Geography - Unit 2 Flashcards
What is climate and some examples of it?
When you record the average temperature and rainfall for a place this is called the climate.This is normally done over a year – creating an average temperature and rainfall for each month of the year. Usually taken over 30 years.e.g. Tropical climate, Desert climate, Continental climate, humid Sub tropical, arctic/polar.
In a climate graph, what do the red lines and blue bars mean. provide measurements
red line - temperature - 0C
Blue line - precipitation - mm
In 150 years, how much has the global temperature increased by?
In 150 years, global temperatures have increased by about 1.5°C.
What is the key term we use for when a graph moves up and down ?
Fluctuate
Tree rings - evidence of climate change
The color and width of tree rings can provide snapshots of past climate conditions. … For example, tree rings usually grow wider in warm, wet years and they are thinner in years when it is cold and dry.
For example, if the tree has experienced stressful conditions, such as a drought, the tree might hardly grow at all in those years.
Global temperature data/ Seasonal changes - evidence of climate change
Seasonal changes impact when trees flower and birds nest, often at the start of spring as temperatures are getting warmer. In recent years, this has been happening earlier each year, suggesting the climate is getting warmer.
Temperature fluctuating in the 1900’s, getting warmer in northern hemisphere in 1930, spreading south in 50’s. When get increasingly warmer until present – it is worse in northern hemisphere and equator.
Sea level rise - evidence of climate change
Sea level has risen by 10-20cm over the last 100 years. This is evidence of a warmer climate because as ocean water warms, it expands making the sea level higher. Also, ice on land melts when it is warmer adding to sea level rise.
Melting Glaciers - evidence of climate change
Glaciers (large areas of ice on land) have been found to be melting and shrinking in size. Arctic ice (in the far north of the world) has been thinning and is has thinned by 65% since 1975!
Young ice melts easily in hotter summer and now older ice is disappearing. Human activity accelerates – polar bears travelling longer distances (look at wildlife patterns; climate models)
Ice has a high albedo meaning it reflects a lot of sun rays back to space, keeping earth cool. Melting ice means more of the earths surface will heat up, melting more ice, repeating this process. This is a positive feedback loop!
Ice cores - evidence of climate change
Scientists drill ice cores from deep (more than 1.6 kilometers) inside the polar ice sheets in Greenland and Antarctica. Each layer of ice tells a story about what Earth was like when that layer of snow fell. 1) The thickness of each layer allows scientists to determine how much snow fell in the area during a particular year and the average temperature. 2)The ice have small bubbles of air that contain gases which are a sample of the atmosphere – we measure this (carbon dioxide and methane) to understand the composition of GHG in the atmosphere.
Some of the Earth’s Heat is trapped =
the Earth warms up
Greenhouse gases?
Methane CH4 , Carbon dioxide CO2, Nitrous Oxide N2O (preferably don’t use it)
Without the greenhouse effect the earth will be?
20OC colder
What do greenhouse gases do to the ozone layer?
Too many greenhouses destroy the ozone layer. Therefore too much sunlight can get through the atmosphere.
What is the biggest GHG?
Water vapour is the biggest GHG but humans can’t influence this.
Temperature without GHG?
Temperatures would be -18 without GHG effect
