Alert! Human-caused climate change started longer than we initially thought. According to a new study, this alarming phenomenon dates back in the 1830s during the industrial era.

The study published in the journal Nature says that paleoclimate records in the past five centuries (500 years) indicate that the constant warming in the tropics and Northern Hemisphere began in the 1830s.

What's the cause, you say? The researchers points the blame to the start of the industrial era, where there was a significant increase of greenhouse gases emitted to the atmosphere.

"It was an extraordinary finding," said Nerilie Abram, lead author and professor from the ANU Research School of Earth Sciences and ARC Centre of Excellence for Climate System Science, in a press release from EurekAlert. "It was one of those moments where science really surprised us. But the results were clear. The climate warming we are witnessing today started about 180 years ago."

The research involve the collaboration of 25 scientists from the U.S., Europe, Asia and Australia, who created and studied reconstructions of climate change in past 500 years to create a timeline and pinpoint where climate change began.

The team analyzed climate information of oceans and continents as well as thousands of years of climate model simulations. They also studied volcanic activity in the 1800s but found that this only contributed a small part to the onset of climate change compared to human activity.

This new discovery breaks the previous assumption in the scientific community that anthropogenic climate change only happened in the 20th century because climate change data before the 1900s was hard to find.

“Actually finding that humans had a measureable impact on the climate in the mid 19th century was somewhat of a surprise,” Abram said via Washington Post. “It’s a finding that, no matter which way we tested, we kept coming up with that same answer.”