Farmers and Glaciers in Northwest China

A farmer in arid Gansu (Source: Mike Moss/Creative Commons).

Extending across the provinces of Inner Mongolia, Qinghai, and Gansu, the Heihe River Basin is the second largest inland river basin in China. With a core drainage area of 130,000 km2, it is home to 121 million people, and roughly 74 million of them practice farming or animal husbandry. In recent years, water demand has rapidly increased, while water availability has decreased due to glacier retreat and groundwater depletion. As a preliminary step to combat this looming crisis, a team of Chinese researchers set out to assess whether local farmers and herders were aware of glacial change and, if so, what their attitudes were toward state and local response strategies. The results, published last month in Theoretical and Applied Climatology, offer an intriguing look at the way local knowledge and state media intersect in rural China.

Guofeng Zhu, a professor of geography and environmental science at Northwest Normal University and the paper’s lead author, spoke with GlacierHub in Mandarin about the stakes of this research for farmers in the region. “Alongside population growth and climate change in recent years, the pressures on the Heihe River Basin’s ecological system have become increasingly severe. Over 70 percent of the water used for agricultural irrigation comes from the river. The question of whether farmers can efficiently adapt is of grave importance to sustainable development in the region,” Zhu said.

Researchers interview a local farmer (Source: Guofeng Zhu/Northwest Normal University).

To carry out the study, the researchers conducted informal interviews in five villages. The villages were selected according to their location along the river, with upstream, midstream and downstream villages all represented. Individual villagers were selected to be interviewed so as to provide a diverse sample size across socio-economic, educational, and occupational values. The team asked open-ended questions and also distributed a multiple-choice survey. The researchers surveyed residents about their impressions of glacier change and used data from the China Meteorological Data Sharing Service Network to assess if residents’ perceptions were accurate.

Runoff from the Qilian Mountains (Source: feelings3allen/Creative Commons).

The glacial data itself paints an unsettling picture: from 1970 to 2012, the total glacier area in China’s northwest shrank by 10 to 14 percent. This, when coupled with population growth and reductions in cultivable land per capita, does not bode well for agriculture intensive areas in arid regions, such as the Hexi Corridor, which feeds nearly the entire population of Gansu Province. The farmers living in this fragile ecosystem are faced with annual droughts that in some years can exact a heavy toll on crop yields and animal abundance. Stemming primarily from changes to the permafrost active layer of the Qilian Mountains, the meltwater that accounts for 15 percent of total runoff of this life-sustaining river is in jeopardy.

Rivers sustain agriculture in this arid region (Source: Dan Lundberg/Creative Commons).

In an interview with GlacierHub, Dahe Qin, a glaciologist at the Chinese Academy of Sciences and an author of the paper, emphasized that the story of the Heihe River Basin resounds throughout the region. “The situation of Heihe is the same as that of the other river basins of the Hexi Corridor. Global warming, as well as degradation to glaciers and the cryosphere, is having a profound impact on the oasis regions, impacting the livelihoods of millions,” he said.

The farmers and herders interviewed seem to be acutely aware of the situation. Of respondents, 82.1 percent indicated that glacier retreat was a fact. Unsurprisingly, those living upstream near the glaciers themselves were most cognizant of this fact, having observed firsthand their retreat. Their perceptions of glacier retreat were also the most highly correlated with scientific observations. Education level was another strong predictor of whether farmers were aware of glacier retreat.

A farmer living in the midstream area is interviewed (Source: Guofeng Zhu/Northwest Normal University).

Gender, ethnicity and age had no impact on awareness of glacier retreat. 85.6 percent of farmers reported that they had heard about glacial change from television. However, simply being a farmer who watches television does not mean that one will become concerned with glacier retreat. The team interviewed farmers living in a nearby river basin who had a much lower reliance on glacier runoff and found that farmers there were less concerned about glacier change than those living in the Heihe River Basin. This finding suggests that concern for glacier change is associated with the degree of reliance on glacier runoff for livelihood.

