This presentation is the review paper of various journals, showing about consequently increase in Carbon in atmosphere and its effects.

1. CARBON RESERVOIRS AND
CARBON CYCLE
S U B M I T T E D T O - P R O F . P . C H O U D H U R Y S U B M I T T E D B Y - R A J D E E P D A S
D E P T . O F E C O L O G Y A N D R O L L - 0 1 1 7 1 7 N O - 2 2 0 1 0 3 9 5
E N V I R O N M E N T A L S C I E N C E 2 N D S E M E S T E R ,
D E P T . O F E C O L O G Y A N D
E N V I R O N M E N T A L S C I E N C E

2. WHAT IS THE CARBON CYCLE?
 The Carbon cycle is the circulation and transformation of carbon back and forth
between living things and the environment.
 Carbon is an element, something that cannot be broken down into a simpler
substance and is often referred to as the “building block of life” because living things
are based on carbon and carbon compounds.
 The amount of Carbon on the Earth and Earth’s atmosphere is fixed, but that fixed
amount of carbon is dynamic, always changing into different carbon compounds and
moving between living and non-living things.

3. Carbon in
Atmosphere
Plants use
carbon to make
food
Animal eats
plants and take
in carbon
Plants and
animals die
Bodies not
decomposed after
many years,
becomes part of the
oil and coal deposits
Decomposers break down
dead things, releasing
carbon to atmosphere and
soil
Fossil fuels are burned;
carbon is returned to
atmosphere
Carbon slowly released from

4.  7 Processes that transfer carbon
i. Photosynthesis
ii. Respiration
iii. Consumption
iv. Decomposition
v. Combustion
vi. Weathering
vii. Dissolve/Vaporize

5. i. Photosynthesis: Plants Consume and release 𝑪𝑶 𝟐
Plants, some bacteria, and some protistans use the energy from
the sunlight to produce glucose from carbon dioxide.
If a plant is to survive, grow and reproduce, it must make a net
in carbon, that is, carbon gained through photosynthesis must be
than carbon lost through respiration.
ii. & iii. Respiration/ Consumption: Animals consume and release carbon
If we think of photosynthesis as the process of making fuel, then
respiration can be thought of as the process of burning that fuel, using it
for maintenance and growth.

6. iv. Decomposition: Plants and animals die
When plants and animals die, most of their bodies are decomposed and
carbon atoms are returned to the atmosphere.
Some are not decomposed fully and end up in geosphere deposits
underground (soil, oil, coal, etc.,) or at the bottom of ocean.
v. Natural Combustion:
Forest and grass fires are a natural, required part of the carbon cycle
that releases carbon into the atmosphere and geosphere.
Fire returns carbon to the soil and “cleans out” unhealthy plants,
allowing new plants to grow.

7. vi. Dissolve/ Vaporize: Carbon Slowly Returns to Atmosphere
Carbon in rocks and underground deposits is released very slowly into
the atmosphere.
This process takes many years and is usually caused by weathering.
vii. Weathering:
Oceans store large amounts of carbon.
Largest exchange of carbon in carbon cycle is the dissolving and
vaporization of carbon dioxide between the atmosphere and ocean surface.

8. CARBON RESERVOIRS
• The carbon dioxide that makes up a small constituent of the
atmosphere is part of a vast planetary cycle, in which carbon
circulates among three active reservoirs and undergoes several
changes of chemical form viz., the atmosphere, the oceans, and the
terrestrial.
• The pre-industrial oceanic carbon reservoir has been estimated at
38240Gt as compared with 600Gt in the atmosphere and1930Gt in
the terrestrial biosphere (850Gt as biomass and 1080Gt as soil)
(Brovkin et al. 2002).

9. • Of the three reservoirs the oceanic one contains by far the largest amount of
carbon. The atmosphere is the smallest in terms of carbon storage, but it plays
a significant role in the cycle as a conduit between the other two reservoirs.
• In 1958 the average annual concentration in the atmosphere was 315
microliter of air, which works out to a concentration of about 0.03 percent and
a total of 671 gigatons of carbon in the atmosphere. 1n 1988 the concentration
was 351 microliters per liter, or 748 gigatons of carbon.
• Based on data from the Geochemical Ocean Sections Study, about 37,000
gigatons of dissolved inorganic carbon is found in the ocean. In 1979 Kenneth
Moper and Egon Degens estimated that the oceans contain an additional
1,000 gigatons of disoved organic carbon and 30 gigatons of particulate
organic carbon.

