USA — Scientists from Harvard and Yale analyzed the possibility of 'dimming the sun' to battle climate change.

If this sounds like it's straight out of a sci-fi movie, it's because it's not real … yet.

Fleets of specially designed aircrafts would fly roughly 20 kilometers above ground in the lower stratosphere.

Once there the planes would spray tiny sulphate particulates to block sunlight in a process that is known as stratospheric aerosol injection.

According to their study, published in the journal Environmental Research letters, this technique could cut the rate of global warming in half.

Researchers who participated in the study state it would be a "remarkably inexpensive" process costing around $2 bn to $2.5 bn a year.

CNN reported the plan doesn't cover greenhouse gas emissions and could have negative consequences such as extreme shifts in weather and endangering crop yields.

It's important to note that the engineers behind this are not suggesting this is the ultimate solution to climate change, but just wanted to estimate technology costs of stratospheric aerosol injection.