Alert Sign Dear reader, online ads enable us to deliver the journalism you value. Please support us by taking a moment to turn off Adblock on Dawn.com.

Alert Sign Dear reader, please upgrade to the latest version of IE to have a better reading experience

.

Earthly matters: All fogged in

January 13, 2013

Email

The recent cold wave across the country not only made temperatures plunge, but also blanketed most of the Punjab, Sindh and Khyber Pukthunkhwa provinces in thick fog. While the residents of Lahore are used to the annual winter fog that starts in December, this year it spread all the way up to Islamabad and Peshawar and down to Sukkur and Larkana divisions. This is certainly unusual, but in keeping with what climate change scientists have warned us about “extreme weather conditions” in the years to come.

According to Dr Qamaruz Zaman Chaudhry, local climate change expert and Vice-President of the World Meteorological Organisation from Asia, “Normally, January is the winter rain season but this year the dry period was extended which might mean a change in climate patterns, although, of course, no single weather event can be explained by climate change”. He further explained: “The continuously dry conditions and the stable cold weather system with no winds concentrated all the pollutants in the lower levels of the atmosphere, causing the fog to spread”.

In his view, the pollutants creating the fog come mainly from across the border. “The main source of the pollutants in our lower atmosphere is Eastern Punjab where all the coal based industries are centred. Of course, we have added our share of the pollutants as well (from factory and car emissions)”. This year, the annual fog that extends into our side of the border stretched all the way to Islamabad. As for the cold, he says that it is “not unseasonable, but because of the fog people started feeling it more”. The foggy conditions lowered the daytime temperature because there was little sunshine to warm up the day.

In places near irrigation canals, rice paddies and rivers where there is more moisture available, the fog gets even thicker. In Chaudhry’s opinion, “The fog will only clear when a weather system from the west will wash away the lower layers of the atmosphere where all the pollutants are trapped”.

In Skardu‚ the temperature had dropped to minus 15 Celsius‚ while in Murree it reached minus three; in Islamabad and Lahore it was one and in Peshawar it was zero Celsius.

Across the border, India’s cold weather wave caught many residents in the north of the country without adequate central heating systems and more than 100 people died. Experts and officials are calling it the “coldest winter in a generation”. An Indian meteorologist stated: “January 2 was the coldest day in the last 44 years”. Ironically, they point the finger at Pakistan for sending in “the bone-chilling wind” from our western mountain ranges!

According to the Indian Meteorological Department, the minimum temperature was three degrees below normal at 4.4 degrees Celsius. One explanation being circulated in their media was that: “Cold air draining down from the Himalayas often causes problems at this time of the year and can lead to the formation of stubborn and extensive fog patches. The relatively weak sunshine is unable to burn it off and it tends to become trapped for several days, if not weeks”. No mention of the fact that cold, foggy days are a particular problem as cool air traps harmful gases and other pollutants near to the ground.

Until industries on both sides of the border start cleaning up their emissions and people start using more fuel-efficient transportation, people will just have to find ways to keep warm and stay indoors from dusk until late morning, when the fog starts to dissipate. After all, breathing in all these trapped pollutants (dust and harmful substances like sulphur dioxide, nitrogen dioxide and carbon monoxide) is not exactly healthy. Until the fog clears, avoid travelling at night and limit your outdoor activities. Those who are most vulnerable include those with pre-existing heart or lung conditions, smokers, and the very young or the elderly.