1. M. K. Wanigasuriya
AG/2008/2737
Department of crop science
Faculty of Agriculture

2. The free encyclopedia ‘Wikipedia’ provide us
with the followings
Climate change is a significant and lasting change in
the statistical distribution of weather patterns over
periods ranging from decades to millions of years. It
may be a change in average weather conditions or the
distribution of events around that average (e.g., more
or fewer extreme weather events). Climate change may
be limited to a specific region or may occur across the
whole Earth

3. •Agriculture is highly sensitive to climate
variability and weather extremes, such as
droughts, severe storms.
•Human activity has already changed
atmospheric characteristics such as temperature,
rainfall, levels of carbon dioxide (CO2) and
ground level ozone.

4.  The demand for world agriculture output will
grow exponentially over coming decades due
to world population growth and expanding
world economies. At the same time, the
agriculture sector will be impacted by changes
in climate that will challenge the productivity
of the world’s
agriculture
resources

5.  The researchers calculated the impact of the
climate trends on global crop yields. Maize
production would have been about six percent
higher and wheat production about four
percent higher had the climate trends since
1980 not existed. The effects on rice and
soybeans were lower and not statistically
significant.

7.  Recent studies indicate that increased frequency of heat
stress, droughts and floods negatively affect crop
yields and livestock
 Climate variability and change also modify the risks of
fires, pest and pathogen outbreak, negatively affecting
food, fiber and forestry.

9.  Average temperature increase
 Change in rainfall amount and patterns
 Rising atmospheric concentrations of CO2
 Pollution levels such as troposphere ozone
 Change in climatic variability and extreme
events
 weed
 pest and pathogen

12. • Increasing atmospheric CO2 levels, driven by
emissions from human activities
• It response for
– enhance the growth of crops
– yield of crop
– Quality of the grain

13.  CO2 can be one of a number of limiting factors
that, when increased, can enhance crop growth.
 A plant takes in atmospheric carbon dioxide
(CO2) during the photosynthesis process,
utilizes the carbon (C) to build the plant
 Increased levels of carbon dioxide have a
positive impact on plant growth such as wheat,
rice and soybeans

14. • high N soil contents increase the relative
response to elevated atmospheric CO2
concentrations
• This increase was caused by removing N
limitation to plant growth through the
application of N fertilizer.
• A decline in N availability may be prevented by
an increase in biological N2 fixation under
elevated atmospheric CO2 concentrations.

15.  The expected rise in CO2 concentration from
390 to 550 umol by the middle of this centaury
will have significant impact of crop
productivity
 Experiments under optimal conditions show
that doubling the atmospheric CO2
concentration increases leaf photosynthesis
by 30%–50% in C3 plant species and 10%–25%
in C4 species

16.  Crop yield increase is lower than the
photosynthetic response
 many limiting factors such as pests, weeds,
nutrients, soil water and air quality,
Temperature

17.  Elevated CO2 will modify many of the grain
quality traits such as proteins , minerals (Zink
and Iron) and fatty acid composition and starch
properties

19. • Global average temperatures have risen by
about 0.13 Centigrade per decade since 1950.
• It is expected to increase to about 0.2
Centigrade per decade over the next two to
three decades.

21.  India and the United States suffered very low rainfall
throughout suffered sharp harvest reductions because of
record temperatures and drought
 In 2003 Europe record level of heat damaged most crops
from the United Kingdom and France in the Western
Europe through Ukraine in the East

22.  lengthen the growing season in regions with a
relatively cool spring and fall
 adversely affect crops in regions where
summer heat already limits production
 increase soil moisture evaporation rates
 increase the chances of severe droughts

24.  An increase in temperature will speed up
development.
 In the case of an annual crop, the duration
between sowing and harvesting will shorten
(for example, the duration in order to harvest
corn could shorten between one and four
weeks).
 The shortening of such a cycle could have an
adverse effect on productivity because
senescence would occur sooner

25. The free encyclopedia ‘Wikipedia’ provide
us with the followings
Seaweed is a loose
colloquial term encompassing macroscopic,
multicultural, benthic marine algae. The term
includes some members of the red, brown and
green algae. Seaweeds can also be classified by
use (as food, medicine, fertilizer, industrial,
etc.)

26.  Seaweed act as "trees of the ocean," providing
food, shelter and habitat for many other living
things.

27.  Warming ocean waters could force hundreds of
Australian seaweed species to shift southward
in search of cooler waters, and eventually, force
them off Australia's continental shelf, and
possibly into extinction, according to a study.
 Changes in seaweed communities could have
dramatic effects on other living things, since
seaweeds provide habitat and food

28. • Changes in rainfall can affect soil erosion rates
and soil moisture, both of which are important
for crop yields.
• The Intergovernmental Panel on Climate
Change( IPCC )predicts that precipitation will
increase in high latitudes, and decrease in most
subtropical land regions—some by as much as
about 20 percent.
• While regional precipitation will vary the
number of extreme precipitation events is
predicted to increase

30.  the ozone that is a byproduct of certain human
activities does become a problem at ground
level
 Unlike most other air pollutants, ozone is not
directly emitted from any one source.

31.  Tropospheric ozone is formed by the
interaction of sunlight, particularly ultraviolet
light, with hydrocarbons and nitrogen oxides,
 which are emitted by automobiles, gasoline
vapors, fossil fuel power plants, and certain
other industries

33.  While stratospheric ozone shields us from
ultraviolet radiation,
 in the troposphere this irritating, reactive
molecule damages forests and crops and other
materials; and injures or destroys living tissue.

34.  Ozone affects plants in several ways.
 High concentrations of ozone cause plants to
close their stomata. These are the cells on the
underside of the plant that allow carbon
dioxide and water to diffuse into the plant
tissue. This slows down photosynthesis and
plant growth.
 Ozone may also enter the plants through the
stomata and directly damage internal cells.

36. • increasing ozone concentrations in future
decades, with or without climate change, will
negatively impact plant production, possibly
increasing exposure to pest damage

37. • Change in climatic variability and extreme
events: Changes in the frequency and severity
of heat waves, drought, floods and hurricanes,
remain a key uncertainty in future climate
change.
• Such changes are anticipated by global climate
models, but regional changes and the potential
affects on agriculture are more difficult to
forecast.

38. • Most of the increase in agricultural production
over the last century is the result of yield
increases rather than agricultural land area
expansion.
• However, due to the world’s rapidly growing
demand for food and the negative yield impact
of climate change on food production, there
will be great pressure to expand the world’s
agricultural land area.

39. • Increased investments in agricultural research
in the world is needed to meet the challenge of
world crop production.
• this investments must be combined with
programs to substantially reduce greenhouse
gas emissions.
• Use renewable energy sources
• Develop home garden concept in the world
• Carbon treading

40.  http://en.wikipedia.org/wiki/Climate_change_n
d_agriculture
 http://www.ucar.edu/learn
 http://www.oecd.org/document
 http://www.epa.gov/climatechange/effects/a
griculture.html
 Wynne Parry, Live Science Senior Writer Date:
27 October 2011 Time: 12:01 PM E
 International conference on the impact of
climate change on agriculture December ,
20,2011 (ICICCA 2011)

41.  Crop and pasture response to climate change
Francesco N. Tubiello ,Jean-François Soussana,
S. Mark Howden