Study reveals connection between Ice Age, climate change

Study reveals connection between Ice Age, climate change


A new study released Thursday finds that the latest Ice Age may be linked with global climate change.

A study published Thursday in the journal Nature finds that humans may not have been the driving force behind the mass extinctions experienced during the Ice Age, instead pointing the figure at climate change.

“We know that these large mammals survived for many hundreds of thousands of years and through periods of warming,” said Duane Froese, a University of Alberta climate scientist who co-authored the study. “The question has been why at this final warming interval…were there so many extinctions?… What this paper does is it sort of ends the debate that there’s a single cause.”

Research teams from around the world, involving more than 40 academic institutions, studied the extinction of six Ice Age mammals and found the impacts of both climate change and humans had distinct and dramatic consequences for each species.

“We find that neither the effects of climate nor human occupation alone can explain the megafauna extinctions,” scientists noted in the report.

Still, the report notes that humans share most of the responsibility when it comes to the demise of the bison, the wild horse and perhaps the mammoth, too.

The report comes as scientists and the International Climate Change Partnership have sought to identify historical trends aimed at determining the effects of climate change. Giant mammals such as saber-toothed cats and cave bears once dominated the world. However, starting about 50,000 years ago, Eurasia lost about 36 percent of these “megafauna,” while North America saw a decline of 72 percent.

The findings add new evidence to the scientific debate about what caused the extinction of a number of creatures during the latest ice age. Researchers wrote in the journal Science last year that humans caused animal extinctions in Australia, while a 2009 study, also published in Science, found that mammoths and mastodons began dying out 1,000 years before humans arrived in North America.

Scientists reached their conclusion after using ancient megafauna DNA, climate data and the archaeological records. With these ancient DNA sequences, researchers could reconstruct aspects of the histories of these populations. The DNA analysis included studying 846 fossil DNA samples, nearly 3,000 fossil bones and 6,300 archaeological-site records. Extracting genetic data from the bones of the Woolly Mammouth took seven years alone.

The report comes a new study shed light on whether climate change is currently taking place. An independent investigation of global warming solidified that global warming remains supported by scientific evidence, represents that most comprehensive independent review of historical temperature records to date. The researchers calculated the average global land temperature has risen by around 1 degree since the mid-1950s.

Despite the unparalleled amount of data analysed in this study, the authors find no clear pattern distinguishing species that went extinct from species that survived, suggesting that it will be extremely challenging for experts to predict how existing mammals will respond to future global climate change.

The study included researchers from the United States as well as Denmark, Australia, Sweden, Spain, the United Kingdom, the Netherlands, Germany, Norway, Russia, China, and Canada. The research was funded, in part, by the Leverhulme Trust, the Awards Fund, the Danish National Research Foundation, the Lundbeck Foundation, the Danish Council for Independent Research, and the U.S. National Science Foundation.