Science: Chapter 7: Earth's Climate System

Global warming

An increase in global average temperature.

Biome Categories

Boreal Forest * Temperate Deciduous Forest * Desert * Temperate Rainforest * Tropical Rainforest Grassland * Permanent Ice * Tundra * *In Canada

Evidence of past climates - ice cores

Dissolved and particular matter in the ice. Matter (dust, pollen, ashes salt etc)gives clues about events and conditions (forest fires, volcanic eruptions etc) Physical characteristic of ice. Examine the physical characteristics of the crystals of frozen water within ice. The composition of trapped air bubbles. Tiny air bubbles in the water may become trapped inside ice, and can be examined at different depths to record the changes of greenhouse gas concentration over the years. Composition of the ice. Water contains different proportions of hydrogen and oxygen isotopes The relative concentration of isotopes in different lares of ice indicates the temperature at the time the ice formed.

Electromagnetic Radiation

Energy that travels in waves that move outward in all directions from a source.

Greenhouse Gases

Gases in Earth's atmosphere that absorb and prevent the escape of radiation as thermal energy. Eg CO2, water vapour, nitrous oxide and methane

Open vs closed system

Open system: A system in which energy and mater cross the system's boundary. e.g. Body Closed system: System that allows energy but not matter to cross system's boundaries. e.g. Upper edge of Earth's atmosphere

Positive vs Negative Feedback loops

Positive Feedback loops: Act to increase the effects of the interacting parts. -closed Negative Feedback loops: Decreases the effects of the interacting parts and helps to maintain a system's equilibrium.

Types of (heat) energy transfer

Radiation, conduction, convection

Climate Zones

Regions that share similar weather conditions.

Anthropogenic

Relating to or resulting from the influence of humans.

Factors that change Earth's climate: Earth and the sun

- Amount of radiation the Sun produces varies - Earth's tilt on it's axis causes seasons - Changes in Earth's rotation/orbit/tilt: Earth's orbit fluctuates due to the gravitational attraction of other planets in the solar system, therefore when Earth's orbit is more elliptical, the planet receives much more solar radiation when it is nearest to the Sun. The angle of Earth's tilt changes app. 2.4 degrees every 41,000 years. Also, precession , a change in the direction of the axis of rotation occurs, as Earth is not a perfect sphere. - The latitude: The areas near the equator receive more concentrated amounts of solar radiation

Indicators and effects of climate change

- Global warming - Changes in polar and glacial ice: Warming temperatures melt ice; Habitat loss for animals such as polar bears, causing them to range more south to find food (dangerous) -Rising sea level and ocean acidity: Rising due to melting glacier, areas of land may become submerged. As H20 gets warmer changes in pH and acidity have occurred. Coral and other sensitive biotic things will be less stable in areas of oceans with less CO2. - Changes in wind and precipitation patterns: This is due to the changes in heat distribution over Earth's surface. High temperatures increase rate of evaporation, increasing annual precipitation. -Desertification: An increase of decrease in precipitation effects reservoirs. Declines in precipitation can cause desertification and limited drinking water -Intensity of storms can become more intense and extreme -electrical damage -Shrinking Wetlands: Wetlands regulate climates, store/filter water.. Low water levels will dry wetlands and reduce habitat.

Factors that change Earth's climate: Human Activity

- Humans burned fossil fuels for energy for centuries, which releases pollutants into the atmosphere, producing the greenhouse effect.

Factors that change Earth's climate: Moving Continents

- Tectonic plates are changing the shapes of continents, and oceans. This affects patterns of water and air circulation. - Volcanic eruptions release aerosols which have a cooling edict on global climate

Factors that change Earth's climate: Atmosphere

- The greenhouse effect occurs naturally to regulate Earth's climate - Wind transfers thermal energy around the world.

Factors that change Earth's climate: Hydrosphere

- Water transfers heat from one area to another - Oceans act as a heat reservoir, due to their large specific heat capacity - Ice and snow reflect solar radiation

El Nino and La Nina

- Winds blowing westward weken, and possibly reverse in El Nino. -Stronger than normal winds push waters further west in La nina years.

Factors that change Earth's climate

1. Earth and the Sun 2. Atmosphere 3. Hydrosphere 4. Moving Continents 5. Human Activity

3 major climate zones Aristotle classified.

1. Tropical Zones 2. Polar Zones 3. Temperate Zones

Thermohaline Circulation

A 3 D pattern of ocean circulation driven by wind heat and salinity.

Köppen Climate Classification System

A Method of identifying and describing climates based on observable features such as temperature and rates of precipitation.

Changing albedo and energy budget

A change in clouds snow or ice will produce change of energy in the atmosphere. Eg. Melting of glaciers and ice caps will decrease albedo of surface and may warm Earth.

Precession

A change in the direction of the axis of rotation.

Energy Budget

A description of the total energy exchange within a system.

Ecozone

A division of Earth surface, separated by neighbouring ecozones by a geological feature.

Climatograph

A graph of climate data for a specific region, the sara are usually obtained over 30 years from observations made at local weather stations.

Atmosphere

A layer of gases surrounding a planet or moon.

Ecoregion

A subdivision of an ecozone characterized by local landforms such as plains lakes, mountains and rivers.

Changing climate/landscapes

Human activities such as farming are effected by the warming climate. Areas that are currently unsuitable for growing crops may in the future be able to.

How do human activities contribute to global warming?

Humans contribute to global warming by changing the natural greenhouse effect (4). Burning fossil fuels is a source of energy that has flourished over the last century (1). This process releases gases and pollutants into the atmosphere, contributing to the greenhouse effect, and global warming (4). Also, deforestation and the clearing of land for agriculture minimizes the amount of carbon dioxide, a greenhouse gas, filtered from the atmosphere (4).

Energy transfer in the atmosphere

Land / water get thermal energy by absorbing suns short-wave radiation. Conduction heats the air through collisions between air and land molecules. Convection moves warm air close to the ground, upwards and cool air down.

Climate

The characteristic pattern of weather conditions within a region (e.g. temperature, precipitation, wind velocity) averaged over a long period of time.

Weather

The condition of the atmosphere at a specific place at a specific time.

Eccentricity

The fluctuation of Earth's orbital path.

Albedo

The fraction of energy reflected by a surface.

Biome

The largest division of the biosphere, large regions that share similar biotic components.

Greenhouse effect

The natural warming caused when gases in Earth's atmosphere absorb thermal energy that is radiated by the Sun and Earth.

Evidence of past climates - tree rings

Tree rings display the age of the tree, how much water and sun the tree received, if there were any forest fires etc..

Köppen Climate Classification System Categories

Tropical moist Climate Dry Climate Moist Mid-latitude climate with mild winters. Moist Mid-latitude climate with Cold winters. ** Ottawa Polar Climate

How are greenhouse gases linked to global warming?

Water vapour and carbon dioxide are gases that absorb and re-emit infrared radiation, producing a warming effect, therefore they are greenhouse gases (1).The net effect of this gradual heating of Earth's atmosphere and surface, also known as global warming (16).

What is the difference between "weather" and "climate"?

Weather - specific place at specific time Climate - averaged over long period of time