There has been some talk recently that the Merapi volcano could shortly produce the largest eruption seen on this planet in the last 10,000 years, which could lead to Global cooling and a possible mini ice-age in some areas.
Indonesia has more than 50 major volcanoes that have erupted in the last 100 years and was the location of a supervolcano 75,000 years ago (Lake Toba, Sumatra) which plunged the Earth into a volcanic winter, eradicating an estimated 60% of the human population.
When we talk of supervolcanoes, we usually think of Yellowstone, which last erupted 640,000 years ago. However, there are several of these large volcanoes and the one thing we can be sure of is that one of them WILL erupt again at some time in the future.
Yellowstone has always been considered the favourite, because many believe that an eruption there is “overdue.” But the volcanic activity in Indonesia (especially at the moment) is much higher, suggesting that this region may provide the global disaster we have all been dreading for so long.
How the population will be affected depends very much on the size of the eruption. It might just cause death and destruction on a localized basis, as we have already seen with the eruptions currently occurring at the Merapi volcano, with some flights in the region also affected. But a VEI 8 eruption (supervolcano) would block out the Sun, causing a cooling of the planet and most probably an ice-age.
It goes without saying that an ice-age, even one lasting just a few years, will have a devastating effect on crops and livestock, and millions would die through starvation (and of course the cold).
As terrible as all of this may seem, it might be the best thing that could possibly happen to the planet (in the long term). With all the wars, killing, crime and disease that our planet has gone through over the centuries, and the ever reducing resources needed to maintain the growing population, a natural disaster of this kind may be the only solution to our problems (better than having someone else decide who should live or die).
Nature always seems to find a way of creating a balance, and mankind manages to survive these events somehow (so far). Yet, knowing that a natural catastrophe is inevitable (be that a supervolcano or maybe a large asteroid), mankind seems in an awful hurry to speed up this process!