Section A - Climate Change Flashcards
What is the evidence for climate change
Warming of the planet
ice melting
Sea levels rising
Temperatures warming
What is the long term evidence for climate change
Fossil records
Ice cores
What is the short term evidence for climate change
Shrinking ice
Rising sea levels
Seasonal changes
What’s happens to shrinking glaciers and melting ice
Glaciers throughout the world are shrinking and retreating
By 2035 the glaciers may dissaper
Arctic sea ice has thinned by 65% since 1975
What’s happens to the rising sea levels
The average global sea level has risen between 10 and 20cm in the past 100 years
When temperatures rise and freshwater ice melts, more water flows to the seas from glaciers and ice caps
When ocean water warms, sea levels expand in volume
What’s happened to the seasonal changes
Studies have suggested that the timing of natural seasonal activities such as tree flowering and bird migration is advancing
What is eccentricity
The earths orbit around the sun varies between being a perfect sphere and an ellipse. When this orbit is an ellipse less sunlight reaches the earth at certain point in its orbit, cooling the climate
A complete cycle will take around 100,000 years
What is axial tilt
The angle of tilt on earths axis changes over a 41000 year cycle. This causes more or less sunlight to reach the ice caps at the poles
What is or precession
Earth doesn’t stay entirely still when it orbits the sun but rather wobbles slowly on its axis like a spinning toy top. This causes the amount of sunlight hitting the earth to vary. A full cycle will take around 26000 years
What are sunspots
Sunspots are dark patches that appear from time to time on the surface of the sun. Over a 11 year cycle the amount of sunspots was rise to a maximum and back down to a minimum amount.
What happens when sunspot activity is at its maxmimum
The sun gives off heat. Sunspots cause explosions of the surface and result in solar flares
What happens when sunspot activity is reduced
The solar input is reduced which leads to cooler temperatures on the earth
Sunspot example?
Very few sunspots were observed from 1645 to 1715. This concided with a so called “little ice age” with extreme winter and much colder average temperatures
How do volcanoes increase climate change
Ash clouds can block out the sun .within the ash cloud/ there is sulphane dioxide particles. They act like tiny mirrors
What are some human cause of climate change
The oil industry Carbon fuels Fossil fuels Mining Aerials Carbon fuels Air pollution Over population Landfill Food miles
What is the greenhouse effect
The atmosphere allows most of the heat from the sun (short wave radiation) to pass through it to warm up the earths surface. However when the earths gives off heat in the form of long wave radiation, some gases such as carbon dioxide and methane, are able to absorb it. These gases are called greenhouse gasses
How is CO2 affecting climate change
CO2 account for an estimated 60% it the enhanced greenhouse effect. Global contribution of carbon dioxide gas increased by 30% since 1850
•deforestation and the burning of wood
•car exhausts
•burning fossil fuels (gas, coal,oil) in industry and power stations to produce electricity
How is methane affecting climate change
Methane is very effective in absorbing heat and it accounts for 20% of the enhanced greenhouse effect
•farm livestock
•burning biomass for energy
•rice farming
•decaying organic matter in landfill sites and compost tips
How is nitrous oxide affecting climate change
Nitrous oxide has very small contributions in the atmosphere and up to 300 times more effective in capturing heat than carbon dioxide •agricultural fertilisers •car exhausts •sewage treatment •power stations producing electricity
What is the enhanced greenhouse effect
The increases effectiveness of the green house effect is what scientist believe is causing recent global warming. By the end of this century, the average global temperature could rise by 1.8-4C. This could lead to a rise in sea level of 28-43 cm
