But this year the skies are clear,

that's because the coronavirus epidemic

had brought much of the country to a standstill

for several weeks causing a huge drop in pollutants

like nitrogen dioxide,

a harmful gas that's emitted when burning fossil fuel.

Compared to previous years it's below typical levels.

- If you close down factories or reducing the amount

of cars on the road you're going

to reduce the pollution levels.

And from that we can deduce that the economic activity

has been decreased.

In early February Chinese president,

Xi Jinping publicly declared a people's war

against the virus,

that extreme measures like shutdowns have prevented people

from returning to work where necessary.

But he also cautioned that those efforts

should not jeopardize economic development.

Now a dramatic change in pollution over the country suggests

that striking that balance could be difficult.

In the past few decades China has grown

to become the world's largest coal consumer.

Its large manufacturing-based economy burns 95&00:01:10,310 --> 00:01:11,750 of the country's coal,

making it the world's biggest emitter of greenhouse gasses.

Usually during the Lunar New Year most industries wind down

for a week and power plants burn a lot less coal.

Coal consumption usually rebounds after the week-long break

which means pollution levels pick up too.

- Because the levels of nitrogen dioxide

in China are so high we can easily detect that from space.

This is what Wuhan,

the epicenter of the coronavirus usually looks like

after the holiday.

The city is a key producer of automobiles,

electronics and heavy machinery.

But this year the demand

for coal hasn't immediately rebounded since many workers

have been stranded at home in locked down cities,

and nitrogen dioxide levels have dipped.

It's not just Wuhan,

it's the same when you look

at other industrial powerhouses in China.

This is what Shandong and Hebei usually look like

after the holiday.

They're know for churning out everything

from textiles and metals to petrochemicals.

But this year they also weren't spared

from the impact of the epidemic.

While skies were clear in many parts of China,

some cities like Beijing are still shrouded in smog.

The city has recorded high levels of air pollutants.

These fine particles are created

during the chemical reaction of gasses generated

from burning fuel.

Heating systems in Beijing's geography

can affect this reading.

But there's one huge source of pollution

that can't be missed,

major steel makers around the capital don't stop production

during the holiday because going offline is costlier

than running all year round.

So during the city shutdown some factories continue

to produce steel.

Li Hongmei is an analyst

who tracks the Chinese metal industry.

- Because of the outbreak all the normal pattern

has been broken so the construction sites are still

in the process of resuming work,

that's why their steel consumption slow down and delayed.

- [Narrator] Steel inventories are now at record high levels

because buyers in the construction industry

are demanding less right now.

Home sales were already cooling before the virus,

now they're below last year levels.

- Whenever you're not so sure about your national economy

you're not so sure about your job security,

about your income.

People definitely will be reducing expenditure

in a investment.

- [Narrator] In recent days Xi has been touting efforts

to meet economic targets while containing the virus,

like heavy stimulus to support banks and tax cuts

for small businesses.

But analysts say it's not clear whether these measures

can help make up for lost ground.

Some factories are slowly resuming production.

- So pollution levels that we're observing from space

are beginning to increase which may indicate

that economic activity could be resuming.

- [Narrator] Beijing recently put out the first full month

of economic data after the virus hit China.

The index tracks business sentiment among manufacturing

and service sectors and it falls

below the lowest level recorded

during the global financial crisis.

An increase in the number of infections overseas

could also put China's economy at greater risk,

complicating efforts to meet Xi's economic goals

for this year.

For now, one of the most visible indicators

to see how it all plays out might be just

to look up at the skies.

(relaxing music)