Geography YEar 4 Climate Change Flashcards
What is Global Climate Change, how long can it last and what issit caused by?
- GCC refers to Long-term variation in global climate (temperature, precipitation, wind patterns).
- it Can last for several decades or longer.
- it’s Caused by natural variability or human activities (anthropogenic factors).
Flashcard 2: What is Global Warming and How Has Climate Changed Over Time?
- Global warming → long-term rise in Earth’s temperature.
- Earth’s temperature ↑ 0.74°C in the last century.
- Glacial period (18,000 years ago) → cooler temperatures, large ice sheets.
- Interglacial period → rising temperatures, melting ice sheets.
How Do Sunspots Affect Earth’s Climate + what type of cycle do they follow?
- The areas surrounding sunspots radiate more energy → increasing solar radiation.
- More sunspots → more solar radiation → higher temperatures on Earth.
- Sunspot numbers follow an 11-year cycle of rising and falling.
what are sunspots?
Sunspots are areas on the Sun with lower temperatures.
How Do Large Volcanic Eruptions Affect Earth’s Climate?
Greenhouse gases (CO₂ & water vapor) → Absorb infrared radiation → trap heat → long-term warming.
Sulfur based particles + Ash + dust reflect sunlight → Scatter and reflect solar radiation, causing temporary cooling.
Cooling from volcanic aerosols alters global wind patterns → affects ocean currents and monsoon systems.
OVERALL volcanic eruptions offset greenhouse gas emissions -> cooling down earth BUT they distrupt the lives of locals
How Do Volcanic Particles Affect Temperature?
- Sulfur-based particles, dust, and ash absorb and reflect solar energy → reducing sunlight reaching Earth.
- This temporarily lowers global temperatures by offsetting the greenhouse effect.
Example of Volcanic Eruption Impact on Climate
Mount Pinatubo (1991):
Global temperature drop: 0.6°C
Cooling effect lasted for 15 months.
What is the Greenhouse Effect and the Enhanced Greenhouse Effect?
- The greenhouse effect is a natural process where greenhouse gases trap heat (longwave radiation) emitted from Earth’s surface.
- The enhanced greenhouse effect occurs when human activities increase greenhouse gas concentrations, leading to higher global temperatures.
How Do Human Actions Contribute to the Enhanced Greenhouse Effect?
- Burning fossil fuels → produces large amounts of CO₂ and other greenhouse gases → intensifies the enhanced greenhouse effect.
- Changing land use (agriculture, urbanization, deforestation) → releases greenhouse gases and reduces CO₂ absorption by trees.
How Does Deforestation Contribute to the Enhanced Greenhouse Effect?
- Deforestation → reduces the number of trees that absorb CO₂ → releases stored carbon back into the atmosphere.
- Clearing forests → exposes soil to sunlight → increases soil temperature and carbon oxidation rate.
How Does Changing Land Use Contribute to the Enhanced Greenhouse Effect (cont.)?
- Land use changes (e.g., agriculture, urbanization, deforestation) → releases greenhouse gases and reduces CO₂ absorption by trees.
- Land use activities → burning fossil fuels → adds more greenhouse gases to the atmosphere.
How Do Livestock Rearing and Decomposition Contribute to the Enhanced Greenhouse Effect?
- Livestock rearing → releases methane → contributes to the enhanced greenhouse effect.
- Natural decomposition → releases methane into the atmosphere.
How Does greenhouse gas Affect Ocean Temperatures?
- Most heat trapped by greenhouse gases is absorbed by oceans.
- Average ocean temperatures have been increasing, but this warming is uneven, with some areas warming faster than others.
What Are the Contributors to the Enhanced Greenhouse Effect? (6)
- Deforestation
- Changing land use
- Burning fossil fuels
- Livestock rearing
- Natural decomposition
- Paddy fields
How Do Paddy rice Fields Contribute to the Enhanced Greenhouse Effect?
Paddy rice fields → rapid decomposition due to high amt of moisture in soil → high methane emissions → contribute to the enhanced greenhouse effect.
How Does Climate Change Affect Ocean Circulation and define global ocean circulation?
- Global ocean circulation is the large-scale movement of water.
- Warm water moves from the equator to the poles, cools, becomes denser, and sinks.
- As climate change heats surface waters, sinking at the poles reduces, slowing down ocean circulation (e.g., Atlantic currents have slowed by 15%).
Why is Ocean Circulation Important? (3)
- Warm ocean currents warm coastal areas, giving milder winter temperatures.
- Warm waters evaporate faster, leading to rainfall in affected areas.
- Cold ocean waters bring nutrients to the surface, supporting phytoplankton growth.
How Does Melting Ice Impact Climate and Water Resources?
- Melting ice caps, glaciers, and permafrost release freshwater in the short term, improving water security.
- However, in the long term, loss of ice reduces surface runoff and contributes to flooding risks.
- Permafrost melting can release ancient viruses and microorganisms, posing health risks to humans.
What is the Impact of Melting Permafrost on Health?
- Resurrected viruses: Examples include 15,000-year-old viruses under Tibetan ice and ancient nematodes from Siberian soil.
- These can pose a health risk as they may infect humans.
How Does Climate Change Affect Disease Migration?
-Tropical diseases (e.g., malaria, dengue) are moving to higher latitudes due to changing climates.
- More areas are now at risk, adding to the disease burden and creating economic and social challenges.
What Are the Positive Effects of Arctic Ice Melting?
- Arctic melting opens up trade routes.
- Shipping traffic has increased in the Arctic region due to longer periods of passable sea ice.
- However, this also creates political tension as powerful countries vie for control over the region.
How Does Rising Ocean Temperature Affect Sea Level and what does rising sea levels lead to?
- Thermal expansion of sea water due to higher temperatures increases sea levels.
How Does Rising Sea Level Impact Agriculture and fisheries?
- Rising sea levels → seawater contaminates groundwater → threatens freshwater fisheries + increases risk of waterborne diseases.
- Rising sea levels → floods padi fields → reduces agricultural yields/destroys crops → affects food security
How Does Rising Sea Level Affect Migration?
- Rising sea levels force people from low-lying areas to migrate to cities or other countries.
- This climate-induced migration can bring challenges to host countries, such as overcrowding and resource strain.