OpenStem

@openstem · Joined Jul 2026

7420 public items8 groups

Note~522 words · 3 min

Earth's climate system: energy balance, feedbacks, and global warming Earth's climate is determined by the balance between incoming solar radiation and outgoing terrestrial radiation. Human emissions of greenhouse gases are disrupting this

Environmental

Environmental · L4 · Earth's climate system: energy balance, feedbacks, and global warming

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Note~579 words · 3 min

Plate tectonics: mechanisms, evidence, and Earth's dynamic crust Plate tectonics is the unifying theory of modern geology, explaining the distribution of earthquakes, volcanoes, mountain ranges, and ocean basins. It describes the lithospher

Environmental

Environmental · L4 · Plate tectonics: mechanisms, evidence, and Earth's dynamic crust

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Note~586 words · 3 min

Oceanography: ocean structure, currents, and the water cycle Oceans cover 71% of Earth's surface to an average depth of 3,800 m (greatest depth: Challenger Deep, Mariana Trench, ~11,034 m). They regulate climate, absorb CO₂, produce 50% of

Environmental

Environmental · L4 · Oceanography: ocean structure, currents, and the water cycle

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Note~343 words · 2 min

Environmental Microbiology: The Biogeochemical Engines Every major biogeochemical cycle is, at its core, a chain of microbial metabolisms. Bacteria and Archaea catalyse nearly every redox transformation that moves nitrogen, carbon, and sulf

Environmental

Environmental · L4 · Environmental Microbiology: The Biogeochemical Engines

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Note~315 words · 2 min

Soil Science: How CLORPT Builds a Soil Profile Pedology is the study of soils as natural bodies — how they form, differentiate into horizons, and vary across landscapes. Every soil profile on Earth is the product of the same five interactin

Environmental

Environmental · L4 · Soil Science: How CLORPT Builds a Soil Profile

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Note~319 words · 2 min

Quantitative Hydrology: Tracking Where the Water Goes Hydrology quantifies the movement and storage of water through a watershed using a small set of governing equations — from a simple mass balance down to the physics of flow through soil

Environmental

Environmental · L4 · Quantitative Hydrology: Tracking Where the Water Goes

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Note~345 words · 2 min

Atmospheric Chemistry: How Photochemical Smog Forms Urban air pollution is less about what comes directly out of tailpipes and smokestacks than about what sunlight does to those emissions afterward. Photochemical smog is a textbook case of

Environmental

Environmental · L4 · Atmospheric Chemistry: How Photochemical Smog Forms

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Note~263 words · 1 min

Environmental Toxicology: Dose, Response, and Trophic Accumulation Toxicology rests on Paracelsus's founding principle — 'the dose makes the poison' — and environmental toxicology extends that idea across whole food webs, where a contaminan

Environmental

Environmental · L4 · Environmental Toxicology: Dose, Response, and Trophic Accumulation

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Note~299 words · 1 min

Remote Sensing & GIS: From Pixels to Maps Remote sensing captures environmental information from a distance — typically satellites or aircraft — while GIS (Geographic Information Systems) stores, analyses, and visualises that information al

Environmental

Environmental · L4 · Remote Sensing & GIS: From Pixels to Maps

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Note~371 words · 2 min

Environmental Law & Regulation: NEPA, CAA, CWA, and the EIA Process Modern U.S. environmental regulation rests on a handful of landmark statutes, each targeting a different medium or procedural gap — and each has close international analogu

Environmental

Environmental · L4 · Environmental Law & Regulation: NEPA, CAA, CWA, and the EIA Process

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Note~323 words · 2 min

Industrial Ecology: Designing Out Waste Industrial ecology reframes 'the economy' as a material metabolism — a set of flows and stocks that can be measured, mapped, and redesigned the way an ecologist maps nutrient cycling through a food we

Environmental

Environmental · L4 · Industrial Ecology: Designing Out Waste

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Note~343 words · 2 min

Environmental Economics: Pricing What Markets Miss Environmental economics starts from a diagnosis: markets routinely fail to price environmental harm, because the cost of pollution falls on third parties outside the transaction that caused

Environmental

Environmental · L4 · Environmental Economics: Pricing What Markets Miss

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Note~293 words · 1 min

Restoration Ecology: Setting Targets and Choosing Interventions Restoration ecology asks two connected questions for any degraded site: what should 'restored' actually mean here, and how much direct intervention does getting there actually

Environmental

Environmental · L4 · Restoration Ecology: Setting Targets and Choosing Interventions

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Note~281 words · 1 min

Wastewater Treatment Engineering: The Three-Stage Train A modern wastewater treatment plant is a staged filter, progressively removing coarser and then finer categories of pollutant — physical, then biological, then chemical — before efflue

Environmental

Environmental · L4 · Wastewater Treatment Engineering: The Three-Stage Train

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Note~265 words · 1 min

Air Pollution Control Engineering: Cleaning the Flue Gas Train Every major air pollutant category — particulates, SO2, NOx, CO, and hydrocarbons — has its own dedicated control technology, engineered around that pollutant's specific physica

