Global Systems Flashcards
Energy Transfers to the Earth and Around
Energy from the Sun reaches Earth through radiation. Once here, it is either absorbed or reflected. Some of the absorbed energy powers the water cycle, drives weather patterns, and is used by plants in photosynthesis.
Importance of Energy Transfers to the Earth and Around
The energy balance on Earth is crucial for maintaining the planet’s climate. Solar radiation is either reflected by clouds and ice (high albedo surfaces) or absorbed by the Earth, which re-emits it as infrared radiation. Greenhouse gases trap some of this heat, warming the atmosphere.
The Earth’s Biospheres
The biosphere refers to the zone of life on Earth, encompassing all ecosystems, from forests to oceans. Earth’s biospheres include land (lithosphere), water (hydrosphere), and air (atmosphere), where living organisms interact. These spheres are interconnected, and energy and materials cycle through them (like water and carbon).
The Water and Carbon Cycles (Cycling of Atoms)
Atoms of water and carbon cycle through different parts of Earth’s systems.
Water Cycle
Involves processes like evaporation, condensation, precipitation, and runoff. Water moves between the atmosphere, oceans, and land.
Carbon Cycle
Carbon moves through the atmosphere, biosphere, oceans, and geosphere. Processes like photosynthesis, respiration, and decomposition move carbon between living organisms and the environment.
The Enhanced Greenhouse Effect
Human activities, like burning fossil fuels, add more greenhouse gases, intensifying the natural greenhouse effect. This extra trapping of heat raises global temperatures, leading to climate change. The increased warming disrupts ecosystems and weather patterns, threatening all living organisms.
The Greenhouse Effect (Naturally Occurring Process)
The Natural Greenhouse Effect
Solar Radiation: The Sun emits energy as visible light, ultraviolet (UV) radiation, and infrared (IR) radiation.
UV light is absorbed by the earths ozone layer
Absorption: About 70% of solar radiation, including visible and IR, is absorbed by the Earth’s surface, warming it.
Re-emission: The warmed surface emits energy as infrared radiation.
Greenhouse Gases: Greenhouse gases like carbon dioxide and methane absorb some of this IR radiation and re-radiate it in all directions, trapping heat in the atmosphere.
Temperature Regulation: This process maintains a warmer Earth, allowing for a stable climate.
Difference Between Greenhouse Effect and Enhanced Greenhouse Effect
The natural greenhouse effect maintains Earth’s climate; the enhanced version accelerates warming.
Drawing Tip: Show two diagrams, one for the natural greenhouse effect, where some heat escapes, and one for the enhanced effect, where more heat is trapped due to higher greenhouse gas concentrations.
Evidence/Indicators for the Enhanced Greenhouse Effect
Rising global temperatures, melting ice caps, and increasing ocean acidity.
Indicators include:
o Higher average global temperatures
o Melting polar ice and glaciers
o Rising sea levels
o More frequent extreme weather events
o Increasing levels of CO₂ measured in the atmosphere
Human Impact on Natural Cycles
Human activities, such as deforestation and industrialization, have altered natural cycles like the carbon and water cycles. Burning fossil fuels increases CO₂ levels, deforestation reduces carbon storage in trees, and excessive water use disrupts natural water flow, all impacting ecosystems.
Melting of Polar Ice Caps and Its Effects.
Melting polar ice raises sea levels, impacting low-lying coastal areas. As ice melts, it adds to ocean volume, threatening areas like small islands and coastal cities with flooding. It also reduces the Earth’s albedo, further accelerating warming.
Long-Term Impacts on Biodiversity Due to Climate Change
Long-term impacts include:
o Extinction of species that can’t adapt quickly
o Disruption of food chains
o Loss of habitats (e.g., coral reefs, Arctic environments) due to temperature changes
o Ocean acidification
More Carbon Dioxide in the Atmosphere
Higher CO₂ levels lead to more carbonic acid in the oceans, affecting marine life. CO₂ dissolves in seawater, forming carbonic acid, which lowers ocean pH (ocean acidification). This harms shell-forming organisms like corals and mollusks, disrupting marine food chains.
Possible Solutions to the Enhanced Greenhouse Effect
Solutions include:
o Shifting to renewable energy sources (solar, wind)
o Reducing deforestation and increasing reforestation
o Improving energy efficiency
o Capturing and storing carbon dioxide
