A new study by a group of scientists in both the United States and Tunisia has reached the conclusion that the asteroid that struck Chicxulub, Mexico 66 million years ago had a major impact on Earth, with temperatures on our planet warming significantly for a period of 100,000 years.

After the impact of the Chicxulub asteroid, large amounts of carbon dioxide were thrust into the atmosphere of Earth, causing temperatures to rise by nine degrees Fahrenheit (five degrees Celsius), as Space report. This sudden temperature spike was discovered after analyzing teeth and bones left behind from ancient fish, according to Phys.Org.

While scientists have long suspected that the asteroid impact on the Yucatan Peninsula caused the Earth’s temperatures to shift upward for a period of hours, the dust in the air caused it to drop dramatically over a time span of what may have been years.

However, carbon dioxide eventually caused temperatures to shoot right back up again, and the new study conducted by lead author Kenneth MacLeod is the very first one to give solid evidence that shows the precise length of the global warming that occurred on Earth for 100,000 years after the Chicxulub asteroid struck the planet.

To solve the long-standing mystery of this period of global warming on Earth, MacLeod and researchers had the ingenious idea of looking at fossilized fish to determine the length of time that temperatures would have soared.

“We thought that we could resolve this question by looking at fossilized bits of fish teeth, scales and bones from the El Kef section in Tunisia. This place is known for having a beautiful record across the interval that we are looking at — the so called Cretaceous-Paleogene boundary — the mass extinction event following the Chicxulub impact.”

Scientists took 40 fish fossils from Tunisia and studied their oxygen isotopes, with samples collected from different time periods before and after the asteroid impact.

“One of the differences is, as temperature increases, the amount of the light oxygen isotope, oxygen 16, in a mineral increases relatively. We are measuring the ratio of oxygen 16 to oxygen 18. Every 1 part per 1,000 that the ratio changes correlates to an about 4.5- to 5-degree [C, or 8.1 to 9 degrees F] change in temperature. We found that there was a really big difference in oxygen isotopes between these three sets of samples — unambiguous.”

Kenneth MacLeod also noted that when it comes to global warming, we should be very concerned with the harm we are currently causing to Earth at the present time.

“If I were to draw a line under the lessons of this study for the modern era, it would be to contemplate the idea that what we are doing in our lifetimes will affect the Earth for the next 100,000 years, which is pretty daunting.”

The new study showing conclusively that the Chicxulub asteroid strike caused the Earth’s temperatures to increase for 100,000 years can be read in the journal Science.