Week 6: Climate change Flashcards
Hysteris meaning
Dependence of the state of a system
Tipping point meaning
A threshold beyond which the system changes rapidly to a new state
The climate we experience is influenced by
External energy sources + internal systems variability + human forcing
Instrumental record of climate data
The direct measurement of climate variables at well-maintained stations
Climate archives
Evidence of the past recorded in geologic and biologic materials
Anthropogenic
Human produced
To investigate further back in time
We need samples of materials that formed in the past
Examples of materials that formed in the past
- Ice cores (capture annual layers of snowfall)
- Air bubbles (CO2, CH4, O2, N2O)
- H2O isotopes: temperature
- Dust, sea salt, volcanic ash
The relationship between carbon emissions and global warming
GHGs in atmosphere, basic physics + data instrumental and archives
Earth’s carbon cycle has
Fast and slow components
Fast earth carbon cycle
Biological and ocean - atmosphere exchanges
Slow earth carbon cycle
Geographical processes (making and weathering rocks)
What makes a fast transfer from rocks to atmosphere that can only be drawn back down slowly (into the ocean, then rocks)
Burning fossil carbon
Global warming impacts
- Temperature (warmer with more heat extremes, including during winter and night)
- Precipitation (changing patterns, more extreme floods and droughts)
- Sea level rise (higher coastal flooding and tides, saltwater incursion into coastal freshwater aquifers)
Ecological footprint
Measures our demands on ecosystems relative to their capacity to be restored
How many hectares are needed for restoration of our ecological footprint and how many are available
20.8 billion hectares required
12.2 billion hectares available