Earth Systems, Climate Change, and Sustainable Agriculture

Vocabulary practice flashcards covering plate tectonics, atmospheric physics, greenhouse dynamics, climate feedback loops, global circulation, and regenerative agroecological systems based on the lecture notes.

Oceanic Crust

A dense, mafic crust primarily composed of basalt and richer in metals, with a thin typical thickness of approximately $5\,\text{km}$, formed at sea floor spreading zones.

Continental Crust

A less dense, felsic crust rich in silica and composed of rocks like granite and pumice, characterized by a thickness of approximately $50\text{--}70\,\text{km}$.

Andes Mountain Formation

Orogenic formation where oceanic crust subducts under continental crust, creating a folded and faulted wedge of fossiliferous limestone at the edge and inland volcanism driven by crustal thickening and $\text{CO}_2$ release.

Himalaya Mountain Formation

A two-stage mountain-building process: first, the ocean between India and Asia closed via subduction; second, after oceanic crust was $100\%$ subducted, two continental plates collided without subduction, resulting in thickening, faulting, and folding.

Albedo

The measure of surface reflectivity (derived from Latin albus, meaning white), where an all-white surface reflects $100\%$ of light ($\text{Albedo} = 1$), an all-black surface reflects $0\%$ ($\text{Albedo} = 0$), and Earth's average is approximately $0.3$.

Solar Radiation

High-temperature ($\approx 6000\,\text{K}$), shortwave, high-energy electromagnetic radiation emitted by the Sun, primarily composed of visible light and ultraviolet radiation.

Terrestrial Radiation

Low-temperature ($\approx 300\,\text{K}$), longwave, low-energy infrared (heat) radiation emitted by Earth's surface after absorbing solar energy.

Electrically Lopsided Greenhouse Gases

Asymmetric molecules such as $\text{H}_2\text{O}$, $\text{O}_3$, and $\text{N}_2\text{O}$ that readily bend, move, and vibrate upon interacting with radiation, enabling them to absorb and re-emit infrared heat.

Symmetric Greenhouse Gases ($\text{CH}_4$ and $\text{CO}_2$)

Greenhouse gases that absorb and re-emit heat energy when molecular collisions disrupt their balance and induce movement.

Natural Greenhouse Effect

The planetary warming process wherein $70\%$ of incoming solar radiation is absorbed and re-emitted as infrared, and $90\%$ of this infrared is trapped and re-emitted by greenhouse gases, raising global average temperature by $33\,^\circ\text{C}$ (from $-18\,^\circ\text{C}$ to $15\,^\circ\text{C}$).

Sulfur Hexafluoride ($\text{SF}_6$)

A synthetic trace gas present at a concentration of $1 / 100\text{ billion}$ in the atmosphere, with a warming effectiveness $7000$ times greater than methane ($\text{CH}_4$).

Water Vapour Feedback Loop

A positive feedback cycle in which rising global average temperature increases atmospheric water vapor storage capacity, resulting in higher atmospheric $\text{H}_2\text{O}$ concentrations that further accelerate global warming.

Arctic Sea Ice Feedback Loop

A warming feedback mechanism where rising global temperatures melt floating sea ice, exposing darker seawater that absorbs more heat and further accelerates ice melt, resulting in an estimated $50\%$ reduction in ice cover.

Greenland Ice Sheet Melt Feedback

A positive feedback mechanism where melting lowers the surface elevation of land-based ice into warmer atmospheric layers, compounded by soot, algae, and bacteria reducing snow cover albedo and accelerating melting.

Coriolis Deflection

The atmospheric effect caused by Earth's rotation where winds are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, reaching a $90^\circ$ deflection after approximately $30^\circ\,\text{N/S}$.

Ferrel Cell

A mid-latitude atmospheric circulation cell whose circulating direction is mechanically driven by the stronger winds of the adjacent Hadley cell rather than direct thermal convection.

Hadley and Polar Cells

Classical thermal convection cells driven directly by uneven planetary heating between the equator and the poles.

Industrial Farming

An agricultural paradigm characterized by large-scale monocultures of annual crops, clean-cleared fields, heavy machinery, synthetic mining-based fertilizers, and chemical biocides (pesticides and herbicides).

Syntropic Agriculture

A process-based agricultural system designed to mimic natural forest dynamics and abundance, where humans organize diverse cooperating species to perform ecological work, resulting in high biodiversity and soil enrichment.

Forest Embryo

The dense polyculture planting strategy in syntropic agriculture of sowing $7\text{--}10$ diverse seeds per square meter ($\text{m}^2$) to initiate multi-tiered natural succession.

Pruning (Syntropic Strategy)

The deliberate cutting back of vegetation to open light and space, trigger plant growth hormones, and cycle up to $200\,000\,\text{kg}$ of organic matter per hectare per year ($20\,\text{kg/m}^2$ fresh, yielding $2\,\text{kg/m}^2$ dry matter) into humus.

Up-Pruning

A pruning strategy that trims lower branches to admit filtered light for understory layers, stimulate root growth hormones, and regulate canopy shade without over-clearing.

Coppice Pruning

Base-level pruning that triggers a massive surge of growth hormones and releases abundant vegetative biomass into the soil for mulching, composting, and animal fodder.

Agroforestry 2.0

A commercial, profit-oriented agricultural model combining intense pruning and planned succession by intercropping rows of diverse trees with field crops or fodder crops.

FMNR (Farmer Managed Natural Regeneration)

A low-cost reforestation method that restores desertified land by surveying, protecting, and pruning the resprouting shoots of the 'underground forest' (ancient native root systems).

Anti-Salinisation Measures

Soil management techniques designed to prevent toxic salt crusting from extreme evaporation, including mulching, establishing tree shade, sunken garden beds, and building soil organic matter (humus).

Forest Gardening

A temperate-zone permaculture system originating in Southwest England that mimics a natural woodland across vertical strata, integrating over $500$ edible perennial and self-sustaining plant species with minimal labor.

Perennial Vegetables

Edible crop plants that survive across multiple seasons and regrow yearly from their root systems without requiring seasonal soil tilling or replanting.

Regenerative Grazing (Planned Grazing)

A grassland management practice where compact livestock herds are rotated between paddocks every $2\text{--}3\,\text{days}$ to mimic wild herbivores (such as buffalo), stimulating rapid root growth and soil carbon sequestration across natural grasslands.

No-Till Farming

An agricultural practice that eliminates mechanical soil disturbance and utilizes cover crops, preserving underground fungal networks, soil biodiversity, and moisture retention.

Agro-Mining

A critical term for extractive industrial agriculture that depletes natural soil fertility, minerals, and organic life, treating living topsoil like an exhaustible mine.