Yet essential to so many species.
That rely on it for an annual cycle,
Of life because they can.

All water-based life is in danger.
As internal water turns to ice.
For organisms that can stand it,
Pressure, like a reverse vice.

Without a way to keep us warm,
Humans' blood vessels burst.
When gangrene sets in after,
A slow death is the worst.

Even atoms are affected,
When the temperature drops.
their fundamental movement,
Slows and eventually, stops.

Much of outer space is frozen,
Locked in dark matter's grace.
It takes a cataclysmic explosion,
To heat a very small place.

In one tiny solar system,
Warmed for four billion years,
One minuscule blue tropical planet,
Has withstood a billion tears.

Every time a freeze creeps in,
With it, our greatest fears.