Unit 14: The Future of Humanity Section 1: Global Climate Change

Climate Change vs. Global Warming Climate Change – refers to overall change in temperatures, precipitation patterns, and storm frequency and intensity. Global Warming – refers to JUST the overall increase in Earth’s average surface temperature

Heat-trapping Ability Greenhouse Gases Specific Gas Heat-trapping Ability Relative Abundance Carbon dioxide (CO2) Low High Methane (CH4) Medium (25x CO2) Moderate Nitrous oxide (N2O) High (298x CO2) Some CFCs VERY High (14,800x CO2) Very Low Even though Carbon dioxide doesn’t trap heat very well alone, it is the highest in concentration (albeit less than 1% of the atmosphere CO2 has a HIGH residence time in the atmosphere, so it sticks around the longest in the air Water vapor is also a naturally potent greenhouse gas

Increasing Global Surface Temperatures Seem to be leading to… Changes in precipitation and wind patterns (major shifts in Jet Stream and other wind currents) leading to more severe storms and in other areas, drought and major temperature extremes (yes, some areas are getting COLDER) Thermal expansion of seawater – heat causes water molecules to expand from one another, causing seawater to spread out… leading to a rise in sea level Melting of polar ice caps – adds freshwater to ocean, causing local salinity problems and increasing volume of ocean, leading to sea level rise

Surface Temperature Increases Correspond to Increasing [ ] of Greenhouse gases

CO2 is our most closely monitored GHG What is the general trend for CO2? What causes the seasonal fluctuations in the [CO2] in the atmosphere?