Global Systems Flashcards
What are the main parts of the nitrogen cycle?
Nitrogen fixing bacteria- convert atmospheric Nitrogen to Ammonium
Nitrifying bacteria- convert Ammonium to Nitrites/Nitrates
Plants get nitrates from soil— food chain
Denitrifying bacteria turns Nitrates to Atmospheric nitrogen
What are the key components of the carbon cycle?
Photosynthesis and Respiration Formation of limestone Wastes/dead organisms CO2 in the air Burning of fossil fuels
What are cyclones caused by and what do they do?
They are caused by low pressure systems that develop when sea temperature is above 26.5 C.
They cause heavy rain, flooding and wind
What are volcanoes caused by and what do they do?
A build up of water and carbon dioxide causes the volcano to erupt and bring magma to the earths surface
They produce large ash clouds that cover the sky and block the sun
How does the greenhouse effect work?
Energy from the sun is short-wave radiation- become long-wave (heat) radiation
Long wave radiation can’t get through greenhouse gases and is trapped close to the surface and warms the earth
How does the orientation of the earth effect the climate?
The earth is tilted on an axis and this causes seasons and differences between the north and south hemisphere
How do ocean currents effect the climate?
The circulate warm/cold water and weather throughout the earth
How does thermohaline circulation work?
The deep currents are cold because heat rises and are salty because ice only freezes freshwater and saltwater is more dense. The rising and sinking of water causes the ocean currents
How does the enhanced greenhouse effect work?
Humans are adding more greenhouse gases to the atmosphere, causing it the accelerate the greenhouse effect and warm the earth
What are some effects of climate change?
Rising sea levels- melts ice Melting ice- even more warming Melting permafrost- more methane More natural disasters Extinction of species
What is some evidence for climate change?
Glaciers retreating and advancing
Ice cores- show amount of CO2
Sea level changes
What does ozone do?
Absorbs harmful UV rays from the sun and protects the earth
How did we create holes in the ozone layer?
The chlorine in CFCs used for refrigeration and air conditioning destroyed the ozone and created ‘holes ‘ which let in UV radiation
What was the Montreal Protocol?
A bunch of countries agreed to stop producing CFCs
