1. Re-cap Greenhouse effect
Draw a diagram
What are GHG’s?
How does it cause warming?
Is it natural?

3. But many scientists do not
Greenhouse gases?
The 4 main greenhouse gases are:
CO2
Methane
Methan
CFCs
Nitrous Oxide
But many scientists do not
think it is purely this!

4. Global Warming What is global warming? Global warming is the rise in
Incoming solar radiation passes through the atmosphere (343 Watts/m²)
Net incoming solar radiation = 240 Watts/m²
103 Watts/m² of radiation is reflected by the atmosphere and Earth’s surface
The radiation that reaches the Earth’s surface is absorbed and the Earth’s surface is warmed. As a result, the earth emits long wave or infrared radiation into the atmosphere
The greenhouse gas molecules trap some of this infrared radiation and re-emit it back to the earth’s surface and warms it further. Added greenhouse gases as a result of anthropogenic activity cause more infrared radiation to be re-emitted, hence further warming.
Some of this infrared radiation is lost into the atmosphere (240 watts/m²)
What is global warming? Global warming is the rise in
temperature of the earth's atmosphere.
It's said that by the time a
baby born today is 80 years old,
the world will be 6 and a half
degrees warmer than it is now.
Global
Warming
Is global warming bad? The earth is naturally warmed by rays
(or radiation)
from the sun which pass through the
earth's atmosphere
and are reflected back out to space again.
The atmosphere's made up of layers of gases,
some of which are called 'greenhouse gases'.
They're mostly natural and make up a kind of
thermal
blanket over the earth.
This lets some of the rays back out of the
atmosphere,
keeping the earth at the right temperature
for animals, plants and humans to survive
(60°F/16°C).
What are the greenhouse gases? Greenhouse gases are made out of:
water vapour
carbon dioxide
methane
nitrous oxide
ozone
chlorofluorocarbons (CFCs)
They are all natural gases, but extra
greenhouses gases can
be made by humans from pollution.

5. How do we know the climate has changed?
The worlds climate has been changing over the last years, sometimes getting hotter and sometimes colder as you can see from the graph below.

6. Learning Objectives & Outcomes
Know – what an invasive species is
Understand – the impact invasive species have
Skills – explanation, comprehension, note taking D
Describe the evidence that can be collected as evidence of climate change
A*-A
Analyse the evidence for climate change to assess how reliable it is
B-C
Explain global warming and explain how evidence is used to show climate change

7. How do we know the climate has changed ?
The problem with global warming is that everyone agrees that it is happening, but there is fierce debate about how and why.
Many scientists believe that climate change is a result of the enhanced greenhouse effect

8. How do we know the climate has changed?
Find out what evidence there is to tell us about past climates.
You need to know how the method works and what is actually tells us about past climates

9. Plenary