Environmental

Environmental · L4 · Air Pollution Control Engineering: Cleaning the Flue Gas Train

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Note~337 words · 2 min

Climate Modeling: How Projections Are Actually Built A climate projection isn't a single forecast — it's the output of a physical simulation run under a defined future scenario, checked against the past, and compared across many independent

Environmental

Environmental · L4 · Climate Modeling: How Projections Are Actually Built

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Note~378 words · 2 min

Conservation Biology & Population Viability Once a species is reduced to a small remaining population, conservation biology asks a hard quantitative question: how small is too small, and what interventions actually change the odds of persis

Environmental

Environmental · L4 · Conservation Biology & Population Viability

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Note~390 words · 2 min

Environmental Acoustics & Noise Pollution Noise is regulated environmental pollution just like air or water contamination — but its physics is governed by a logarithmic scale that trips up intuition at almost every step, from simple additio

Environmental

Environmental · L4 · Environmental Acoustics & Noise Pollution

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Note~348 words · 2 min

Human Health Risk Assessment When a contaminant is found in soil, water, or air, regulators need a systematic way to translate 'this chemical is present at this concentration' into 'is this a health concern, and how much of one?' The USEPA'

Environmental

Environmental · L4 · Human Health Risk Assessment

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Note~366 words · 2 min

Integrated Water Resources Management Water is simultaneously a drinking-water source, an agricultural input, an industrial resource, a habitat, and (across borders) a geopolitical issue. IWRM is the management philosophy that tries to hold

Environmental

Environmental · L4 · Integrated Water Resources Management

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Note~377 words · 2 min

Renewable Energy Systems Engineering Comparing renewable energy technologies — and integrating them into a working power grid — requires more than knowing a generator's nameplate rating. Two metrics, capacity factor and LCOE, and two engine

Environmental

Environmental · L4 · Renewable Energy Systems Engineering

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Note~445 words · 2 min

Solid Waste Management Engineering Municipal solid waste (MSW) — everything from food scraps to packaging to demolition debris that households and businesses discard — has to go somewhere. Engineering that 'somewhere' safely, and increasing

Environmental

Environmental · L4 · Solid Waste Management Engineering

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Note~342 words · 2 min

Environmental Impact Assessment: Process and the Mitigation Hierarchy EIA exists to put evidence in front of a permitting decision before it's made — not to approve or block a project itself, but to make its likely environmental consequence

Environmental

Environmental · L4 · Environmental Impact Assessment: Process and the Mitigation Hierarchy

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Note~249 words · 1 min

Seismic Body Waves Two types of body waves propagate through Earth's interior: Travel-Time Tomography Given observed P-wave arrival times tᵢⱼ from earthquake j to station i, the forward model integrates slowness s = 1/V along the ray path:

Environmental

Environmental · L5 · Seismic Tomography and Inverse Problems

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Note~216 words · 1 min

The Rotating-Frame Navier–Stokes Equations In a frame rotating with angular velocity Ω (e.g. Earth), the momentum equation per unit mass for an incompressible fluid is: The centrifugal term Ω×(Ω×r) is absorbed into the effective gravity g.

Environmental

Environmental · L5 · Rotating Fluid Dynamics: Geostrophy and Ekman Balance

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Note~354 words · 2 min

Reservoirs, Fluxes, and the Mass-Balance Equation Quantitative biogeochemistry treats a cycle — carbon, nitrogen, phosphorus, sulfur — as a set of discrete reservoirs (boxes), each holding mass M_i, linked by fluxes F_ij that move material

Environmental

Environmental · L5 · Box-Model Formulation of Biogeochemical Cycles

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Note~344 words · 2 min

Isotope Ratios as Climate Recorders Stable isotope ratios are reported as δ values, in per mil (‰) deviation from a reference standard: Because lighter isotopes (¹⁶O, ¹²C, ¹H) react and evaporate/condense slightly faster than heavier ones (

Environmental

Environmental · L5 · Paleoclimate Proxies and Isotope Geochemistry

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Note~357 words · 2 min

Beer–Lambert Extinction Monochromatic radiation traveling through an absorbing gas attenuates exponentially with the optical depth it traverses: τ is dimensionless — a count of e-foldings of attenuation, not a physical distance. A band is '

Environmental

Environmental · L5 · Atmospheric Radiative Transfer

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Note~341 words · 2 min

The Levins Model: Occupancy, Not Abundance Classical population models track abundance N within a single population. Metapopulation theory instead tracks the fraction p of discrete habitat patches currently occupied across a landscape — abs

Environmental

Environmental · L5 · Landscape Ecology and Metapopulation Dynamics

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Note~309 words · 2 min

The Central Problem: Autocorrelation Inflates False Confidence Standard significance tests (t-tests, OLS trend tests) assume independent observations. Environmental time series — temperature, streamflow, CO₂ anomalies — are routinely serial

Environmental

Environmental · L5 · Environmental Statistics: Trend Detection in Serially Correlated Data

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