1. A method of adjusting environmental variables in an adaptive parameter adjustment runtime environment, the method comprising: executing a parallel program by the adaptive parameter adjustment runtime environment, including beginning operations with a set of default global parameter values; maintaining, by a parameter control engine, a list of configurable parameters; changing, by the parameter control engine, a parameter value for a parameter in the list of configurable parameters; determining, by the parameter control engine, whether an effect of changing the parameter value is positive, negative, or neutral; responsive to determining that the effect of changing the parameter value is positive, changing, by the parameter control engine, the parameter value for the parameter; responsive to determining that the effect of changing the parameter value is negative, changing, by the parameter control engine, the parameter value for the parameter to a previous value; and responsive to determining that the effect of changing the parameter value is neutral, performing, by the parameter control engine, a list management operation on the list of configurable parameters.