Earth formed 4.6 billion years ago and originally had a hot climate without life. Photosynthesis began over 3 billion years ago which produced oxygen and removed greenhouse gases, leading to cooling periods. Around 3 million years ago, Earth began cycles of glacial and interglacial periods. Global greenhouse gas emissions are rising, with China and the US being the top two emitters. The evidence of rapid climate change includes increased global temperatures, rising sea levels, shrinking ice sheets, and ocean acidification.

2. History of Earth’s Climate
• Earth formed ~4.6 billion years ago
• Originally very hot
• Sun’s energy output only 70% of present
• Liquid water present ~4.3 billion years
• Life appeared ~3.8 billion years ago
• Photosynthesis began 3.5-2.5 billion years ago
– Produced oxygen and removed carbon dioxide and methane
(greenhouse gases)
– Earth went through periods of cooling (“Snowball Earth”)
and warming
• Earth began cycles of glacial and interglacial periods
~3 million years ago

3. GLOBAL WARMING

5. Greenhouse gases

6. COUNTRY GHG EMISSION IN MT % GLOBAL TOTAL
WORLD 45261.2517 100 %
CHAINA 11735.0071 25.93
US 3526.2589 11.87
EUROPIAN UNION 4224.5217 9.33
INDIA 2909.0566 6.43
RUSSIA 2199.117 4.86
JAPAN 1353.347 2.99
BRAZIL 1017.8745 2.25
countries by greenhouse gas emissions

8. Comparing energy sources in terms of their
global warming pollution.

9. Countries by Carbon Dioxide Emission

10. country CO2 emission in KT
In 2015
% CO2 emission by
country
Emission per capita
In T in 2015
WORLD 36,061,710 100 %
CHAINA 10,641,789 29.51% 7.7
US 5,172,336 14.34% 16.1
EUROPIAN UNION 3,469,671 9.62% 6.9
INDIA 2,454,968 6.81% 1.9
RUSSIA 1,760,895 4.88% 12.3
JAPAN 1,252,890 3.47% 9.9
GERMANY 777,905 2.16% 9.6
Countries by CARBON DIOXIDE Emission

11. CO2 Emission per Capita

12. The evidences of rapid climate change
1] Global temperature rise
The planet's average surface temperature has risen
about 2.0 degrees Fahrenheit (1.1 degrees Celsius)
since the late 19th century, a change driven largely by
increased carbon dioxide and other human-made
emissions into the atmosphere. Most of the warming
occurred in the past 35 years, with 16 of the 17
warmest years on record occurring since 2001.

14. 2] Warming Oceans
The oceans have absorbed much of this increased
heat, with the top 700 meters (about 2,300 feet) of
ocean showing warming of 0.302 degrees Fahrenheit
since 1969.

15. 3] Shrinking ice sheets
The Greenland and Antarctic ice sheets have decreased in
mass. Data from NASA's Gravity Recovery and Climate
Experiment show Greenland lost 150 to 250 cubic kilometers
(36 to 60 cubic miles) of ice per year between 2002 and 2006,
while Antarctica lost about 152 cubic kilometers (36 cubic
miles) of ice between 2002 and 2005.

16. Global sea level rose about 8 inches in the last century. The
rate in the last two decades, however, is nearly double that of
the last century.
4] Sea level Rise
5] Glacial Retreat
6] Decreased Snow Cover
7] Extreme Events

17. Since the beginning of the Industrial Revolution, the acidity of
surface ocean waters has increased by about 30 percent. This
increase is the result of humans emitting more carbon dioxide
into the atmosphere and hence more being absorbed into the
oceans. The amount of carbon dioxide absorbed by the upper
layer of the oceans is increasing by about 2 billion tons per
year.
8] Ocean Acidifications