Environmental

Hydrosphere

• Water distribution: 97% oceans, 3% freshwater
• Water cycle: Evaporation, precipitation, runoff
• Ocean chemistry: Salinity, pH, currents

Lithosphere

• Rock cycle
• Soil formation
• Mineral resources

Environmental Issues

• Climate change
• Air pollution
• Water pollution
• Deforestation
• Biodiversity loss
• Waste management

Sustainability Principles

# Example: Carbon footprint calculation
def carbon_footprint(energy_use, emission_factor):
    """
    Calculate CO2 emissions.
    energy_use: kWh or liters
    emission_factor: kg CO2 per unit
    """
    return energy_use * emission_factor

# Common emission factors
emission_factors = {
    'electricity': 0.5,  # kg CO2/kWh
    'gasoline': 2.3,    # kg CO2/liter
    'diesel': 2.7       # kg CO2/liter
}