Download Climate Change Notes

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
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?
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.
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.
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.
Climate Change
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?
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!
Climate Change
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.
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.
Climate change
Studying Climate Changes:
• Scientists use tree rings, pollen from
plants, and ice cores to study
climate change and carbon dioxide
levels.
Climate change
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).