Photo by Lee Klinger, UCAR Digital Image Library
The Biosphere Affects Climate
There are many different ways that the biosphere
(the plants, animals
and other life on our planet) affect climate. Some produce greenhouses
gases and promote warming of our planet through the greenhouse effect, while others reduce the amount
of greenhouse gases promoting cooling of our planet.
By trapping heat, greenhouse
gases contribute to our planet's warming. Because of its involvement
in the Earth's carbon cycle
and nitrogen cycle, the biosphere influences the amounts of some of the major
greenhouse gases such as methane, carbon dioxide, and nitrous oxide. Listed
below are some of the biosphere's major influences on greenhouse gases.
- Plants: Carbon dioxide is taken out of the atmosphere by plants during the
process of photosynthesis. This promotes cooler climates. Plants also respire
carbon dioxide during the night, releasing some back into the atmosphere,
but on average, they take much more carbon dioxide out of the atmosphere than
they put in.
- Farm animals: Methane gas is produced as farm animals such as cattle and
sheep digest their food.
- Wetlands and rice patties: microbes in natural wetlands and rice paddies
produce methane gas.
- Factories and power plants: to make power for most factories and power
plants, fossil fuels, the remains of ancient plant and animal bodies, are
burned releasing carbon dioxide gas into the atmosphere.
- Cars and trucks: Carbon dioxide gas is released when fossil fuels, the remains
of ancient plant and animal bodies, are burned to power cars and trucks.
- Fertilizers: Nitrous oxide gas is produced when nitrate and ammonium in
human-produced fertilizers breakdown in the soil.
- Wildfires: carbon dioxide is released into the atmosphere as wildfires burn. However, if a forest of similar size grows again, about the same amount of carbon that was added to the atmosphere during the fire will be removed. So, fires affect greenhouse gases in the short term, but not on long timescales.
Of the items listed above, notice that humans control many of those that produce
greenhouse gases. Burning fossil fuels in power factories or automobiles puts
more greenhouse gases into the atmosphere as does agriculture that uses fertilizers,
making rice patties, or increasing the amount of livestock. Humans start some
wildfires too. Today, because human activities release greenhouse gases into
the atmosphere, far more greenhouse gases are currently produced than consumed,
contributing to global warming.
