Oil prices have continued to plummet to a four-year low as the ongoing trade war threatens to impact energy demand.Tit-for-tat retaliation between the United States and China has raised concerns of a global recession.The decline in crude oil prices is a result of the aggressive trade agenda of US President Donald Trump and OPEC+ decision to loosen supply curbs.The market outlook remains uncertain with the potential for further downside risk to oil demand.