Sparkling blue skies reigned over Beijing and other Chinese cities in the initial months of this year, but the smog has returned as the country's plants and factories sputter back to life.
It is a visible sign that priorities have shifted in the second-largest economy in the world - ensuring that growth is now Beijing's main focus, while environmental goals take a backseat.
Premier Li Keqiang signalled as much at the opening of the country's legislative meetings last Friday when he unveiled a stimulus package amounting to almost 3.6 trillion yuan (S$717 billion) and said economic performance was of "crucial significance".
Experts fear this money could be spent on "dirty" industries and infrastructure projects to spur economic growth, a move that could erase years of progress and be a setback for China's climate and emission targets.
In a departure from usual practice, Premier Li did not announce a target for economic growth this year, but neither did he set a goal to reduce energy intensity, which is the energy consumption per unit of gross domestic product (GDP).
Mr Li Shuo, senior adviser with Greenpeace East Asia, said the energy intensity reduction target was a notable omission and "sends a signal that economic considerations trump all other issues amid the difficulties that Covid-19 created".
The shift in priorities has raised concerns - pandemic aside, this year was supposed to be a crucial one for China's environmental goals. It is the final year of both its three-year "battle for blue skies" and its 13th Five-Year Plan, as the country's economic and social development agendas, set in five-year blocs, are called.
While it appears that Covid-19 threatens to upend Beijing's environmental targets for this year, China was committed to meeting them against the odds, Environment Minister Huang Runqiu said on Monday, on the sidelines of the meetings in Beijing.
It has set goals for reductions in energy and carbon intensity, emissions of major pollutants, and to increase its proportion of non-fossil fuels used.
"It will be difficult, but we are confident to complete it," Mr Huang said, conceding that there will be challenges in meeting targets for carbon intensity (the amount of CO2 produced per unit of GDP) and air quality in cities.
Greenpeace's Mr Li said whether or not China would make progress on environment indicators would depend on how its "macro economic policies unfold over the next few months".
"Not setting a GDP target for 2020 alleviates the immediate concern that Beijing will unleash more traditional infrastructure projects," he said.
But initial signs are not promising. Beijing has approved 7.9 gigawatts of new coal-fired power plants so far this year, more than the 6.3 gigawatts it gave the nod to in the whole of last year.
Coal is the most carbon-intensive fossil fuel and accounted for close to 60 per cent of China's energy use last year.
The coal approvals indicate that local governments were keen to boost the economy with large construction projects, say experts, who are worried that this trend could take hold.
Mr Huang had also warned against returning to "old paths, where the ecology and environment are sacrificed as the price to pay for economic growth, or to a model where we pollute first and clean up later".
Mr Li of Greenpeace called these traditional infrastructure projects "carbon bombs" and pointed out that decisions Beijing makes now would have a bearing on whether it could meet targets under the 2015 Paris Climate Agreement.
Under the pact, China had agreed to reduce carbon intensity by 60 per cent to 65 per cent below 2005 levels by 2030.
Mr Ma Jun, director of the non-profit Institute of Public and Environmental Affairs, said the biggest issue is ensuring China's economic recovery is one that is "green and low-carbon in nature".
"If this is not done right, it can increase the difficulty of meeting climate goals... Putting investments into coal power could hurt us in the long run," he said.
Beijing should take the chance to be more forward-looking and invest in infrastructure like renewable energy assets, and help its companies become more green and energy-efficient, he said.
Driving significant portions of its infrastructure spending to "power grid expansions and upgrades, efficiency improvements, and renewable energy generation" would, in the long term, benefit China environmentally, strategically and economically, said Nicholas Institute for Environmental Policy Solutions senior fellow Jackson Ewing.
"All of these will take political will, even as other concerns loom large," said Professor Ewing.