Carbon Cycle and Greenhouse Effect

Anaerobic bacteria

________ suvived, died, and became sedimentary rock called stromatolites.

Where is Carbon found on Earth?

Sediments and rocks (fossilized material)

Ocean, atmosphere (stores inorganic carbon - dissolved carbon dioxide and hydrogen carbonate ions)

Soil (mixture of organic and inorganic)

Biomass (living things) can become fossilized or stored as oil

Methane - produced by decaying organic and inorganic material by methanogenic archaeans under anaerobic conditions

Peat - organic matter that isn’t entirely decomposed (acidic/anaerobic conditions in waterlogged soils)

Fossils VS Oil

Oil, gas, and coal - come from partially decomposed organic matter

Oil and gas formed when this matter accumulated in porous rock

Fossils - animals such as reef-building corals and mullscs have hard parts that are composed of calcium carbonate

these become fossilized as limestone

How can carbon be released into the atmosphere?

Respiration

Methane

Combustion

Largely responsible for recent increases of carbon in the atmosphere

Components of carbon cycle

synthesis of carbohydrates from atmospheric carbon dioxide and water (along with sunlight as the energy source) using photosynthesis (fixed carbon in organic compounds from inorganic compounds)

consumption of carbohydrates by both producers and consumers through the cellular respiration

waste products and dead plant and animal material are decomposed by decomposers

any animal and plant matter that isn't decomposed can fossilize

through the combustion of oil natural gas and plant materials, stored carbon compounds are converted into carbon dioxide and water vapour

the carbon dioxide produced during this cycle is stored in the atmosphere and in the oceans until used during photosynthesis

Source VS Sink

Carbon source - emits carbon

Carbon sink - receives/stores carbon

The Greenhouse Effect

natural process necessary for life as we know it

without a natural greenhouse effect, the earth would be 33 degrees (Celsius) colder

when energy from the sun enters the earth’s atmosphere, about a third of it is reflected back into space

most of the rest is absorbed by the surface of the earth

the earth emits this energy as long wave radiation/heat

greenhouse gases can absorb longwave radiation and retain it in the atmosphere

water vapor

carbon dioxide

methane

nitrogen oxides

Water vapour

transpiration

evaporation cellular respiration

fossil fuel combustion

Carbon dioxide

respiration

fossil fuel burning

decay of materials

Carbon dioxide removed from the atmosphere by:

photosynthesis

absorption from ocean

cellular respiration

Consumption of carbohydrated by both producers and consumers through the ________.

Oil

________ and gas formed when this matter accumulated in porous rock.

Methane

present in smaller quantities than carbon dioxide, but more effective at trapping heat

produced from the decay of matter without the presence of oxygen

sources:

wetlands

rice paddies

animal digestive processes,

fossil fuel extraction

decaying garbage

Synthesis

________ of carbohydrated from atmospheric carbon dioxide and water (along with sunlight as the enrgy source) using photosynthesis (fixed carbon in organic compounds from inorganic compounds)

Nitrous Oxide

soils and oceans

humans contribute through soil cultivation

use of fertilizers, nylon production

burning of organic material and fossil fuels

Ocean, atmosphere (stores inorganic carbon

dissolved carbon dioxide and hydrogen carbonate ions)

Methane

produced by decaying organic and inorganic material by methanogenic archaens under anaerobic conditions

Peat

organic matter that isnt fully decomposed (acidic/anaeurobic conditions in waterlogged soils)

Oil, gas, coal

come from partially decomposed organic matter

Fossils

animals such as reef-building corals and mullscs have hard parts that are composed of calcium carbonate

How has the atmosphere changed over time

~3 billion years ago, the atmosphere was anoxic

anaerobic bacteria survived, died, and became sedimentary rock called stromatolites

photosynthesis evolved, used carbon dioxide, and produced oxygen, this showed up as black iron oxide bands in stromatolites from 2.5-1.8 million years ago (after atmospheric oxygen increased)

How have humans affected the climate?

combustion of fossil fuels is putting more carbon into the atmosphere than can be naturally cycled

leading to increased greenhouse gases

by increasing the number of greenhouse gases humans have increased the amount of long-wave radiation trapped

changing land use:

replacing forests with farmland or asphalt increases energy reflected off the earth's surface

also releases some stored carbon into the atmosphere and decreases the means of reabsorbing carbon (less photosynthesis)

atmospheric aerosols

industrial and agricultural activities are adding significant quantities of particles into the atmosphere

impact

an average rise of only 4 degrees C would increase sea levels by 60cm

melting ice and thermal expansion of seawater

ice caps will disappear in the next century if rapid warming continues

disruption of ocean currents could lead to changing weather patterns

gulf stream slows, Britain and Europe could cool, heat is retained in the gulf of Mexico causing hurricanes

the most significant warming is predicted for Russia Canada and West Africa

dissolved carbon dioxide in oceans could threaten coral reefs

coral bleaching is caused by acid from increased carbon dioxide, the stress causes the coral to expel symbiotic algae, losing their colour and dying

Consequences of rising global temperatures on the arctic

increased rates of decomposition of detritus previously trapped in permafrost

expansion of the range of habitats of temperatures species

disrupt ecosystem

loss of ice habitat

changes in the distribution of prey species

affect higher trophic levels

increased success of pest species

political impacts