Oceans produce more than half of our oxygen (shoutout phytoplankton!) , absorb most of the heat from global warming, and covers 70% of our planet.
But they're also changing faster than ever.
So what will the ocean look like in 1000 or even 10,000 years from now?
Let's start with 30 years from now.
The number of fish in the sea has dropped by 50% since 1970s.
So maybe you should consider settling down with that dud, boyfriend or girlfriend because honey, there's not plenty of fish in the sea anymore.
In 30 years, there'll be more plastic in the ocean than fish by biomass, and species like sea bass, usually coming along north Carolina shores, will be up near New Jersey as marine life migrates to cooler waters.
Sea levels have actually risen 5 to 8 inches in the last 100 years and continue to rise.
By 2050, 190 million people will be facing a sinking city.
Ho chi Minh City will be below sea level, Alexandria in Egypt under water, and Mumbai, one of the largest and most densely populated cities in the world, submerged.