In future, climate change is likely to be the single most significant cause of biodiversity loss, writes Sanjay Gubbi, assessing its overall impact. A lot is written about the ill-effects of global warming and its impact on humans. This climate crisis will have an equal or perhaps more disastrous effect on non-human life forms and their eco-systems. Even if considered speculative, it is worth assessing its impact on biodiversity. Though the possible impact on floral communities has been documented, the effect on fauna needs more scientific studies. Some wildlife species might see behavioural changes, some genetic changes over a period of time and others which are unable to adapt could follow the path of Dodo. Himalayan glaciers With 33,000 sq km of glaciers, Himalayas have the largest glaciers outside the polars. Increasing temperatures would result in the melting of glaciers and high altitude wildlife species such as snow leopard, bharal, ibex, musk deer and others could possibly face the brunt. Himalayas give birth to seven major rivers including Ganges, Indus, Bramhaputra, and these rivers could flood due to ice melting, causing immense damage to wildlife habitats in the plains. The Sunderban mangroves spread across India and Bangladesh are an important habitat for tigers and either rise in sea level or the drying out of the Bramhaputra river will impact this key tiger habitat. Annual floods in the Khaziranga National Park in Assam, where fewer than 1,500 individuals of the critically endangered one-horned rhinoceros and Asiatic buffalo survive, make animals move to higher grounds. Impact on lesser known species It is not just the big mammals which suffer, other smaller mammal species like pikas found in the cold Himalayas can be impacted. Pikas are densely furred, and thus cannot dissipate heat easily. If this smaller wildlife is exterminated, it could have domino effect on the food web in the area as these lagomorphs are an important food source for Tibetan wolf, lynx, palla's cat, red fox and certain prey birds. Birds would also be highly impacted. As climatic factors change, bird migration and breeding cycle is affected as food sources and habitats will considerably vary. Due to change in climatic conditions, birds could migrate to their wintering grounds where temperature and food availability would still not be conducive to their activity. The star among the bird species, the critically endangered Siberian Crane, is speculated to be already impacted by global warming. Fewer than 3,000 of these majestic cranes survive in the world. During winter they migrated from Europe to areas with mild temperatures and once these regal birds wintered in Keoladeo Ghana National Park (Bharathpur) in Rajasthan. Increasing drought due to higher temperatures is thought to be one factor that caused this subpopulation to become locally extinct. Northern pintail, ruddy shelduck, crested grebe, sandpipers, white stork, marsh harrier and many other bird species that migrate from Europe to India could all be influenced by changing climatic conditions. The impact on several lesser known species could go unnoticed. Changes in rainfall pattern will severely impact species such as frogs and toads since frogs rely on water to breed. Any reduction or change in rainfall could reduce frog reproduction. Higher temperatures would contribute to the drying of breeding pools and, as a result, to the deaths of tadpoles and eggs. Bees, butterflies, flowering plants could all be impacted due to change in seasons. Pollination of plant species would also suffer. Ocean dwellers Ocean dwelling wildlife would see a drastic change. As oceans gets warmer, fish stocks will move north, impacting the ecological cycle of the area. In India, some changes have already been witnessed in the seas. False trevally, an economically and culturally important fish found in the Gulf of Munnar region, is facing a severe threat over the last few years due to decreased rain that flushes critical nutrients from the land into the Gulf of Munnar which is vital for the survival of this fish. Melting of ice in the poles could raise sea levels, submerging nesting habitats for sea turtles and other wildlife. The sex ratio of young sea turtles could vary as the temperature of eggs determines their sex. Cold sites will produce more males and hotter climates will produce more females in reptiles and change in climatic conditions can skew sex ratios. Forest vegetation Would this temperature difference directly impact forests? Yes, say scientists of the IISc who carried out climatic and vegetation change modelling studies. Change in rainfall pattern is speculated to decrease tropical rainforests and increase in dry forests. The eco-sensitive shola forests of the Western Ghats could give way to expanded grasslands due to increase in temperature and reduction in fog. What's to be done? Apart from the vastly suggested reduction in the use of greenhouse gases and energy consumption, maintaining habitat contiguity is of prime concern to conserve wildlife species. Current protected areas in India need to be better strengthened and should form a part of larger contiguous landscapes with biological corridors. Over the past 150 years, deforestation has contributed an estimated 30 per cent of the atmospheric build up of CO2. Our natural forests are the biggest carbon sinks and in this new economic era, forests should not be sacrificed for the purpose of developmental activities.