There is a scene in the movie “The Truman Show” when Truman is asked why he wants to go to Fiji. He holds up a golf ball to indicate where he is and then turns it around and says for Fiji “you can’t get any further away before you start coming back”. What Truman is demonstrating is the idea of the antipodes, which is any area on the globe that is at the exact opposite point as another.
Since ocean covers most of the world’s surface, there are few places that are antipodal to other land territory. In fact, only 15% of the Earth’s land has an antipode that you can plant two feet on. For example, most of Argentina happens to be antipodal to China and central Asia. Similarly, much of the Indonesian archipelago is antipodal to parts of South America. In contrast, the antipode of the continental United States lies in the middle of the Indian Ocean (not exactly Fiji).
Lost Continents
Today, we know that the Earth is a sphere, and that you can travel by air or sea to areas that may be antipodal to you. However, historically, antipode lands were a much more fantastic concept. Ancient and medieval scholars developed maps that showed Europe, Asia, and Africa as three continents located in a northern hemisphere. In the southern hemisphere of the globe, they drew land labelled as “Antipodes”.
Many scholars thought this opposite side of the Earth was impossible to get to. They didn’t understand gravity. Instead, they believed that any potential explorers who reached the edge of the northern half of the globe would fall off into the void of space. Some scholars even used this to argue against the idea of a spherical earth, saying such as situation was preposterous. Although such a situation seems to be more consistent with flat earths. Even more bizarre, some scholars thought antipodes land was inhabited with creatures that lived upside down. They even had inverted feet that grew out of their heads!
The Great Barrier
Greek and Roman cartographers had more advanced notions on the shape of the world than some their medieval successors. Aristotle was one of the first to propose the Earth was round and each end had a temperate and “frigid” (cold) zone. A “torrid” (hot and dry) zone that ran along the Equator separated the hemispheres. Its inhospitable climate prevented the passage of humans. I think that this idea probably came from the large Sahara Desert seeming impenetrable to ancient travelers. Essentially, the torrid zone was a great barrier of thick jungles and barren deserts.
What happened in the antipodal land beyond the barrier was anyone’s guess. Its inhabitants were termed “Antichthones” by Greek philosophers. Later, medieval Christians picked up on these ideas. They suggested that since the torrid zone was impassable, Jesus Christ must have appeared to these people separately or else left them irredeemable. This reminds me of the premise behind the Book of Mormon. It claims that Christ appeared in North America thousands of years ago. Perhaps Joseph Smith, the founder of Mormonism, read about antipodes.
The Ideal Climate
Obviously, the Equator is not actually an impenetrable barrier. Many trans-Equator migrations have occurred throughout human history. This is apparent from human beings being present on every continent except Antarctica well before the modern era began. However, I think there is a reason that many ancient civilizations arose in subtropical or semi-temperate locations. Mesopotamia, the Indus Valley, ancient Egypt, China and even Greece are all roughly located along the Tropic of Cancer. One exception is the Norte Chico culture in what is now Peru. However, this bias for the subtropics is likely because these latitudes are better for growing agriculture. They also provide comfortable temperatures for humans year-round. Therefore, civilizations were more likely to develop in these areas earlier in history.
Over the last 6000 years of recorded history, human societies sprung up and prospered in areas with average annual temperatures of 11- 15°C. This temperature range is considered the ideal niche for human activity. These places include Europe, central North America, China, and parts of the Middle East and central Asia. Outside of this, there are other areas; like highland central Mexico that has a more temperate climate due to the altitude; and areas of South Asia, that have monsoons.
Climate Change and a New Torrid Zone
According to scientific estimates, if no efforts are made to reduce climate change, the Earth’s mean temperature is on track to increase by 3°C by 2100. It is important to realize that this refers to the global average and will hit some areas of the globe harder than others. Especially those already outside the ideal niche or on its margins. Places with extreme heat, like the Sahara Desert, currently cover 0.8% of the Earth’s land surface. Climate change will cause these areas to greatly expand, possibly covering 19% of the Earth’s surface by 2070. Such a vast swathe of territory will include the southern United States, northern South America, most of Africa, and significant parts of India and South-East Asia!
This map from The Economist magazine shows such areas. When I first looked at this I noticed the affected areas were largely within a band along the Equator. It reminded me of the Torrid Zone that separated the known world from the antipode continents on those early medieval maps. Ultimately, early explorers were not prevented from travelling the world. But, climate change may be creating a real Torrid Zone in the modern one.
Interestingly, many of the places within this new Torrid Zone have the highest population growths in the world. Assuming an increase in average global temperature of 3°C, approximately 3.5 billion people will be living in this Torrid Zone by 2070. They will then face two choices: adapt to the higher temperatures or migrate somewhere else. Most will migrate. Think about locations in the world today that are difficult to live in – the Amazon, the Sahara, Antarctica. All have very different climates, but all have very low human populations. Similarly, people who adapt to the new extremes could be few and far between.
A Humanitarian Crisis
This migration will be a serious problem for both the migrating people and those already in the more desirable places. For example, take the European migrant crisis and the high levels of Syrian refugees. There are plenty of issues related to how to provide shelter and keep them healthy. Failing that, homelessness, unemployment, crime, poor integration, racism inevitably arose. This contributed to changes in attitude, social tension, and aggressive politics across Europe that continues today.
However, the main difference with the Syrian refugee crisis is the numbers. The European country with the most refugees was Germany. But this was still under 1 million. The refugee crisis pales in comparison to future numbers of climate refugees. Where will those 3.5 billion people go and how will they be looked after? What kinds of social tension will arise from this? Many governments were not prepared to deal with thousands of refugees. Due to climate change, for the next 50 years there could be 70 million additional refugees worldwide every year. This migration is just one example of the effects of climate change, and it alone would change the world. No wonder we have a “climate emergency”.
In ages past, the torrid zone was believed to be a region that prevented the movement of people. The high temperatures kept people in place. In the future, a new torrid zone may push people around the globe rushing to get out of it. Today, society is not prepared to deal with this situation and is not doing enough to prevent it.
Note: The data referenced in this post comes from the following study.
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