Geography 2EX G7 CH3

What are compass points?

N, NNE, NE, ENE, E, ESE, SE, SSE ,S, SSW, SW, WSW, W, WNW, NW, NNW

Whole circle bearing

Degrees measured from clockwise

Reduced bearing

N-1-90*

E-1-90*

S-1-90*

W-1-90*

Greenhouse effect

A greenhouse allows sunlight to enter but prevents some of the heat from leaving. The trapped heat warms the greenhouse. Making the temperature inside higher than that of the outside

How the greenhouse effect works

Water vapour, CO2, CH4 are greenhouse gases

They absorb and trap heat within the atmosphere, keeping the earth warm for the living things to survive

Since when has the greenhouse enhanced

Since the 18th century human activities have released large amounts of greenhouse gases into the atmosphere. Enhancing the greenhouse effect.

Global warming

Increasing concentrations of greenhouse gases trap more heat, leading to a rise in global heat

What will happen if the temperature rise continues

long term climatic changes

What is climate change

Significant long term changes in climatic patterns

The cause of climate change

Natural process, largely caused by the increasing emissions of greenhouse gases from human activities

Describe the future global mean temperature

Likely to rise by 1.5 degrees Celsius

High latitude regions may experience larger increase compared with the tropical regions

Describe the future change in the global rainfall pattern

Become more extreme with larger regional differences.

High latitude regions may receive more rainfall

Extreme rainfall events may also become more intense and occur more frequently

Examples of fossil fuels

They are coal oil and natural gas

How do fossil fuels harm the environment

The extraction and burning of fossil fuels emit al lot of greenhouse gases

What are fossil fuels usually used for?

They are mostly used for transportation and power generation.

State three different sources of farming activities

1. Opening up farmland

2. Pastoral farming

3. Use of chemical fertilisers

Opening up farmland

Trees are carbon sinks as they absorb and store CO₂ through photosynthesis. However they have been cut down for more farmland. There are fewer trees to absorb CO₂. Farmers tend to increase fertility by burning vegetation. This also releases CO₂ into the environment.

Pastoral farming

Commercial pastoral farming emits large quantities of CH₄ and N₂O. In cattle rearing, CH is produced when cattle digest their food. The decomposition of their manure also releases methane and N₂O. Of which methane and N₂O are more powerful greenhouse gases that can trap more heat than CO2

Use of chemical fertilisers

Farmers often use a lot of chemical fertilisers to increase soil fertility. However, when these fertilisers decompose, they release N₂O, which adds more greenhouse gases to the atmosphere.

State two types of industrial activities that are the major causes of climate change

1. Cement production

2. Refrigerant and aerosol production

Cement production

It is the major greenhouse gas emitter in the world. Cement is widely used as a building material and its demand has greatly increased due to rapid urban and industrial development;. However, the production of cement releases large amounts of CO2

Refrigerant and aerosol production

The production of refrigerants and aerosols produce chlorofluorocarbons (CFC). CFCs are man-made greenhouse gasses that are powerful heat absorbers. CFCs have been phased out today, they will remain within the atmosphere and keep enhancing the greenhouse effect in the near future.

Waste treatment

Billion tonnes of waste are produced worldwide because of urban development and population growth. Currently landfilling and incineration are the major ways of waste treatment. However both methods give off a lot of CO2. CH4 is also produced in landfills when waste decomposes.

Causes of climate change in Hong Kong

1. Increase in local emissions

2. Increase in regional emissions

Increase in local emissions

Most of our greenhouse gases come from coal and natural gas for power generation. Which accounts for more than half of the total emissions.

Transport is the second biggest source of greenhouse gases. The heavy flows of people and goods, as well as the growing number of cars consume huge amounts of fossil fuels and produce a lot of greenhouse gases

Increase in regional emissions

Rapid urban and industrial development have taken place in the zhujiang region since the 1980s. The increase in population, factories, power plants and cars resulted in huge emissions of greenhouse gases, causing climate change in the region.