**4. Impacts and implications**

### **4.1 Ecosystem and biodiversity**

The increasing impacts of climate change on biodiversity become a progressively more significant threat in the coming decades as projected. The pressure of ocean acidification, resulting from higher concentrations atmospheric CO2 and loss of Arctic sea ice threatens biodiversity across an entire biome and beyond. The frequent extreme weather events with changing pattern of rainfall and drought, warming temperatures as projected there are significant impacts on biodiversity and ecosystem [27]. According to IPBES the three major challenges like land degradation, biodiversity loss and climate change increasingly dangerous impact on the health of our natural environment degrading land, pollution and overexploitation to land-use change and habitat loss threat to wildlife globally. As per the IPCC [28] AR4 projection 10% of species assessed approximately are in high risk of extinction for every 1 °C rise in global mean temperature, within the range of future

scenarios modelled in impacts assessments (typically <5 °C global temperature rise). In particular, aquatic freshwater habitats and wetlands, mangroves, coral reefs, arctic and alpine ecosystems, and cloud forests are vulnerable to the impacts of climate change.

Nepal is rich for globally significant biodiversity with 118 major ecosystems and 75 vegetation types harboring important flora and fauna occupying 39.6% (5,830,360 ha) forest area. Currently, out of total area of the country, 44.74% (6.61 million ha) is covered by the forests land including 17.32% Protected Areas (PAs) and 82.68% by other forest management regimes [29]. Nepal has established 20 protected areas with the goal of nature conservation covering 23.39% (34419.75 sq.km.) land area with2 12 National Parks, 1 Wildlife Reserve, 1 Hunting Reserve, 6 Conservation Areas, and 13 Buffer Zones extending from lowlands of Terai to high mountains.

Globally, Nepal occupies about 0.1% of global landmass harboring 3.2% flora and 1.1% fauna of the world's biodiversity including 5.2% of mammals, 9.5% birds, 5.1% gymnosperms and 8.2% bryophytes [30]. Similarly, Nepal government has declared 27 mammals, nine birds, 3 reptiles [31] under protection category. Among 208 mammal species recorded in Nepal, regionally 8 of them critically Endangered, 26 Endangered, 14 Vulnerable and 7 species nearly Threatened. Out of 886 bird species found in Nepal, 42 of them are globally threatened [32]. The species of flora and flora of Nepal listed in CITIES includes, 50 mammals, 108 birds, 29 Reptiles, 2 amphibians and 476 species of plants [33]. The updated checklist of CITES flora after CoP 17 includes, 154 species with 1 species in Appendix I, 149 species in Appendix II and 4 species in Appendix III [34].

The use of resources like grazing, fodder and fuelwood collection, timber extraction, collection of herbs, medicinal and aromatic plants, poaching, hunting and fishing are major threats for conserve biodiversity conservation. Among the 700 species medicinal plants in Nepal, more than hundred species exploited for commercial purposes. Loss and fragmentation of natural terrestrial and aquatic habitats and restricted mobility of migrant species due to habitat fragmentation is crucial problem. Poaching of rare species such as the tiger, rhino, bear (*Selenarctos thibatenus),* musk deer, snow leopard, gharial, and others is also critical problems. Nepal were to lose its remaining humid tropical forests, 10 species of highly valuable timber, six species of fiber, six species of edible fruit trees, four species of traditional medicinal herbs, and some 50 species of litde known trees and shrubs would be lost forever. Likewise, severely affected wildlife habitats are 200 species of birds, 40 species of mammals, and 20 species reptiles and amphibians [35].

The loss of biodiversity and vegetation leads to the changing pattern of natural environmental conditions occurring from numerous fundamental systems and decreasing number of species biodiversity due to modified environment and increased pressure on forest and vegetation [36]. The major impacts on biodiversity and ecosystems are loss of habitat due to encroachment of forest areas, expansion of agriculture and settlement in forest area, development of infrastructure within the forest area, planned priority projects within forestland to uplift economic development. Other major problem also leads to degradation of habitat due to overharvesting of biological resources, overgrazing and uncontrolled forest fire. Similarly, poaching and illegal wildlife trade, human-wildlife conflict, invasion by alien plant species, stone, gravel and sand mining threats ecosystem and biodiversity of the country. Nepal lost forest area by 2.1 percent and 1.4 percent during 1990–2000 and 2000–2005, respectively [37]. Nepal's forest area heavily degraded with loss of important biodiversity imposing landslides, and soil erosion, felling of trees for building materials and over lopping for fodder and fuel wood [38]. The unplanned infrastructure development such as schools, hospitals, temples, water storage

### *Climate Change in Asia and Africa - Examining the Biophysical and Social Consequences…*

tanks and other infrastructure within the forest area, particularly in the Tarai and Siwalik, 82,934 hectares forestland was reported under illegal occupation [39].

The major identified climate change impacts on forest and biodiversity in Nepal resembles; (a) increased temperature and rainfall variability, (b) changes in phenological cycles of tree species and shifting of tree line in the Himalaya, (c) shifts in agro-ecological zones, prolonged dry spells, and higher incidences of pests and diseases, (d) increased emergence and quickened spread of invasive alien plant species, (e) increased incidence of forest fire in recent years, (f) depletion of wetlands [40, 41]. The large scale development is a hallmark of the modern world, providing society with things humans' value but at an environmental cost [42, 43]. The major impacts on terrestrial or aquatic ecosystem associated with the developmental projects are:

