Early onset of industrial-era warming across the oceans and continents

• Published in: Nature (London) Vol. 536; no. 7617; pp. 411 - 418
• Main Authors: Abram, Nerilie J., McGregor, Helen V., Tierney, Jessica E., Evans, Michael N., McKay, Nicholas P., Kaufman, Darrell S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 25.08.2016; Nature Publishing Group
• Subjects: 19th century; 20th century; 704/106/413; 704/106/694; Anthropogenic factors; Climate; Climate change; Climate Research; Continents; Earth and Related Environmental Sciences; Emissions; Environmental Sciences; Forecasts and trends; Geography; Geovetenskap och miljövetenskap; Global warming; Global Warming - history; Greenhouse Effect; Greenhouse gases; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; Human Activities; Humanities and Social Sciences; Industry - history; Klimatforskning; Models, Theoretical; multidisciplinary; Natural history; Natural Sciences; Naturvetenskap; Ocean circulation; Oceans; Oceans and Seas; Paleoclimate; Science; Simulation; Surface temperature; Temperature; Time Factors; Tropical Climate; Uncertainty; Northern Hemisphere; Southern Hemisphere
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature19082

The evolution of industrial-era warming across the continents and oceans provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use post- ad 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. Reconstructions of ocean and land temperatures since ad 1500 indicate that sustained, industrial-era warming of land areas in the Northern Hemisphere and tropical oceans began earlier than previously thought, around the mid-nineteenth century. An early climate signature of industrial development The impact of industrial activities on climate is generally thought to have become apparent at the beginning of the twentieth century. Here Nerilie Abram et al . present reconstructions of ocean and land temperatures since AD 1500 indicating that sustained, industrial-era warming of land areas and tropical oceans in the Northern Hemisphere began earlier than was previously thought, around the mid-nineteenth century. Tentative evidence suggests that the initiation of warming was delayed in the Southern Hemisphere.