Even though there was a slight decrease in global greenhouse gas emissions in 2020 because of the COVID-19 pandemic and the current La Niña event (a weather pattern in the Pacific that usually lowers global carbon emissions), it wasn't enough to offset previous increases.

"Since CO2 stays in the atmosphere for a very long time, each year's emissions add to those from previous years and cause the amount of CO2 in the atmosphere to keep increasing," Richard Betts, head of the climate impacts group at the Met Office and lead researcher for the forecast, said in a statement.

Related: 10 steamy signs in 2020 that climate change is speeding up.

Although the total amount of CO2 emitted worldwide in 2020 was down 7% from previous years, emissions have almost returned to pre-pandemic levels, according to the Met Office. 8

That means we have a lot of work to do to meet the International Panel on Climate Change's goal of limiting global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels.

"Reversing this trend and slowing the atmospheric CO2 rise will need global emissions to reduce, and bringing them to a halt will need global emissions to be brought down to net zero," Betts said.

"This needs to happen within about the next 30 years if global warming is to be limited to 1.5 degrees Celsius."