In a world with billions of different species fighting for survival and superiority, it is natural that one will rise above the rest. But no society can last forever. Just like an individual, a species must die out sooner or later. Normally, one species replaces another, but this time it could be different. This time, humans could be the architects of their own destruction.

Naturally, it is possible that humans will outlive the earth. By the time the earth is uninhabitable, humanity could be spread over multiple planets or even multiple solar systems. But in the event that humanity does come to an end, these are some of the most interesting ways it could go.

8: Solar flare. Solar flares disrupt the magnetic Earth’s magnetic field when they touch it. Effects of this radiation are increased radio static, high inaccuracy in radio transmissions, and disruption of electrical circuits. One power grid or a few sensitive pieces of technology are not a huge concern, but a big flare could knock out power in the entire world. In the future, when just about everything is dependent on electricity, a global outage could result in serious problems.

7: Failed experiment. Most of the ways we expect the world to end are natural, external factors, but humans are very capable of getting it done themselves. For this one, particle accelerators are the most likely cause, but there are others. Of course, a synthetic black hole or singularity could be the cause. These are not easy to create, but even more difficult to control, and a man-made black hole would swallow the earth in seconds. Of course other types of experiments could also spell disaster for the human race, such as artificial diseases or nuclear weapon testing.

6: Aliens. It is unlikely that when aliens contact Earth, their first idea will be to conquer it like they do in movies. However, there are some very real threats associated with extraterrestrial contact. One risk is that the bacteria or similar organisms that could be unintentionally transmitted to Earth might be so much stronger than bacteria we know that our organisms will be wiped out completely. But the most sinister threat may be the aliens themselves. There is a good chance that the aliens that make it to Earth will be so much more advanced than us that they view us as we would view single-celled organisms on Mars. They would experiment and take samples, and the damage to our society could be catastrophic.

5: Mass insanity. Advancements in all fields of science have led to significantly longer, safer, more comfortable, and less exciting lives. In the future, when robots have taken people’s jobs and humans have no work to do, the human existence could be so dull and artificial that boredom will be a serious psychological concern. Thousand-year lifespans, or even non-physical existence, could have serious mental consequences. Eventually, boredom will lead to insanity, and that just can’t end well.

4: Artificial intelligence. Many sci-fi books and movies develop the idea of robots that break free of their programming and go on to attempt to take over the world. While it is unlikely to happen that suddenly, sooner or later it will become a problem. There are already robots that have developed their own indecipherable language that not even the people who built them understand. Robots have better senses, thinking speed, and reaction time than humans, and without the burden of emotions, they are able to make much better decisions. It is only a matter of time until an AI figures out that the world is better off with robot leaders than humans ones.

3: Nuclear war. This is fairly self-explanatory. In the event of another world war, which might not be as far away as people want to think, new technologies would make it much faster and deadlier than any other war in human history. Perhaps the deadliest weapon used would be the atomic bomb, which can out an entire city instantly and make much of the surrounding area uninhabitable for decades. The technology has improved drastically since WWII. There are already existing bombs that are over 6,000 times more powerful than the Hiroshima blast, and the total amount of nuclear weapons in existence could destroy the earth dozens of times.

2: Biological warfare. Antibiotic-resistant diseases are here, and that’s bad news in itself. Some countries are already manufacturing artificial diseases, and if they are used, the entire human population can be wiped out in days. A resistant disease with no cure manufactured to spread fast and kill instantly could spread to all continents via air travel. In fact, given the high rodent population in most big cities, an antibiotic-resistant form of the bubonic plague is not impossible. If there is no way to make a cure, there might not be anything to do but sit back and watch history repeat itself.

1: Global warming. It is a natural cycle, but this one is different. Humans create 114 billion (114,000,000,000) kilograms of greenhouse gases every day, which drastically increases global temperature. Even if it is stopped, the results will be catastrophic. But the truth is no matter how long we postpone it, it’s unavoidable. There has to be a storm after a calm. The only reason humans are still alive is that the Earth’s climate has remained unchanged for the previous 20,000 years, but the “heat age” is long overdue and the climate will give way eventually, and the eruption will be more sudden the more we postpone it. Even if no other apocalypse occurs, it’s only a matter of time before the Earth will be uninhabitable. We can only hope Mars will be ready to be colonized by then.