Conditions for life on earth

soil formed from the remains of organisms; decomposers/detritivores; break down dead organisms/forms humus; organic sorting/mixing/aeration/improve structure; release nutrients/ nutrient recycling; weather/erode/break up bedrock/parent material

vegetation/soil biota reduces the rate of runoff; vegetation reduces wind erosion; vegetation reduces impact/damage due to rain; root binding/slope stabilisation; humus binds soil together;

Water: role of water;; solvent for chemical reactions transport within organisms mineral uptake required for photosynthesis aquatic habitats anomalous expansion specific heat capacity/temperature regulation albedo acts as a carbon sink Temperature: importance of temperature range;; suitable for stable biological molecules/enzymes warm enough for chemical/metabolic reactions liquid water Geology: importance of geology;; mass controls gravity/gravitational pull retention of atmosphere source of minerals magnetic field protects from solar wind

needed for photosynthesis; climate/temperature control/heat absorption/acts as greenhouse gas; raw material for carbonaceous structure; eg coral reefs, exoskeletons, shells

energy for photosynthesis; energy for hydrological cycle/winds/ocean currents;

(evapo)transpiration/ evaporation;

Mass Distance from sun Axis of rotation Speed of rotation Magnetic field

Presence of liquid Temperature range Atmospheric gases Solar insulation

1.Large mass and gravitational pull which keeps the atmosphere close 2. Contains important gases: CO2, N2 AND CH4 3. Temperature and pressure means water is in liquid form

Suitable temperature range for enzyme action and water in liquid state Provides energy for photosynthesis Amount absorbed depends upon the albedo of the surface

1.Rotation and tilt of the earth on its axis and its orbit around the sun 2.Controls daily and seasonal variations in isolation and temperatures 3. Enough day length to stop temperature extremes and light for photosynthesis

Solvent water Transport within organisms Temperature controls Anomalous expansion on freezing (most dense at 4°C) High specific heat capacity Aquatic habitats Absorption of UV radiation

Carbon dioxide for photosynthesis and the synthesis of carbohydrates, proteins and lipids Nitrogen for protein synthesis

Atmospheric oxygen Carbon sequestration by photosynthetic organisms Biogeochemical Transpiration

Lack of ancient historical data. * Limited coordination between researchers. * Lack of sophisticated equipment for accurate measurements. * Lack of data collection in many areas. * Reliance on proxy data, eg dendrochronology, pollen analysis.

• Collection of long-term data sets. • The use of electronic monitoring equipment. • Gas analysis of ice cores. • Isotope analysis of ice cores. • Improved carriers for monitoring equipment, eg helium balloons, aircraft, satellites.

Provides a suitable temperature range on Earth which maintains liquid water and allows for photosynthesis

Provides a suitable temperature range on Earth due to its atmospheric behaviour

Earth’s orbit and its rotation and tilt on its axis controls daily and seasonal variations in insolation and therefore temperature

Deflects harmful solar radiation which could be biologically damaging

Earth’s mass and gravitational force retains an atmosphere which provides gaseous resources and maintains liquid water (due to pressure and temperature)

Biogeochemical cycles Oxygen production Ozone layer Carbon sequestration

Reactions between oxygen and UV in the stratosphere created the ozone layer which protects Earth from harmful UVC and UVB radiation

Photosynthetic organisms reduced atmospheric CO2 levels which reduced the greenhouse effect