The setting, characters and general storyline are great. The art is simple but clear (though I do have a few tips and tricks that you might find useful, if you'd like), and the characters are interesting. I especially like your rabbit-men.... and find the idea of using a roman culture for them intriguing.
As to the story arcs:
The first story arc was VERY good. An interesting twist having the child unafraid and trusting around the saurian--- and afraid of the rabbit
The second story arc--- where the entire planet is turned into a "no humans allowed" single giant nature preserve-slash-historical site--- I gotta nitpick to death, I'm afraid.
1) I'm afraid you aren't taking into account how much maintenance and care ancient relics, historical landmarks, and sacred buildings require.... or what happens to them when they are neglected. Can you imagine what a few decades of dust, mold, mildew, insects, birds, animals, and invading weeds and plants would do to the Sistine Chapel? The Leaning Tower of Pisa? The Taj Mahal? the White House? Mount Rushmore? It's a daily battle to protect these places even NOW. A century of abandonment would reduce them to rubble.
2) The conflict between the Islamic Jordanians--- called 'palestinians' nowadays--- and the people of Israel is not over <I>land.</i> Pick up a trading card and lay it on the fifty yard line of a football field--- that is the ratio of Jewish land--- Israel--- to the land owned and ruled solely by Islamics. (yes, the Palestinians have a homeland. It's called JORDAN.) The PLO has been OFFERED land, and nationhood, over and over again... and walked away every time... the west bank was recently GIVEN to them, the Jewish families that had been living there for over fifty years thrown out--- and the Palestinians promptly used it as a launching site for mortars and suicide attacks.
It's not about land. The Israelis want to keep their ancient and sacred homeland.
The Palestinians want to push the Israelis into the sea.
No. Simply making the land a "shared memorial" would not end the conflict. Moving everyone to separate planets would only postpone the resumption of hostilities as long as it took the Islamics to get a rocket to fly from one to the other. It is the <I>existence</i> of the Jews that is anathema to them.
3)"City of all religions." Outside of the gratuitous slap to the face this would be for the Jewish people--- who lived there, built that city, tended that land while six empires (Egyptian, Babylonian, Persian, Greek, Roman, British) rose and fell, who maintained a presence in the Holiest city in both Judaism and Christendom even when their national borders were erased off the map and their people were hounded across the earth.... <I>you cannot legislate unity between theologies that are all mutually exclusive of one another.</i> Especially in light of how many religions teach "kill the infidel...."
Even the most peaceful religions would consider such a compromise of their beliefs for the sake of political niceties morally unacceptable.... and those that WOULD join hands would be the sort of "faiths" you couldn't trust alone with either your daughter or your silverware. (You think a hardnosed zealot is a menace, wait till a compromiser gets ahold of you..)
4) There is a phenomenon in economics known as THE TRAGEDY OF THE COMMONS. Basically put: when property, land, resources, etc. belong to you and you have a right to use them, you tend to care for them. When something is a 'public trust' that 'belongs to everyone' (Another way of saying it belongs to nobody), it falls prey to abuse (if it is used for something) or neglect (if it cannot be used for anything.)
Public trust, public property, public park, public toilet. Little difference in the level of nastiness.
As a national park, at least, people would be allowed to enjoy the beauty and wide open spaces (after all the sacred sites and historical monuments blocking the view crumbled to gravel from neglect, of course). But with a complete ban on humanity, it becomes nothing more than a useless, muddy rock hurtling through space. And how soon after that will people quit caring? Or become angry and resentful of the Elite Few--- politicians, government flunkies, etc-- who are allowed to walk on the surface of the Earth and breathe its air?
When you put something up on a shelf, eventually noone cares if it falls off and goes smash.
5) "RESTORING THE EXTINCT SPECIES." Two words: "Jurassic" and "Park."
If you're going to grow extinct species in jars and let them loose on the planet, where are you going to stop? the Bison? The mammoths? The dinosaurs?
And that brings up another question: what about climate?
Wrap your brain around this: <I>None of the environmental nail-biters even know whether or not the current planetary climate is the ideal one.</i> According to their own timeline, the planet was once a fecund jungle, and at another, a frozen, glacier-covered tundra that would send a penguin diving for his long woolen undies. Even within recorded history the world's climate has dramatically changed, without any human intervention--- from the Medieval Warming Period, when Vikings were farming in Greenland, to the Little Ice Age, when the permafrost crept south and killed their settlements (said little ice age we are still emerging from, btw. It isn't global warming, its' global <I>defrosting.</i>) So, when all the dirty polluting world-destroying Hyoomans are gone.... which way are all Our Scientific Betters going to twist the thermostat? And what will they do when, <I>despite every human on earth being gone,</i> the climate CONTINUES to change in accordance with the cycles of earth, moon, and sun?
6) Criminal organizations and lawless nationalities being in charge of half the earth's security forces.
Wait. What?
Best scenario possible: Fox. Henhouse. No more need be said.
7)The villain's motivation. Unless he's supposed to be barking mad, it makes no internally consistent sense. If he hates how man has "corrupted the earth," I would think that his agenda would be, at most, to use the earth as a weapon against hated humanity (as a source for bioengineered plagues and diseases or ravenous disease carrying pests--- a whole "vengeance of nature" thing.) Instead he's trying to destroy the earth itself..... by covering it with "humans" who have (by his estimation) even less environmental sense than the ones around now.
8)the fact that nobody, except the villain, is objecting to any of this. I don't care how few people were left on Earth--- they're being EVICTED. And just as the neighborhood was improving, too!
Now, all of the above may be a lead-up on your part to making a point: that <I>even when you give the Utopian fanatics everything they want---</i> a planet earth utterly devoid of humanity, cultures and religions stripped down to PC meaninglessness; tinpots, criminal overlords and despots treated with the same respect and given the same legitimacy as free nations and elected governments; species that died out millennia ago restored and let loose whether they still belong on the earth or not; the treasures of humanity put up on a shelf where they are no use to anyone; and honest law abiding people evicted from their homes----- <I>they still aren't going to be happy.</i>
At least I'm <I>assuming</i> that is the eventual direction you're taking...
Side note: yes, rabbits are unclean to both Jews and Muslims.
<I>To eat.</i>
For that matter, so are birds of prey, any fish without scales, and any mammal that does not chew cud and have cloven hooves. Rabbits and pigs are only notable because they were given <I>as examples.</i> (A rabbit, technically, "chews its cud" (don't ask), but does not have cloven hooves.... a pig has cloven hooves, but does not chew its cud.)
The 'cleanness" or 'uncleanness' of those animals was only relevant per their status as food animals.... pigs primarily became such a big deal because they were such a common food animal among the Gentiles.