1. Draft Essential Principles with Fundamental Concepts By Marlene Kaplan & David Herring NOAA & NASA

2. Some discussion notes Noted that these EPs look a lot like the same EPs that were previously produced from the Climate Literacy Workshop, raising the question for the need for a different set of EPs. Noted that some Fundamental Concepts will likely support more than one EP. **Decisions humans make today will influence the future climate, but these are complex and have social and economic costs

3. 1. Earth is surrounded by a thin atmosphere that sustains life The atmosphere has 5 layers, each comprised mainly of gases and particles –Some of those gases come from geologic processes –Some of those gases come from sunlight-driven chemical reactions –Some of those gases come from life itself The atmosphere protects life forms from harmful solar rays The atmosphere distributes warmth and energy (average ~15°C) The atmosphere distributes water The atmosphere protects us from space debris and sun events (solar flares, etc.)

4. 2. Solar energy drives many atmospheric process The atmosphere receives energy from the sun, some of which is absorbed, some reflected, and some transmitted to the surface. Variation in exposure to sunlight causes the seasons Absorbed sunlight creates temperature differences that cause movements in the atmosphere –Convection is one such motion that leads to cloud formation & precipitation –Atmospheric movements create pressure differences that result in winds and weather patterns The chemistry of the atmosphere is influenced by incoming sunlight (e.g., formation of ozone)

5. 3. Atmosphere circulations transport gases, particles & energy Gases in the atmosphere absorb sunlight and emit heat –These gases, sometimes called greenhouse gases, keep Earth warm –Water vapor is Earth’s primary greenhouse gas; other important GHGs are carbon dioxide, nitrous oxide, methane & ozone –Many of these gases are essential to life; e.g. the oxygen we breathe, the ozone that shields us from UV Sun-warmed air carries moisture into the atmosphere Latent heat contained in water vapor is released into the atmosphere when clouds form The atmosphere contains solid and liquid particles, called aerosols –Plant respiration leads to aerosol formation –Winds transport bio-aerosols, sea salts,and dust, without which clouds wouldn’t form

6. 4. The atmosphere changes over time and space giving rise to weather and climate Temperature differences cause movements in the atmosphere –Convection forms clouds, leads to precipitation –Pressure gradients cause winds, frontal systems Weather and climate are related and linked, but distinctly different subjects –Weather is short-term, localized conditions in the atmosphere –Climate is long-term, large-scale statistical average conditions Severe weather and climate changes can adversely impact ecosystems and humans

7. 5. The atmosphere constantly interacts with other components of the Earth system Gases are exchanged with the other spheres –E.g., plants absorb CO2, give off oxygen Water is exchanged with the other spheres –E.g., plants absorb water and evapotranspire Energy & momentum is exchanged with the other spheres –The ocean and land surfaces release heat, cause drag –Winds influence ocean currents –Rains and temperature patterns determine ecosystems The atmosphere carries biomolecules –Winds transport dust & nutrients –Pollen & seeds

8. 6. Through measurement and the application of physical principles, humans can understand & predict the behavior of the atmosphere Humans observe and measure the physical and chemical state of the atmosphere –We use surface-, air-, and space-based instruments to observe & measure the atmosphere –We also use proxy data sets (ice cores, sediment layers, tree rings, etc.) to understand past weather & climate patterns –We use computer models to simulate weather & climate Our ability to predict weather differs from our ability to predict climate—climate is easier to predict –Weather is governed by the chaos and instability of the system happening at short-term, local scales –Climate is governed by a small number of well-understood forcings and feedbacks at long-term, large or global scales –Our understanding and ability to predict allows humans to make better decisions about our impacts on weather & climate, & vice versa

9. 7. The atmosphere and humans are inextricably linked The atmosphere impacts humans –Weather affects almost every aspect of our daily lives (tourism, agriculture, travel, etc.) –We need air to breathe Poor air quality affects our health Humans impact the atmosphere –Humans are changing the chemistry of the atmosphere, with global consequences (e.g., ozone hole; global warming) Humans add gases that help trap heat & raise Earth’s surface temperature Humans add particulates that can both cool and warm the surface by reflecting or absorbing sunlight Humans add pollutants that impact human and environmental health (e.g., respiratory complications, acid rain, etc.) –Human-released particles modify clouds to sometimes delay, sometimes intensify rainfall –Humans change the surface, which affects the warmth and particulates the surface gives to the atmosphere.