Newly released data show that global CO2 emissions had returned to pre-pandemic levels by the end of last year and surpassed them in some major economies.

Why it matters: The International Energy Agency warned that clean energy efforts are falling short.

• It's important to clear the decks by noting that a tragic, economy-hobbling pandemic is not a climate policy and is a terrible reason for emissions cuts.
• But the IEA and other multilateral agencies have called on nations to stitch support for clean energy into their recovery packages — and warn that's not happening nearly enough.

What they're saying: "The rebound in global carbon emissions toward the end of last year is a stark warning that not enough is being done to accelerate clean energy transitions worldwide," IEA executive director Fatih Birol said in a statement.

• "If governments don’t move quickly with the right energy policies, this could put at risk the world’s historic opportunity to make 2019 the definitive peak in global emissions," he said.

The big picture: IEA estimates that global energy-related CO2 emissions fell by 6% last year, the steepest drop since World War II.

• IEA's chart above shows monthly emissions levels compared to 2019.
• In December, emissions had crept 2% above the prior year's levels as activity rebounded.
• China was the only country to see an increase on a full-year basis in 2020, albeit a small one.

How it works: Separate new analysis in Carbon Brief explores why emissions in China, the world's largest emitter, actually rose in 2020 despite the big restrictions early in the year.

• "China’s return to economic growth after its first Covid-19 lockdown has relied on stimulating polluting sectors, such as construction and heavy industry," writes Lauri Myllyvirta of the Centre for Research on Energy and Clean Air.

Threat level: Substantial global cuts are needed every year for decades to get the world on to track to meet Paris Agreement's goals for limiting long-term temperature rise.

• That's especially true for deal's most ambitious, long-shot target of preventing more than a 1.5°C increase above preindustrial levels.
• The UN estimates that global greenhouse gas emissions would need to decline by roughly 45% by 2030 compared to 2010 levels — that is, about a pandemic's worth of decline every year.