Could We Survive Without the Sun?

It lights up our days, it keeps us warm and is showers us with the Vitamin D that helps our bodies absorb calcium, iron, magnesium, phosphate and zinc. We take it for granted that the sun is just going to keep on shining… But what if it didn’t? Could we survive on planet Earth without the rays of the sun beating down on us?

Put simply, the answer is no. Here’s why:

Farewell to photosynthesis

Without sunlight plants would be unable to photosynthesise. Most would die within a few weeks, while larger flora would continue to endure for several years, perhaps even decades. This means the agricultural industry would crash and burn. We would no longer be able to grow crops to eat, or to keep livestock fed. The lack of living trees would also mean that the air would be severely lacking in oxygen. As plants also purify airborne toxins the atmosphere would become much dirtier.

Plummeting temperatures

Climatic conditions do effect temperature to some extent, but at the end of the day it’s the sun that radiates heat. After a year with no sunlight scientists predict that the earth’s temperature would plummet to minus 100 degrees. The top of the oceans would freeze over which would have a devastating impact on marine life. Not to mention the end of the fishing industry. Interestingly, the top layer of ice would act as an insulator which means that it would take hundreds of thousands of years for the oceans to freeze entirely. After millions of years the planet would reach a stable -400° at which point everything would be frozen through, including the world’s oceans.

Out of orbit

As well as heating Earth and providing us with energy, the sun also keeps the planet in orbit. If the massive ball of blazing hot plasma suddenly disappeared Earth would be knocked out of orbit, leaving it free to float aimlessly around the solar System.

According to scientists at the University of Rochester there is a small hope for humans if the sun was to burn out. Nuclear or geothermal-powered habitats could keep humankind alive, with nations such as Iceland already heating 87% of its homes using geothermal energy.

Want to know more about the world’s intrinsic reliance on sunlight? ‘Bright Lights, Big Science The physical phenomenon that has helped to shape human history and open up our world’ is a fascinating article, delving into the story of light itself.

Image via Flickr Creative Commons. Photo credits: PandiYan V