Also worth noting that the air lifted to higher altitudes on the sunward side winds up descending on the nightside, gaining kinetic energy as it does so. The extremely slow rotation rate and atmospheric superrotation plus the massive scale height makes this a possibly significant energy input which is unaccounted for. There isn't enough time or gas here for it to matter, but on Venus it lends support to the idea that the equilibrium surface temperature is set by the cloud reflectivity ~50 to 60 km up, as the system can't relax and cool faster than the input/output at that altitude allows, making a literal pressure cooker, if you will.
_______________________________________
In other news, we have been picturing sabertooth tigers wrong in a really obvious way once you see the reasoning:
http://antediluviansalad.blogspot.com/2016/05/your-puny-lipped-sabertooth-kitty-is.htmlfront/closed, side/closed, side/slightly open
side/yawn~bite, side/flehmen
Sabertooths don't have sexual display tusks (which have very low enamel content in all but young animals) they have killing tools which have to be kept sharp. Exposing them to air means they aren't bathed in saliva and lose calcium, get abraded by grit, are vulnlerable to being kicked, and so forth.
Sabertooths also have great big foraminae in their upper jaw which don't make sense if they're only feeding a normal sized patch of whiskers. Whiskers which wouldn't be close to the bite target unless the upper lip was a lot larger anyways.
Cats aren't able to see what they bite, they use whiskers to aim their killing bites more precisely, of course a sabertooth would do the same.