1. Youth Unit: Let’s LEARN!
What is climate change?

3. Overview
Introduction
What causes climate change?
Hazards and impacts

4. Top Tips! Test what you’ve learnt afterwards with the
Climate Change Quiz
For a fun way to learn what climate change is try
Y-Adapt Session 2

5. Introduction

6. Weather
Weather refers to conditions like rain, temperature and wind over hours to days
LOOK out the window now. What is the weather like?

7. Climate
Climate refers to average weather conditions over a long period of time (30+ years)
THINK about what the weather is normally like on your birthday? - Is it normally dry or wet / hot or cold?

8. Climate change
Climate change is a statistically significant change in the state of the climate (average weather) that persists for an extended period of time (decades or longer)
ASK an elder what the weather was normally like 30 years ago, in your birthday month? Has it changed?

9. What causes climate change?

10. The greenhouse effect Sunlight passes through the atmosphere to earth
At earth’s surface it’s reflected back through the atmosphere to space
However! After it is reflected, greenhouse gases can trap heat in the atmosphere
We call this process the greenhouse effect; as it is similar to a greenhouse
Greenhouse gases act like a big blanket around the earth, trapping heat
Can anyone explain this?

11. Greenhouse gases
Greenhouse gases trap heat from the sun in the atmosphere, after it is reflected from earth
Greenhouse gases occur naturally in the atmosphere
Without them, the earth would be very cold – about minus 18°C ! All water on earth would freeze, the oceans would turn to ice and life as we know it would not exist
Major greenhouse gases are shown in the blue box

12. Human activity
Over the last 100 years, since the industrial revolution, greenhouse gases have rapidly increased in the atmosphere
This is due to human activities which release greenhouse gases
Electricity from coal or diesel generators and industry or pollution from factories contribute the most

13. Global warming
More greenhouse gases trap more heat in the atmosphere, leading to global warming
Since 1880, global temp has increased by almost 1°C
How much this rises depends on how much more greenhouse gas is released
Temp could rise by almost 5°C by 2100 (IPCC, AR5). However, countries around the world agreed to keep this below 2°C 
Humans have added so much greenhouse gas to the atmosphere, that even if all emissions stopped today, the planet would still continue to warm for decades to come

14. 1°C or 2°C warmer sounds small?
1°C or 2°C - might not sound like much, but think about what happens when your body temperature is increased by 1 or 2 degrees?
You would immediately fall sick and get a fever

15. Global warming & the water cycle
Global warming intensifies the water cycle
Higher temps increase evaporation of water from sea, lakes, rivers
Warmer air holds more water vapour, resulting in more intense rainstorms. This can lead to flooding
More floods where water runs off into rivers and streams, does little to dampen the soil. This and increased temps can lead to drought  
Weather patterns across the world are effected over time
This results in CLIMATE CHANGE
THE WATER CYCLE
The earth has a limited amount of water. It keeps going around in what we call the “Water Cycle”:
The sun heats water in rivers, lakes or the ocean. Water EVAPORATES becoming water vapour.
The vapour rises into the air. When it reaches the colder atmosphere it CONDENSES to form clouds.
As more water vapour collects in the clouds, the clouds become heavier. When they can't hold the water vapour, water falls back from the clouds back to Earth as PRECIPITATION - such as rain, hail or snow.
The precipitation COLLECTS in the oceans, lakes or rivers, or may end up on land.
We know that changes in the water cycle are increasing the risks of floods and droughts (climaterealityproject).

16. Hazards and impacts

17. Climate change, hazards & impacts
Climate Change is exacerbating a range of weather related hazards around the world
Climate change makes some hazards more frequent
Climate change makes some hazards more intense
These hazards impact people around the world
The same hazard can have different impacts for different people – see Let’s Act to find out more

18. Scientists project: Temperature increase (0.3 – 4.8°C by 2100)
Heat waves - more often and last longer
Extreme precipitation events (rain, snow)
- more often and more intense
Precipitation increases in wet regions
Precipitation decreases in dry regions
Increase in tropical cyclone wind speeds
Decreased snow / ice extent
Rising sea level
Warming and acidification of oceans
What do you think that scientists project?
Temperature increase range shows projected increase of global mean surface temperature by the end of the 21st century (2081–2100) relative to 1986–2005, depending on how much greenhouse gas emissions are reduced
Source: IPCC 2014, AR5

19. Here are some climate & weather events impacted by climate change
Can you guess which hazards & impacts they might relate to?

20. Changing seasons Rainy season may be delayed in some regions
CHANGINE SEASONS
HAZARDS
Rainy season may be delayed in some regions
Spring might come earlier in other regions
Seasons may become more intense
IMPACTS
Crops may die
Farmers may need to change crops
Incomes are lost
Transportation is interrupted
Financial losses
Water availability
Today, climate change is leading to shifts in what seasons used to look like. Spring might come earlier in some parts of the world. Rainy seasons are delayed in other parts. Seasons are getting more extreme too. This is predicted to worsen in the future.
Changing seasons affect farmers. For example if the rainy season is delayed, crops already planted might fail. Farmers might need to change crops to those that grow better to keep up with the new climate conditions.
Changing seasons also affect fresh water availability. In the Northern Hemisphere, an earlier spring causes earlier peaks in snow melt and river flows. This means less water is available in the summer and autumn when demand is often highest (Earth observatory (2017)).

