J. Ind. Geophys. Union ( January 2009 )
Vol.13, No.1, pp.43-48
Climate Change, Urbanization - What citizens can do
U.S.De and V.K.Soni1
Department of Environmental Sciences, University of Pune, Pune
1India Meteorological Department, Pune
Email: firstname.lastname@example.org & email@example.com
Anthropogenic Climate Change of post industrial era is expected impact on all sectors of the society
and needs strategic steps to reduce it.
Mitigation efforts include global effort leading to curtailing the emission of green house gases.
Adaptation measures on the other hand complement the mitigation measures by reducing the
impact of global warming. Historically, mitigation has received more media attention due to its
global canvas; while the adaptation measures have remained in the back ground. In this paper,
authors have presented certain simple concepts which can be undertaken at the people's level to
combat the impacts of Climate Change. In the field of mitigation, people can help reduce emission
by reducing their consumption and demand for energy through use of:
(i) Energy efficient gadgets.
(ii)Eco friendly transport such as cycle for short distances and bus or car pool for longer distance
(iii) Local products of food and clothing, thus avoiding energy expended in transportation.
(iv) Schools can encourage travel to and from by school buses rather than by individual transport
Urbanization is linked with development and has been quite rapid in recent years. While urban
areas cover only 3% of the global land, it gives shelter to nearly 26% of the global population. The
phenomenal increase in the population during the last fifty years has led to rapid industrialization
and high rate of urbanization which have created tremendous pressure on natural resources like
land, air and water. The urban population has increased three and half times, from 62.4 million
in 1951 to 217.6 million in 1991 and it again increased to 286 million in 2001. A typical case is
that during last 180 years, the urban area in the city of Pune has grown from a mere 5 Sq. Km to
700 Sq. Km. from 1901 to 2001. The urban population has grown from 1.64 lakhs to 42 lakhs.
Bangalore, Hyderabad and other growing towns tell the same story. Such unplanned growth leads
to widespread damage to existing ecosystem, deforestation and loss of agriculture land, apart from
its effect on climate and environment. Tall concrete buildings cement roads and tarmac change
the albedo of the urban areas and reduce the free flow of air. 'Heat island' is an urban effect, which
is felt in all major cities in India. A study for Bangalore shows significant rise in minimum
temperature during recent decades. Likewise the city of Pune shows these signatures also. Urban
planning and decongesting the major urban centers by diversifying industries and other activities
is needed to make urban climate more agreeable and safe for human settlement. More green cover,
lakes and well spread parks are needed to make growing cities a more comfortable place to live.
Action is needed now before it becomes too late to repair the damage to climate and environment
due to urbanization. Citizens can play a crucial role in reducing the impacts of climate change and
urbanization. Some of these are projected in the paper.
Climate Change and Urbanization
Global warming and climate change is a widely
accepted fact now. The impact of global warming are
now reported all over the world. These include
reduction in ice and snow covered areas, earlier timing
of spring events, migration of birds etc. According to
the fourth assessment report of the IPCC these
impacts would be more (Parry, Canziani & Palutikaf
This paper highlights the various international
efforts aimed at reducing the climate change or the
global warming through mitigation. However, even if
efforts to stabilize the emission at a desired and agreed
U.S.De and V.K.Soni1
level (say 550 ppm by 2020) are successful; warming
would continue after several decades from 2020.
Adaptation provides a response to reduce the impact
from such residual warming and is necessary as
suggested in the latest assessment report of the IPCC.
In this context the role of policy makers, government
and private parties are important (Munasinghe & Swart
2005). Yet an individual citizen or group of citizens
can also make a significant contribution to response
strategies for reducing the impacts of global warming.
The paper makes a central theme on this aspect.
Nearly 47% of the global population lives in cities;
though cities cover barely 1.5% of the total land area
of the earth. Though, the major attention has been
on the mega cities, those with population of more
then 10 million, however majority of urban dwellers
live in cities with medium or small size. As per a
recent UN survey, by 2050, nearly 70 % of the global
population will be living in the cities. The migration
will be most significant in Asia.
