Factors that Affect Climate Change

Factors that Affect Climate Change

Activity: Views on Climate Change What is your view on climate change? Write down either:What you believe about climate changeWhat you have heard someone say about climate change

Add your view to the Venn diagram on the board

Before We BeginAtmosphere: thin layer of gases that surround EarthWeather: condition of the atmosphere at a specific time (describes wind, temperature, amount of moisture, etc.)Climate: characteristic pattern of weather conditions in a region including: temperature, wind, precipitation, etc. over a long period of time History of Climate ChangeClimates have changed many times over the billions of years of Earths history

And NowIn 1988 an international scientific panel was organized to study the evidence & advise governments about the effects of climate change

http://www.cbc.ca/news/technology/story/2011/12/05/environment-co2-emissions-record.html Factors that Affect Climate Change: The Sun (most important)The AtmosphereThe HydrosphereMoving ContinentsHuman ActivityFactor #1: The SunEnergy from the Sun is the MOST important factor that affects climate on EarthChanges in Solar Activity:

Factor #1: The SunMovements of Earth in SpaceSeasons are caused by a combination of Earths tilt (23.5 ) & Earths annual orbit around the Sun

Factor #1: The SunChanges in Earths Rotation, Orbit & Tilt (Milankovic early 1900s)Eccentricity: due to gravitational attraction of other planets, the orbit of Earth fluctuates slightly over 100 000 years (elliptical) Changes length & intensity of seasons

Factor #1: The SunTilt: angle the Earths tilt on its axis changes 2.4 over 41 000 yearsGreater the tilt, greater the temperature differences between summer & winter

Wobble: Earth is not a perfect sphere, so wobbles slightly as it rotates on its axisAmount & intensity of solar energy received in different hemispheres is affected

Revolution, Rotations & Earths Tilt Animationhttp://www.mathsisfun.com/earth-orbit.html

Factor #1: The SunEffect of Latitude on Climate & SeasonsCurved shape of the Earth affects the amount of sunlight reaching surfaceRays that hit Earth more directly have a higher intensity than those hitting at an angleEquator = highest intensity45 = moderate intensityPoles = lowest intensity

Factor #2: The AtmosphereEarths atmosphere can absorb and reflect solar radiation It can also prevent radiation from escaping into space.

Factor #2: The AtmosphereGreenhouse Effect: Natural part of Earths climate systemCaused by gases in Earths atmosphere that absorb energy that is radiated by the Sun & EarthEnergy Transfer in the Atmosphere

Factor #2: The Atmosphere Wind: movement of air from an area of high pressure to low pressure (convection)Warm air risesCold air sinks

Factor #2: The AtmosphereWinds disperse heat energy through the atmosphere Affects global ocean currents & precipitation patterns

Factor #3: The HydrosphereHydrosphere: all water in its different forms on Earth (liquid water, ice & water vapour)Oceans & lakes act like heat reservoirsWater has a large specific heat capacity (lots of energy is required to raise one gram by 1 C in temperature vs. other substances)Ice and snow reflect heatAlbedo: amount of light reflected by the surface of the object

Activity: Specific Heat Capacity of Earth MaterialsTurn on the lamp and record the temperature of soil, sand and water each minute for 10 minutes

Turn off the lamp and record the temperature of soil, sand and water each minute for 10 minutesFactor #4: Moving ContinentsEarths 12 tectonic plates change the shape of oceans and continents

Affects:Heat transferWind patterns PrecipitationOcean currents

Factor #4: Moving ContinentsVolcanic EruptionsVolcanoes are located at the boundary of tectonic plates

Volcanic eruptions spew ash & particles into the atmosphere (aerosols) which reflect solar radiation, cooling the Earth

Volcanic eruptions also add large amounts of greenhouse gases (CO2) to the atmosphere which might cause global temperatures to riseMount Pinatubo Erupted in June 1991 - Philippines

Factor #5: Human ActivityWarming trend since the 1970s caused partially by humans (anthropogenic)

Factor #5: Human ActivityBurning of fossil fuels (since the Industrial Revolution 1700s) has increased concentration of gases in the atmosphere

These gases produce the greenhouse effect

Homework:Page 278 # 1, 2, 4, 6, 7