climate change and agri.pptx

8/10/2019 climate change and agri.pptx

1/33

Climate Changeand Agriculture

Alona T. Nieva


2/33


3/33

limate changeis a significant and lasting change in the statistical

distribution of weatherpatterns over periods ranging from decades to

millions of years.

- wikipedia-

Climate change is a long term alteration in global weather patterns,

especially increases in temperature and storm activity.

http://earthhour.org/page/about/what-climate-change

Climate Change
http://en.wikipedia.org/wiki/Weatherhttp://earthhour.org/page/about/what-climate-changehttp://earthhour.org/page/about/what-climate-changehttp://earthhour.org/page/about/what-climate-changehttp://earthhour.org/page/about/what-climate-changehttp://earthhour.org/page/about/what-climate-changehttp://earthhour.org/page/about/what-climate-changehttp://earthhour.org/page/about/what-climate-changehttp://en.wikipedia.org/wiki/Weather


4/33

Climate change is brought about by the build-up of greenhouse gases in

the atmosphere, which significantly changes the normal or expected

weather patterns and conditions in a specific region of the Earth.

http://www.onehotearth.com/what-is-climate-change.html
http://www.onehotearth.com/what-is-climate-change.htmlhttp://localhost/var/www/apps/conversion/tmp/scratch_8/The%20Greenhouse%20Effect%20-%20YouTube.wmvhttp://www.onehotearth.com/what-is-climate-change.htmlhttp://www.onehotearth.com/what-is-climate-change.htmlhttp://www.onehotearth.com/what-is-climate-change.htmlhttp://www.onehotearth.com/what-is-climate-change.htmlhttp://www.onehotearth.com/what-is-climate-change.htmlhttp://www.onehotearth.com/what-is-climate-change.htmlhttp://www.onehotearth.com/what-is-climate-change.htmlhttp://www.onehotearth.com/what-is-climate-change.html


5/33

The history of the scientific discovery of climate

change began in the early 19th century when ice

ages and other natural changes in paleoclimate were

first suspected and the natural greenhouse effect first

identified.


6/33

In the late 19th century, scientists first argued that

human emissions of greenhouse gases could change the

climate, but the calculations were disputed. Many

other theories of climate change were advanced,

involving forces from volcanism to solar variation.


7/33

In the 1960s, the warming effect of carbon dioxide

gas became increasingly convincing, although some

scientists also pointed out that human activities, in the

form of atmospheric aerosols (e.g., pollution ), could

have cooling effects as well.


8/33

During the 1970s, scientific opinion increasingly favored the

warming viewpoint.

By the 1990s, as a result of improving fidelity of computer models

and observational work confirming the Milankovitch theory of the

ice ages, a consensus position formed: greenhouse gases were deeply

involved in most climate changes, and human emissions were

bringing serious global warming.


9/33

Agriculture, also called farming or husbandry, is the cultivation of

animals, plants, fungi, and other life forms for food, fiber, biofuel and

other products used to sustain human life.

Agriculture was the key development in the rise of sedentary human

civilization, whereby farming of domesticated species created food

surpluses that nurtured the development of civilization.


10/33

Climate Change and Agriculture

Climate change and agriculture are interrelated processes, both of

which take place on a global scale

Global warming is projected to have significant impacts on

conditions affecting agriculture, including temperature, carbon

dioxide, glacial run-off, precipitation and the interaction of these

elements


11/33

Climate Change and Agriculture

These conditions determine the carrying capacity of the biosphere toproduce enough food for the human population and domesticated

animals.

Assessment of the effects of global climate changes on agriculture

might help to properly anticipate and adapt farming to maximize

agricultural production


12/33

General Effects of Climate Change in Agriculture

productivity, in terms of quantity and quality of crops

agricultural practices, through changes of water use

(irrigation) and agricultural inputs such as herbicides,

insecticides and fertilizers

environmental effects, in particular in relation of frequency and

intensity of soil drainage (leading to nitrogen leaching), soil

erosion, reduction of crop diversity


13/33

rural space, through the loss and gain of cultivatedlands, land speculation, land renunciation, and hydraulic

amenities.

adaptation, organisms may become more or less

competitive, as well as humans may develop urgency to

develop more competitive organisms, such as flood resistant

or salt resistant varieties of rice.

