Definition:
The most general definition of climate change is a change in the statistical
properties of the climate system when considered over periods of decades or
longer, regardless of cause. Accordingly, fluctuations on periods shorter than a few
decades, such as El Niño, do not represent climate change.
The term sometimes is used to refer specifically to climate change caused by
human activity; for example, the United Nations Framework Convention on
Climate Change defines climate change as "a change of climate which is attributed
directly or indirectly to human activity that alters the composition of the global
atmosphere and which is in addition to natural climate variability observed over
comparable time periods." In the latter sense climate change is synonymous with
global warming.
Global Warming:
Global warming is the increase in the average temperature of Earth's near-surface
air and oceans since the mid-20th century and its projected continuation. Global
surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) between the start
and the end of the 20th century. The Intergovernmental Panel on Climate Change
(IPCC) concludes that most of the observed temperature increase since the middle
of the 20th century was very likely caused by increasing concentrations of
greenhouse gases resulting from human activity such as fossil fuel burning and
deforestation.
An increase in global temperature will cause sea levels to rise and will change the
amount and pattern of precipitation, probably including expansion of subtropical
deserts. sWarming is expected to be strongest in the Arctic and would be
associated with continuing retreat of glaciers, permafrost and sea ice. Other likely
effects include changes in the frequency and intensity of extreme weather events,
species extinctions, and changes in agricultural yields. Warming and related
changes will vary from region to region around the globe, though the nature of
these regional variations is uncertain
Are climate change and global warming the same thing?
Not exactly, but they’re closely related, and some people use the terms
interchangeably. Global warming causes climates to change. "Global warming"
refers to rising global temperatures, while “climate change” includes other more
specific kinds of changes, too. Warmer global temperatures in the atmosphere and
oceans leads to climate changes affecting rainfall patterns, storms and droughts,
growing seasons, humidity, and sea level.
Also, while “global warming” is planet-wide, “climate change” can refer to
changes at the global, continental, regional and local levels. Even though a
warming trend is global, different areas around the world will experience different
specific changes in their climates, which will have unique impacts on their local
plants, animals and people. A few areas might even get cooler rather than warmer.
Effects of Global Warming & Climate Changes:
Over 100 years ago, people worldwide began burning more coal and oil for homes,
factories, and transportation. Burning these fossil fuels releases carbon dioxide and
other greenhouse gases into the atmosphere. These added greenhouses gases have
caused Earth to warm more quickly than it has in the past.
How much warming has happened? Scientists from around the world with the
Intergovernmental Panel on Climate Change (IPCC) tell us that during the past 100
years, the world's surface air temperature increased an average of 0.6° Celsius
(1.1°F). This may not sound like very much change, but even one degree can affect
the Earth. Below are some effects of climate change that we see happening now.
• Sea level is rising. During the 20th century, sea level rose about 15 cm (6 inches)
due to melting glacier ice and expansion of warmer seawater. Models predict that
sea level may rise as much as 59 cm (23 inches) during the 21st Century,
threatening coastal communities, wetlands, and coral reefs.
• Arctic sea ice is melting. The summer thickness of sea ice is about half of what it
was in 1950. Melting ice may lead to changes in ocean circulation. Plus melting
sea ice is speeding up warming in the Arctic.
• Glaciers and permafrost are melting. Over the past 100 years, mountain glaciers
in all areas of the world have decreased in size and so has the amount of
permafrost in the Arctic. Greenland's ice sheet is melting faster too.
• Sea-surface temperatures are warming. Warmer waters in the shallow oceans
have contributed to the death of about a quarter of the world's coral reefs in the last
few decades. Many of the coral animals died after weakened by bleaching, a
process tied to warmed waters.
• Heavier rainfall cause flooding in many regions. Warmer temperatures have led
to more intense rainfall events in some areas. This can cause flooding.
• Extreme drought is increasing. Higher temperatures cause a higher rate of
evaporation and more drought in some areas of the world.
