Climate change has been talked about in the scientific community for more than a century, but it has only been a couple of decades since it became a public issue. Back in 1896, Swedish chemist Svante Arrhenius became one of the first notable scientists to introduce the thought of climate change as he presented evidence of greenhouse gases warming the Earth’s atmosphere. For years now, scientists have been trying to determine just when climate change started, and they may have their answer.

While some believed that climate change started in the late 1800’s, it turns out it was even earlier than that, dating back to the Industrial Revolution of the middle part of the century according to a new study. Many new factories started to pop up around the world at this time, releasing a lot of carbon dioxide emissions into the atmosphere. Researchers thought that the effects of climate change had not been seen until the past couple of decades, but there were small changes around that time that planted the seed for what we see today.

Volcanic eruptions also played a part in early climate change as the early 1800’s saw many of these eruptions that caused an increase in the atmospheric temperature. This turned out to only be temporary as there were no lingering greenhouse gases, and the Earth experienced a cooldown a couple of decades later before starting to increase once again. Some believed volcanoes played a big part in climate change, but not according to the study.

Nerilie Abram was the lead author for the study and serves as a professor at the Australian National University in Canberra. Abram said that the study “tells us that our climate system is able to respond relatively quickly to greenhouse gases,” even if those changes are quite small. Co-author Nicholas McKay added that “It means that our actions as a society, both positive and negative, can result in an immediate impact.”

So how did the authors of the study find that climate change had been going on for so long without atmospheric temperatures readily available dating back to the 1800’s? They had to go to the bottom of the ocean to find out. The ocean floor is covered with many corals that have growth rings similar to trees, and they are able to give a clue as to what the temperature was at the time when a new growth ring was added.

Abram said that “Somebody living in the 1830s or even the 1890s would not have been able to distinguish that there was a change afoot” as the temperature changes were so small at the time. It took more than a century’s worth of recordings to find out just how massive the change has been in recent years and gave an indication as when these major changes started to accelerate. Ocean temperatures are one of the biggest indicators of climate change, and it has helped explain why some of the ice is melting in the polar regions.