Climate & Environment
Between droughts and delugesNepal has of late witnessed deluges, unseasonal flash floods and landslides, long droughts and avalanches.
The year 2022 has been marked by record-breaking extreme weather events worldwide, bringing droughts and deluges.
And the phenomenon is on the rise and increasingly unpredictable.
From the “climate carnage” in Pakistan to 1,000-year floods, severe drought and temperature records worldwide, the warnings have turned into headlines, resulting in untold suffering of millions and incalculable loss of lives and property.
And all of it is happening sooner than warned in a world reeling from the socioeconomic aftereffects of the pandemic and the Ukraine war, which has directly affected food security, forcing countries to impose export bans and duties.
Climate scientist Santosh Nepal, who researches water resources and climate change at the International Water Management Institute-Nepal, says extreme weather events have increased significantly over the years and have become more frequent.
“In 2021, we witnessed one-in-1,000-year floods followed by devastating wildfires globally. This year has featured record-breaking heat waves followed by worst recorded flood disasters,” says Nepal, who is also a contributing author of global and regional assessment reports, including the Intergovernmental Panel on Climate Change report.
“All recent scientific studies indicate that there’s a rapid-onset of events which are unexpected (non-seasonal) and more dangerous as they have immediate impacts compared to a slow-onset of disasters which take time to develop.”
And there’s new writing on the wall.
Last week, a new report from the UN Environment Programme issued a stark warning that the world faces a “rapidly closing window” to limit global warming to well below 2C or to 1.5C this century.
The new report also says meeting global climate goals now requires “rapid transformation of societies” to avoid dangerous levels of warming as it warns that the world is likely headed for around 2.6C warming under existing policies.
“A warmer climate will intensify very wet and very dry weather and climate events and seasons, with implications for flooding or drought,” says Mandira Singh Shrestha, programme coordinator for Climate Services at the International Centre for Integrated Mountain Development.
“We see a shift in the regional weather patterns and the water cycles in Nepal. This year, the late retreat of the monsoon by a fortnight brought continuous rainfall throughout Dashain in central and western Nepal, resulting in floods and landslides.”
But the delay in the retreat of the monsoon by 15 days was enough to hammer Nepal with tragic consequences for the people. Lives were lost to flash floods and landslides, leaving a trail of devastation.
According to the National Disaster Risk Reduction and Management Authority, the 100 days of the monsoon killed at least 92 people and injured 61.
The government data also shows 11 people have gone missing and 5,465 have been displaced across the country in 344 incidents of floods, landslides and heavy rainfall.
While western Nepal was the most affected by the incessant rains, scientists say some parts of the region saw less rainfall due to the increased precipitation variability, leaving farmers challenged with less water availability and inducing an almost drought-like situation affecting paddy cultivation.
The impacts of the climate crisis on agriculture already pose a threat to Nepal’s food security and the economy. According to the Ministry of Agriculture, only last year, untimely rainfall in October caused a loss of 325,258 tonnes of paddy worth around Rs8.26 billion.
“It is increasingly hard to predict the weather as we witnessed last year in western Nepal, which witnessed record rainfall for two weeks past monsoon,” says Nepal, who has spent the past 16 years studying river basins and climate change in South Asia.
“The late retreat of the monsoon this year also resulted in a deluge and although the damage was comparatively less, it is a worrisome phenomenon that requires more research and consequent adaptation solutions for agriculture.”
Extreme precipitation, unseasonal rain-induced flash floods and landslides, prolonged drought, snow and hail storms, and avalanches have been intense in Nepal lately and recurrent, threatening mountain tourism and even forcing villages to migrate.
Scientific literature over the past few years has also warned that Nepal’s climate will likely get warmer and wetter and its impacts will only turn deadlier.
According to a 2019 report ‘Climate Change Scenarios for Nepal’ published by the Ministry of Forests and Environment, mean temperature for all seasons is projected to increase by 1.7C to 3.6C by 2100 and precipitation, barring the pre-monsoon season, could increase by 11-23 percent.
The projections are alarming because a warming earth is also a wetter earth. For every 1C increase in temperature, the atmosphere can hold an extra seven percent moisture, according to scientists who say extreme weather events are the consequence of an intensification of the global water cycle due to rising global temperatures and how it distributes water around the planet, influenced by the human-accelerated climate crisis. (The water cycle is a natural process in which liquid water evaporates into vapour, condenses to form clouds and precipitates back to the earth through rain, snow or hail.)
The global water cycle, according to scientists, is a continuous movement of water through the climate system from its liquid, solid and gaseous forms among reservoirs of the ocean, atmosphere, cryosphere and land.
As recent and past disasters have shown, water (or the lack of it) is an essential element of extreme climate events. Any disruption in the water cycle is thus critical to our environment and survival, but how exactly is the climate crisis disrupting the water cycle and how does it influence climatic conditions?
“Increasing temperature and warming of the atmosphere is not only resulting in changes in precipitation but also in the rate of evaporation,” says Shrestha, who specialises in disaster risk management.
“Land-use and land-cover changes also drive regional water cycle changes through their influence on surface water and [earth’s] energy budget.” (In layperson’s terms, the earth’s energy budget is the balance between the energy that the earth gets from the sun and the energy that flows back into outer space.)
The energy budget is thus vital in establishing the earth’s climate by keeping the temperature relatively constant.
But a significant imbalance in the energy balance primarily driven by human activities has increased the amount of carbon dioxide and other greenhouse gases and aerosols in the atmosphere.
Scientists say this imbalance increases temperatures on earth, contributing to an overall increase in atmospheric moisture and precipitation intensity with life-threatening consequences. At the same time, the water cycle takes a direct hit and speeds up.
“Due to global warming and increase in temperature, the water cycle is changing and is assessed to be intensifying through a higher exchange of water between the surface and the atmosphere,” says Shrestha.
Increasing temperature results in warmer air, resulting in dry land and more water vapour, which has two stark impacts on the world—drought and deluge.
A geographically diverse Nepal is already reeling under the two impacts of the disrupted water cycle—drought and heat waves in the cultivation season and heavy rainfall, deluges and landslides in the harvest season.
“Water cycle changes bring prolonged droughts with longer dry seasons,” Shrestha warns as she recollects last year’s forest fires that followed an unusually dry winter and spiked air pollution levels.
Short-duration rainfall extremes have also been observed across the country, resulting in flash floods and landslides which are more recurrent than before and even happen in higher elevations with disastrous consequences for people and infrastructure, as witnessed in Manang and Melamchi last year.
“There is a change in the nature of precipitation with rainfall occurring in higher elevations, bringing cascading disasters and economic losses,” says Shrestha.
“The 2022 late monsoon rainfall also resulted in a number of avalanches affecting the mountaineering expedition.”
At higher mountain regions where glacier shrinkage is perennial, snow accumulation has lately been delayed. There is less snow and it melts earlier as temperatures increase, directly impacting the country’s snow-fed rivers.
“Globally, the frequency of intense precipitation events was projected to increase while the frequency of all precipitation events was projected to decrease, leading to the contradictory-seeming projection of a simultaneous increase in both droughts and floods,” says Shrestha.