Biosphere. “Every creature is better alive than dead,

“Every creature is better alive than dead,

men and moose and pine trees,

and he who understands it aright

will rather preserve its life than destroy it.”

~ Henry David Thoreau

Warm up

Earth is truly a remarkable planet. It is the only planet in our solar system that has the components necessary to support life. The planet is only a tiny part of the universe, but it is the home of human beings and many other organisms.

The biosphere is all about life. Scientists use the term biosphere to describe our living world. This is where all of the trees, bugs, and animals live. The biosphere extends to the upper areas of the atmosphere where birds and insects can be found. It also reaches deep into the ground at a dark cave or to the bottom of the ocean. The biosphere extends to any place where life (of any kind) can exist on Earth.

These organisms can live on Earth because it has an atmosphere. The atmosphere moderates daytime and nighttime temperature swings. The atmosphere filters radiant energy during the day, preventing the surface from overheating. At night the atmosphere prevents most of the radiant heat from escaping back into space, keeping the surface warm.

- What other spheres of the physical environment do you know?