Global warming is defined as the increase in average surface temperatures on Earth over the past century due to greenhouse gas emissions. The main causes are the greenhouse effect trapping heat from the sun and human activities increasing greenhouse gases in the atmosphere. Effects include more extreme weather, rising sea levels, and disrupted ecosystems. While some nations have taken steps to reduce emissions, current trends show temperatures and impacts continuing to increase without serious global action on solutions to mitigate further warming and help societies adapt.

1. GLOBAL WARMING
Presented by:
Rashed Minhaz

2. Outline
• Global warming: Definition.
• Facts and Causes.
• Effects.
• Current situation.
• Solutions.
• Conclusion.

3. Global warming
• Global warming: The phenomenon of increasing
average air temperatures near the surface of
Earth over the past one to two centuries and its
related effects. Multiple lines of scientific
evidence show that the climate system is
warming.[Many of the observed changes since
the 1950s are unprecedented in the instrumental
temperature record which extends back to the
mid-19th century, and in paleoclimate proxy
records covering thousands of years

4. Climate change
• Global warming causes climate change. Not only
climate become chaotics but also natural
disasters occur frequently. Climate change
deniers have argued that there has been a
“pause” or a “slowdown” in rising global
temperatures, but several recent studies,
including a 2015 Paper published in the journal
Science, have disproved this claim. And scientists
say that unless we curb global-warming
emissions, average temperatures could increase
by up to 10 degrees Fahrenheit over the next
century.

5. Causes of global warming
• GREEN HOUSE EFFECT :The greenhouse effect is the process by which
absorption and emission of infrared radiation by gases in a planet's
atmosphere warm its lower atmosphere and surface. On Earth, an
atmosphere containing naturally occurring amounts of greenhouse
gases causes air temperature near the surface to be about 33 °C
(59 °F) warmer than it would be in their absence. Without the
Earth's atmosphere, the Earth's average temperature would be well
below the freezing temperature of water. The major greenhouse
gases are water vapour , which causes about 36–70% of the
greenhouse effect; carbon dioxaide(CO2), which causes 9–26%;
methane (CH4), which causes 4–9%; and ozone (O3), which causes
3–7%. Clouds also affect the radiation balance through cloud
forcings similar to greenhouse gases. Human activity since the
Industrial Revolution has increased the amount of greenhouse
gases in the atmosphere

6. Causes of global warming
• Global warming occurs when carbon dioxide and
other air pollutants and greenhouse gasses
collect in the atmosphere and absorb sunlight
and solar radiation that have bounced off the
earth’s surface. Normally, this radiation would
escape into space—but these pollutants, which
can last for years to centuries in the atmosphere,
trap the heat and cause the planet to get hotter.
That's what's known as the greenhouse effect. It
is the main cause of global warming.

7. Causes of global warming
• Aerosols and soot: Global dimming, a gradual reduction in the
amount of global direct irradiance at the Earth's surface, was
observed from 1961 until at least 1990. Solid and liquid particles
known as aerosols, produced by volcanoes and human-made
pollutants, are thought to be the main cause of this dimming.
• Solar activity: Since 1978, solar irradiance has been measured by
satellites. These measurements indicate that the Sun's radiative
output has not increased since then, so the warming that occurred
in the past 40 years cannot be attributed to an increase in solar
energy reaching the Earth.
• Variations in Earth's orbit: The tilt of the Earth’s axis and the shape
of its orbit around the Sun vary slowly over tens of thousands of
years. This changes climate by changing the seasonal and latitudinal
distribution of incoming solar energy at Earth's surface.

8. Effects of Global warming
• Scientists agree that the earth’s rising temperatures are fueling
longer and hotter heat waves, more frequent droughts, heavier
rainfall, and more powerful hurricanes. The earth’s ocean
temperatures are getting warmer, too—which means that tropical
storms can pick up more energy. So global warming could turn a
category 3 storm into a more dangerous category 4 storm. In fact,
scientists have found that the frequency of North Atlantic
hurricanes has increased as well as the number of storms that reach
categories 4 and 5. The impacts of global warming are being felt
across the globe. Extreme heat waves have caused tens of
thousands of deaths around the world in recent years. And in an
alarming sign of events to come, Antarctica has been losing about
134 billion metric tons of ice per year since 2002. This rate could
speed up if we keep burning fossil fuels at our current pace, some
experts say, causing sea levels to rise several meters over the next
50 to 150 years.

9. Effects of Global warming
Each year, scientists learn more about the consequences of global warming,
and many agree that environmental, economic, and health consequences are
likely to occur if current trends continue. Some of these possible effects are:
• Melting glaciers, early snowmelt, and severe droughts will cause more
dramatic water shortages and increase the risk of wildfires.
• Rising sea levels will lead to coastal flooding.
• Forests, farms, and cities will face troublesome new pests, heat waves,
heavy downpours, and increased flooding. All those factors will damage or
destroy agriculture and fisheries
• Disruption of habitats such as coral reefs and Alpine meadows could drive
many plant and animal species to extinction.
• Allergies, asthma, and infectious disease outbreaks will become more
common due to increased growth of pollen-producing ragweed, higher
levels of air pollution, and the spread of conditions favorable to pathogens
and mosquitoes.

10. Current Situation
• The current weather situation can be
described in the following graph.

11. Current Situation
• In recent years, China has taken the lead in global-
warming pollution, producing about 28 % of all carbon
dioxide emissions. The United States comes in second.
News articles like “Change will continue through this
century and beyond”, “Temperatures will continue to
rise”, “Frost-free season (and growing season) will
lengthen”, “Changes in precipitation patterns”, “More
droughts and heat waves”, “Hurricanes will become
stronger and more intense”, “Sea level will rise 1-4
feet by 2100” are common.This is also a fact that the
current situation are going to lead us to a disasterous
situation.

12. Solutions
• Because we are already committed to some level of climate
change, responding to climate change involves a two-
pronged approach:
• Reducing emissions of and stabilizing the levels of heat-
trapping greenhouse gases in the atmosphere
(“mitigation”).It can be done by either either by
reducing sources of these gases or enhancing the sinks that
accumulate and store these gases.
• Adapting to the climate change already in the pipeline
(“adaptation”). The goal is to reduce our vulnerability to
the harmful effects of climate change. It also encompasses
making the most of any potential beneficial opportunities
associated with climate change

13. Solutions
• Government policies are major factor in this regard. Because some head
of the nations does not care about the global warming. They call it a
hoax.They are the greatest obstacle for the climate activitists. Most
countries in the world are parties to the United Nations Framework
Convention on Climate Change(UNFCCC). The ultimate objective of the
Convention is to prevent dangerous human interference of the climate
system. As stated in the Convention, this requires that GHG concentrations
are stabilized in the atmosphere at a level where ecosystems can adapt
naturally to climate change, food production is not threatened, and
economic development can proceed in a sustainable fashion.The
Framework Convention was agreed in 1992, but since then, global
emissions have risen. If the world leaders can not come to an solution, the
anti-climate activity can not be stopped also the the activity to protect the
world from global warming will be hindered.Before China was against the
activity but now they agree with the situation. On the otherhand the
present president of America tells that all of these are hoax.

14. Conclusion
• Global warming will effect the world as a
whole. It is just that some will suffer more and
some will less. The future will become
unhabitable due to this. It is not wise to not
take necessary steps to prevent global
warming even knowing the situation that the
global warming will bring. Some necessary
steps may save us from the catastrophe that
global warming can possibly cause. As we
know prevention is better than cure.