|What would happen if the earth had no photosynthesis?
Vegans would die!
Without photosynthesis there would be no supply
of oxygen and slowly the oxygen would get used up
by oxidation such as rust formation.
Furthermore, by removing plants, all of the many
many animals that depend on plants would get very
very hungry and gradually die.
The food chain of almost all animals rely on
photosynthesis. We eat plants (which
photosynthesize) and animals. Animals eat other
animals (which eat plants) and plants. Plants
photosynthesize. So, large animals (like us) in
general probably wouldn't exist. There are a
couple ecosystems that don't use photosynthesis to
supply all their energy. These get their energy
from heat-loving bacteria that live on underwater
volcanoes and get their energy there. These
ecosystems are very deep in the ocean and include
worms and blind crabs. They're pretty creepy, here
are a lot of the crabs living on a volcanic vent
here to see
It can be difficult to know what would happen if
you made such a dramatic change to the world. But
one thing we know for sure is that animals
wouldn’t exist and any living things left would be
microscopic. Many living things obtain their
energy directly from the sun in the case of plants
or indirectly as in the case of animals. If
there was no photosynthesis, plants and animals
likely could not exist. In addition the
atmosphere would have very little oxygen because
photosynthesis releases a large amount of oxygen
into the air. It is possible that some very basic
organisms could still exist like the deep sea vent
bacteria that don’t get their energy from the sun.
In fact, some scientists think that the first
cells ate chemicals that were created in the
atmosphere. So cells like these might continue to
live. Otherwise, the Earth would be a pretty
barren lifeless place without photosynthesis.
If there was nothing on Earth that could do
photosynthesis, then the only life on Earth would
be small bacteria and other things similar to
bacteria. Most life on Earth depends on
photosynthesis. Plants use photosynthesis to make
sugar for energy and most animals need plants for
food. Even carnivores, like lions, need plants,
because their prey (animals like antelope) eat
The Earth would still have an iron-rich ocean. I
don't know whether the air would have more carbon
dioxide, or if all of the carbon dioxide would
have been locked away in carbonate rocks and we
would have an entirely nitrogen atmosphere. Life
would be found only in geothermal vents where it
is possible to get energy without relying on the
sun. There would be no "advanced" multicellular
life such as the kinds that we are familiar with.
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