While 90 percent of those polled believed that global warming is the primary cause of glacier reduction, roughly 30 percent of respondents did not believe that waste burning and car exhaust were factors. This attention to global, large-scale factors and the comparative lack of concern with local impact surfaced in other interesting ways. Respondents located the causes of air pollution in other, more industrial regions, and believed that changes to glaciers were the result of complex, trans-regional forces.

A herder living in the upstream area is interviewed (Source: Guofeng Zhu/Creative Commons).

Accordingly, the burden of mollifying the impact of climate change was overwhelmingly seen to be the task of governments and transnational organizations: the U.N. (56.4 percent), central government (52.7 percent), and polluting enterprises (47.8 percent) were most responsible in the eyes of respondents, whereas just 21.3 percent believed that the local government was responsible for ecological restoration and management. Because most farmers did not believe they were responsible for causing glacial changes, only 11.1 percent responded that individuals or households should bear the burden of resolving the problem. The authors point to the role of the media in shaping these views, with many responses being impacted by news of the recent Paris Climate Agreement.

According to the authors, although outside expert knowledge is often inaccessible within these communities, it nonetheless plays a significant role in shaping local livelihoods. Farmers feel powerless before the hegemony of scientific knowledge: they are ever more uncertain of traditional knowledge and thus increasingly incapable of making important decisions for their own future. Zhu emphasized that farmers need to be encouraged to hold on to traditional knowledge and practices. “Our survey showed that farmers commonly view traditional herding and farming livelihoods as backward, and they aspire to urban life. That they psychologically reject farming and herding and are unfamiliar with traditional practices will weaken efforts at curbing climate change,” he said. By understanding farmers’ perceptions of glacier change, policymakers are better equipped to help them adapt to deleterious changes in their environment.

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Could Temperate Rainforests Survive Global Warming?

Douglas Island. Source: Joseph/Flickr
Douglas Island. Source: Joseph/Flickr

Nowadays, most of Europe’s temperate rainforests and the coast redwoods are disappearing as a result of over-harvesting. However, temperate rain-forests in Tongass and Great Bear (British Columbia) remain relatively intact. The Pacific Coastal Temperate Rainforest (PCTR) ecosystem stretches 4000 kilometers along coasts from northern California through Oregon, Washington and British Columbia to Alaska.

Known for its diversity, the PCTR region contains unscathed old-growth forests, substantial glaciers, wild fisheries, and human communities with economies based on natural resources and tourism. Studies show that global-scale warming will have stronger effects on the northern PCTR’s climate rather than regional and decadal time scale climate processes, including El Nino Southern Oscillation, Pacific Decadal Oscillation, and Arctic Oscillation. The northern PCTR is anticipated to undergo warming and receive less precipitation in snow in the coming decades.

Ecosystem linkages in the northern Pacific coastal temperate rainforest (PCTR). (Source: Shad O'Neel et al.)
Ecosystem linkages in the northern Pacific coastal temperate rainforest (PCTR). (Source: Shad O’Neel et al.)

Glacier coverage in northern PCTR is roughly 16% – there are 141 lake-terminating glaciers and 49 tidewater glaciers in the region. With so many glaciers, the region is particularly susceptible to ecosystem-level impacts of glacier change. Moreover, glacier mass loss rate in the region is anticipated to rise, with a total glacier volume loss of 7200 – 10000 cubic meters by the end of the twenty-first century. Glacial volume variability in northern PCTR involves prominent physical and chemical changes in hydrology, which should not be neglected because it serves as the primary source of freshwater to the Bering Sea. In addition, regional species diversity and species turnover could be influenced by glacier runoff.

On Benjamin Island. Source: Joseph/Flickr
On Benjamin Island. Source: Joseph/Flickr

A recent study published in BioScience discussed impacts of glacier volume change on surface water hydrology, biogeochemistry, coastal oceanography, and ecology. Total freshwater discharge from northern PCTR adds up to 870 cubic kilometers, half of which originates from glacier-covered area. More importantly, extremely short glacier-to-ocean stream length in the area, around 10 kilometers, allows rapid transfer of riverine substances, including sediment, nutrient, and organic matter, to estuaries and fjords. In other words, glacier change alters the terrestrial hydrologic cycle, which is significantly connected to near-shore marine ecosystem.