21. Drier & longer droughts
HAZARDS
Water shortage
Wind erosion
Desertification
Increased risk of wild fires
IMPACTS
Less or no crops
Animals may die
Less water supply
Incomes are lost
Financial losses
People become sick
Migration
Droughts have been drier and lasting longer in recent years thanks in part to climate change. Higher temperatures increasing evaporation combined with less rain causes can cause more drought.
Droughts can be devastating to the environment. But droughts also have serious consequences for people’s livelihoods. They really affect farmers, but also the water supply and people's health.
Over the longer term some crops and animals will not be able to survive the drier conditions. Farm workers and their families may have to migrate.

22. Increased temperatures & heat waves
HIGH TEMP & HEAT WAVES
HAZARDS
Heat stroke
Water shortage
Increased malaria
Dengue
Sea level rise
IMPACTS
People get sick or die
Animals get sick
Crops may die
Food shortage
Damaged forests
The 10 hottest years ever recorded have all occurred since The hottest year on record is It broke the record set in 2015, which itself broke the record setting 2014 (climatecentral, 2017).
A long period of unsusually hot weather can cause illness that is especially dangerous to the elderly, small children and sick people. Exposure to the sun could result in fainting, heat exhaustion and heat stroke.One of the worst heat wave was recorded in the year 2003 when more than 70,000 Europeans died .
Another risk related to warming is that mosquitoes like heat! They can fly faster, bite more, breed faster and move into new areas that used to be to cold for them. Mosquitoes can carry diseases.

23. Melting glaciers & polar ice
HAZARDS
Sea level rise
Less ice to reflect sunlight, leads to increased warming
IMPACTS
Flooding in low lying coastal areas
Coastal areas & cities threatened
Loss of wildlife / biodiversity
Water can soak up a lot of heat. When the oceans get warmer, sea ice begins to melt in the Arctic and around Greenland. NASA's satellites show us that every summer some Arctic ice melts and shrinks, getting smallest by September. Then, when winter comes, the ice grows again.
But, since 1979, the September ice has been getting smaller and smaller and thinner and thinner in the Arctic this now decreases 13% every 10 years! (NASA, 2017).
Glaciers are another form of melting, shrinking ice. Glaciers are frozen rivers. They flow like rivers, only much slower. Lately, they have been speeding up (NASA kids, 2017).
As more sea ice and glaciers melt, the global sea level rises.

24. Sea level rise SEA LEVEL RISE HAZARDS IMPACTS
Sea level has risen 17 cm in the last 100 years.
In the last 10 years, it has risen twice as fast as in the previous 90 years
IMPACTS
Coastal erosion
Higher risk of storms leading to coastal flooding
Salt water intrusion in coastal areas – impacts drinking water and health risks such as diarrhoea
As the ocean gets warmer, the water actually expands! Sea level has risen 17 centimetres in the last 100 years. In the last 10 years, it has risen twice as fast as in the previous 90 years (NASA kids, 2017).
One immediate risk of sea level rise is that with every storm there is a higher risk of coastal flooding.
Another risk is that a rise in sea level causes salt water intrusion in coastal areas. This can cause problems for drinking water and can lead to more cases of diarrhoea.
Sea levels are projected to continue rising. The rate is expected to be even faster, with some predictions up to 8-16 mm per year.

25. More intense rainfall & increased likelihood of floods
HAZARDS
Flooding
Flash floods
Landslide
Erosion
IMPACTS
Vector-borne diseases (esp. malaria and dengue fever)
Water-borne diseases (esp. diarrhoea)
Extreme floods and population displacement
Higher temperatures are leading to more intense rainstorms. This is because of increased evaporation of water from the sea, lakes and rivers and because warmer air can hold more water vapour. More intense rainfall increases the likelihood of flooding.
The immediate risk is that sudden intense rainfall can cause flash floods where drainage systems are unable to cope with so much water.
In the medium term, wet season flooding may happen more often and the water levels may be higher. Vector-borne diseases (malaria and dengue fever) and water-borne diseases (especially diarrhoea) are linked to flooding.
In the long term, extreme events such as river floods may cause population displacement.

26. Extreme winds & stronger storms
EXTREME WINDS & STORMS
HAZARDS
Severe wind
Storm surge
Flooding
IMPACTS
People die
Animals die
Loss of income
Financial losses
Higher temperatures lead to warmer and wetter environments.
In the future, climate change will likely lead to stronger tropical storms, cyclones and hurricanes. However, it may lead to a decrease in the number of storms (NOAA, 2017).
In general, rainfall will become more intense, which will lead to increased impact from storms.

27. What can we do?
Climate Change Mitigation: Action taken to stop climate change by reducing the amount of greenhouse gasses in the atmosphere
Take a look at ‘Let’s ACT!’ section of the youth unit to find out more about what YOU can do
Climate Change Adaptation: Action taken to deal with climate change impacts and reduce the effects on lives, livelihoods and ecosystems

28. References
IPCC (2014) AR5 Synthesis Report;
IPCC WGII (2014) Climate Change and the Ocean;
Nasa Kids (2017)
Graphic accreditations
Rebeka Ryvola
Photograph accreditations
Brigitte Rudram
Image accreditations
The Noun Project 
Y-Adapt images