Agriculture and food security
Impacts on crops
It can affect crop yield. How?
- Very simple. Just change or affect the inputs i.e. irrigation, solar radiation and
prevalence of pests.
Rise in temperature (due to Global Warming) affects the crops.
As it can affect agriculture productions poorest countries will be first to hit by the wrath
of CC (climate change) (IPCC report, 2001)
Report says – crop yield would be reduced in tropical and sub-tropical region because of
changed availability of water and pest incidence.
Though rising CO2 can stimulate plant growth, it also reduces the nutritional value of
most food crops. Rising levels of atmospheric CO2 reduce the concentrations of protein
and essential minerals in most plant species, including wheat, soybeans, and rice.
Impacts on livestock
Heat waves (projected to increase under climate change) affects animals both directly
and indirectly. Over time, heat stress can increase vulnerability to disease, reduce
fertility, and reduce milk production.
Drought may threaten pasture and feed supplies. Drought reduces the amount of
quality forage available to grazing livestock.
Climate change may increase the prevalence of parasites and diseases that affect
Increases in carbon dioxide (CO2) may increase the productivity of pastures, but may
also decrease their quality. Increases in atmospheric CO2 can increase the productivity
of plants on which livestock feed.
Impacts on Fisheries
Many aquatic species can find colder areas of streams and lakes or move north along
the coast or in the ocean. Nevertheless, moving into new areas may put these species
into competition with other species over food and other resources.
Some marine disease outbreaks have been linked with changing climate.
Changes in temperature and seasons can affect the timing of reproduction and
migration. Many steps within an aquatic animal’s lifecycle are controlled by
temperature and the changing of the seasons.
Impacts on Indian agriculture
Productivity of agriculture depends on the rainfall and its pattern.
So, phenomenon like El Nino can disturb this pattern → affecting productivity
Change in rainfall pattern mean threat to agri., economy and food securiiy.
Summer rainfall – 70% of total annual rainfall – now this shows what would be result if
we miss just one monsoon.
According to studies by 2050s the summer rainfall would see decline.
By 2050s –
- Semi desert area of north west India – higher rainfall than normal
- Central India – 10-20% decrease in rainfall
Productivity of crops may decrease because of increase in temperature and decrease in
Decline in productivity of rabi crops than kharif season crops.
Rising temperature will increase the use of fertilizers resulting in higher GHG emissions,
ammonia and cost of crop production.
Water stresses and insecurity
Water cycle and water demand
Water cycle’s delicate balance of precipitation, evaporation will change.
Increase in temperature → Increased evaporation → it may dry out some areas and fall
as excess precipitation on other areas.
As temperatures rise, people and animals need more water to maintain their health and
thrive. Many important economic activities, like producing energy at power plants,
raising livestock, and growing food crops, also require water. The amount of water
available for these activities may be reduced as Earth warms and if competition for
water resources increases.
Many areas world, currently face water shortages. The amount of water available is
already limited, and demand will continue to rise as population grows.
In the western part of the India, less total annual rainfall mean that less water will likely
be available during the summer months when demand is highest. This will make it more
difficult for water managers to satisfy water demands throughout the course of the
Water quality could suffer in areas experiencing increases in rainfall. For example, in the
North and North east increases in heavy precipitation events could cause problems for
the water infrastructure, as sewer systems and water treatment plants are
overwhelmed by the increased volumes of water.
Heavy downpours can increase the amount of runoff into rivers and lakes, washing
sediment, nutrients, pollutants, trash, animal waste, and other materials into water
supplies, making them unusable, unsafe, or in need of water treatment.
Freshwater resources along the coasts face risks from sea level rise. As the sea rises,
saltwater moves into freshwater areas.
As more freshwater is removed from rivers for human use, saltwater will move farther
Drought can cause coastal water resources to become more saline as freshwater
supplies from rivers are reduced.
Water infrastructure in coastal cities, including sewer systems and wastewater
treatment facilities, faces risks from rising sea levels and the damaging impacts of storm surges.
Impacts on water situation in India
Increased pressure on water resources.
Himalayan glaciers’ fresh water for perennial rivers, in particular the Indus, Ganga, and
Brahmaputra river systems had undergone substantial changes as a result of extensive
land use (e.g. deforestation, agricultural practices and urbanization), leading to frequent
hydrological disasters, enhanced sedimentation and pollution of lakes.
