LAHORE, Oct 29: The average autumn temperatures have risen by over three degrees Celsius over the past eight years in Lahore as compared to previous decades, according to data released by the Pakistan Meteorological Department. The changes have occurred due to a global climate change, which is causing gradual disappearance of autumn in some parts of the world, experts told Dawn.

A weather station on Jail Road recorded the October mean minimum temperature up by an average of three degrees Celsius: from 17.3 degrees Celsius during 1971–2000 and up to 20.6 degrees Celsius in the period 2000 – 2007. The 1931 – 1960 average was 17.3 degrees Celsius.

The figures for November are even more significant. The November mean minimum temperature rose by 3.5 degrees Celsius: 11.2 degrees Celsius in the period between 1971 and 2000 as opposed to 14.7 degrees Celsius in the period between 2000 and 2007. The 1931 – 1960 average was 9.6 degrees Celsius.

Similarly, the winter has also shrunk with average temperatures steadily risen in urban Lahore as compared to a station based outside the city – a phenomenon attributed to urbanisation, or the creation of “urban heat islands”.

Despite a harsh winter in 2007, average winter temperatures have also risen. At the Jail Road monitoring station, the January mean minimum was 7.9 degrees Celsius in the period 2000-2007, 6.7 degrees Celsius during 1971-2000, and 5.1 degrees Celsius during 1931-1960.

This contrasts sharply with a monitoring station in Lahore Cantonment (near the site of the old Lahore airport), where the January mean minimum for the period 2000-2007 was 5.0 degrees Celsius – a full 2.9 degrees Celsius cooler than the city centre at Jail Road.

Commenting on the results, M Manzoor, an official at the Meteorological Department said the disparity in winter temperatures between the city centre and the cantonment station could be attributed to urbanisation. “There are far more cars, people, and industries in the city centre which creates local, or ‘micro-climatic’ changes,” he said.

Rafay Alam, an environmental lawyer and activist, added that global climate change was adversely affecting seasons in this region. “The monsoon season arrived in the 1st week of June this year for the first time ever,” he said, adding that the seasonal migration and breeding patterns of birds were also affected as the onset of spring came sooner. — Issam Ahmed