According to a new study, coral proxy sea surface temperature (SST) evidence suggests the northern South China Sea (nSCS) naturally warmed and cooled at rates of 1 to 1.5°C per decade from about ~5300-5100 years ago.

Image Source: Wu et al., 2026

In contrast, the nSCS temperature record has been flat to slightly declining in recent decades (Ma et al., 2021).

Image Source: Ma et al., 2021

A 2021 coral proxy study indicates from ~6000 to 2000 years ago nSCS annual SSTs were 3-4°C warmer than they were from 1994 to 2004, with the modern SSTs the coldest of the last ~6000 years.

Image Source: Zhou et al., 2021