Focus on Science: ACSP's Main Research Goals in Nepal

Research Goals:

There are two principle research objectives for this research expedition: a) examine climate change impacts on the local ecosystem and the communities that depend up it, and b) sample snow and ice on Mt. Everest and Mt. Lhotse peaks. There are also several smaller projects led by other P.I.’s that will occur during the expedition.

Climate Change and Land Use in Sagarmatha National Park, Nepal

The goal of my work in the Himalayas is to document changes in high mountain ecosystems as they respond to the integrated effects of multiple stressors, including human land use decisions and climate variability and change. I work to identify and analyze patterns of land use and land cover change through time within the Everest region and to determine how management systems and anthropogenic activities are affecting conservation efforts in these protected areas and the livelihood systems at their fringes.

I spent the 2009/10 academic year in Nepal on a Fulbright Senior Scholar award working with graduate students teaching and collecting data extensively throughout the Everest region and the proposed expedition will allow us to resample these areas after a decade of change. To date we have collected 850 ecological ground reference data points and conducted 75 opportunistic and systematic field interviews with our Nepali colleagues to elicit people’s perception on causes and consequences of land cover changes. We used remote sensing data to detect land cover change and forest disturbance over two decades (1990 – 2010) in the Makalu-Barun protected areas that corresponded to the Nepali civil war.

After the collapse of the monarchy in Nepal in the early 2000’s, contemporaneous with a Maoist civil war (1996 – 2006), many government functions ceased. The conflict itself was driven by perceived inequalities in resource availability and this drove subsequent local responses to the abdication of resource management on the part of the central government resource exploitation in the region (Yonzon, 2004).

In lesser-developed countries, armed conflicts are typically associated with detrimental effects on land-based resources and biodiversity (Dudley et al. 2002; Velho et al. 2014). In Nepal, numerous studies have focused on land use - land cover (LULC) change (Zomer et al. 2001; Chettri et al. 2013) but few of these have discussed the potential environmental implications of the Maoist Civil War on LULC change and resources management practices

(Baral and Heinen 2006; Byers 1996; All et al., 2014).

Our 2009/10 initial results revealed that the amount of forestland had decreased by

almost 10 % over the 20-year period. The area also showed a significant decrease in shrub cover

and a significant proportional increase in grass cover. When examining the spatial pattern, it becomes apparent that the lower elevations, where the locals can easily access timber, experienced a significantly higher rate of forest cover change during the civil war. The pattern is more pronounced in the major valleys where the main trekking routes are located and the buffer

zone where the human pressure is higher. However, in the high elevations, there is a large

increase in area classified as forest or woodland as trees move into former shrub/grasslands and

as grass moves into former glaciated lands.

While our findings will be supplemented during the proposed expedition, we can surmise

that social factors including political conflict, the difficulty to enforce park management

strategies, increasing tourist demand, and consequent natural resources exploitation contribute to

explain some of the changes and conversions in forested area. It appears that proximal and distal

human-induced changes might be overwhelming any potentially beneficial climate change

impacts on growing conditions or the length of the growing season and subsequent high

elevation regreening.

Black Carbon Deposition on Himalayan Glaciers and Impacts on Future Water Supplies

The goal of our snow and ice sampling work on Mt. Everest and Mt. Lhotse is to

understand how air pollution and dust deposition increase the rate at which glaciers melt - and

thus threaten the downstream users of this water over the long-term. Our team of five climbers

will sample snow and ice from 5200 meters to 8848 meters on these peaks in order to measure

the surface particulates present. Light absorbing particles (LAPs) such as dust and soot (black

carbon) on snow and glacier ice are of significant importance for understanding hydrological

system functions (Bond et al., 2004). Black carbon (BC) is an organic substance that absorbs

light strongly in the ultraviolet, less so in the visible. BC is emitted from burning fossil fuels

(diesel and coal), biofuels (wood, dung and crop residue), open biomass burning associated with

forest clearing, and burning of urban waste (Bond et al., 2004). Mineral dust absorbs solar

radiation less efficiently by mass than BC, but can be present in much higher mass

concentrations. Dust can come from local sources or long-range transport from desert regions.

In the short term, BC and LAPs can significantly increase snowmelt rates, thus affecting

runoff quantity and timing. LAPs absorb solar radiation, which is converted to heat energy that

is conducted to surrounding snow and ice leading to melting and research has shown that snow

loss rates due to LAPs can be substantial. Painter et al (2010) found that dust deposition on

Colorado snow led to the snowpack melting out 4-5 weeks earlier than would have been

expected without LAPs. Over a 10-year period LAPs were shown to have the potential impact of

melting up to 713 kg/m 2 /year of ice on a Nepalese glacier - equivalent to 26% of observed mass

loss (Ginot et al., 2014). In the long term, persistent LAPs can lead to long term glacier loss,

thus draining natural reservoirs which provide year round water. From a societal standpoint, this

information is critical for water managers in water stressed regions.

Various measurements of LAPs have been conducted in Asia, but none have been

attempted above 6500 meters and so our work will fill a critical gap in the high Himalaya. Past

results have shown a large spatial variability in LAP mass – as measured through refractory

black carbon (rBC). Ginot et al. (2014) saw black carbon values as high as 100 nanograms of

rBC per gram of liquid (ng/g) on Mera Peak, Nepal in the dry season. Much lower values

averaging 2 ng/g but peaking at 32 ng/g were observed by Kaspari et al. (2011) in the Everest

region of Nepal. Ye et al. (2012) who reported values between 20 and 70 ng/g of BC in

northwestern China seasonal snow at altitudes up to 3500m. Our work at higher elevations on the ridgelines and summits should provide a more regional view of LAP deposition.

An additional important property of LAPs is that they do not evaporate or melt with the snow and ice and thus accumulate over time. Ming et al., (2016) showed that this effect, combined with dry deposition on a northern China glacier led to increases in surface BC and dust of 94 and 69 times the values observed fresh snow on a northern China glacier. Additionally, long range transport from desert regions in China, Africa, and the Arabian Peninsula may have effects on Himalayan glaciers (Budhavant et al., 2016). Even if we had good understanding of the transport of LAPs to glaciated regions, there are still substantial uncertainties in the quantity of LAPs actually deposited on glaciers and that is why our field expedition to sample the glaciers is so critical.