Re-use, recycled and use only what is needed.
What can the whole world (international) do to lessen the impacts of global warming? Need a good answer for my assignment
To slow down on the hamburgers. Seriously, we're breeding methane machines
Start with these:
Overcome the denial of the willfully ignorant.
Abandon fossil fuels.
Convert to renewable energy.
Replant lost forests and create new forests to filter the air.
Even if the entire world adopted these suggestions tomorrow, we are still facing the repercussions of the CO2 overload on the climate for (at least) decades to come. The ancient arctic glaciers are now gone in many places, nothing we can do to restore them and sea levels are rising. A spiral of warming is underway.
Employ your favorite search engine to research this subject for yourself.
Carrier has been in the news.
Perhaps AC's installed within the Arctic Circle and on Antarctica would work---assuming we can find a place to exhaust the warm air.
(Hey, if Archimedes can say "Give me a lever and a place to stand and I will move the earth," then I can day-dream.)