General Effects of Climate Change in Agriculture


14/33

Effects of Climate Change in Agriculture

Effects on quantity and quality

is essential to plant growth. Rising CO2

concentration in the atmosphere can have both positive and negative

consequences.

quantity

Carbon dioxide

Increased CO2 is expected to have positive physiological effects by

increasing the rate of photosynthesis

The effects of an increase in carbon dioxide would be higher on C3 crops

(such as wheat) than on C4 crops (such as maize), because the former is

more susceptible to carbon dioxide shortage.


15/33



quantity

Studies have shown that increased CO2 leads to fewer stomata developing

on plants which leads to reduced water usage.

Under optimum conditions of temperature and humidity, the yield

increase could reach 36%, if the levels of carbon dioxide are doubled.


16/33



quality

According to the IPCC's TAR, "The importance of climate change

impacts on grain and forage quality emerges from new research. For rice,

the amylose content of the grain

a major determinant of cooking

qualityis increased under elevated CO2" (Conroy et al., 1994).

Cooked rice grain from plants grown in high-CO2 environments would

be firmer than that from today's plants.


17/33



quality

However, concentrations of iron and zinc, which are important for

human nutrition, would be lower (Seneweera and Conroy, 1997).

Moreover, the protein content of the grain

decreases under combined increases of

temperature and CO2(Ziska et al., 1997)


18/33



quality

Studies have shown that higher CO2levels lead to reduced plant uptake

of nitrogen (and a smaller number showing the same for trace elements

such as zinc) resulting in


19/33



Reduced nitrogen content in

grazing plants has also been

shown to reduce animalproductivity in sheep, which

depend on microbes in their gut

to digest plants, which in turndepend on nitrogen intake.


20/33


Agricultural surfaces and climate changes

Climate change may increase the amount of arable land

in high-latitude region by reduction of the amount of

frozen lands.


21/33

A 2005 study reports that temperature in Siberia has increased three degree

Celsius in average since 1960 (much more than the rest of the world).


However, reports about the impact of global warming on Russian agriculture

indicate conflicting probable effects : while they expect a northward

extension of farmable lands, they also warn of possible productivity losses

and increased risk of drought.


22/33


salinity

Sea levels are expected to get up


23/33


Low lying areas

Bangladesh India

Vietnam


24/33


warmer atmospheric

temperature

extreme rainfall events

Hydraulic cycle

Soil erosion


25/33


However, because the ratio of carbon to nitrogen is a constant, a doubling of

carbon is likely to imply a higher storage of nitrogen in soils as nitrates, thus

providing higher fertilizing elements for plants, providing better yields. The

average needs for nitrogen could decrease, and give the opportunity of changing

often costly fertilization strategies.


26/33


greater risks of erosion


27/33


weeds would undergo the same acceleration of cycle as cultivated

crops


28/33


Global warming would cause an increase in rainfall in some areas, which would

lead to an increase of atmospheric humidity and the duration of the wet seasons.

Combined with higher temperatures, these could favor the development of

fungal diseases. Similarly, because of higher temperatures and humidity, there

could be an increased pressure from insects and disease vectors.


29/33

Impact of Agriculture on Climate Change

El Nio effects on agriculture


30/33

mpact of agriculture on climate change

The agricultural sector is a driving force in the gas emissions and

land use effects thought to cause climate change.


31/33

http://en.wikipedia.org/wiki/File:Greenhouse_Gas_by_Sector.png


32/33


Livestock and livestock-related activities such as deforestation and increasingly

fuel-intensive farming practices are responsible for over 18% of human-madegreenhouse gas emissions


33/33

climate change and agri.pptx

Documents

Transcript of climate change and agri.pptx