Canadian Journal of Pure & Applied Sciences

Abstract: Globally climate change and loss of biodiversity are major environmental threats that we are facing today. Changes in species habitats compositions, and consequently changes in ecosystem functioning are some major effects of climate changes. There are various natural or anthropogenic activities that cause fluctuations in the climatic condition. Natural causes are volcanic eruptions, variability in the solar radiations, plate tectonic and orbital fluctuations of the Earth. While other are human activities that causes the climatic variations such as deforestation, over exploitations of natural resources, industrial toxic effluents, extensive agricultural practices, mismanagement of valuable resources and many more. When climate fluctuates from normal level, it has adverse effects on the biodiversity. Firstly it affects the temperature either increase or decrease at extreme level that leads to various changes within the ecosystem and then their interaction with wild or aquatic species causes disruption in different activities perform by the producers, herbivore and carnivore fauna. Due to climatic variations glaciers are starting to melt, increases the aquatic level which ultimately leads to the flooding conditions and produce harm to human being, destruct the habitat as well as disturbs the animals of aquatic ecosystem. On the other hand when the water of these melting glaciers enter into the sea it decreases its salinity which causes threats to the survival of many marine species. Ice covers in the upper surface of water also melts due to temperature increase and this phenomenon influence the productivity of phytoplankton upon which the whole marine life depends on. In addition it causes strong storms and tornados which made severe destructions, also drought due to less rains and prolonged heat waves influence badly on biodiversity. Several species are also affected by the threats of climate fluctuations as they adapt themselves or migrate for their survival. Other impacts of climate change includes early migration of birds and delayed return due to harsh weather conditions, changes in breeding cycle and the synchrony of two mutual species that are interlinked with each other in various aspects of predation and availability food. Species of sea turtle lost several nesting sites, due to sea levels rise and unsustainable coastal developments. In this paper we review natural causes and anthropogenic activities and their effects on biodiversity, terrestrial ecosystem, change on species phenology, population range and its composition, habitat fragmentations, affected functions of ecosystem, coral bleaching, migration of aquatic species, and rising sea levels.