B1b 8 How people

busyicicleMechanics

Feb 22, 2014 (3 years and 8 months ago)

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B1b 8 How people
affect the planet

8.1 The effects of the population
explosion

Learning objectives


Understand the effect that a growing population
has on our planet

New arrivals


How many people on
Earth?


240 per minute


Less than a million years


Massive effect on every
aspect of the planet

Population growth


1000’s years


low population


All of human history up to the early 1800s for
world population to reach 1 billion


1960 = 3 billion


World now gains 1 billion people every 11 years

Why is it happening?


Natural predators


Lack of food


Waste products


Disease


Top of food chain


Grow your own


Land fill


Cures and treatment


Increased numbers of people


Increased standard of leaving

Effect on resources


People need land


Housing


Industry


Infra
-
structure


Farming


Billions of acres


Crops and animals


Quarrying


Stone, ores and precious
stones



Destroys natural habitats


Wipes out species


Less land available


Raw resources used up


Not replaced

Pollution


Bodily waste, packaging, uneaten food,
disposable goods


land fill


Land cannot be used


Water pollution


Toxic chemicals


Fertilisers and herbicides


Metals


Water pollution


Learning outcomes


Human population is expanding extremely
rapidly


Using more resources than are being produced


Massive effect on natural habitats


1.
How has our standard of living increased?

2.
In what ways are habitats destroyed?

B1b 8 How people
affect the planet

8.2 Acid rain

Learning objectives


Understand how acid rain is formed


Know the effects acid rain has on the
environment

Fossil fuels


Stored carbon from atmosphere


Taken in during photosynthesis


Fossilisation


coal, oil and gas


Burning fossil fuels

Carbon + oxygen


carbon dioxide


Also release other chemicals


Sulphur


Oxides of nitrogen from cars

What’s the chemistry?

Sulphur dioxide
from volcanoes

Carbon dioxide
and sulphur
dioxide from
power stations

Oxides of nitrogen

S

O

O

H

H

O

S

O

O

H

H

O

Sulphur dioxide + water sulphurous acid

Formation of acid rain



Effects of acid rain


Strong acid speeds up chemical
weathering of rocks and buildings


Rivers, lakes and streams


become more acidic


animals and plants cannot survive


Soil that becomes more acidic


less nutrients so trees and other
plants cannot grow


damages trees by breaking down the
waxy coating of leaves.

Cleaning up our act


Reduce gases


catalytic convertor


Gases travel over transition metals


Gases react




Power stations react sulphur gases with quicklime


Flue gas desulphurisation


Scrubbing

Carbon monoxide + nitrogen oxides


carbon dioxide + nitrogen

Learning outcomes


Burning fossil fuels releases sulphur and
nitrogen compounds in gases


Acid rain formed by dissolving these gases


Acidifies water, destroys plant life and
damages buildings


1.
How does acid rain damage trees?

2.
Why does acid rain often effect ‘clean’
countries?

B1b 8 How people
affect the planet

8.3 Global warming

Learning objectives


How do combustion and living things affect our
atmosphere


What are the consequences of global warming

Greenhouse effect


Past few hundred
years


gradual
average increase


Global warming


What’s the problem?


Increases energy in
atmosphere


More turbulent


Storms, floods,
droughts

gas

greenhouse gas?

carbon dioxide

methane

CFCs

ozone

nitrogen oxide

yes

yes

yes

yes

yes

Greenhouse gases


Greenhouse gases


reflect infrared radiation
back at Earth


Effects of global warming


Global warming causes climate change


Temperature


Some areas hotter, some colder


Costal flooding


Sea levels rise as increase in temperature causes glacial melt


Plants


Some crops may grow better, some won’t


Rainfall


Some areas will become wetter, some drier

Deforestation


Large scale for timber and farmland


200, 000 square miles per year (twice UK)


2.5 acres per second


130 species per day


Slash and burn = increased carbon dioxide


Decaying vegetation = increased carbon dioxide


Carbon sink no longer available


No carbon cycle = increased carbon dioxide

Cows, rice and methane


Methane


major greenhouse gas


increasing


Rice paddy fields


Swampy conditions


release methane


Flatulent cows


1.5 million


500 litres of methane a day

In the atmosphere
is a layer of

greenhouse

gases.

Light from sun warms the
Earth

The warm Earth gives off
infrared radiation.

Some infrared radiation
escapes back into space

Some infrared radiation
is reflected back by the
greenhouse gases. This
makes the Earth
warmer than it would be
without the greenhouse
gases
.

Learning outcomes


Greenhouse effect is causing an increase in average
global temperatures


affect climate


Large
-
scale deforestation contributes to problem


Methane form cows and rice production


1.
Why are the number of rice fields and cows
increasing?

2.
How is deforestation increasing carbon dioxide?



B1b 8 How people
affect the planet

8.4 Sustainable development

Learning objectives


Understand what sustainable development is


Know ways we can conserve energy

Sustainable development


Human progress =
environmental stability


Conserving natural
resources


Improves quality of life


Reduce risk to future
generations

What can we do?


Farming


Reuse plant remains


No fertilisers


Animal waste


Replant hedgerows


Avoid erosion


Woodland


Needed for paper


Less trees than other
countries


Forestry Commission



Replace trees felled


Fishing


Fish cannot maintain population


Cod are endangered


Must reduce amount caught


Fisherman stick to quota

Conserving resources


Reduce, re
-
use, recycle


Newspapers


trees


Glass


energy


Aluminium


ore and energy


Energy efficiency


Insulation and new technology


Less transport


Public transport (less fossil fuel)


Walk or cycle (no fossil fuels)

Learning outcomes


Sustainable development = improving quality of
life without compromising future generations


Using natural resources


Reduce, reuse, recycle



B1b 8 How people
affect the planet

8.5 Planning for the future

Learning objectives


Understand hw pollution can be monitored


Know why we need to plan

Developed World


1
st

world = Few people using loads of resources


3
rd

world = Loads of people using few resources

Making decisions


Sustainable development


impact of building
needs to be considered


Field studies


show impact


Look at similar impact elsewhere


Air quality


Lichen


Water quality


invertebrates


Cleaner = more species


Impact can be assessed


decisions made

Brown or Green?


Need more houses


where to build them


Green field








Both have advantages and disadvantages




Brown field

SSSI’s


Sites of Special Scientific
Interest


Unique landscape


Rare species


Migration or breeding
ground


Protected by law


similar schemes all
around the world

Learning outcomes


Why are field studies important for sustainable
development?


What is the difference between brown and green
field sites?


Why should we not build on SSSI’c