People climb to board an overcrowded passenger train as they travel home to celebrate Eid al-Fitr festival, which marks the end of the Muslim holy fasting month of Ramadan, at a railway station in Dhaka, Bangladesh, July 5, 2016. Reuters/Adnan Abidi

Scientists have warned that Earth’s sixth mass extinction is already underway. This means that three quarter of the planet’s species could soon disappear.

Experts believe that humans have damaged the planet’s ecosystem so badly it is facing the biggest mass extinction since the dinosaurs were wiped out 66 million years ago. There is not much humans can do as the event is already in progress. While the previous five mass extinctions were brought about by natural causes, the current biological annihilation is mainly human-caused. The study has been published in the journal Proceedings of the National Academy of Sciences.

According to lead researcher Gerardo Ceballos, while some may look at the study as nothing more than just alarmism, the problem is in fact more severe than previously thought. In recent decades, up to 50 percent of all individual animals have been lost, scientists who assessed many common species across the globe have revealed. Moreover, there has been a rapid decline in populations of land vertebrates such as amphibians, reptiles, birds and mammals. Still, they are not currently considered endangered.

“Population extinctions, however, are a prelude to species extinctions, so Earth’s sixth mass extinction episode has proceeded further than most assume. The resulting biological annihilation obviously will have serious ecological, economic and social consequences. Humanity will eventually pay a very high price for the decimation of the only assemblage of life that we know of in the universe,” researchers involved in the study wrote.

It could be too late to halt the decline, and all signs point towards even more powerful assaults on biodiversity in the coming two decades, the researchers wrote. While shrinkage in human population is almost impossible, a lot can be done on the consumption front such as diversity protection laws, wildlife reserves etc.

According to News.com.au, the five previous mass extinctions were Cretaceous-Tertiary (65 million years ago), Triassic-Jurassic (c 200 million years ago), Permian-Triassic (c 250 million years ago), Late Devonian (c 360 million years ago) and End-Ordovician (c 443 million years ago).