4.2 Climate Controls Student PDF

Climate Controls + Energy Global Warming Global Warming Long term heating of Earth’s climate system due to human activities that increase heat trapping greenhouse gas Observed since pre-industrial period Focuses on global average temperature Climate Change Long term changes in ave...

Climate Controls + Energy Global Warming Global Warming Long term heating of Earth’s climate system due to human activities that increase heat trapping greenhouse gas Observed since pre-industrial period Focuses on global average temperature Climate Change Long term changes in average weather patterns experienced in local, regional and global climate Currently driven by human activity Often used interchangeable with climate change, but not exactly the same thing How do we know the world is warming? Air Temperature Temperature over Ocean of the Lower Humidity Atmosphere Arctic Glaciers Snow Sea Ice Ocean Heat Content What can Global Air Temperature we do? Sea Surface Sea Level over Land Temperature Credits and data sources: NOAA Ocean Warming Ocean heat content increasing Temperature sensors on buoys and in “floats” shows increase in heat energy stored in top 1km of ocean Causing water to expand Raising global sea levels Affects marine ecosystems Humidity Increasing Water vapour in air is increasing Measurements over land and water show more water vapor in the air Air feels stickier when it’s hot Air conditioners use increases Glaciers Melting Photographs, historical painting, long term records show most mountain glaciers are melting and retreat in size 1941 Agriculture crops and human water supplies dependent on water from glaciers 2004 Glaciers Melting 1941 2004 Snow Cover Decreasing Satellite images show that the area of land covered by snow is decreasing During spring in the Northern Hemisphere is getting smaller 1941 Snow is melting earlier Changes when and how much water is available for nature and people 2004 Snow Cover Decreasing 1941 2004 Energy Budget - Imbalance What causes change in Watts/m2 (energy)? What causes the imbalance? 1. Increased solar activity - ? 2. Reduced reflectivity/albedo - ? 3. Increase in greenhouse effect - ? Energy Budget - Imbalance What causes change in Watts/m2 (energy)? What causes the imbalance? 1. Increased solar activity - ? 2. Reduced reflectivity/albedo - ? 3. Increase in greenhouse effect – clear evidence of change Energy Budget – incoming solar energy Energy Budget - Imbalance What causes change in Watts/m2 (energy)? What causes the imbalance? 1. Increased solar activity – not impacting change 2. Reduced reflectivity/albedo - ? 3. Increase in greenhouse effect – clear evidence of change Earth’s Reflectivity – Albedo Albedo = a measure of the surface’s reflectivity Light colour = high reflectivity Fresh snow albedo = 0.84 Glacial ice = 0.2 – 0.6 11 Ice Albedo What does this map show us? Compares anomaly of albedo in 2012 from the the average No colour change = 0 = no anomaly Blue = decrease in reflectivity from avg Ice albedo has decreased in Greenland  Ice Albedo Net increase in energy on Earth What is the effect of increased Earth’s Temperature temperature on albedo? What is the effect of albedo changes on the Earth’s climate Energy Absorption Amount of system? glacier Ice from sun Feedback loops in Earth’s Albedo of climate system glacier  Ice Albedo Terrestrial radiation Net increase in energy on Earth Which type of feedback loop is Earth’s Temperature this? Also notice the other feedback loop Energy Amount of Terrestrial radiation increases when temp Absorption glacier Ice from sun is high, which decreases Earth A stabilizing feedback loop Albedo of Lots of connections, lots of glacier questions Energy Budget - Imbalance What causes change in Watts/m2 (energy)? Which climate controls cause the imbalance? 1. Increased solar activity – not impacting change 2. Reduced reflectivity/albedo – clear evidence of change 3. Increase in greenhouse effect – clear evidence of change Learning Objectives Identify the 3 primary factors that effect energy flows (and energy balance) in our climate system Identify the evidence that shows which factor(s) create imbalance in the energy budget Define albedo. Determine the impacts of changing albedo on the hydrosphere, atmosphere (and other climate system components). Define anomaly. Understand how to identify anomalies in data.