An ecosystem is a geographic area where plants, animals and other organisms as well as weather and landscapes work and combine together to form a bubble of life. Ecosystem comprises both biotic as well as abiotic components, every factor in an ecosystem directly or indirectly dependent on the other factors. A sudden change in temperature, weather condition, soil moisture, precipitation often affect what types of plant will grow there as well animals that depend on plants for food and shelter will have to adapt to the changes,move to another ecosystem, or perish.

Nepal is one of the best known biodiversity hotspot, accumulating nearly quarter of the land area located in protected areas. Due to abrupt ecological and climatic transitions, Nepal and other Himalayan regions are most vulnerable to climate change. Climate change can alter the species habitat, their behavior of interaction in ecosystem, as well overwhelm the capacity of ecosystem to mitigate extreme events such as flooding, firing etc. Ecosystem entails all the living as well as non living creatures with which they interact like air, water and sunlight. Ecosystem perturbation due to climate change contributes direct impacts such as reduced water supply and quality, loss of iconic species, landscapes, wetlands, distorted rhythms of nature, and the potential for the extreme events to overwhelm the regulatory and ecological services of ecosystems. According to scientific research, if the same condition continues then there is the very possibility that over a century will jeopardize the integrity of the many terrestrial ecosystem on which we depend on.

Climate is an important environmental component that influences on ecosystem. The change in the climatic condition not affect ecosystem in a single way but in a diverse way such as warming enforce species to higher latitudes or higher elevations , changes in the timing of seasonal life cycle events, Range shift, food web disruptions, buffer and threshold effect, pathogens parasites and disease emergence, extinction risks. The report by National Climate Assessment 2009 has presented that climate change is likely the leading factors decreasing the population and shifting habitat range of America Pika, (Ochotona princeps) too. In Nepal forest and grassland in the various eco regions are heavily converted, fragmented and degraded as a result of which various species are under threat from local extinction. Most of the vulnerable species are tiger (panthera tigris), Asian elephant,greater one horned rhinoceros, clouded leopard, snow leopard, wild dog. We can also see that the climate change has altered the pattern of flowing time, pattern of habitat distribution of some species of crops. It has not only affected biodiversity but also in the production of crops. The varieties are becoming susceptible day by day,promotion of bug and superbug, changing of minor pest into major one has been consequences of climate change.

To sum up, Climate change is real as well as destructive problems that enforce and enhance various ecological imbalance which should be taken into consideration by joint effort. Climate resilent approaches should be enforced, conservation and adaptation strategy should be encouraged for the protection and preservation of ecological diversity.