US greenhouse gas emissions tumbled below their 1990 level for the first-time last year as a result of the response to the coronavirus pandemic.
A preliminary assessment from research group Rhodium says that overall emissions were down over 10%, the largest fall since World War II.
Transport suffered the biggest decline, with emissions down almost 15% over 2019. Energy emissions also fell sharply, due to a decline in the use of coal.
In transport, the restrictions on international travel and non-essential journeys saw demand for fuel fall sharply. At the peak of restrictions, demand for jet fuel was down 68% on 2019, with petrol down 40%.
They have both bounced back as travel bans were eased later in the year but jet fuel demand was still 35% down in December compared to the previous year.
When it comes to electricity though the picture is more complicated as the demand for electricity was down just 2% but emissions fell by over 10%.