We live in the Anthropocene age, meaning that humans and their activities have dominated the whole planet. Land use changes are taking place. Roads and concrete infrastructures increase flash floods, landslides, debris flows and soil erosion, even during normal precipitation
When it rains in Kathmandu, the city floods and traffic snarls up.
And, people blame it on 'climate change'. If it rains in Kirtipur and does not in Bhaktapur, people again link it to 'climate change'.
We erect houses on the river banks, build roads by cutting mountain slopes, and change the landform through construction. River banks and sloping terrain are prone to disasters during the monsoon season, but without scientific evidences, loss and damage outstretched due to the geologic fragility are again attributed to 'climate change'.
Short-term, spatial and temporal variation in the atmospheric condition is weather. Rainfall in Kirtipur and a sunny day in Bhaktapur at the same time is weather. Climate is a statistical terminology and represents an average condition of weather over a relatively longer period of time, often taken over a 30- year period as a reference.
Climate change represents a long-term shift in the weather and atmosphere-related changes happening over decades or even centuries. Climate and climate change cannot be observed; we can just expect them and experience their impacts. If Manang, located in the high mountains that have a cold climate, experiences increased mean temperature in the recent period compared to the mean temperature of the past, it's "climate change".
The scientific basis for the status of climate drive has improved markedly in the last decades. Nepal has experienced a mean temperature rise of 0.34°C per decade from 1976 to 2015, with an increase in the maximum air temperature by 0.45°C per decade and the minimum temperature by 0.09 °C per decade. No clear trend is observed in precipitation of Nepal.
The proxy impact indicators of climate change - shrinkage of glaciers, emergence of new glacial lakes and expansion of their surface area, snow cover change in the mountains, tree line and snow line shift, changing vegetation patterns - all clearly mark climate change, but the role of the changing climate on the recent disastrous events is not clear.
The flood in Pakistan (August-September 2022) that killed 1,678 people and affected one-third of the country, flood in the Mela-mchi River of Nepal (June 2021), floods in eastern and central Tarai (2017 and 2019), landslide of Achham (September 2022) that killed 22 people, and flash floods in the Kathmandu Valley are examples of other recent disasters. Are these events really happening due to climate change? All hazards that lead to disasters are not attributable to climate change, but surely have "fingerprints" of human-caused modifications of the natural environment.
No clear trends are observed for floods and landslides and casualties from them in Nepal. In the last decade, the highest human casualties have been observed - 166 in 2017 by floods and 148 in 2016 by landslides, followed by 131 in the 2013 floods and 138 in the 2015 landslides.
In addition, no correlation was observed between the hazards.
Climate change is a complex and interconnected issue.
In recent years, there is an increased tendency to blame and attribute all disasters to climate change, which is scientifically and technically not correct.
We live in the Anthropocene age, meaning that hus f h t a n N w w m c D c omans and their activities have dominated the whole planet. We are witnessing land use changes due to human activity. Roads and concrete infrastructures increase flash floods, landslides, debris flows and soil erosion, even during normal precipitation. The use of heavy equipment and heavy road traffic in geologically fragile areas trigger landslides, rockfalls and slope failures, and debris flows.
In Nepal, unpaved roads have increased rapidly in the last decade. Until 2011, about 22,000 km of road network was reported in Nepal. But by 2020, there was a strategic road network of 15,000 km and more than 70,000 km of local roads, according to the Department of Roads. The country has a road density of about 34.4 km per 100 sq km, up from 13.5 km in 2008. Only about 10 per cent of the roads are blacktopped, though.
Rapid urbanisation has resulted in significant change in buildup areas over the last three decades, especially in the Tarai and all major cities. Urban expansion in Nepal has quadrupled and covers approximately 0.32 per cent of the total land area.
Increased urban flash floods in the Kathmandu Valley at Hanumante River in Bhaktapur, and Dhobikhola, Balkhu and Kuleswor in Kathmandu are largely due to the obstruction of the natural flow path of the rivers by the people, not climate change. Such events will continue to be faced by the people in the region even without any climate change. Roads, dams and human constructions along the southern border of Nepal have caused flooding and water logging during the monsoon and are not attributable to climate change.
A report published last year on the Melamchi flood disaster concludes that the June incident cannot be attributed to a single factor, instead it is due to the cascading effects from multiple anthropogenic and climatic factors and processes.
The World Weather Attribution initiative, analysing the Pakistan floods, concludes that it cannot quantify exactly how much climate change contributed to the floods. Scientists confirmed that several factors contributed to the extreme event there.
All disasters should not be seen through the lens of climate change, instead a wide-angle view of the issues can enlighten us to understand and address them. Recent disastrous events should not be attributed directly to climate change, which is not only misleading but a misinterpretation of climate science.
Thakuri is a climate scientist and Dean of Graduate School of Science and Technology, and Graduate School of Engineering, Mid-West University, Nepal
A version of this article appears in the print on October 21, 2022 of The Himalayan Times.