Whenever you see a study that is described as a "first of its kind," be wary. Don’t be wary of the warning being given, but be wary of those who are going to use the newness factor of the study to attempt to discredit you. They will claim it hasn’t been proved and therefore isn’t viable as evidence.

According to research which looked at temperatures in 10 million year intervals, four of the past five major extinctions over 520 million years can be linked to warmer tropical seas. The tropical seas are the only seas that can be mapped using fossil records, and subsequently go back hundreds of millions of years. A warmer sea is a natural indicator of a warmer atmosphere.

"We found that over the fossil record as a whole, the higher the temperatures have been, the higher the extinctions have been," said University of York ecologist Peter Mayhew, the co-author of the peer-reviewed research published in the Proceedings of the Royal Society B, a British journal.

The research found that each time the tropical seas being studied reached 7 degrees warmer than they are now, and maintained such a temperature for several million years, there was a die-off. However, the researchers are certain to clarify that it is not necessarily the only reason for die-off.

For example, the most recent mass extinction of 65 million years ago was most likely caused by a meteorite strike. This was the strike that wiped out the dinosaurs, though Mayhew believes that extinctions were already taking place.

So while the records match up, there is not necessarily a cause and effect relationship between the two, according to Mayhew.

However a second study, to be presented at a scientific convention this Sunday, does attempt to make a sort of connection evident.

Peter Ward, a University of Washington biology and paleontology professor, authored the study that focuses on carbon dioxide. His research linked the natural increase of carbon dioxide to the warming of the air and oceans. The warmer water produced less oxygen and subsequently produced more microbes. These, in turn, would eject hydrogen sulfide in to the atmosphere. Not a happy place for anyone to live!

The bit that really distresses some people, me included, is the fact that we are within a century of reaching those same temperature levels.

The Nobel Prize-winning Intergovernmental Panel on Climate Change warned that "20 to 30 percent of animal species assessed so far are likely to be at increased risk of extinction" if something isn’t done about the temperature levels.

So, though in Earth’s history it took millions of years for mass extinctions to occur, scientists believe that it could take only several decades. This is because that when we reach those temperatures, we will have already seen mass problems for animals. It will be just one more thing they’ll have to adjust to, and maybe just one thing too many.

"Since we’re already seeing threshold changes in ecosystems with the relatively small amount of climate change already taking place, one could expect there’s going to be severe transformations," said biologist Thomas Lovejoy, president of the H. John Heinz Center for Science, Economics and the Environment in Washington.

As for those who believe that reverting to a warmer temperature more in line with the Earth’s historical average, Pennsylvania State University geological sciences professor Richard Alley has this to say: "This will give scant comfort to anyone who says that the world has often been warmer than recently so we’re just going back to a better world …"

Live Science - Extinctions Linked to Hotter Temperatures