Higher concentrations of atmospheric carbon dioxide affect crops in two important ways: they boost crop yields by increasing the rate of photosynthesis, which spurs growth, and they reduce the amount of water crops lose through transpiration.

2. Title :
Elevated CO2 and its Impact on Crop
Production

3. Outline
 Elevated CO2
 Elevated CO2 and it’s Causes
 Effects of Elevated CO2 on Climate Change
 Effects of Elevated CO2 on Crop Production
 What if CO2 keeps Elevating ?
 ( Elevating CO2 and it’s possible Mitigations )
 Conclusion

4.  Elevated CO2
• The increase of CO2 concentration in the atmosphere.
• In the past 60 years, carbon dioxide in the atmosphere has
increased 100 times faster than it did during the end of the last ice
age.
• The global average carbon dioxide set a new high record in 2021:
414.72 parts per million.
(NOAA | climate.gov, 2022)

5.  Global Average Atmospheric CO2 concentration
Today, CO2 levels have reached 419 ppm (it was 407.4 ppm in 2018)
higher than at any point in at least the past 800,000 years.
( Climate.nasa.gov, 18 Oct 2022 )
Mauna Loa Observatory ( gml.noaa.gov, 2022 )

6.  Causes of CO2 Elevation
Man made causes are as follows:
• Deforestation
• Burning of Wood
• Fossil Fuel Combustion
Deforestation Burning of Wood Fossil Fuel Combustion
( Climate.nasa.gov, 2021 )

7.  Causes of CO2 Elevation
Natural causes are as follows:
• Organisms’ respiration & decay
• Carbonate rocks weathered
• Forest Fires
• Volcanic Eruption
( Ces.fau.edu, 2021 )
Forest Fire Volcanic Eruption

8.  Climate Change
• It occurs when change in Earth’s climate system result in new
weather patterns that remain in place for an extended period of time.
• This length of time can be as short as a few decades to as long as
millions of years.
 Causes
 Release of these
Greenhouse gasses
 Global Warming due to
entrapping of these gases
( IPCC, 2014 )

9.  Effects of Elevated CO2 on Climate Change
• Human activities release more carbon dioxide into the
atmosphere than natural processes can remove.
• It causes the amount of carbon dioxide in the atmosphere to
increase.
• Plants and soils together currently absorb an estimated 30
percent of the CO2 emitted by human activities each year.
( News.stanford.edu, 2021)

10. • Burning of fossil fuels has increased the concentration of
atmospheric CO2 over time.
• It then causes change in the overall climate which effect the natural
processes in different ways.
 Effects of Elevated CO2 on Climate Change
( Climate.gov, 2022 )

11.  Effects of Elevated CO2 on Climate Change
The basic reason of climate change is due to following two terms:
o Greenhouse Effect
o Global Warming
Increasing concentration of CO2 in the atmosphere is causing:
• Entrapping of Earth leaving harmful radiations
• Increase in the global average temperature
( NRDC.org, 2021 )

12. o Greenhouse Effect:
The trapping of sun’s warmth in the planet’s lower atmosphere.
( Climate.nasa.gov, 2019 )

13. o Global Warming
It is a gradual increase in the overall temperature of the earth’s
atmosphere.
( joboneforhumanity.org, 2017 )

14.  Effects of Elevated CO2 on Crop Production
• The resulting increase in CO2 will lead to a variety of
effects on major agricultural crops used to feed the global
population.
• Many of which effects may yet be unknown, since more
research is being carried out on this subject.
( Front. Physiol., 08 August 2017 )

15.  Effects of Elevated CO2 on Crop Production
These effects can be either;
 Positive Effects
Or
 Negative Effects

16.  Positive Effects
 Increased Photosynthesis in plants
 Increase in Carbohydrates
 Greater Growth
 Increase in N-fixation
 Increase in WUE
 Negative Effects
 Decrease in quality of specie (Next gen. seed)
 Decline in variety of nutrients
 Decline in protein concentrations (including vitamins and
some macro- & micro-nutrients)
( Ainsworth and Long, 2005 )
(Fernando et al., 2015)

17.  Effect of e(CO2) on C3 and C4 plants
 About 85% of plant species are C3 plants.
 This includes most of the weeds along with important C3 crops like
wheat, rice, barley, cotton, soybean, etc.
 C3 plants are more competitive than C4 plants, which is why weeds
give such high competition to the main crop. (Even if it is a C3 crop)
 E(CO2) increases WUE of C3 species by increasing their CO2
assimilation and reducing their transpiration rate.
 Under water stress and e(CO2) conditions, C3 plants will survive
more efficiently than C4 plants. ( Journal of Bioscience, 2005 )

18.  Effect of e(CO2) on C3 and C4 plants
• The C3 plants show saturation at 450 ppm and the C4 plants
show saturation at 360 ppm of CO2 concentration in the
atmosphere.
• C4 plants such as corn, maize, sugarcane, etc are more efficient
in picking up CO2 only when it is found in low concentration.
• In intercropping condition, C4 plants’ shoot dry weights
decrease under elevated CO2 concentration.
( Serc.carleton.edu; Taub, 2010 )

19.  Climate change, if CO2 concentration keep increasing?
Future effects:
• Temperature will continue to rise.
• Frost-free season (and Growing Season) will lengthen.
• Changes in precipitation patterns.
• Exacerbation of droughts and heat waves.
• Hurricanes will become stronger and more intense.
• Global sea level will rise 1-4 feet by 2100. (While it had only
risen 8 inches since 1880)
• Arctic likely to become Ice-Free. (Possibly by summer before
mid-century)
( Climate.nasa.gov, 2018 )

20.  Possible Mitigations for Carbon concentration in
the atmosphere
• Afforestation
• Improved fuel efficiency
• Capture and use of landfill and digester gases
• Green Infrastructure
• Increase use of renewable energy
• Carbon Sink
( Thegef.org, 2021 )

21. • E(CO2) actually reduces plant growth when combined with other
likely consequences of climate change.
• Namely, higher temperatures, increased precipitation or increased
nitrogen deposits in the soil. ( News.stanford.edu )
• Too much carbon dioxide can reduce the amount of valuable
nutrients the plant produces including iron, zinc and vitamin C.
( Cfaes.osu.edu )
 Conclusion

22. • Yield does increase in many cases, but quality of the yield also
goes down with it. (Seed quality)
• More researches are needed to show more evident results that
the e(CO2) concentration can be used after some improvements
to it, for the future commercial use in the crop production.
• And if these researches give fruitful results in the future, then
maybe hopefully we can achieve the supply of food demand the
9.8 billion population will need by 2050 and later.