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Top Threats to Humanity & Existential Risks

Instructor: Yuanxin (Amy) Yang Alcocer

Amy has a master's degree in secondary education and has been teaching math for over 9 years. Amy has worked with students at all levels from those with special needs to those that are gifted.

Read this lesson to learn why our climate is a top threat to humanity. You'll also see how natural disasters, water crises, and weapons can endanger the human species.

Existential Risks

Looking back over the years and thinking about the many movies that have come and gone, do you remember the disaster ones, the films that show either the whole world ending or a whole state going under? Well, those scenarios aren't too far from the truth if those events were to happen.

An existential risk is a top threat that can wipe out humanity
existential risk

It's not just movie people who talk about things that endanger humanity. Scientists around the world also talk about this subject. Why? Because if people keep doing what they are doing, then these scenarios may actually happen and wipe out humanity. There is actually a word for these types of risks and threats to humanity. They are called existential risks. This is a big topic among scientists, and each year a new list of what is most likely to happen is created.

Let's see what this list looks like in 2017.


In 2017, climate change is the threat considered most likely to happen according to a survey of 750 experts performed by the World Economic Forum. You've probably heard about how big of an impact climate change has on the planet. The main issue with climate change is rising temperatures. Scientists frequently talk about how the Earth's ocean temperatures are rising. This leads to a melting of the glaciers, which in turn leads to higher ocean levels. If ocean levels rise too much, it is very possible that New York City will be underwater. In fact, according to Climate Central (an independent organization comprised of scientists and journalists), with a rise in sea levels of 20 feet New York City would be underwater, as would Lower Manhattan. Of course, this isn't going to happen overnight. But, according to Climate Central, a 2 degree Celsius rise in the Earth's temperature will make the glaciers melt enough to cause a 20 foot rise in the ocean levels, and this may happen by the year 2200.

It's not only rising ocean temperatures that climate change would affect. Climate change also increases the likelihood of extreme weather events such as droughts and flash floods. When California has droughts, it affects its crops. Since California is an agricultural state, when California's farms are affected by droughts, it affects how much food is available to people in both California and the other states that California feeds. Droughts can also force people to move away from their homes to seek areas with enough water. Flash floods can be deadly as well. People and animals caught in a flash flood usually have no escape as waters move at great speeds, making escape nearly impossible.


Another top threat to humanity comes from weapons. The weapons we are referring to here aren't just guns, but rather weapons of mass destruction. One famous weapon of mass destruction is the nuclear bomb. Back in 1945, it was said that all it would take to destroy the world was between 10 and 100 super bombs. This super bomb is what we today call the hydrogen bomb.

However, it's not only nuclear bombs that threaten humanity. Bio-warfare is also a possibility. Just recently, on April 4, 2017, Syrians were the victim of a chemical attack that killed children and adults alike. This was a local event, but if something similar were to happen on a global scale, you can picture the resulting devastation (and how this would be an existential risk).

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