At the time of independence more than 75% of
population was village based and the country was an
agriculture-oriented nation. With the industrialization
and development, more and more people migrated
towards the big cities. New cities which were small,
also developed and become large towns based on
industries. Such growth caused large-scale changes in
demographic patterns; for example a city like Pune has
grown from small town of 1.5 lakh population in 1901
to population of 42 lakh in 2001.
Although cities grew in size and population they
were not fully sustainable. Use of large energy in
industries, automobiles, concrete buildings became
more and more common. However, the infrastructure
such as roads, bridges, drainage and water supply did
not fully cope up with growing migration. This created
a large divide in the quality of life between the richer
and poorer section of population. Not only social and
economic problems arose but also such growth led to
problems related to environment and climate. The
paper deals with the later two issues in detail in the
As a citizen we are using energy, air, water and other
resources either collectively or individually. In the
modern world of changing life style we can think of
various small actions which can be made more
rational and sustainable towards the environment and
climate. These include the following:
(1) Use of energy through various daily appliances
and gadgets, heating, cooling and ventilating in
(2) Use of energy in the transport
(3) Use of water for our domestic needs
(4) Use of resources in our own life in the form of
food and other manufactured goods
The portfolio of actions which aim at reducing the
emission is termed as mitigation. These include steps
to increase the sinks of emission and decreasing the
source of emission.
Globally most of the emissions occur in the
production of energy through use of fossil fuel - coal,
oil and natural gas. This is here that nearly 2/3rd of
the global emission is produced. This energy is used
in various day to day activities.
There is a great scope of reducing emission by
citizen initiatives in all these sectors, by reducing
• Design of buildings can be made in such a way to
make optimum use of airflow and sunshine to cut
down electricity bills.
• We use many electrical gadgets such as
refrigerators, air conditioners, room heaters,
washing machines in our daily life, these can be
kept in good working conditions to avoid power
loss and reduce energy demand. Buy electrical
gadgets of higher energy star ratings. The BEE
(Bureau of Energy Efficiency) Star Energy Efficiency
Labels have been created to standardize the energy
efficiency ratings of different electrical appliances
and indicate energy consumption under standard
• Use of CFLs can also reduce nearly 50% of
electricity bill. The International Energy Agency
(IEA) estimates that the global electricity bill could
be reduced by nearly one-tenth if there were a global
switch to energy-efficient lighting. Simple steps like
switching off lights and other gadgets when not
needed are a good habit for all of us.
• Transport is yet another sector which not only
increase greenhouse gas emission mainly CO2 but
also impairs the air quality through release of
carbon mono-oxide, hydrocarbons and particulate
matter. Using public transport, car pooling and for
short distance walking makes good practice.
Maintaining the car or two wheeler in efficient
condition can reduce fuel cost and hence emission
up to 20%. Changing over to CNG in place of
liquid fuel is also a good move to reduce emission
from automobiles in both personnel as well as
public sector. Table I shows the rapid rise of
automobiles in India during last 50 years.
• Water supply in modern cities to large residential
Climate Change, Urbanization - What citizens can do
blocks is dependent on pumps which need energy.
Proper and economy in use of water is thus
essential to cut down electricity. In a city of one
million people a saving of one liter per person per
day will lead to a saving of 30 million liters of water
per month to be pumped in a single big city.
There are many other steps which one can think
of as a citizen to reduce demand on energy and hence
the emission; for example by vigorously planting more
trees in urban areas and preventing cutting and felling
of trees in the name of development of roads and
Each of the greenhouse gas released stays in the
atmosphere for several years thus even if the emission
targets are agreed to and are put in place the global
warming would continue for several years.
In order to reduce the impact of this residual
warming adaptation to climate change is equally
important. As per the Fourth Assessment Report of
IPCC a mix of mitigation and adaptation is needed
in our response to global warming. So far we have seen
how citizens can contribute to mitigation efforts by
reducing emission. We shall now see how we as
citizens can also help in adaptation to global warming.
• One of the major impacts of global warming will
be on the water resources which will be under
stress due to changes in the rainfall distribution.
Thus the economic use of water and recycling of
water will be needed. Water from kitchen can be
used for gardening while recycled water can be used
for toilets and washing roads etc.
• Rain harvesting is one of the important options to
increase the water availability in domestic and
• In order to combat the fury of more and intense
tropical storms provision of shelters and
construction of dykes in the coastal areas are also
good adaptation options.
