Biodiversity in danger: Rapid global warming threatens ecosystems

With all living organisms connected to form food web, impact on even one species has potential to disturb life

KARACHI: Global warming is altering ecosystems everywhere, with species changing their habitats and behaviour in a life-and-death struggle to survive. Ecosystems in Karachi are also not immune to this change and many plant and animal species are believed to have moved or become extinct due to the changing environment. Given how intricately all living organisms are connected to each other to form the food web, impact on even one species has the potential to disturb life as we know it.



Tahir Rasheed, an environmental expert currently working with South Punjab Forest Company (SPFC), says dearth of scientific data makes it difficult to prove changes in local ecosystems but cautious observations over a long period confirm disturbance in the natural order.



“We are a research-deficit country and there’s no concrete work on this issue except for sporadic studies. Based on personal experience and what older people have observed, we can say changes have occurred in Karachi in terms of plants and animals found in the city,” Rasheed says, adding that extreme weather events such as heatwaves and cyclones have damaged habitats for not just the humans but the city’s flora and fauna as well.

Explaining how climate change affects ecosystems, an expert from the International Union for Conservation of Nature (IUCN), Danish Rashdi, says changes in the atmosphere have an adverse impact on rain pattern, soil conditions, rangeland productivity, species health and reproduction as well as competition for food among the species - the combine effect of which is disorder in our ecology.

“Rising temperatures and weather change result in species moving from lower altitudes to higher levels in search of optimal temperature for survival. Plants also adapt to weather patterns but erratic change may cause death and disappearance of certain species,” Rashdi shares.



This whole process, he says, affects the ecosystem of the region and hence human livelihoods. “In the case of Lyari in Lasbela district, the population of a very rich and well-settled village migrated due to the changes in environmental conditions which affected the socio-economic and ecological setting of the area,” Rashdi explains.

Survival of the fittest

Sharing specific observations from Karachi, environmental expert Rasheed says there were certain areas in Karachi where one could easily witness parakeets and parrots flying around but not anymore.

“They have now been replaced with another species called kite. Karachi was also home for Egyptian and griffon vultures and they were found in abundance in areas around Lyari River and on small hills within the city but they are missing today,” he lists.

These animals are either extinct or have been replaced by a different species. “This is an indicator how climate change has affected our ecosystem,” he says.



With reference to changes in aquatic life, SPFC’s Rasheed mentions the increase of Indian mackerel species in the Arabian Sea in the last 15 to 20 years. “Iran, where the species was never found, is now catching and exporting it. Similarly, the population of Indian oil sardine has declined due to changes in sea currents and tides,” he states.

Apart from relocation, Rasheed says behaviour of certain species has also changed due to climate change. “Japanese threadfin breams always lived at the bottom of sea but now they are seen at the surface. Resultantly, their catch has also increased because of this change,” he says.

Rasheed says climate change is the likely reason behind these changes along with many other factors.

Protecting ecosystems

Though climate change is a global phenomenon, IUCN’s Rashdi says adaptation measures can be taken at local level to retard its impact. “Forestry projects on public and private land and in urban areas may improve local weather conditions and rain patterns. Carbon sequestration by these plants may also have positive impact on our agricultural and rangeland zones,” he says.



By supporting and improving the local weather, Rashdi explains, we will be able to support local species of fauna and flora that ensure balance in our socio-economic and ecological systems.

Additionally, SPFC’s Rasheed calls on the relevant authorities to make concentrated efforts particularly in the field of data collection to predict the future implication of changes in our habitats and be better equipped to deal with them.

This is the third of a four-part series on the effects of climate change in Karachi

Published in The Express Tribune, September 18^th, 2016.