Module 3: Main Content

Module 3: Main Content

1. Climate

   • Definition
     • Climate refers to the average weather conditions of a place over a long period of time
   • Hong Kong
     • Features
       • Subtropical
       • Monsoon
         • seasonal wind
     • Seasons
       • Spring
         • warm with moderate rainfall
         • humid wind from the Pacific Ocean
       • Summer
         • hot and humid
         • onshore SW monsoon from the sea
           • onshore: from sea to land
         • typhoons are common
       • Autumn
         • mild and dry
         • fine and stable weather
       • Winter
         • cool and dry weather
         • offshore NE monsoon from dry inland areas
           • offshore: from land to sea
   • Features
     • Seasonal temperature difference
       • High
       • No
       • Moderate
       • Low
     • Rainfall distribution
       • Even
       • Uneven

2. Weather

   • Definition
     • Weather is the condition of the atmosphere for a place over a short period of time

3. Climate change in Hong Kong

   • Situation
     • The annual mean temperature of Hong Kong has increased
     • The number of hot nights has increased and cold days has decreased
     • Both summer and winter have been getting warmer
   • Causes
     • Urban Development
       • Urban Heat Island Effect
         • Urban Heat Island Effect

4. Global warming

   • situation
     • The global average temperature has risen over the last century and the rate of increase has become faster in the recent decades
     • Change in rainfall varies from region to region. Some regions are likely to see increases in rainfall, while some regions are likely to experience decrease in rainfall
   • main cause
     • greenhouse effect
       • original function
         • natural process by which the atmosphere traps some of the energy from the sun, keeping the Earth warm enough to support life
       • ingredient
         • carbon dioxide
         • methane
         • nitrous oxide
       • operation
         • Greenhouse Effect
       • Problem
         • The amount of greenhouse gases in the atmosphere has become excessive and the rate of the greenhouse effect has become uncontrolled
         • Causes
           • human activities
             • burning of fossil fuels
               • Due to urban and industrial development, there is a rapid rise in the demand for power in the last century. Cars, factories, and power plants burn fossil fuels such as coal, oil, and natural gases to generate power.
             • deforestation
               • Trees have been cleared for farming or urban development. Fewer trees are available for absorbing carbon dioxide in the atmosphere.
             • more farming activities
               • The rise in world population led to the increase in demand for food.
               • fertilizers
               • cattle ranching
             • waste treatment
               • Creation of landfills often requires deforestation
               • Burning of waste
               • Waste disposed in the landfill
         • Effect
           • Melting of ice and rising sea level
             • As temperature rises, melting of ice occurs in the polar regions and on high mountains
             • Seawater expends with temperature. Together with the meltwater, the average sea level rises and floods coastal lowland
           • Changes in climate and more extreme weather events
             • Heat waves, cold spells, blizzards, stronger tropical cyclones, droughts and flooding will occur more often
           • Changes to ecosystem
             • Animals and plants may move and grow towards the polar regions because places previously too cold for them become warmer
             • Some wildlife species will become extinct when they cannot adapt to climate change. For example, polar bears may lose their habitat because of melting of ice
           • Disruption to human life
             • Some people may become climate refugees as rising sea levels will flood settlements in lowlands
             • Extreme weather conditions may destroy farmland and reduce food production
             • Reduction in size of glaciers means a decrease in fresh water supply
               • glaciers: 冰川
             • A warmer environment promotes more widespread of tropical diseases(1). More extreme weather conditions will trigger heat stroke or heart diseases(2)
               • 1: malaria, dengue fever 2: heat stroke
         • Solution
           • international
             • Set up intergovernmental organisations to gather experts from all over the world to discuss and conduct research on climate change
             • Sign agreements to set limits of greenhouse gas emission for each country
               • Kyoto Protocol and Paris Climate Agreement
             • Set up funding to help less developed countries to adopt greener technologies
           • national
             • Set regulations to meet targets agreed in international agreements
             • Develop renewable energy
             • Improve energy efficiency by encouraging public to save energy
             • Change laws to encourage less-polluting industries
             • Close factories and power plants that release too much greenhouse gases
             • Protect forests and plant more tree
           • individual
             • Change habit and lifestyle
             • Care about the issue of global warming
           • Others
             • adapt to changes brought by global warming
               • strengthen structure of buildings so that they are more resistant to storms and floods
               • Improve infrastructure to prepare for extreme weather events
               • Develop and grow crops that are more tolerant to changing climatic conditions