Atmosphere and Climate Change Overview

Atmosphere and Climate Change

• The atmosphere acts as a boundary between Earth and space, primarily composed of nitrogen, oxygen, and other gases like CO2, H2O, and argon. It's a dynamic system.
• Differential heating drives global climate patterns, explained by the three-cell model (Hadley, Ferrel, and Polar).
• The three-cell model influences precipitation and temperature distribution, impacting biome structure and productivity.
• The greenhouse effect is a natural process where greenhouse gases (GHGs) trap heat, maintaining suitable temperatures for life.
• Global Warming Potential (GWP) measures how effectively a GHG traps heat compared to CO2. For example, one unit of methane has a GWP of 21.
• Enhanced greenhouse effect results from human activities increasing GHG concentrations, leading to global warming.
• Climate change encompasses global warming and broader environmental shifts.

Climate and Weather

• Climate describes atmospheric conditions over long periods, driven by seasonal variations in temperature and precipitation.
• Weather describes short-term atmospheric conditions.
• Anthropogenic CO2 emissions have significantly increased CO2 concentrations, especially since 1980.
• Analysis of ice cores, tree rings, and sediments shows a positive correlation between atmospheric CO2 and global temperatures.
• Primary sources of GHGs include burning fossil fuels, land-use change (deforestation), and soil degradation.
• Climate change impacts ecosystems, from local to global levels (shifts, resilience).
• Climate change influences ocean circulation, sea levels, extreme weather events, desertification, and coral bleaching.
• Desertification is the process of fertile land turning into desert.
• Human societies are impacted by climate change across many aspects (health, water supply, agriculture, infrastructure).
• Negative and positive feedback loops are associated with climate change, some having long time lags. Positive feedback loops destabilize systems.

Addressing Climate Change

• Mitigation reduces the causes of climate change.
• Adaptation manages the impacts of climate change.
• Mitigation involves reducing global warming, lowering energy consumption, and reducing GHG production.
• Some strategies entail energy efficiency, renewable energy, dietary changes, agricultural adjustments, carbon taxes, and carbon removal.
• Carbon capture and storage (CCS) and enhancing carbon sinks are methods to remove CO2.
• Adaptation strategies include structural changes (flood defenses) and non-structural changes (drought-resistant crops).
• Decarbonizing the economy means reducing CO2-emitting energy sources and switching to renewable resources.
• Coordinated global efforts are crucial for preventing catastrophic climate change (IPCC, NAPA, UNFCCC).
• Albedo measures surface reflectivity (high albedo reflects, low albedo absorbs).
• Evidence shows that the Earth has already exceeded planetary boundaries for change.