evidence: Climate models suggest that precipitation is increasing in both amount and intensity as global temperatures warm34. Instrumental observations validate intensifying precipitation in northern Australia in the twentieth century35 and show that the late 20th-century warming trend in the SW Pacific has increased the likelihood of more extreme northeast Australian flooding33. The multivariate Jeannie River rainfall record extends the northern Great Barrier Reef pre-industrial baseline to 1746 CE and shows that average wet-season precipitation has increased by 125 mm (10%) since 1746 (Fig. 5, Supplemental Fig. 8). More dramatically, precipitation variability in northern Queensland has more than doubled since 1850 CE (110% increase in the standard deviation of summer rainfall from 21-yr windows centered on 1850–2007; Fig. 6). Increasing variability is consistent with amplified precipitation extremes in the tropics as the climate warms; global temperature has increased by ~1.1 K from 1850 to 2017, and local temperature at Jeannie River has increased by a similar amount36.