• In the agriculture sector option to change the crops
depending upon the changes expected in rainfall
pattern is also a useful step.
• Extremely heavy rainfall like the July 2005 event
over Mumbai (De< Rao & Rase 2006), may become
more frequent causing flooding, loss of property and
human life as a result of climate change.
Adaptation options to counter such situations
include, planning better drainage in the cities and
keeping them functional before the wet season.
• By planting trees and providing better building
design, the impact of intense heat wave can be
reduced to a large extent.
Human settlements grew at central locations near river
banks, ports for trade and commerce. Most of today's
mega cities are examples. The matter of concern is
that by 2050 it is projected that 70% of the people
will live in cities. Furthermore the growth rate will
be more in the developing countries and in medium
India will be dominated by its rural population for
some more time. Number of urban agglomeration/
town has grown from 1827 in 1901 to 5161 in 2001
in India. In the 2001, countries urbanites made up
27.8 % of the total population. Number of cities with
population more than one million has increased from
5 in 1951 to 23 in 1991 and to 35 in 2001. As per a
UN report the urban population in Africa and Asia is
expected to double between 2000 and 2030. Asia's
urban population will rise from 1.3 billion to 2.64
billion meanwhile the urban population will change
from 870 million to 1.10 billion. By then every 7 out
of 10 urbanite will be from Asia and Africa (GEO,
2003). Unless proper city planning is put in place such
growth will only produce inequality and degrade
Most of the migrants will be the rural poor who
will live in slums or scatter settlements. Urbanization
leads to many changes which have direct linkage with
the climate and environment. Some of the major
changes are as follows:
(1) Change in land use pattern
(2) Growth in population density
(3) Use of transport and energy intensive operations
(4) Industrial growth
(5) Increased consumption and generation of waste
We shall now look into these aspects and their
inter relationship with the environment which later
affects the climate.
(iv) Urbanization and Environment
Landsberg (1981) drew attention to the role of
urbanization on climate and environment. The
urbanization leads to changes in the natural land use
pattern; removal of trees, construction of building
roads and tall buildings. These changes modify the
surface albedo and natural drainage. Cement and
concrete structure also change the thermal
The growth of population density leads congested
dwelling units, poor sanitation and unhygienic
conditions. Large population also leads to greater
consumption of food, water and energy; putting a great
stress on environment.
Poorly constructed buildings lead to poor
ventilation, lack of proper sunlight exposure, which
affect the health of the residents. During heavy rains
water logging, disruption of water supply and drainage
lines create additional risk of water borne diseases.
One of the biggest threats to the environment is the
runaway growth of mega cities. These cities if located
near the coast are responsible for marine pollution and
could destroy coastal ecosystem and wetlands.
The city life is characterized by use of automobiles
and other forms of transport using internal combustion
engines, steam and diesel locomotives. Since 1960's
the number of motor vehicles is increasing at rate
faster than the population. It is estimated that there
were 50 million cars all over the world in 1950, which
have risen to 600 million in 2002. By 2020 it will be
touching 1 billion mark. Vehicle production in India
is increasing at the rate of 15-20% per year. As per a
recent media report (T.O.I.), Delhi is adding 963
vehicles on its road every day while Bangalore is adding
500 vehicles. The story is no different in other metros
or tier-II and tier-III cities. Table 1 shows the rapid
growth of automobiles in India, in various sectors.
Table 1. Total Number of Registered Motor vehicles
(in Lakhs) in India from 1951 - 2004
All Two Cars, Buses Goods Others
Vehicles Wheelers Jeeps, Vehicles
1951 3.06 0.27 1.59 0.34 0.82 0.04
1961 6.65 0.88 3.10 0.57 1.68 0.42
1971 18.65 5.76 6.82 0.94 3.43 1.70
1981 53.91 26.18 11.60 1.62 5.54 8.97
1991 213.74 142.00 29.54 3.31 13.56 25.33
2001 549.91 385.56 70.58 6.34 29.48 57.95
2004 727.18 519.22 94.51 7.68 37.49 68.28
Source:Department of Road Transport and Highways,
Govt of India
These cause the problem of air pollution, as a
result of exhaust gases and particulate matter. As per
a recent study by IIT, Chennai, 70% air pollutants are
from automobile emission in the mega city of
Chennai. Some of these exhaust gases like CO2 is a
major greenhouse gas while Carbon Monoxide, NOx
and hydrocarbons are major health hazards for the
people on road as vehicle emit within the breathing
zone of people. The increase of automobiles is major
concern for air quality in the Indian cities.
