*Geological hazards* = natural events caused by processes inside or on Earth’s
crust that can damage people, property, and ecosystems.
*Main types + causes:*
1. *Earthquakes*
*Cause*: Sudden movement of tectonic plates along faults. Energy releases as
seismic waves.
*Impact*: Building collapse, tsunamis, landslides, loss of life. Example: 2005
Kashmir earthquake.
2. *Volcanic eruptions*
*Cause*: Magma, gas, and ash rise from mantle to surface through weak
points in crust.
*Impact*: Lava flows, ash fall, pyroclastic flows, climate cooling from aerosols.
Example: Mount Pinatubo 1991 cooled Earth 0.5°C.
3. *Landslides & mudflows*
*Cause*: Gravity + heavy rain + weak slopes + deforestation.
*Impact*: Roads blocked, villages buried, rivers dammed. Common in Khyber
Pakhtunkhwa hills.
4. *Subsidence & sinkholes*
*Cause*: Ground collapses when underground water, oil, or minerals are
over-extracted.
*Impact*: Buildings crack, infrastructure fails.
5. *Tsunamis*
*Cause*: Underwater earthquakes or landslides displace huge water volumes.
*Impact*: Coastal flooding, erosion, saltwater damage to farmland.
*Key idea*: Hazards themselves aren’t “bad”. They become “disasters” only
when humans + property are in the way. Risk = Hazard × Exposure ×
Vulnerability.
*2. What is Environmental Sustainability?*
*Environmental sustainability* = meeting our needs today without destroying
the ability of future generations to meet their needs. Based on 3 pillars: *People,
Planet, Profit*.
*Core principles:*
1. *Use resources at renewal rate*: Don’t cut trees faster than forests grow.
Don’t use groundwater faster than rain refills it.
2. *Pollute less than Earth can absorb*: CO₂, plastic, chemicals should not
exceed nature’s cleaning capacity.