Atmospheric dispersion, CO₂ emissions, greenhouse effect, ecosystem dynamics, traffic flow, and population — quantitative tools for environmental engineering.
— simulatorsQ: What is the difference between carbon neutral and net zero?
A: Carbon neutral means balancing emissions with offsets (forest carbon sequestration, CCS). Net zero is the broader concept of reducing absolute emissions to near zero, with only residual emissions offset. The 2050 net zero target under the Paris Agreement requires both deep reductions and high-quality offsets.
Q: What does the Lotka-Volterra model predict?
A: The predator-prey equations dx/dt = αx - βxy, dy/dt = δxy - γy produce cyclic oscillations. Prey grows when predators are scarce; predators crash when prey disappears. Real systems show this in lynx-hare cycles. Equilibrium: x* = γ/δ, y* = α/β.
Q: How is Pasquill atmospheric stability class determined?
A: Stability classes A–F (A: unstable, F: stable) are determined from surface wind speed and solar radiation (daytime) or cloud cover (nighttime). Class A gives large σy, σz (rapid dilution); Class F gives small values (poor dilution). Used in environmental impact assessment for air quality.
Q: What is life cycle assessment (LCA)?
A: LCA quantifies environmental impacts across the full product lifecycle: raw material extraction → manufacturing → transport → use → end-of-life. Standardized by ISO 14040/14044. A contentious issue in EV vs ICE LCA is how to account for battery manufacturing emissions and grid electricity carbon intensity.