Industries of various types are generally located
near the cities and industries are the major source of
air, water and land pollution. Release of dust, smoke
and chemically hazardous gases lead to poor air quality
near the industrial sites. Dust from mines specially coal
and asbestoses when inhaled by the workers produce
chest related diseases. Dust from brick clines, fly ash
from coal fired thermal power plants cover large areas
in the neighboring towns and cities. Efforts to reuse
fly ash in form of bricks etc have not been very popular.
Most of the energy needed to support industries
and urban life style is produced by using fossil fuel
i.e. coal, petrol, diesel or natural gas. Each of these
results in the increase in emission of greenhouse gas
CO2. The fourth assessment report of
Intergovernmental panel on climate change (IPCC)
published recently states that most of the observed
increase in global temperature since mid-20th century
is very likely due to the observed increase in human
induced GHG concentration.
Thus urban life style and industrialization have a
definite role in causing global warming. Global
warming can lead to climate change, including
increased frequency and intensity of storms, flood and
droughts. At the same time the rise in the sea level
by 90 cm by the end 21st century would be disastrous
to many urban centers located near the coast. While
this is the picture in the global scale; urbanization
leads to substantial changes in the urban climate.
Some of these are as follows.
Urbanization produces a warmer city center as
compared to the neighboring surroundings. The
temperature could be 5-10 oC warmer particularly
during the winter nights. The effect is known as the
Urban Heat Island (UHI) and is seen almost at all
the big cities of the world.
Tall buildings towers, bridges and flyovers retard
the free flow of air so that suspended pollutants are
not effectively removed. Lack of open ground leads to
less infiltration of rainwater in the ground as the tar
roads and cement pavements are impervious to the
percolation of rainwater. This increased runoff leads
greater risks of floods/water logging. Heavy rains during
the southwest monsoon and northeast monsoon
seasons cause floods in some location. Tropical
cyclones are also responsible for such floods. The
severity of floods is further enhanced in urban
locations due to poor drainage system. The urban
development very often takes place in a manner in
which buildings and roads occupy the flood planes of
the rivers and streams. This causes high run offs/
stagnation of water which cannot find its natural exit
due to blocking of its flood plane. In August 2000 such
an incident affected the popular city of Hyderabad,
U.S.De and V.K.Soni1
which had 24 cm of rain on 27 August. More recently
on 27 July Santacruz recorded a rainfall of 94.4 cm of
rain, a record in itself. The event caused a loss of over
1000 crores and killed over 500 people. In 2006 such
incidents though on a less severe scale were reported
from Bangalore and Chennai.
Presence of dust and aerosols in the city air leads
to reduced solar incident energy; and increase in
humidity. These factors make the city 'microclimate'
different from the surrounding semi-urban or rural
location. Increased dust and aerosols also lead to
lowering of atmospheric transparency, leading to poor
visibility during winter. Studies carried out for the
cities in India particularly large airports indicate that
atmospheric transparency is greatly reduced during
winter as the dust and other suspended particles stay
close to the ground due to stable thermal stratification
and low winds. The studies also indicate that the
incoming solar radiation is also reduced due to the
presence of dust and aerosols over urban areas. All the
stations of IMD solar radiation network are showing
decreasing trend in global solar radiation and bright
sunshine duration. Figure 1 shows this effect for a
few stations in India. The reduction in sunshine
hours could be as high as 20% in Delhi, Kolkata and
Bangalore. A study by Padmanabhamurty (2004) has
shown that due to lower wind speed and lower mixing
height (which depends on turbulence) the ventilation
coefficient is low in most of the cities in winter
making these areas of poor quality.