• Ecosystems are changing. As temperatures warm, species may either move to a
cooler habitat or die. Species that are particularly vulnerable include endangered
species, coral reefs, and polar animals. Warming has also caused changes in the
timing of spring events and the length of the growing season.
• Hurricanes have changed in frequency and strength. There is evidence that the
number of intense hurricanes has increased in the Atlantic since 1970. Scientists
continue to study whether climate is the cause.
• More frequent heat waves. It is likely that heat waves have become more
common in more areas of the world.
• Warmer temperatures affect human health. There have been more deaths due to
heat waves and more allergy attacks as the pollen season grows longer. There have
also been some changes in the ranges of animals that carry disease like mosquitoes.
• Seawater is becoming more acidic. Carbon dioxide dissolving into the oceans, is
making seawater more acidic. There could be impacts on coral reefs and other
marine life.
Impact Of Climate Changes In Pakistan:
How Climate Change Is Impacting Pakistan:
Pakistan is home to some of the worlds most beautiful and varied landscapes and
wildlife. However, like many countries, Pakistan is experiencing the effects
climate change. The world is becoming warmer. Over the past 200 years average
temperature of the earth's surface has risen by 0.74 degrees C. It is expected to
increase by another 1.8° C to 4° C by the year 2100. The primary explanation for
the rise in temperature is human activities. The growing rate of industrialization,
the burning of greater quantities of fossil fuels (e.g.: coal, gas and oil) and the
unchecked destruction of forest cover has resulted in increased levels of Carbon-
dioxide (CO2) being emitted into the atmosphere. This carbon covers the earth,
trapping its heat, causing global warming.
In Pakistan a number of indigenous species of plants and animals are facing
extinction as a result of climate change. Rising sea levels, and accelerated melting
of glaciers in the Himalayas are threatening the natural habitat of rare animals such
as the Markhor and Ibex. Pakistan depends heavily on Kashmir’s water for
agricultural irrigation. As global warming hastens glacial melting, it changes the
flow patterns of the glacier-fed rivers that flow into Pakistan. Apart from the
change in volume, the water is reaching the country’s fields at the wrong
time.Climate change is also causing dramatic changes in weather patterns such as
increased droughts and flooding, and changes in freshwater supply. In the plains
the Blind Dolphin is threatened by extinction due to declining water levels in the
Indus River. While along the coastal areas rare coral reefs which sustain hundreds
of species of marine life are threatened as a direct result of increased surface
temperatures.
Changes in ocean circulation, in the atmospheric concentrations of greenhouse
gases or haze particles, and in the ice cover, have been invoked to explain the
drastic change in weather and temperature patterns over the years. Like all over the
world, in Pakistan too, these changes have resulted from the effects of human
activities and the destruction of the earth's protective ozone layer. Although human
induced warming is among the most pervasive threats to the web of life, the
burning of fossil fuels ; coal, gas and oil, is dangerous too, as it releases Carbon-
dioxide (CO2) into the atmosphere. This carbon blankets the earth, trapping its
heat, and causing global warming.
This global warming is causing damage to Pakistan's environment, as well. Among
the impacts felt and seen are biodiversity loss, rise in the sea level, increased
draught, shifts in the weather patterns, increased flooding, changes in freshwater
supply and an increase in extreme weather events. These could also lead to
alterations in forests and crop yields. Not only that, climatic changes could also
affect human health, animals and many types of eco-systems.
By disrupting the entire ecosystem, climate change ultimately affects the way
millions of Pakistanis live. However, there is still hope, if we take urgent action to
control climate change now. Youth, are the future and have the most at stake. They
can play an important role in helping bring about this change.
