With the ever-rising temperature of the earth, global warming has become the most pressing concern for scientists but now they have found evidence of ancient global warming that was caused by a comet explosion, some 55.6 million years ago.

The new study conducted by scientists found proof of the ancient climate crisis along the New Jersey coast, reports Phys.Org. Their discovery says that an extraterrestrial object, most possibly a comet, hit the earth 55.6 million years ago, causing a huge release of carbon dioxide that warmed our planet in a major way. The warm period is known as the Paleocene-Eocene Thermal Maximum (PETM), and it bears a strong resemblance to the present crisis of global warming.

Though the study does not say that the comet strike led to PETM, but the previous studies corroborate it. According to researcher Dennis Kent, who co-authored the study, the incident could very well be the genesis of the PETM as the earth got warm in a hurry and this suggests where it came from. He had suggested in 2003 too that the PETM was caused by a comet.

He had based his theory on the basis of magnetized clay particles found in New Jersey but now the fresh study offers some more evidence. It has traced tiny spherical droplets of glass called microtektites, a kind of mineral that is formed when an extraterrestrial object hits the earth and dissipates vaporized material, which later solidifies while flying through the air.

In other news, it is being said that the comet impact could have helped the mammals in dominating the earth. The strike could be the possible reason of the expansion of mammal groups in the Eocene time period, reports BBC.

However, objections have been also raised by some experts and they say that space impacts have had a profound impact on the ecosystem of earth. An asteroid strike took place in the Yucatan Peninsula of Mexico, some 66 million years ago, and it led to the extinction of dinosaurs. Now, this is quite a contrast to what is being said with relation to the expansion of mammals.