全球变暖global warming
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Global Warming
Introduction
Global warming refers to an unequivocal and continuing rise in the average temperature of Earth's climate system. Since 1971, 90% of the warming has occurred in the oceans. Despite the oceans' dominant role in energy storage, the term "global warming" is also used to refer to increases in average temperature of the air and sea at Earth's surface. Since the early 20th century, the global air and sea surface temperature has increased about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Each of the last three decades has been successively warmer at the Earth's surface than any preceding decade since 1850.
Methane
Ozone
Greenhouse Gases
The Burning of Fossil Fuels
Land Use Change: Deforestation
Fossil fuel burning has produced about three-quarters of the increase in CO2 from human activity over the past 20 years. Estimates of global CO2 emissions in 2011from fossil fuel combustion, including cement production and gas flaring, was 34.8 billion tones, an increase of 54% above emissions In 1990. Coal burning was responsible for 43% of the total emission, oil 34%, gas 18%,Cement 4.9% and gas flaring 0.7%.
7
Changes in land use, particularly deforestation caused almost one fourth of the increase. Plants remove carbon in the form of carbon dioxide from the atmosphere during the process of photosynthesis, but release some carbon dioxide back into the atmosphere during normal respiration. Only when actively growing can a tree or forests remove carbon. Both the decay and burning of the wood release much of this stored carbon back to the atmosphere. Therefore, deforestation is one of the major causes of the enhanced greenhouse effect. 9
Main Effects
Glacier Retreat
Sea Level Rise
Reduce the Diversity of Animals and Plants
Glacier Retreat
Sea Level Rise
How to Face Global Warming
I. Take effective actions to prevent global warming • Reduce the emissions of greenhouse gases (such as energy conservation, increased energy efficiency, and satisfying more of society's power demands with renewable energy and nuclear energy sources) • Enhance natural sinks (such as reforestation)
II. International Cooperation
Βιβλιοθήκη Baidu
Thank you!
Main Cause: Greenhouse Gases
• Scientific understanding of the cause of global warming has been increasing. In its fourth assessment (AR4 2007) of the relevant scientific literature, the International Panel on Climate Change (IPCC) reported that scientists were more than 90% certain that most of global warming was being caused by increasing concentrations of greenhouse gases produced by human activities. In 2010 that finding was recognized by the national science academies of all major industrialized nations. Affirming these findings in 2013, the IPCC stated that the largest driver of global warming is carbon dioxide (CO2) emissions from fossil fuel combustion, cement production, and land use changes such as deforestation.
Greenhouse Gases
Water Vapor
36-70% of the greenhouse effect
Major Greenhouse Gases
Carbon Dioxide
9-26% of the greenhouse effect
4-9% of the greenhouse effect 3-7% of the greenhouse effect
Introduction
Global warming refers to an unequivocal and continuing rise in the average temperature of Earth's climate system. Since 1971, 90% of the warming has occurred in the oceans. Despite the oceans' dominant role in energy storage, the term "global warming" is also used to refer to increases in average temperature of the air and sea at Earth's surface. Since the early 20th century, the global air and sea surface temperature has increased about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. Each of the last three decades has been successively warmer at the Earth's surface than any preceding decade since 1850.
Methane
Ozone
Greenhouse Gases
The Burning of Fossil Fuels
Land Use Change: Deforestation
Fossil fuel burning has produced about three-quarters of the increase in CO2 from human activity over the past 20 years. Estimates of global CO2 emissions in 2011from fossil fuel combustion, including cement production and gas flaring, was 34.8 billion tones, an increase of 54% above emissions In 1990. Coal burning was responsible for 43% of the total emission, oil 34%, gas 18%,Cement 4.9% and gas flaring 0.7%.
7
Changes in land use, particularly deforestation caused almost one fourth of the increase. Plants remove carbon in the form of carbon dioxide from the atmosphere during the process of photosynthesis, but release some carbon dioxide back into the atmosphere during normal respiration. Only when actively growing can a tree or forests remove carbon. Both the decay and burning of the wood release much of this stored carbon back to the atmosphere. Therefore, deforestation is one of the major causes of the enhanced greenhouse effect. 9
Main Effects
Glacier Retreat
Sea Level Rise
Reduce the Diversity of Animals and Plants
Glacier Retreat
Sea Level Rise
How to Face Global Warming
I. Take effective actions to prevent global warming • Reduce the emissions of greenhouse gases (such as energy conservation, increased energy efficiency, and satisfying more of society's power demands with renewable energy and nuclear energy sources) • Enhance natural sinks (such as reforestation)
II. International Cooperation
Βιβλιοθήκη Baidu
Thank you!
Main Cause: Greenhouse Gases
• Scientific understanding of the cause of global warming has been increasing. In its fourth assessment (AR4 2007) of the relevant scientific literature, the International Panel on Climate Change (IPCC) reported that scientists were more than 90% certain that most of global warming was being caused by increasing concentrations of greenhouse gases produced by human activities. In 2010 that finding was recognized by the national science academies of all major industrialized nations. Affirming these findings in 2013, the IPCC stated that the largest driver of global warming is carbon dioxide (CO2) emissions from fossil fuel combustion, cement production, and land use changes such as deforestation.
Greenhouse Gases
Water Vapor
36-70% of the greenhouse effect
Major Greenhouse Gases
Carbon Dioxide
9-26% of the greenhouse effect
4-9% of the greenhouse effect 3-7% of the greenhouse effect