But what concerns many scientists is what occurred next: In just the last 100 years, the average temperature has increased by 1.3 degrees. Although global temperatures of the last decade have not exceeded peak Holocene highs, they are warmer than 75% of the epoch.
“Global temperature, therefore, has risen from near the coldest to the warmest levels of the Holocene within the past century,” the researchers wrote.
By the end of the century, climate warming models predict an additional increase of 2 to 11.5 degrees, due largely to carbon emissions, the study noted.
The Science study was not the first to use such proxies to assess the ancient climate, but it was the first to pull together so many of them from all over the world, the researchers said. Previous studies used only regional data, which may be influenced by localized events like monsoons and the cyclical ocean-warming phenomenon known as El Niño.