Climate Change Impacts, Atmospheric Composition and Tectonic Processes

Evidence for Climate Change

• Glacier Retreat: The decline of mountain glaciers is accelerating globally.
• Sea Level Rise: Caused by melting continental ice and the thermal expansion of ocean water.
• Increased Global Mean Temperature: Leads to glacier retreat and rising sea levels.
• Frequent Extreme Phenomena: Increased frequency of droughts and floods.
• Biological Shifts: Organisms are modifying their behavior and distribution patterns.

Atmospheric Composition

Dry, clean air consists primarily of Nitrogen (78%) and Oxygen (21%). The remaining 1% is mostly Argon, while Carbon Dioxide represents only 0.0036%. Additionally, the air contains water vapor and aerosols.

The Greenhouse Effect

1. Albedo: 30% of solar radiation is reflected by the atmosphere.
2. Absorption: 19% of solar radiation is absorbed by clouds.
3. Surface Absorption: 51% of solar radiation is absorbed by the Earth's surface, which returns energy in the form of infrared radiation.

Sea Level Changes

• Water Cycle Changes: The withdrawal of seawater and its accumulation on continents as ice causes sea levels to drop.
• Thermal Expansion: Sea levels rise during warm periods as oceanic water expands due to higher temperatures.

Drivers of Climate Change

• Burning Fossil Fuels: Emissions of greenhouse gases are primarily due to burning oil and coal.
• Deforestation: The loss of forest trees leads to an increase of CO2 in the atmosphere.
• Agriculture and Livestock: Certain activities, such as livestock farming, emit methane. The primary cause of climate change is the increase in greenhouse gases of anthropogenic origin, with water vapor being the most influential greenhouse gas.

Climate Models and Projections

• Global Temperature: Expected to increase between 1.4°C and 6°C.
• Sea Level: Projected increase of 20 to 80 cm.
• Weather Phenomena: Droughts will become more frequent.
• Environmental Effects: Loss of biodiversity and alteration of seasonal patterns.
• Health Effects: Tropical diseases may spread to regions that currently have temperate climates.

Prevention and Mitigation

Earthquakes

• Seismic Hazard Maps: Establish maps to adjust preventive rules for individual cases.
• Earthquake-Resistant Construction: Implement standards such as limiting building height and using steel structures to provide elasticity.

Geological Features

• Oceanic Ridge: Large submarine elevations where magma emerges from the asthenosphere.
• Subduction Zone: Areas where the lithosphere is destroyed.
• Transform Faults: Regions characterized by the lateral displacement of one plate over another.