TETRACHLOROETHYLENE (PCE)

A toxic chlorocarbon, widely known as “perc,” which forms a colorless liquid widely used for dry cleaning of fabrics.

THALWEG

Subsurface, groundwater stream percolating beneath and in the general direction of a surface stream; lowest thread along the axial part of a valley.

THC

Delta-9-tetrahydrocannabinol, more commonly known as THC, one of the naturally occurring cannabinoids found in cannabis

THE CLEAN DEVELOPMENT MECHANISM (CDM)

One of three market-based mechanisms introduced by the Kyoto Protocol to assist countries in finding ways to meet their GHG Emissions reductions targets. The CDM allowed industrialized countries to implement an emissions reduction project in a developing country and, in doing so, generate a marketable Certified Emissions Reduction (CER) credit.

THE INTERNATIONAL EMISSIONS TRADING (IET) MECHANISM

One of three market-based mechanisms introduced by the Kyoto Protocol to assist countries in finding ways to meet their targets. The IET mechanism allowed industrialized countries with unused, excess carbon allowances to sell these excess allowances to other industrialized countries that exceeded their targets.

THERMAL SPRING

A warm or hot water spring; many occur in regions of recent volcanic activity and are fed by water heated by contact with hot rocks far below Earth’s surface.

THERMOELECTRIC POWER

Electrical power generated by use of fossil-fuel (coal, oil, or natural gas), geothermal, or nuclear energy.

THERMOKARST

An irregular land surface formed in a permafrost region by melting ground ice and a subsequent settling of the ground.