It's a little harder to kill the planet in Sid Meier's Civilization VI: Gathering Storm today, but it'll kill you back twice as hard after today's major update. In today's Antarctic Late Summer update, Firaxis have heavily revised how fast climate change sets in, but greatly increased the damage it can do to the planet if you let it escalate too far. For those who want to see the world burn without having to spend any fossil fuels on it, there's also a world creation slider that lets you increase the frequency of disasters, just for funsies. You can see the full patch notes here, and a video summary below.
Firaxis figure that it will take most players around twice as long to raise the sea level by one increment, but the penalties for doing so are far greater. More coastal tiles can disappear underwater, mega-storms are more common, and those storms can wreck the fertility of land at higher phases of climate change. It's also possible for an extremely eco-friendly nation to have a negative carbon footprint, mitigating some of the damage done by other nations. A tall order, but CO2 emissions from units are halved by the Advanced Power Cells technology now.
Not everything is doom and gloom for the planet. Pillaging has been made a little less powerful and chaotic. Now if a nuclear reactor is pillaged it can't trigger a nuclear accident, and it's possible to recover reactors using the 'Recommission Nuclear reactor' project. It appears that Firaxis have slowed down military advances as well, with unit upgrades costing a third more than before. WMD attacks now also consume the WMD whether they were successful or not, which they amusingly did not before. Drop a nuke? Didn't go off? Eh, send someone to pick it up and we'll try again.
There's a great many more changes, including balance tweaks to ten nations, aiming to get them all a little more in line. Canadian miners are apparently very hardy folks, gaining an extra point of production from mines in Snow and Tundra. For the Egyptians, they now get culture buffs for building the Sphinx on flood plains, making it a risky but rewarding wonder to build. Spain is encouraged to build Missions abroad, with a nice +2 faith, +1 food and +1 production bonus if built on a different continent to your capital - those expansionist so-and-sos.
You can see the full and very extensive patch notes here. Naturally, it includes a mountain of bug-fixes and minor improvements that didn't make the summary video above, and Firaxis say this is just the first step for some of the changes they have in mind for the game.