Chronic winter drought and decades of unmanaged forest biomass have turned wildfires into a systemic risk for Nepal. We need to re-learn to convert fire fuel in forests into fertilizer for crops.
On 11 January, a huge forest fire spread rapidly from China into the forests of Sindhupalchok, 40km northeast of Kathmandu. The newly-opened Tatopani border checkpoint was closed. Smoke from the fire spread across central Nepal, blocking the sun.
The fire burnt itself out within a few days, but the border stayed closed for longer. Such wildfires were once rare in mid-winter, and traditionally peaked between March and May as temperatures rose ahead of pre-monsoon showers.
What is unsettling is not just the early onset of the fires, but also their scale. This shift is not accidental, the pattern has been unfolding over years due to winter drought, weakening post-monsoon moisture, and the accumulation of dry forest biomass as Nepal’s forest area doubled in the past 30 years.
Together, these factors have made forests tinder dry in spring, just waiting for a spark. Nepal has experienced winter drought in eight of the past ten years (this winter was an exception). Winter rain and snow at higher elevations play a decisive role in maintaining surface moisture, recharging shallow aquifers, and keeping forest floors damp enough to resist ignition. When winter rains fail, forests dry out months earlier than usual.
Satellite-based assessments show a steep decline in surface moisture across the middle mountains of Nepal, particularly in areas with dense forest cover but limited undergrowth management. Springs that once flowed year-round are now seasonal.
More than half of the springs in the mid-hills have either dried up or show significantly reduced discharge, a trend closely linked to declining soil moisture and disrupted recharge zones. Dry soil does not just threaten water security — it helps the vegetation ignite.
FUEL WITHOUT FUNCTION
For decades, Nepal’s forests have been accumulating dry leaf litter, fallen branches, shrubs, and deadwood. Historically, this biomass was not considered waste because rural households regularly collected leaf litter for livestock bedding, which was later composted and returned to farms as fertilizer.
Forest floors were therefore relatively clean while the mulch fertilized farms. That relationship has steadily eroded due to outmigration, changes in livestock systems, restrictions on access to community forests, and the growing availability of chemical fertilisers.
Community forests across the country today are thick with dry twigs, branches and leaves — a highly combustible carpet. When prolonged drought dries this biomass, even a small spark from a herder’s intentional fire, a cigarette, or lightning strike can trigger massive fires.
Under such conditions, the question is no longer whether fires will occur, but how intense and widespread they will be. Forest fires are often framed as an environmental issue concerning trees and wildlife. In reality, their impact extends far beyond forest boundaries.
Smoke travels faster and further than flames. Fine particulate matter, especially harmful PM2.5, spreads across countries. In recent fire seasons, air quality monitors in Kathmandu have recorded air quality levels several times higher than WHO guidelines. The smoke adds to Kathmandu’s own pollution and lingers for days.
Flights are cancelled or delayed in cities like Pokhara, and poor visibility blocks mountain views affecting tourism. Health facilities report spikes in respiratory complaints, particularly among children and the elderly. Just as wildfires have multi-sectoral causes, the impact of forest fires go beyond forests.
One critical dimension remains largely invisible: the soil. The fires cause silent damage beneath the ash, and the emergency does not end when the flames subside. Beneath the surface, soil suffers long-term damage. Organic matter burns away, beneficial microorganisms die. The soil structure weakens, reducing the land’s ability to absorb and retain water. The scorched earth is more prone to erosion, increasing the risk of floods and landslides once the rains return.
