According to the authors,
"Temperature estimates...show higher temperatures in the early Holocene, a cooling of ∼2° by [8,000 years before the present] and after relatively stable temperatures to the present."and as demonstrated by graphs from the paper below:
|Horizontal axis is thousands of years before the present. Graph A shows temperature proxy from Antarctic ice cores, graph B shows 0-150m depth ocean temperature in black|
Contrary to popular belief, the global oceans have warmed only 0.09C (9 hundredths of one degree) over the past 55 years (Levitus et al 2012). The entirely natural warming of the Eastern Equatorial Pacific Ocean at the beginning of the Holocene ~10,000 years ago found by this paper is over 22 times greater by way of comparison. The IPCC claims irreversible, catastrophic 'tipping points' will occur from global warming of 1.5 - 2.0C, but hundreds of temperature proxy papers have demonstrated no such tipping points occurred with temperatures 1.5C up to 6C warmer many times in the past.
Related: New paper finds the 18+ year 'pause' of global warming is not due to missing heat hiding in the deep oceans