To provide the most accurate answer, historical data on energy industry emissions in Oklahoma from 1995 to 2015 would be needed. However, in general, it is known that many states in the U.S., including Oklahoma, saw shifts in emissions due to various factors such as changes in energy production, increased adoption of renewable energy sources, and regulatory measures.
Typically, during this period, some states experienced a decrease in greenhouse gas emissions due to the transition away from coal towards natural gas and renewables. If I had to choose based on general trends observed in many regions from that timeframe, I would suggest:
"Greenhouse gas emissions decreased."
However, please verify with specific data regarding Oklahoma’s emissions for the most accurate answer.