10. Atmospheric Carbon Concentration:

11. • The most recent assessment of the Intergovernmental Panel
on Climate Change (IPCC) (Houghton et al. 2001) has
estimated CO2 levels in year 2100 are between ca.500 and
1000ppm compared with annual average levels which have
recently reached 370ppm .The estimates of the associated
temperature change are between 1.5 and 5.5◦C and those of
sea-level change between 0.1 and 0.9m. The uncertainties in
the estimates reflect, in part, incomplete understanding of the
carbon cycle.
• Indermuhle et al. (1999) proposed that the 20ppm increase in
CO2 since the mid Holocene (ca.8000 years ago) was caused
by a ca.200Gt decrease in the terrestrial biomass over this
period. This is very large and equivalent to ca.30 years of fossil

12. • Broecker has proposed an alternative explanation for the increase in CO2 since
the mid-Holocene (Broecker et al . 1999, 2001): that of a long-term response of
the oceanic carbonate system to a ca. 500 Gt increase in terrestrial biomass
during the Early Holocene. Mechanism involves four stages:
(i) an ‘instantaneous’ increase in deep water [𝐶𝑂3
2−
] as a response to the
biomass increase;
(ii) a deepening of the calcite lysocline resulting in an imbalance between
carbonate input and output
(iii) calcite preservation to restore balance (Broecker et al. 1993; Chapman et al.
1996));
(iv) leading to a decrease in [𝐶𝑂3
2−
] and long-term (of the order of 5kyr) increase
in atmospheric CO2.

13. • There are at least 3 arguments in favour of the fact that the
observed increase in atmospheric 𝐶𝑂2 is due to emissions
related to human activity:
i. The rise in atmospheric 𝐶𝑂2 concentration closely follows
the increase in emissions related to fossil fuel burning.
ii. The inter-hemispheric gradient in atmospheric 𝐶𝑂2
concentration is growing in parallel with 𝐶𝑂2 emissions.
That is, there is more land mass in the Northern
hemisphere, and therefore more human activity, and thus;
higher emission, which is reflected in the 𝐶𝑂2 growth in the
Northern hemisphere

14. iii. Fossil Fuels and biospheric carbon are low in Carbon 13.
The ratio of carbon 13 to carbon 12 in the atmosphere has
been decreasing.

15. • Terrestrial Carbon Processes:

16. • Gross primary production (GPP): is the sum of gross C
fixation by autotrophic C-fixing tissues per unit ground or
water area and time.
• Net primary production (NPP): is GPP - AR. It includes not
only the growth of primary producers (biomass
and tissue turnover above and belowground in terrestrial
ecosystems) but also the C transfer to herbivores and root
symbionts (for example, mycorrhizal fungi), the excretion of
organic C from algae, etc. Global terrestrial NPP has been
estimated to be 60 Gt C/yr., that is, about the half of GPP is
incorporated in new plant tissue. The other half is returned
the atmosphere as 𝐶𝑂2 by autotrophic respiration, that is,
respiration by plant tissues.

17. • Net Biome Production (NBP): is the carbon accumulated by
the terrestrial biosphere when carbon losses from non-
respiratory processes are taken into account including fires,
harvests/ removals, erosion and export of dissolved organic
carbon by rivers to the oceans. NBP is small fraction of the
initial uptake of 𝐶𝑂2 from the atmosphere and can be
or negative at equilibrium it would be zero.
• NBP is a critical parameter to consider for long term carbon
storage. NBP is estimated to have averaged 0.2+/-0.7 Gt
during 1980s and 1.4+/-0.7 Gt C/yr., during 1990.

18. Indicator of Human
Influence during the
Industrial Era

19. • Key Points:
i. Global atmospheric concentrations of carbon dioxide, methane, nitrous oxide have
all risen significantly over the last few hundred years.
ii. Historical measurements show that the current global atmospheric concentrations
of carbon dioxide, methane, and nitrous oxide are unprecedented compared with
the past 800,000 years
iii. Carbon dioxide concentrations have increased substantially since the beginning of
the industrial era, rising from an annual average of 280 ppm in the late 1700s to 401
ppm as measured at Mauna Loa in 2015—a 43 percent increase. Almost all of this
increase due to Human activities.
iv. The concentration of methane in the atmosphere has more than doubled since
preindustrial times, reaching approximately 1,800 ppb in recent years. This increase
is predominantly due to agriculture and fossil fuel use.
v. Over the past 800,000 years, concentrations of nitrous oxide in the atmosphere
rarely exceeded 280 ppb. Levels have risen since the 1920s, however, reaching a new
high of 328 ppb in 2015. This increase is primarily due to agriculture.

20. REFERENCE
• Barker, S., Higgins, J.A., Elderfield, H.,The Future of the cycle: Review, The Royal
Society, 10,1098/rsta.2003.1238
• Schlesinger, W., Andrews, J., Soil Respiration and Global Carbon Cycle,
DOI:10.1023/A:1006247623877
• Chapin F.S., Reconciling Carbon-Cycle Concept, Terminology, and Methods,
Ecosystems (2006) 9:1041-1050
• Ingram, J.S.I., Managing carbon sequestration in soils: concepts and
terminology, Agriculture, Ecosystems and Environment 87 (2001) 111-117
• https://teeic.indianaffairs.gov/carbon/carboncycle
• http://globecarboncycle.unh.edu/CarbonPoolsFluxes.shtml
• https://www.epa.gov/climate-indicators/

21. THANK YOU