1. Climate Change
Climate – The average year after year pattern of temperature, precipitation, winds and clouds in an area.
Climates are classified mainly by two factors:
1.) Temperature
2.) Precipitation

2. Climate Change Evaporation:
Evaporation cools the surface of the Earth as it forms water vapor (It takes energy with it). So, how does evaporation affect climate?
When clouds form, they reflect sunlight helping to cool the planet.
When water vapor condenses to form clouds, it releases energy warming the atmosphere.
Water vapor is a greenhouse gas so it traps energy helping global warming.
Water vapor… Good or Bad?

3. Climate Change
Salinity – the total number of dissolved salts in a sample of water.
Salty water is more dense than fresh water
Evaporation increases the salinity of the ocean because only water is evaporated leaving the salt behind.

4. Climate Change
Rain, snow, and melting ice bring fresh water to the ocean. This lowers the salinity and the density of ocean water.
Salty, cold water sinks and warmer less salty water rises toward the surface.
Changing ocean water density controls deep ocean currents in this way.

5. Climate change
Deep ocean currents work together with wind-driven surface currents to exchange warm and cold water between the equator and the poles.
Currents affect climate by moving cold and warm water around the globe.
Surface currents cool or warm the air above it influencing the climate (temp, clouds, & precipitation) of the land nearby.

6. Climate Change

7. Climate Change Glacial Melting at the Poles (Feedback system)
As temps rise, ice melts
More dark ocean is exposed which absorbs more radiation increases the rate of melting
Also, there is now less ice to reflect the sun
This accelerates the rate of ice melting
More fresh water dumped into the ocean alters ocean currents which alters climate
Not to mention where all this extra water is going to go… Massive flooding?

8. Climate Change Carbon Dioxide and Global Warming:
Global Warming: The gradual increase in the temp of the atmosphere
Greenhouse gases like CO2, water vapor, and methane trap heat energy. This is good to keep our planet warm, but can be bad if levels get too high.
Human activities are the greatest cause of the increasing levels of greenhouse gases like CO2!

9. Climate Change

10. Climate change
Scientists think rising levels of carbon dioxide are a major factor in global climate change.
Until the late 1800’s the levels of carbon dioxide remained about the same.
Over the last 120 years, the average temperature of the troposphere has gone up at a steady rate, 0.7°C total in that time.

11. Climate Change Causes of Natural Climate Change:
Shifts in the Earth’s tilt, axis, or rotation may have been the cause of ice ages.
Sunspots can increase temperatures on Earth.
Volcanic activity release gases and ash that filter out radiation and cool the Earth.
Continental drift over millions of years change the climate by moving that landmass to a different latitude.

12. Climate change Studying Climate Changes:
Scientists use tree rings, pollen from plants, and ice cores to study climate change and carbon dioxide levels.

13. Climate change

14. Climate Change Possible effects of Global Climate change:
Higher temps causing desertification (China).
Hotter planet causes ocean to hold more energy creating thermal expansion (rising sea levels) and increasing the strength of hurricanes (Katrina, Sandy)
Warming atmosphere and water speed up glacial melting causing sea levels to rise even more.
Glacial melting also causes salinity changes in the ocean which changes ocean currents affecting climate all around the world. (shifting growing regions and flooding coastal cities everywhere).