Pakistan is experiencing rising temperatures and longer heat waves at a time when the number of rainy days have also reduced. Extreme temperatures are having serious impacts on urban centres which lack greenbelts to help minimise the sufferings. At the top of that, our construction has nothing to the weather trends and climate, resulting in generating an oven effect in the cities. On the other hand, the higher temperatures and heatwaves are also affecting the agriculture sector badly, pointing to an urgent need to modify the existing crop pattern. With Pakistan going through the worst economic crisis in its history, climate change poses a serious threat to the country which must ensure food security for its 240 million people who have been crushed by a record high inflation amid shrinking purchasing power. A latest study published in Science Advances and reported  has confirmed this trend, saying that climate change is causing heatwaves to slow to a crawl, exposing humans to extreme temperatures for longer than ever before.

While previous research has found climate change is causing heatwaves to become longer, more frequent and more intense, the new paper differed by treating heatwaves as distinct weather patterns that move along air currents, just as storms do. For every decade between 1979 and 2020, researchers found heatwaves slowed down by an average of five miles (eight kilometres) an hour per day. "If a heatwave is moving slower, that means heat can stay in a region longer, so that has effects on communities," senior author Wei Zhang of Utah State University told. – the comments clearly describe the experience we are having in Pakistan The researchers divided the world into three dimensional-grid cells and defined heat waves as a million square kilometre zones where temperatures reached at least the 95th percentile of the local historical maximum temperature. They then measured their movement over time in order to determine how fast the hot air was moving.

They also used climate models to determine what the results would have looked like absent human-caused climate change, and found manmade factors loomed large. "It's pretty clear to us that a dominant factor here to explain this trend is anthropogenic forcing, the greenhouse gas," said Zhang. The changes have accelerated in particular since 1997 and in addition to human causes, weakening upper atmospheric air circulation may play a part, the paper said. The duration of heat waves also increased, from an average of eight days at the start, to 12 days during the last five years of the study period. "The results suggest that longer-traveling and slower-moving large contiguous heatwaves will cause more devastating impacts on natural and societal systems in the future if GHG keep rising, and no effective mitigation measures are taken," the authors wrote.

Credit: Independent News Pakistan