Freshwater runoff in ice-free basins and glacierized basins is primarily dependent on precipitation and surface energy balance respectively, because positive energy balance can result in glacier melting. The authors of the study, Shad O’ Neel et al, also found that glacierized watersheds tend to have higher annual freshwater discharge. The streamflow variability of glacierized basins varies in dissimilar patterns on different time scales. According to O’Neel and his colleagues, as glacier melt increases as a result of warmer temperature in the future, it will be more difficult to predict the variability of streamflow originated from glacierized basins.

Toward the Chilkats. Source: Joseph/Flickr
Toward the Chilkats. Source: Joseph/Flickr

In general, glacier ecosystems have strong impacts on biogeochemistry of downstream marine ecosystems through the release and cycling their nutrients, organic matter, and contaminants. The origin of organic matter in glacier ecosystem can be attributed to a variety of sources, including aerosol deposition, subglacial biological processes, as well as subglacial organic matter. In fact, glacier runoff in northern PCTR releases tremendous amount of organic matters. Those organic matters are primarily produced through microbial production and atmospheric deposition rather than plant detritus, which appears to be extremely bioavailable to heterotrophic organisms. In other words, glacier ecosystems are a significant source of organic matter in both riverine and near shore marine ecosystems. Unfortunately, melting mountain glaciers also bring pollutants to the near shore aquatic ecosystems, such as fossil fuel combustion byproducts and mercury. Moreover, downwelling caused by wind-forced Ekman transport has a consequence of nitrogen delivery to near shore region from off shore waters. In return, high flux of glacier runoff brings iron to off shore regions.

Kayak and Herbert Glacier. Source: Joseph/Flickr
Kayak and Herbert Glacier. Source: Joseph/Flickr

The coastal ocean circulation in northern PCTR is dominated by the counterclockwise Alaska Coastal Current, which transports heat, nutrients, and organisms northward to the Arctic. Freshwater runoff also plays an important role in affecting the vertical stratification of coastal water column. Specifically, coastal waters are well mixed and replenished with nutrients in winter. And they become stratified due to freshwater runoff in spring. Shad O’ Neel et al. pointed out that the impact of glaciers on physical oceanography of the northern PCTR is conspicuous in glacierized fjords. Cold and low-density freshwater discharge from seafloor glacier upwells to the surface while mixing with fjord water. As it rises to the surface, it leads to submarine melt of the ice cliff, and contributes to fresh overflow plume. Furthermore, nonlinear freshwater flow dynamics associated with deep-water calving fronts results in catastrophic glacier recession. As a result of a decrease in active tidewater glaciers in Alaska, the amount of fjords with glacier-driven circulation and tidewater glacier habitat also decline.

Dinner Time. Source: Kyle Breckenridge/Flickr
Dinner Time. Source: Kyle Breckenridge/Flickr

According to the study, glacier runoff generally leads to increase in regional species diversity and species turnover. For instance, “streams with moderate basin ice cover (5% – 30%) tend to have the highest macroinvertebrate taxonomic diversity, although macroinvertebrate abundance is generally low in these watersheds”, as described by the article. Glaciers also directly affect upper trophic level species in fjords, on which important fishery and tourism industries rely. Icebergs calved from glaciers serve as protection for predators, a habitat for harbor seals, and a resting space for seabirds.

In sum, the northern PCTR is economically significant to northern California, British Columbia, and Alaska due to diverse resources. Understanding both long-term and short-term glaciological variability is essential to decision-making and risk management processes. After all, glacier volume and extent variability is closely linked to surface-water hydrology, biogeochemistry, coastal oceanography, and ecology. Therefore, Shad O’Neel et al. suggested that “a holistic scientific approach should be undertaken to begin to resolve these uncertainties in ways that maximize utility to the resource management community and allow efficient and informed decision-making in an era of rapid ecosystem change”.

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