The phrase "more emitting" refers to the act of releasing or discharging larger amounts of a substance or element into the environment. Some synonyms that could be used to replace this phrase include "more polluting," "more releasing," "more expelling," "more venting," "more discharging," and "more exuding." These terms all convey the idea of something being released into the air or environment in larger quantities. It is important to consider the context in which this phrase is being used, as different synonyms may have slightly different connotations or nuances that could affect the intended meaning of the message.