What country emits the most GHG? 

China emits the most greenhouse gases (GHG) .

Structural analysis of the top-five most GHG emitting economies

The paper does not provide information about which country emits the most GHG. The paper analyzes the economies of the top-five most GHG emitting countries in 2011 and their goals for GHG emissions reduction.

Policies undermine Brazil's GHG goals.

The provided paper does not mention which country emits the most GHG. The paper discusses citizen science programs and policies related to reducing emissions in Brazil.

China’s Building Energy Use and GHG Emissions

The provided paper does not mention which country emits the most GHG. The paper is about China's building energy use and GHG emissions.

Advancements in theory of GHG observation from space

China emits the most greenhouse gases (GHG) according to the provided paper.

Greenhouse gases emissions and electric power generation in Latin American countries in the period 2006–2013

The paper does not provide information on which country emits the most GHG. The paper is about classifying Latin American countries based on their greenhouse gas emissions and electric power generation efficiency.