Climate & Environment
The fourth Assessment Report (2007) of the Inter-governmental Panel on Climate Change (IPCC) has projected an alarming picture of the earth’s future. The report estimated an increase of 0.74oC in global mean temperatures from 1906 to 2005. Studies have also indicated that there is steady increase in the concentration of Greenhouse Gases (GHGs) in Earth’s atmosphere. In summary, some of the facts and figures related to climate change are:
- surface air temperature for the period 1901 - 2000 indicates a significant warming of 0.4oC for 100 years;
- it is projected that by the end of the 21st century, rainfall will increase by 15 - 31% and the mean annual temperature by 3oC to 6oC;
- accelerated melting of glaciers with intensification of monsoon can lead to flood disasters in the Himalayan catchments;
- a trend of sea level rise of 1 cm per decade has been recorded along the Indian coast;
- deltas will be threatened by flooding, erosion and salt intrusion;
- loss of coastal mangroves will have impact on fisheries; and
- increased temperatures will impact the agricultural production.
Cloud cover over India as seen by INSAT-3D
Climate is the long term average of the weather parameters. Climate varies from place to place due to the geographical setup of our country. Thus, India is divided into a number of agro-climatic regions, and the economic activities of the country are highly dependent on the climatic characteristics. There are several Essential Climate Variables (ECVs), which are important for understanding and monitoring the global climate system and these can be best observed using space based systems.
Issues related to natural environment and climate change needs understanding of the interactive physical, chemical and biological processes that regulate the total Earth System, the changes that are occurring in the system, and the manner in which they are influenced by the natural forces and human activities.
The ISRO/ DOS Centres are engaged in various research studies and activities related to the Earth’s climate system, designing sensors and satellites, and established ground based observations systems for studying the climate and environmental parameters.
ISRO has designed and developed indigenous systems for ground based observations of weather parameters. It includes (i) Automatic Weather Station (AWS) to providing hourly information on critical weather parameters such as pressure, temperature, humidity, rainfall, wind and radiation from remote and inaccessible areas; (ii) Agro Metrological (AGROMET) Towers to measure soil temperature, soil moisture, soil heat and net radiation, wind speed, wind direction, pressure and humidity; (iii) Flux Tower for multi-level micrometeorological observation as well as subsurface observations on soil temperature and moisture over the vegetative surfaces; (iv) Doppler Weather Radar (DWR) to monitor severe weather events such as cyclone and heavy rainfall; (v) GPS Sonde and Boundary Layer LIDAR (BLL) for observing vertical profiles of atmospheric parameters. GPS Sonde provides temperature, pressure, humidity and wind parameters; and BLL provides vertical concentrations of aerosols and boundary layer height.
Climate change has strong influence on natural systems. Monitoring and assessment of impact requires long-term databases of parameters, gathered employing remote sensing and ground based methods; and suitable models for forecasting the changes. ISRO, with strong constellation of geostationary and polar orbiting satellites, has been actively pursuing climate change research with a focus on specific indicators, like, Glacier melt, desertification, Land use and land cover change and agents, like, GHGs, Aerosols, etc.
With a view to understand the science aspects of changing climate, ISRO, through its ISRO Geosphere Biosphere Programme (ISRO-GBP), with multi-institutional participation, has been pursuing studies on climate over the past two decades. The studies have addressed atmospheric aerosols, trace gases, GHGs, paleoclimate, land cover change, atmospheric boundary layer dynamics, energy and mass exchange in the vegetative systems, National Carbon Project (NCP) and Regional Climate Modelling (RCM).
A programme on National Information system for Climate and Environment Studies (NICES) has been initiated in September 2012 at National Remote Sensing Centre, Hyderabad. This new national initiative would contribute towards specific needs of climate change, which would be evolved through research needs and national imperatives. The core strength on design, production and operation of Earth observing tools would be imbibed in order to generate valuable synoptic information on climatic variables through atmospheric, oceanic and terrestrial observations. The programme would build strong interface with International and National climate research community for achieving the objectives of climate change and environment studies.