全球变暖(quán qiú biàn nuǎn) - global warming in Mandarin

全球变暖 (quánqiú biànnuǎn) is the standard term for global warming, built from three plain pieces: 全球 (quánqiú), "the whole globe", 变 (biàn), "to change", and 暖 (nuǎn), "warm". Put together it reads almost exactly like the English phrase, which makes it one of the easier compound nouns to remember.

It belongs to the same cluster of vocabulary as 气候变化 (qìhòu biànhuà), "climate change", and the two terms overlap in everyday use even though strictly 全球变暖 (quánqiú biànnuǎn) refers to the temperature rise itself while 气候变化 (qìhòu biànhuà) covers the wider set of effects. News articles and school essays use both, often in the same paragraph.

Watch the word order: 变暖 (biànnuǎn) is "become warm", verb before adjective, which is the normal Mandarin pattern for this kind of resultative compound. English speakers sometimes want to say "暖变" by analogy with "warming", but that is not a word.