The Earth might have begun responding to increasing anthropogenic greenhouse gas emissions as early as 1830, according to a paper issued Wednesday by the 2k Network and Past Global Changes (PAGES). “Drawing on a roughly 500-year history of temperatures in the oceans and on land, the [research] group concluded that the warming of the planet may have started early in the 1800s – and much earlier than typical climate change graphs depict,” a PAGES press release says.
The data, published Wednesday in the journal Nature, finds that sometime around 1830, the world’s oceans began warming. “It tells us that our climate system is able to respond relatively quickly to greenhouse gases, at least in some areas,” Nerilie Abram, an associate professor of Earth sciences at the Australian National University in Canberra and the paper’s lead author, said in the release.
The researchers developed their ocean temperature timeline by studying data from microscopic organisms buried on the sea floor that would have once been on the surface, and by studying the growth of coral.
The changes in temperature would have been small and slow growing, but present, according to Abram. “Somebody living in the 1830s or even the 1890s would not have been able to distinguish that there was this change afoot,” Abram said in the release. “It’s by having this long record now that extends almost 200 years from that point that we can go back and say ‘Well, this was when the changes first started.’”
The data shows that the climate can react very quickly to changes in greenhouse gases, which is not a wholly undesirable finding, according to Northern Arizona University Earth sciences and environmental sustainability associate professor Nicholas McKay, another author of the study: “It means that our actions as a society, both positive and negative, can result in an immediate impact.”