A team of US researchers have newly theorized that when 80% of the population of large-bodied mammals in the Americas was hunted to extinction following the arrival of humans some 13,000 years ago, the resulting sudden decrease in methane emitted naturally by the animals may have been the primary catalyst for the dramatic Younger Dryas event, a sudden planetary cooling that lasted for at least 1,000 years.

Until now, the onset of the Younger Dryas “cold snap” was known to be sudden, but its cause has long been a mystery. Supreme Master Television spoke with one of the study’s authors, Dr. S. Kathleen Lyons, a paleobiologist at the Smithsonian Institution in the USA.

Dr. S. Kathleen Lyons – Resident Research Associate, Paleobiology, Smithsonian Institution (F): Approximately 13,500 years ago was when humans arrived in North America, and within 2,500-3,000 years, by 10,000 years ago, the last of these large mammals had gone extinct.

My co-authors and I all believe that human hunting was primarily responsible, because if you look at the pattern and the timing of the extinctions across the globe, what you find is that on every continent where there was an extinction of these large mammals, it’s coincident with the arrival of humans, but not necessarily coincident with climate change.

VOICE: Dr. Lyons and her colleagues’ findings suggests that the decrease in atmospheric methane as the populations of giant hunted mammals declined was significant enough at that time to disrupt the planet’s temperature and cause a relatively short ice age.

Dr. Kathleen Lyons (F): The extinct mammals could have been producing anywhere between 9 and 25 teragrams of methane each year. Corresponding to the time that mammals went extinct, we do record, from ice cores, a drop in methane that’s then coincident with the Younger Dryas cold snap.
And what we found was that the rate of the change in methane at the Younger Dryas is significantly higher than at any other time over the last 500,000 years.

VOICE: Our appreciation Dr. Lyons and colleagues for your research showing how such drastic human actions could have far-reaching tragic consequences. At this fragile time on our planet, when raising livestock for killing is creating a similar ecological imbalance, may we turn to virtuous lifestyles in harmony with other species to preserve all lives on Earth. 

In various discussions, Supreme Master Ching Hai has connected past human behavior with current times to urge for fast and proper environmental action.

http://www.nature.com/ngeo/journal/v3/n6/full/ngeo877.html