Short Term Climate Change Flashcards
What are two natural short term causes of climate change?
El Nino Events
Volcanic Eruptions
How long do the effects of a volcanic eruption effect the climate for?
1-3 years
By what percentage can volcanic eruptions reduce the earth’s temperature?
10-15%
How often do El Nino events occur? Where?
Twice per decade, around Christmas time in the Pacific Ocean.
What happens during a normal year? (El Nino Events)
Normally, South-East trade winds hold warm water on the east coast of Asia and toward Australia.
Rising air due to warm waters in Australia causes low pressures meaning clouds form which leads to rain in Australia.
The trade winds push cool water from the east side of the Pacific west. The sun heats this water up which causes a lot of it to evaporate which leads to monsoon rains over south east Asia.
The east Pacific (areas such as California and Peru) have low sea temperatures and are dry.
What happens during an El Nino event year?
Twice per decade an El Nino event occurs. The trade winds die down allowing the warm water to physically travel east.
This changes the climate in the east because sea temperatures are warmer. Not only does this disrupt the fishing industry but it also leads to more evaporation causing rains and mudslides in Peru and some parts of California.
It changes the climate in the west because the sea temperatures are very cold. Far less evaporation occurs which means no clouds form to give monsoon rains and Australia experiences droughts which can lead to bush fires.
What example can be used of an impact of El Nino events in Australia?
“Black Saturday” bush fire of 2011. This killed 173 people and destroyed 60 homes.
How do volcanic eruptions change the earth’s climate?
Volcanoes erupt which releases ash and sulfur dioxide into the atmosphere.
This material travels high into the stratosphere (10-50km above the earth’s surface). High powered winds then blow the ash around the earth. The ash then reflects a lot of incoming solar radiation. This has a cooling effect on the planet, reducing temperatures unto 10-15%. Volcanic eruptions are cited as the cause of some cooling during the little ice age when there was many eruptions.