The risks of climate change for Pakistan:
• Changing weather patterns, such as increased flooding, droughts, changes in
freshwater supply and an increase in extreme weather events
• Reduced Agricultural output
• Himalayan Glaciers melting rapidly
• Increased air pollution in Pakistani cities such as Karachi and Lahore
• Biodiversity loss: hundred of rare plants and animals in danger of extinction
• Increased health risks
• Extinction of rare plant and animal life
• Increased exposure to extreme weather events
• Heightened water insecurity
• Reduced agricultural productivity
Effects of Climate Change on Pakistan:
Despite the fact that Pakistan contributes only 0.43 per cent of the world’s total
Greenhouse Gases and is 135th in world’s ranking, yet it is faced with severe
climate changes. Pakistan is among the countries which will be hit hardest by
effects of climate change even though it contributes only a fraction to global
warming. A recent report has described Pakistan as the 12th most vulnerable
country. Pakistan was already witnessing severe pressures on natural resources and
environment.
Impacts of climate change are evident in Pakistan which is facing multiple threats
from climate change. Agriculture sector is one example where low productivity,
water shortage, mismanagement etc are further worsening the situation. Studies
show that wheat and rice production will decline due to climate change. Water
supply, already a serious problem in many parts of the country, will decline
dramatically, affecting food security. Yearly. while the crop productivity is
expected to decline due to climate change. This challenges our food security plans
and deserve immediate action to avert poverty and food shortage. The fragile
ecosystem of coastal belt is under severe threat due to climate change. Fourteen
cyclones are recorded from 1970 to 2001 on Sindh coast. Mangrove , large tropical
evergreen tree, genus Rhizophora, that grows on muddy tidal flats and along
protected ocean shorelines. Mangroves are most abundant in tropical Asia, Africa,
and the islands of the SW Pacific. forests have declined from 260,000 hectares in
1970 to just 86,000 hectares in Sindh (95%) and Balochistan (5%) coast.
Mangroves absorb 70-90% of wave energy and effectively stop sea encroachment
in deltaic region. The sea has encroached in Indus delta spoiling around 2 million
fertile land in districts Badin and Thatta. The fact that Pakistan is not a polluter yet
it is on top hit list of 12 countries to be among the hard hit countries due to climate
change. Among the most effective measures to face the climate change are i)
Mitigation ii) Adaptation iii) Capacity Building and iv) Mainstreaming.
Export industries such as fisheries will also be affected due to the pollution.
Coastal areas are also at risk of being inundated, flooding the homes of millions of
people living in low-lying areas. Droughts in 1999 and 2000 caused sharp declines
in water tables and dried up wetlands, severely degrading ecosystems. Although
Pakistan contributes least to global warming one 35th of the world’s average of
carbon dioxide emissions temperatures in the country’s coastal areas have risen
since the early 1900s from 0.6 to 1 degree centigrade largely due to the degradation
of the mangrove forest. Precipitation has decreased 10 to 15 per cent in the coastal
belt and hyper arid plains over the last 40 years while there is an increase in
summer and winter rains in northern Pakistan. The level of air pollution in
Pakistan’s large cities is estimated to be 20 percent higher than international
standards.
Climate Change Cost Pakistan $3.5 Billion in 18 Years:
Climate change in South Asia has impacted on Pakistan a loss of around $3.57
billion over the past 18 years, according to a World Bank report. The report alarms
Pakistan of the existence of five major risks related to climate change/global
warming and potentially risking half of the country’s population.
The report, released on Tuesday (December 08, 2009), warns of disasters in five
main areas: rise in sea level, glacial retreat, floods, higher average temperatures,
and high frequency of droughts. Around 23% of the country’s land and nearly 50%
of the entire population is vulnerable to the damage resulting from these potential
disasters. To stop an increase in harmful carbon emissions that contribute to
climatic disasters, Pakistan and other South Asian countries need to formulate and
implement clean technology policies and turn to environment-friendly energy
resources.
Pakistan has huge reserves of coal that are used for running several industries on
local scale in many areas. But emissions from coal persistently threaten the
atmosphere with emissions that lead to escalating the greenhouse effect. The
World Bank report mentions the Bank’s interest in developing hydropower
capacity in Pakistan and Nepal. Also, it is suggested to import natural gas from the
Middle East for industrial use instead of using coal, in order to protect the country
from climate-related disaster.
