Broad Coverage

Environmental change, specifically climate change, has emerged as a major concern in the 21st century. Demand for energy, water and food for raising the standard of life are driving the environmental changes. Deforestation and CO2 emissions from fossil fuels such as coal and petroleum are the main causes for climate change. The major environmental problems for India in the coming decades include air and water pollution, heat waves and changes to monsoon rainfall and glacier retreat due to climate change, impacts of climate change on our food, water and forestry resources, biodiversity loss, sea level rise and the consequent impacts on our coastal communities. Ocean acidification, often referred to as the evil twin of global warming, is also likely to cause disturbance to marine life including corals and fisheries in the Indian Ocean. India has already taken major initiatives to improve our scientific understanding of environmental change and to adapt to and mitigate these changes. Some of the urgent scientific and engineering challenges in the area of environment change are discussed below.

Climate Science

Locally generated knowledge on climate sciences is strategically crucial for providing sound guidance on the impacts of climate change on various sectors in India. In the last 3 decades, several countries have developed mathematical models to project future climate change but India lags behind in model development. Since climate model development is essentially a scientific and engineering exercise and since there is plenty of expertise in science and engineering in India, India should identify the development of one or more earth system models as a key national priority. Creation of a long term climate observation network and objective assessments of extreme events and climate change impacts on agriculture, forestry, water resources, glaciers, health, coastal zones, corals and fisheries should be also considered as national priorities. Resources for creating skilled manpower in this domain should be provided by the government of India.

Monsoon Prediction

Simulation and prediction of the Indian Summer Monsoon on seasonal and intraseasonal scales is one of the major challenges in weather and climate sciences. Skill of numerical and empirical models in predicting monsoons has improved in recent years but there is still considerable scope of improvement. Forecasting skill can be improved by better representation of physical processes in climate models. Dedicated research into numerical methods is also required if India were to develop its own model for weather and climate. With increasing amounts of data available from satellites and other sources, studying monsoons is also a 'Big Data' challenge. Newer machine learning techniques can be used to mine this data and obtain new insight. Improved utilization of this data also requires extensive research into data assimilation to provide better initial conditions for forecasts. All this would require interdisciplinary research combining skills of various IITs and IISc in weather, climate, turbulence studies, applied mathematics and computational science.

Ocean Studies

Oceans play an important role in modulating monsoons. Understanding the interplay between the atmosphere and oceans requires in-situ data collection and modeling. Hence, more oceanic expeditions and high resolution ocean modelling capability would be needed to understand the complex thermodynamic structure and circulation in the Indian Ocean. By taking up anthropogenic carbon dioxide, oceans help to mitigate climate change. They also support corals and fisheries in coastal regions. However, invasion of anthropogenic carbon dioxide into ocean water leads to ocean acidification which is often referred to as the "evil twin of global warming" or the "other CO2 problem". The acidified waters could be detrimental to marine organisms as calcification rates in marine calcifying organisms could be reduced. Hence, there is an urgent need to study the chemistry and biology of Indian Ocean waters using extensive observations and complex earth system models that simulate the ocean biogeochemistry.

Air Pollution

Air pollution continues to remain a public health concern despite various actions taken to control air pollution. The problem becomes more complex due to multiplicity and complexity of air polluting source mix (e.g., industries, automobiles, generator sets, domestic fuel burning, road side dusts, construction activities, etc.). The urgent needs in this theme are extensive data compilation, management and interpretation of the monitored air quality, development of grid based emission inventory of the specified pollutants (PM10, PM2.5, SO2, NOx, CO, benzene, metals and PAHs), meteorological and air quality modeling of these pollutants with prediction capabilities.

Aerosols and Climate

Aerosols are suspended particulates in the atmosphere and they are believed to be mitigating global warming by increasing the planetary albedo, although the sign and magnitude of aerosol effects on climate are uncertain. In addition to contributing to air pollution, aerosols could alter precipitation and winter fog patterns in India. The problem becomes complex when the interaction of aerosols with clouds, their chemical composition and vertical distribution are considered. Resolving the role of aerosol on Indian summer monsoon rainfall and winter fog and mitigation of the undesired effects of aerosol should be priority areas for research.

Water Resources & Water Pollution

Climate change is likely to affect the Indian Summer Monsoon Rainfall and hence water resources in this country. Climate change impacts in the water sector include potential shortage of fresh water and inadequate ground water recharge. Climate warming is likely to increase the evaporative loss of water from our reservoirs. Increase in irrigation and the consequent decline in ground water storage is also another major challenge in the water sector. Further, our water ways are highly polluted by nitrates and heavy metals as a result of excessive fertilizer and pesticide usage in the agriculture sector and by industrial wastes. A rigorous scientific program for improved understanding of water cycle in a changing climate, adaptation of water management strategies to climate change and waste water recycling is essential for the country.