Gangotri glacier is retreating about 28 m per year and is expected to increase under
changed climate conditions, which would lead to increased summer flows in some river
systems followed by glaciers disappearance.
As a result of increase in temperature significant changes in rainfall pattern have been
observed during the 20th century in India.
Different rivers like Kosi, Ganga, Ghaghara, Son, Indus and its tributaries and Yamuna
had changed their course a number of times. Recent devastating floods in Nepal and
Bihar is result of same (due to change of course of River Kosi)
Food production has to be increased by 2020 in order to feed India’s ever-growing
It is feared that the fast increasing demand for food in the next 2 or 3 decades could be
quite grim because of soil degradation and climate change.
Rise in population will increase the demand for water leading to faster withdrawal of
water and this in turn would reduce the recharging time of the water tables → Result →
availability of water bound to reach critical levels sooner or later.
Growing demand of water in agriculture, industrial and domestic sectors →
overexploitation of the groundwater resource.
The falling ground water levels in various parts of the country have threatened the
sustainability of the groundwater resources.
Agriculture sector – largest consumer of water in India – 83% (If used judiciously, the
demand may come down 68% by 2050)
To meet above demand augmentation of the existing water resources by development
of additional sources of water or conservation of the existing resources and their
efficient use will be needed.
The consequences of future climatic change may be felt more severely in developing
countries such as India, whose economy is largely dependent on agriculture and is
already under stress due to current population increase and associated demands for
energy, freshwater and food.
Rise in sea levels
Sea level rise can be both due to thermal expansion as well as melting of ice sheets.
Since 1993, sea level has been rising at a rate per year, significantly higher than the
average during the previous half-century.
IPCC predicts that sea levels could rise rapidly with accelerated ice sheet disintegration.
Global temperature increases of 3-4°C in future meaning – 330 million people being
permanently or temporarily displaced through flooding
Warming seas will also fuel more intense tropical storms.
Impacts on Coastal States in India
The short and long term variations in sea level impact the coastal ocean in many
Long term sea level rise is expected to have a significant impact on the straight coast as
well as islands, barrier reefs, entrance processes of river estuaries, inlets, bays, coastal
lagoons, etc, which will subsequently have a cascading effect on environmental
processes of these coastal environments.
Coastal states – Maharashtra, Goa and Gujarat face a grave risk from the sea level rise,
which could flood land and cause damage to coastal infrastructure and other property.
Goa will be the worst hit – will lose large % of land + famous beaches and tourist
The Global Environmental Outlook (GEO-6) report of UN – “Nearly 40 million Indians will
be at risk from rising sea levels by 2050, with people in Mumbai and Kolkata having the
maximum exposure to coastal flooding in future due to rapid urbanization and
Mumbai’s – northern suburbs like Versova beach, tidal mud flats and creeks – vulnerable
to land loss and increased flooding.
Flooding will displace a large number of people which will put greater pressure on the
civic amenities and rapid urbanization.
Sea water percolation due to inundations can diminish freshwater supplies.
Threatening to existence of coral reefs, phytoplankton, the fish stocks and the human
People living in the Ganges Delta share the flood risks associated with rising sea levels.
Ecosystems and Biodiversity
Climate Change has the potential to cause immense biodiversity loss, affecting both
individual species and their ecosystems.
The projected extinctions of flora and fauna in the future will be because of adverse
impact of human activities.
According to International World Wildlife Fund (WWF) species from the tropics to the
poles are at risk.
Many species have started to move but many may be unable to move to new areas
quickly enough to survive changes that rising temperatures will bring to their historic
WWF asserted that 1/5th of the world’s most vulnerable natural areas may be facing a
“catastrophic” loss of species.
Climate change will have catastrophic impact on the marine ecosystems. Climate change
→ ocean acidification → affect marine organism productivity, reproduction, way they
This is expected to negatively affect shell forming organisms, corals and their dependent
Impacts on India’s biodiversity
Mountain ecosystems which are hot spots of biodiversity are fragmented and degraded
because of increase in temperature and human activities.
Himalayan Ecosystem which are lifeline of India, China, Pakistan, Nepal are threatened
by climate change.
Prediction – there will be an increase in the phenomenon of Glacial Lake Outburst
Floods (GLOFs) in the Himalayas causing catastrophic flooding downstream with serious
damage to life property, forests, farms and infrastructure.
