Climate change , causes, impacts and solutions.pptx

this topic is prepared from millers book titled "living in the environment".

1. Climate change Presented by: Faisal Sadiq Roll No. 266 Class: BS 7th semester Subject: Environmental Biology

2. Whether: short-term changes in atmospheric variables in a given area over a period of hours or days, such as T emperature Precipitation Wind Pressure Climate: average weather conditions of the earth or of a particular area over a long period of time ranging from decades and centuries to thousands of years.

3. The earth’s climate is affected by

4. For the past 1,000 years, the average temperature of the atmosphere has remained fairly stable but began to rise after industrial revolution Climate change

5. Natural Greenhouse Effect About 1% of the earth’s lower atmosphere is composed of greenhouse gases,

6. Evidences of climate change since 1906, the average global surface temperature has risen by about 0.74 C° Annual greenhouse gas emissions rose 70%. , glaciers are melting During the 20th century, the world’s average sea level rose by 19 centimeters

7. Factors affecting atmospheric temperature CO2 Emissions It plays an important role in determining the average temperature of the atmosphere . concentration of CO2 rose from 285 parts per million (1850), to 389 ppm in 2010. 450 ppm is an estimated threshold, or irreversible tipping point , that could lead to an irreversible climate change . Burning of fossils deforestation

8. Since the Industrial Revolution C arbon dioxide rose from a level of 280 ppm to 389 ppm in 2010. methane (CH4): ___________ 70% Agriculture Nitrous oxide ( N2O) _________20 % use of nitrogen fertilizers. has 298 times the warming potential than CO2.

9. Role of ocean: The world’s oceans absorb CO2 from the atmosphere( 25–30% ) The ability of the oceans to absorb CO2 also decreases when water temperatures increase. Increasing levels of CO2 in the ocean have increased the acidity A cidity threatens corals phytoplankton ocean food webs

10. Effects of Cloud Cover The role played by clouds is quite uncertain . Warmer temperatures increase evaporation of and create more clouds, which can cool or warm the atmosphere thick cumulus clouds could decrease temperature by reflecting more sunlight back into space . thin, cirrus clouds could increase temperature by preventing heat from escaping into space.

11. Air Pollution air pollution from human activities has slowed the rate of atmospheric warming. Aerosols released by volcanic eruptions and human activities such as sulfate particles tend to reflect incoming sunlight and cool the lower atmosphere . Also serve as a condensation nuclei that form cooling clouds But since such pollution kills more than 800,000 people a year

12. Impacts of climate change Severe Drought when evaporation exceeds precipitation for a prolonged period. southern Australia western United States wildfires increase Dessert expansion Water crises declining biodiversity

13. Ice and Snow Melt Light-colored ice and snow help to cool the earth by reflecting incoming solar energy glaciers store water as ice during cold wet seasons and releasing it slowly to streams during warmer dry seasons.

14. Permafrost Is Likely to Melt The amount of carbon locked up as methane (CH4) in permafrost soils is 50–60 times the amount emitted as carbon dioxide from burning fossil fuels each year If the permafrost melts, significant amounts of CH4 and CO2 will be released

15. Sea Levels Are Rising Degradation of at least one-third of the world’s coastal estuaries, wetlands, and coral reefs. Disruption of many of the world’s coastal fisheries. Flooding of agricultural lowlands and deltas in coastal areas where much of the world’s rice is grown. Bangladesh . Saltwater contamination of coastal aquifers Submersion of low-lying islands

16. Extreme Weather atmospheric warming will increase the incidence of extreme weather events . As a warmer atmosphere can hold more moisture, some areas will experience severe droughts and heat waves and other will face other increased flooding from heavy and prolonged snow or rainfall Threat to Biodiversity

17. Agriculture problem Farming, probably more than any other human activity, depends on a stable climate. Thus, farmers will face dramatic changes due to shifting climates

18. Health issues Prolonged heat waves will increase numbers of deaths and illnesses, especially among older people, people in poor health, and poor who cannot afford air conditioning . A warmer, CO2-rich world will be a great place for rapidly multiplying insects, microbes, toxic molds, and fungi that make us sick,

19. Solutions Reduce Greenhouse Gas Emissions reduce fossil fuel use, especially use of coal is 80 % of the solution Shift from nonrenewable carbon-based fossil fuels to a mix of low-carbon renewable energy resources. Stop cutting forests and plant trees which remove CO2 from the atmosphere. Shift to more sustainable and climate-friendly agriculture.

20. To manipulate certain natural conditions to help counter an enhanced greenhouse effect . scientists have suggested to inject sulfate particles into the stratosphere. Some scientists reject the idea of launching sulfates into the stratosphere as being too risky because of our limited knowledge about possible unknown effects. Geo-engineering

21. Governments actions regulate carbon dioxide and methane as air pollutants. phasing in carbon taxes on each unit of CO2 or CH4 emitted by fossil fuel use subsidies to businesses to encourage their use of energy- efficiency technologies, low-carbon renewable energy sources, and more sustainable agriculture.