The Quarternary period is the most recent geological time period, spanning from 2.6 million years ago to today
In the period before the quarternary period, the Earth's climate was warmer and quite stable.
Evidence of climate change:
Ice cores - Scientists analyse gases trapped in a long core of ice to determine the temperature changes overtime
Temperature Records - Using things like thermometers and historical weather reports and harvest dates can further date the change in climate
Pollen Analysis - Scientists identify and date preserved pollen to show which plant species were living at that time
Tree Rings - Scientists take cores and count rings to find the age of a tree, the ring thickness shows what the climate was like
Natural Causes of Climate Change:
Orbital Changes - Variations in way earth orbits the sun (stretch, tilt, wobble) affect how much solar radiation we receive, and may have been the reason behind glacial periods
Volcanic Activity - Major eruptions eject large quantities of material into the atmosphere, some of these reflect the sun's rays causing the earth to cool causing short-term changes in climate
Solar Output - Changes in the sun's energy output may lead to some minor effects towards climate change, reduced solar output can cause the climate to be cooler in some areas
Human Causes of Climate Change:
Burning fossil fuels - CO2 released into the atmosphere when fossil fuels are burnt
Cement Production - Since it is made of limestone which contains carbon, when it is produced it emits a lot of CO2
Farming - Livestock produces a lot of methane, and flooded rice paddies can emit methane
Deforestation - Plants which take in CO2 are destroyed which stops CO2 from being absorbed, as well as CO2 being released from burning wood
Effects of Climate Change on the Natural World:
Glacial shrinkage due to rising temperatures
Sea Ice Shrinkage due to rising temperatures
Rising Sea Levels due to melting sea ice
Species decline (e.g. Coral)
Changing precipitation patterns
Effects of Climate Change on the Human World:
Deaths due to heat have increased
Water shortages in many places
Many crops worldwide suffering due to rising temperatures
Lower Crop Yields worldwide
Increasingly extreme weather
Mitigation Strategies to reduce Climate Change:
Alternative Energy Production - Using nuclear and renewable energy to reduce greenhouse gas emissions (e.g. UK using more offshore wind farms)
Carbon Capture - Capturing CO2 and transporting it to safe places where it can be stored (e.g. underground)
Planting Trees - Increases amount of CO2 which is absorbed from the atmosphere through photosynthesis
International Agreements - The 2015 Paris Agreement aims to reduce greenhouse gas emissions and to limit global warming.
Adaptation Strategies for Climate Change:
Changing Agricultural Systems - Planting new crop types more suited to conditions, or using biotechnology to make more resistant crops
Managing Water Supply - Water meters, rainwater/waste water can be collected and recycled
Coping with Rising Sea Levels - Better flood warning systems, physical defences, building raised flood shelters