If you want to get down to the nitty-gritty and find the biggest single emitter, it's difficult.

NPR: And the Biggest Producer of Greenhouse Gases Is ��

An HSS emitter can put a message to a single person standing in a crowd 200 feet away, without anyone on either side able to hear it.

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An HSS emitter can transmit a message to a single person standing in a crowd 200 feet away, without anyone on either side being able to hear it.

FORBES: Now Hear This