The God of Weeds

It cooled the world,
Ate all the gas
That kept seas warm
And sank with that.

It was a fern,
Green, a weed,
A scum that choked
The waves it cloaked.

The top of Earth
Was thin, green sheets
Of this one weed.
What are weeds? Words.

Tons of its plants
Lived, died, and sank.
When ice comes back,
Give weeds the thanks.