Sensing Climate Change Through Earth Observations: Perspectives at Global and National Level

The window to mitigate and adapt to climate change is closing very fast for humanity. Unless drastic measures are introduced and implemented with unambiguous policy oversight, the Earth is going to witness irreversible damage to biophysical systems to the peril of life on this planet. Emphatic arguments on access of climate alerts to everyone, by the United Nations, highlight the need to build a comprehensive system observing the trinity of the ocean, land and atmosphere. Earth observation systems comprising remote sensing in increasingly innovative interactions of energy and matter offer unprecedented scope of watching phenomenon across spatial scales. Coupling these observations with substantiated process models gives insights into future scenarios at reasonable levels of confidence. Current review attempts to comprehend remote sensing systems in place, for observing atmosphere followed by ocean and land phenomenon as well as the information systems, in Indian context, designed for application by varied users. Data and information derived by range of sensors on board Indian satellites are discussed, and latest understanding of vulnerability patterns in varied land cover contexts such as snow, water, crop, and forest is summarized for benefit of decisions across hierarchy of managing natural resources. However, a wide variety of phenomenon linked to climate change impact which could not be covered does not exclude the scope of applying Earth observation technology far and wide. Global and national perspectives, hence, deliberated herewith correspond to the generic know-how of the current technological scope and application to mostly operational needs.