We live in a world plagued with a perpetual threat of nuclear war, volatile world leaders, irresponsible people and an assorted set of life extinguishing threats to our environment. This has prompted people from around the globe to ask “How much longer do we have?”
The best way to address this issue is not to ask when, but how will the world end.
Here is a compilation of the greatest threats to the Earth as we know it.
1) Human influence:
Humans play a key role in the biosphere, with the large human population dominating many of Earth’s ecosystems. The large-scale loss of species caused by human influence since the 1950s has been called a biotic crisis, with an estimated 10% of the total species lost as of 2007.At current rates, about 30% of species are at risk of extinction in the next hundred years. In the present day, human activity has had a significant impact on the surface of the planet. More than a third of the land surface has been modified by human actions, and humans use about 20% of global primary production.
There are multiple scenarios for known risks that can have a global impact on the planet. Considering these projections, non renewable resources are expected to be fully consumed within a 100 years.
2) Random Events
There is always a possibility of random, unforseen events taking place in the cosmos that could have a damning impact on life on Earth. For example, a 40-fold increase in the number of comets reaching the inner Solar System. Impacts from these comets can trigger a mass extinction of life on Earth. These disruptive encounters occur at an average of once every 45 million years. The mean time for the Sun to collide with another star in the solar neighborhood is approximately 3 × 1013 years, which is much longer than the estimated age of the Milky Way galaxy, at ~1.3 × 1010 years. This can be taken as an indication of the low likelihood of such an event occurring during the lifetime of the Earth.
The energy release from the impact of an asteroid or comet with a diameter of 5–10 km (3.1–6.2 mi) or larger is sufficient to create a global environmental disaster and cause a statistically significant increase in the number of species extinctions. The mean time between major impacts is estimated to be at least 100 million years. During the last 540 million years, simulations demonstrated that such an impact rate is sufficient to cause 5–6 mass extinctions and 20–30 lower severity events.
Computer simulations of the Solar System’s evolution over the next five billion years suggest that there is a small (less than 1%) chance that a collision could occur between Earth and either Mercury, Venus, or Mars. During the same interval, the odds that the Earth will be scattered out of the Solar System by a passing star are on the order of one part in 105. In such a scenario, the oceans would freeze solid within several million years, leaving only a few pockets of liquid water about 14 km (8.7 mi) underground.
There is a remote chance that the Earth will instead be captured by a passing binary star system, allowing the planet’s biosphere to remain intact. The odds of this happening are about one chance in three million.
3) Climate Change:
Of course, the most immediate and significant threat is that of climate change. As expressed accurately by Agent Smith in The Matrix, human beings are the cancer of the planet. Post the Industrial Revolution, Human intervention has sown its seeds in practically every niche and corner of the ecosystem. I need not educate you about Global Warming and the hole in the ozone layer. Rapidly changing climates are already melting significant portions of of our glaciers and have given countless species the ‘endangered’ and ‘extinct’ tags. If this goes unchecked for even a while longer, we could have a global disaster on our hands in less than a millenium.
Over the course of the last century, there has been a shift in focus from the environment killing humans to humans killing humans. The rise of narcissistic world leaders with polarising and extremist views and policies has only pushed our race to the edge. We have reached the point where asteroids are actually less threatening than human flesh and blood. Conflicts that could easily lead to nuclear warfare, capable of obliterating our very existence could break out any day.
Hence, as much as we would like to think that the Earth would die of natural causes, this could be far from the truth. Our most imminent catastrophe can only be prevented by developing a scientific temper and being more accepting of different cultures and views around the world.