Climate Change Flashcards
(24 cards)
Climate definition
the statistics of weather prevailing in a location
Climatic variability:
shorter term departures from average climate
Climate change
long term changes to those statistics
What type of hazard is climate change
context hazard that alters the magnitude and frequency of existing hazards (e.g storms), or human vulnerability (e.g through sea level rise)
Scale of weather
hours days months
Type of weather
wet and dry season
Climate variability type
ENSO 2-7 yrs
NAO
Climate variability scale
Months and decades
Climate change type
Global warming, cooling
Climate change scale
decades, centuries
What is El Nino
Named after the period it occurs at ( every 2-7 yrs Christmas), its the increase temperature change of the ocean
Example of El Nino in action in the Pacific
Warm surface waters off the coast of Peru led to reduced fish harvests in some years
Southern Oscillation
the cycle of varying strength of atmospheric pressure.
Southern Oscillation in normal years
high pressure in the central pacific, low pressure to the West (Australia)
Sothern Oscillation in some years
low pressure in the central pacific, high pressure in Australia
ENSO occurence
Pacific Ocean: change in interaction between ocean and atmosphere
ENSO process
1) warm water from the western Pacific Ocean flows eastward
2) warming of the central and eastern Pacific.
3)lead to changes in atmospheric circulation patterns
4) weakening of trade winds and increased rainfall in the eastern Pacific and drought in the western Pacific
ENSO driven by …
quantity of heat stored in the upper layers of the Pacific Ocean
ENSO Western Pacific impacts
Droughts e.g. China 1877-78
Wildfires (Australia, SE Asia e.g. 1997-98 = 5,000,000 ha of forest lost)
ENSO Eastern Pacific impacts
Floods in Peru (1997-98)
- 500,000 homeless
- Utility damage: US$ 2.6 billion
- Collapse fishing industry
MEI
Multivariative ENSO Index is the is a measure of the El Niño-Southern Oscillation (ENSO) climate phenomenon that is based on several key atmospheric and oceanic variables
More El Niño years since 1980.
2023
1/4 of the year -increase activity and warmth
Mitigation for ENSO
- Predictions improved considerably – several months in advance
- Early warning & action
- Peru 2015: declared 60 day state of emergency & spent 20 million USD on flood and drought prevention (e.g. built reservoirs, insurance, Red Cross actions)
Improvements
*understanding of ENSO dynamics and likelihood
- understanding of ENSO signatures and how they unfold into socio-economic impacts
- Uncertainty over how ENSO may be affected by future climate change
Some studies suggest impacts will be more intense “Super El Niño”
Some predict that an extreme ENSO will happen more often
