
In my novel, MALI, the Northern Hemisphere has been swept into the beginning of a new ice age as a result of climate change. Temperatures have plummeted dramatically over just a few years, rendering the entire Northern Hemisphere uninhabitable. But what could we actually expect if a new ice age were to begin?
The last ice age started 117,000 years ago and reached its peak around 20,000 years ago. Back then, all of Scandinavia was buried under glaciers of ice several kilometres thick, including most of Denmark. Temperatures had reached their absolute lowest, and Scandinavia and North America were completely uninhabitable for humans. Mammoths, woolly rhinoceroses, steppe bison, and giant deer, which had roamed the Danish tundra steppes during much of the ice age, were similarly forced to move further south.
But then something happened 14,700 years ago. To simplify, warm ocean currents began flowing northwards, and within a few decades, average temperatures across Scandinavia and North America rose by 10 degrees Celsius. At that time, polar bears roamed the shores of northern Jutland. The glaciers melted rapidly, and in North America, a vast glacial meltwater lake formed, five times the size of Denmark, alongside the North American ice sheet, until the ice dam around the lake finally broke 12,800 years ago. When that happened, so much meltwater flooded into the ocean that the warm currents abruptly slowed, causing temperatures in Northern Europe to plummet once again. Within just a few years, Northern Europe experienced a dramatic drop of 10 degrees, plunging the Northern Hemisphere back into a short ice age period.
The birch forests that had sprung up in the intervening years disappeared almost overnight, and the large tundra steppes re-emerged. The people who had followed the reindeer and the warmer climate north 14,200 years ago were once again forced to move south. The environment had simply become too cold and inhospitable for them to survive the winter temperature drop. However, it is likely that they followed the migrating animals north again during summer, only to be driven south again by the autumn storms. This period, known as the Younger Dryas, lasted for the next 1,000 years, until the ice age finally ended after a total of 115,000 years.
It is difficult to say for certain how cold it actually was in Denmark during the last ice age, but it would be reasonable to assume that temperatures over the glaciers were similar to those recorded over central Greenland today. Here, the annual average temperature is -30 degrees Celsius, and the lowest official temperature recorded by the Danish Meteorological Institute (DMI) is -63 degrees Celsius. It is not unlikely, however, that winter temperatures could drop as low as -70 degrees Celsius. In other words, it was freezing cold. Even though temperatures in front of the ice on the tundra were somewhat milder, they probably did not rise much above freezing, even in summer.
Since the end of the last ice age, humans have moved into the areas that were previously covered by ice. Agriculture, towns, roads, and industries have emerged to such an extent that none of the people living in the Northern Hemisphere today are used to relocating due to weather changes. We have become stationary.
The big question is: what would the consequences of a new ice age be for us today if it suddenly arrived? For instance, if it were triggered by a collapse of the Gulf Stream. While most scientists today agree that human CO2 emissions have delayed the next ice age, no one can predict with certainty the full extent of such a collapse. However, there is broad consensus that the average temperature in the Northern Hemisphere would drop by 10-12 degrees Celsius within just a few years, exactly as was seen during the Younger Dryas period. Farmland would freeze over instantly, and acute food shortages would arise in a very short time. Areas currently home to hundreds of millions of people would become completely uninhabitable. Scandinavia, the UK, Northern Europe, and North America would all be affected. These populations would be forced to abandon their homes and seek refuge further south in areas already populated by hundreds of millions of people, areas that may have neither the space, desire, nor resources to accommodate the vast number of climate refugees.
In short, while ice ages are more the rule than the exception in Earth's long life cycle, it is not a period we should provoke.
What can we do to prevent the threat of a new ice age?
In 2015, 196 countries signed a global agreement under the UN Climate Convention to limit global warming to 1.5 degrees Celsius by 2030 and, at most, 2.0 degrees Celsius. Meeting this target is crucial in preventing a critical weakening of the Gulf Stream and the risk of being catapulted into a new ice age.
To achieve the climate goals set by the convention, it is vital that the world reduces nitrogen emissions into the atmosphere and adopts a more sustainable lifestyle. Sustainability must and should be one of the most important political objectives for all the world’s leaders, and it is our duty as citizens to hold them accountable.
(This post is a translation of a post I published in September 2022 on my Danish speaking blog).
Photo by: Adam Derewecki from Pixabay
Sources;
Comments