hope this helps alot

I am having trouble also and can't find any information on global warming. I am not
looking for cheats i want hints or walk through.

I might help. I finished it in less than 24 hours and got Gateway Arch.

but i didnt say i would help :D

I heard you have to make the town heavily polluted first, remove small parks, ponds,
trees, anything that's green, then place HD industrial zone on top of them, also scatter a
lot of coal power plant all over the town. Then the city will become very polluted,
afterwards, Mr. Maxis will see you and introduce you to a professor, then he'll offer a
time machine for you to go to the future and see the effect of global warming, be careful,
you can't go back to the present time

When your ready, do these steps. You can do it any time, but I recommend once you've got
the important stuff:

1: Demolish all structures (Big Tree is optional)
2: Build Big Parks while leaving a space of 4x4 on the map.
3. Put down 12 Nuclear Plants at the bottom of the map and a few Energy Incinerators.
4. Build your buildings and roads. Don't add AN THING ELSE other than HD Residential, HD
Commercial and HD Industrial buildings (recommend making the roads between every Park)
5. Once your Population can't increase, add more buildings of the type that has more space
on the RCI bar.
6. Next thing you know you can't add any more buildings nor improve anything at 80% to
90%. So go do it the cheating way. To do that, simply save in a save file then exit.
Continue the game again. Repeat this until you complete the game.
7. Once the credits have finished, simply go and save your game. From then on, you'll need
to REMOVE ALL GREENERY and replace them with pollution making devices (eg., Coal Plants,
Industrial zones, Garbage incinerator, etc.) I've also heard you can detonate Nuclear
Plants and get them to deal devastating damage to the environment.
8. Wait. It took me just about 3 months for Maxis arrives with Professor Sim.When they do
arrive, he'll ask you if you want to go to the future or not.
9. The end. Also type in MONEYBAGS in password to get max money. Hope this helps! ^-^