BEIJING, Nov 1, 2023 (BSS/AFP) - A thick haze has this week smothered Beijing
and surrounding areas, with tens of millions of people in northern China
under severe pollution warnings.

Here's what you need to know about the smog in northern China:

- Just how bad is it? -

China's weather office has said "foggy and hazy" conditions are prevalent in
the capital Beijing, the megacity of Tianjin, and parts of the provinces of
Hebei, Shandong and Hubei, home to more than 100 million people in total.

Many of Beijing's 22 million residents donned face masks on Wednesday morning
as they snaked through streets shrouded in a grey haze.

The pollution in some areas has been classified as "severe" and has at times
lowered visibility to less than 50 metres (164 feet).

Beijing has experienced five days with "unhealthy" pollution levels in the
last week, compared to just three such days in the past three weeks, air
quality monitoring firm IQAir's data showed.

IQAir said Beijing was the third most-polluted major city on Earth on
Wednesday, just ahead of Bangladesh's capital Dhaka.

Beijing's concentrations of hazardous PM 2.5 particles were more than 20
times higher than World Health Organisation guidelines, the firm said.

PM 2.5 particles, if inhaled, can have serious health risks, linked to
premature deaths in people with heart or lung disease, as well as a host of
breathing and other health issues, according to the US Environmental
Protection Agency.

- Are things getting better? -

A decade ago, Beijing routinely choked in off-the-charts smog that stoked
public health anxiety and was dubbed the "airpocalypse" by Western
commentators.

China declared "war on pollution" after winning the Winter Olympics bid in
2015, shutting down dozens of coal plants and relocating heavy industries.

That has brought significant improvements, but air quality often remains
below World Health Organization standards and severe pollution is common in
China's capital.

In March and April, Beijing experienced six days when pollution levels were
considered "very unhealthy" -- meaning air quality had reached emergency
levels, data from the US embassy showed.

Beijing also experienced five days of "unhealthy" pollution levels around
October and November last year.

China is the world's biggest emitter of the greenhouse gases driving climate
change, such as carbon dioxide.

A recent jump in approvals for coal-fired power plants has added to concerns
that China will backtrack on its goals to peak emissions between 2026 and
2030 and become carbon-neutral by 2060.

- What are the causes? -

The capital's location plays a role. Nestled between deserts to the north and
dense industrial clusters to the south and east, the direction of the
prevailing wind can often determine whether the city sees blue skies or dense
smog.

But the bad air is also man-made: highly-polluting heavy industry, the common
use of coal burning for electricity and vehicle emissions, IQAir said.

Beijing's city government has blamed "unfavourable weather conditions" such
as high humidity and unseasonably hot temperatures.

It has said that colder weather may help dissipate the pollution.

- What steps have been taken? -

The second-highest air pollution alert is in place in Beijing until the end
of Thursday.

The alert orders businesses, builders and transport firms to cut their
emissions as a matter of urgency.

Further curbs, such as temporary bans on the use of some high-emissions
vehicles, will come into force if the highest alert -- already in force in
parts of Hebei province -- is triggered.

Authorities have also urged residents to reduce outdoor activities and
strenuous exercise during periods of high pollution.