IB - Enviromental System and Socieities - TOPIC 6 global warming

TOPIC 6: GLOBAL WARMING

GHG gases:
Carbon dioxide
Water vapor
Methane

Function: they allow short wavelengths of radiation to pass through the Earth, but they trap the longer wavelengths that are radiated from the earth. (Greenhouse effect)
Greenhouse effect
The GHGs allow short wavelengths of radiation to pass thought the Earth’s surface. It regulates the Earth’s temperature keeping conditions warmer than without the effect and more hospitable to life.
Examples of greenhouse gases
Carbon dioxide CO2
Methane CH2
Nitrogen oxides, NOx
Chlorofluorocarbons (CFCs)
Global Warming
An increase of average temperature of the earth’s atmosphere
Global mean temperature
Earth thermal balance
Factors that influence the temperature:
Solar energy influx (input)
Chemistry of the atmosphere changes (outputs)
Albedo (output)

The variation in themperature lead to anomalies:
Positive  Warming
Negative  Cooling
Dangerous because species do not have time to adapt
Albedo
The ability of the Earth’s surface to reflect light
- opposite relation with the global temperature which means:
Increased albedo leads to decrease in global temperature
Decreased albedo leads to increase in global temperature

Anthropogenic source
Is how humans impact global warming.
1. GHGs
Burning fossil fuels
Deforestation
Fridge coolants, aerosol cans
2. Rice farming, Landfil
Produce methane
3. Use of fertilizers nitrous oxides form decomposition of fertilizers
4. Albedo and hardsurfaces
Heat sinks caused by artificial landscape Effects of increasing temperature (environment)
Biome shifting
Changing weather patterns
Spread of tropical diseases and pests
Influencing productivity of biomes
Rising sea level
Increase severity and number of storms
Effects of increasing temperature (social)
Scarcity of water
Agricultural areas may shift
Costal area may be flooded
The Intergovernmental Panel on Climate Change (IPCC)
It brings together scientists politicians and other interested parties in three working groups.
Group 1: scientific aspects of the climate system and climate change
Group 2: The consequences and response of society to climate change
Group 3: options to reduce GHG emissions.
Global Dimming

Carbon sequestration

Kyoto Protocol is an international treaty that sets binding obligations on industrialized countries to reduce emissions of GHGs. (1997)
Copenhagen Accord
It recognizes that warming should be kept under 2° but fails to reach expectations to provide an effective extension of Kyoto
Pollution Management Strategies
Activity: change in lifestyle (choices of transport, energy use, consumer goods and service), tax on CO2 emmisons.
Release: development of technologies to extract GHG from the atmosphere and store them
Clean up: carbon sequestration.
Negative feedback loop

Positive feedback loop

Greenhouse effect diagram