Indian desert is rich in species diversity of mammals and winter migratory birds.
There are sign of expansion by deserts i.e. desertification.
Change in climate pattern – floods in Barmer district of Rajasthan in 2006.
Mangrove forests acts as carbon sink and habitat for diverse species of plants and
animals. Any change in salinity or sea level will affect these unique forests.
Wetlands – natural barrier to flooding and cyclones.
Corals – world’s most productive ecosystem. Coral bleaching because of climate change.
Peninsular rivers are heavily dependent on monsoon thus peninsular ecosystem is
India is a agrarian economy heavily dependent on monsoon and so we need to tackle
problem of climate change effectively
Climate change and Health
Warmer average temperatures will lead to hotter days and more frequent and longer
heat waves. It will increase heat related deaths.
Exposure to extreme heat can lead to heat stroke and dehydration, as well as
cardiovascular, respiratory, and cerebrovascular disease.
Low-income households and older adults may lack access to air conditioning which also
increases exposure to extreme heat.
Urban areas are typically warmer than their rural surroundings.
Air quality impacts
Changes in the climate affect the air we breathe both indoors and outdoors. Warmer
temperatures and shifting weather patterns can worsen air quality, which can lead to
asthma attacks and other respiratory and cardiovascular health effects.
Particulate matter (PM) is the term for a category of extremely small particles and liquid
droplets suspended in the atmosphere.
Some PM such as dust, wildfire smoke, and sea spray occur naturally, while some is
created by human activities such as the burning of fossil fuels to produce energy.
Inhaling fine particles can lead to lung cancer, chronic obstructive pulmonary disease
(COPD), and cardiovascular disease.
Impacts from Extreme Weather Events
Extreme weather events, such as extreme precipitation, flooding, droughts, and storms,
threaten the health of people during and after the event.
Extreme events can affect human health in a number of ways by –
- Reducing the availability of safe food and drinking water.
- Damaging roads and bridges, disrupting access to hospitals and pharmacies.
- Interrupting communication, utility, and health care services.
- Contributing to carbon monoxide poisoning from improper use of portable
electric generators during and after storms.
- Creating or worsening mental health impacts such as depression and posttraumatic stress disorder (PTSD).
Vectorborne diseases are illnesses that are transmitted by disease vectors, which
include mosquitoes, ticks, and fleas.
These vectors can carry infectious pathogens, such as viruses, bacteria, and protozoa,
from animals to humans.
Changes in temperature, precipitation, and extreme events increases the geographic
range of diseases spread by vectors and can lead to illnesses occurring earlier in the
The risks for climate-sensitive diseases can be much higher in poorer countries that have
less capacity to prevent and treat illness.
People can become ill if exposed to contaminated drinking or recreational water.
Climate change increases the risk of illness through increasing temperature, more
frequent heavy rains and runoff, and the effects of storms.
Climate impacts can affect exposure to waterborne pathogens (bacteria, viruses, and
parasites), toxins produced by harmful algal and cyanobacterial blooms in the water and
chemicals that end up in water from human activities.
Changing water temperatures mean that waterborne Vibrio bacteria and harmful algal
toxins will be present in the water or in seafood at different times of the year, or in
places where they were not previously threats.
Runoff and flooding resulting from increases in extreme precipitation, hurricane rainfall,
and storm surge will increasingly contaminate water bodies used for recreation (such as
lakes and beaches), shellfish harvesting waters, and sources of drinking water.
Extreme weather events and storm surges can damage or exceed the capacity of water
infrastructure (such as drinking water or wastewater treatment plants), increasing the
risk that people will be exposed to contaminants
Food Safety and Nutrition
Climate change and the direct impacts of higher concentrations of CO2 in the
atmosphere are expected to affect food safety and nutrition.
Extreme weather events can also disrupt or slow the distribution of food.
Climate change will have a variety of impacts that may increase the risk of exposure to
chemical contaminants in food. For example, higher sea surface temperatures will lead
to higher mercury concentrations in seafood, and increases in extreme weather events
will introduce contaminants into the food chain through storm water runoff.
Higher concentrations of carbon dioxide in the air can act as a “fertilizer” for some
plants, but lowers the levels of protein and essential minerals in crops such as wheat,
rice, and potatoes, making these foods less nutritious