As indicated above the reduction of wind speed
over the Indian cities varies from 54% for Delhi, 59%
for Mumbai, 37% for Kolkata, 30% for Chennai, 58%
Figure 1. Long term trends in global solar irradiance (in Wm-2) at major cities in India
Climate Change, Urbanization - What citizens can do
for Bangalore and 23% for Nagpur (Rao & Jaswal 2000).
The same study and the studies by De & Rao (2004)
also support this and show an increasing trend in
rainfall ranging from 14 to 4% in many cities. These
features of the 'city climate' have been reported from
different cities in the world. There also appears to be
an increasing trend in rainfall over urban locations as
seen in different cities of India. Development of urban
cities should be sustainable and not economic and
physical only. As stated earlier mitigation efforts as
well as adaptation have to go hand in hand. Any
agreement on freezing the emission at an agreed level
will not have any immediate effect and global warming
would continue for several years beyond. At the same
time cost-benefit analysis is dependent on the precise
knowledge of impacts at regional as well local levels
(De 2001). The same is true for planning adaptation
strategies. Thus while mitigation efforts need global
participation and adaptation can be practiced regionally
or locally in different sectors. In both these ways one
aims at reducing the negative impact of climate
change; participation at citizen level (De 2008) are
important because of their cumulative influence in
keeping our planet and environment at a lesser risk from
these impact. Recycling of water, rain harvesting, use
of eco-friendly devices and a less consumptive life style
can help us in making a sustainable urban environment
and better climate for its population (WMO 2004).
De, U. S., 2001. Climate change impact - Regional scenario,
Mausam, 51, 201-217.
De, U.S. & Prakash Rao, G.S., 2004. Urban climate trends-
Indian scenario, J. of Ind. Geophys. Union, 8 (3), 199-203.
De, U. S., 2008. Coping up with climate change, IMSP
workshop on climate change for teachers, July 12,
De, U.S., Prakash Rao, G. S. & Rase, D.M., 2006. Deluge
in Mumbai, Bulletin of WMO Bull., 55 (2), 126-128.
GEO, 2003. Global Environmental outlook, UNEP,
Landsberg, H. E., 1981. The urban climate, Int. Geophys.
Series, 28, Academic Press, New York.
Munasinghe, M. & Swart, R.,2005. Primer on climate
change and sustainable development: facts, policy
analysis and applications, pp 445, Cambridge Univ,
Padmanabhamurty, B., 2004. Environmental Meteorology,
p-292, I. K. International Pvt Ltd, New Delhi.
Parry, M., Canziani, O. & Palutikaf, J., 2008. Key IPCC
conclusions on climate change impacts and
adaptations, WMO Bull. 57, 78-85.
Rao, G.S.P. & Jaswal, A.K., 2000. Effect of urbanization on
meteorological parameters, Mausam, 55 (3), 429-440.
WMO (2004), Weather, climate water and sustainable
development, WMO No. 974.
(Revised accepted 2008 December 15; Received 2008 November 31)
U.S.De and V.K.Soni1
Dr U. S. De is a first class M. Sc. Geophysics from the Banaras Hindu University. He
joined the India Meteorological Department in April 1963 in Seismological Division and
was posted at Central Seismological Observatory, Shillong. He was selected for the Indian
Institute of Tropical Meteorology in 1965 and worked there till 1972 and carried out useful
studies in atmospheric dynamics and weather forecasting research. In 1973 , he rejoined
IMD as Meteorologist and worked their till his retirement as Additional DGM(Research).
He was a senior faculty in the training centre of IMD from 1975 to 1995 in addition to
being the Head of Weather forecasting activities at Pune. His research areas include
dynamics of atmosphere, climate variability, natural hazards, extreme weather events and
environmental issues. Since 2002, he is a visiting faculty in the Department of
Environmental Science, University of Pune. He is also a PhD guide of BHU and UOP.
Several students did their PhD under his guidance. He was member of various technical
commissions of the WMO from 1992-2001.
He has published more than 150 papers in national and international journal. He is frllow
of IGU and a fellow of Indian Meteorological Society.
Mr V. K. Soni is a postgraduate in Physics from IIT Roorkee. He is working as Meteorologist
in Air Pollution Division of India Meteorological Department, Pune. His research areas
include Precipitation Chemistry, Aerosols and Solar Radiation. He is also a faculty in
training centre of IMD. He has published 10 research papers in national and international