A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

Rank
Quality criterion for coal.

Reduction
The gain of one or more electrons by an atom, molecule or ion.

Reduction commitment
A commitment by a Party to the Kyoto Protocol to meet its quantified emission limit.

Reforestation
Planting of forests on lands that have previously contained forests but that have been converted to some other use.

Regional scale
A geological feature that crosses an entire basin.

Remediation
The process of correcting any source of failure.

Renewables
Energy sources that are inherently renewable such as solar energy, hydropower, wind and biomass.

Rep. Value
Representative value.

Reproductive dysfunction
Inability to reproduce.

Reserve
A resource (q.v.) from which it is generally economic to produce valuable minerals or hydrocarbons.

Reservoir
A subsurface body of rock with sufficient porosity and permeability to store and transmit fluids.

Residual saturation
The fraction of the injected CO₂ that is trapped in pores by capillary forces.

Resource
A body of a potentially valuable mineral or hydrocarbon.

Retrofit
A modification of the existing equipment to upgrade and incorporate changes after installation.

Risk assessment
Part of a risk-management system.

Root anoxia
Lack, or deficiency, of oxygen in root zone.

Root zone
Part of the soil in which plants have their roots.