Climate change and its impact on water resources

The issue of economic development is intrinsically connected with global warming. The temperature of the planet rises because of indiscriminate exploitation of its resources and destruction of the environment. The effect of global warming further intensifies temporal and spatial variations in precipitation, melting of snow and water availability. 

An American Meteorological Society study report observes that year 2016's global heat record including extreme heat in Asia happened purely because of global warming due to human activities like the burning of fossil fuel. The NASA ranked 2017 the second warmest year after 2016. Seventeen of 18 earth's very warm years have been since 2001. Overall, fuelled by the emission of CO2 and other greenhouse gases (GHG), temperatures have increased more than one degree Celsius since the late 19th century. In order to avoid the worst consequences of climate change, scientists say global temperature must not increase more than two degree Celsius.

Scientists have claimed that more than a quarter of Earth's land will become significantly drier even if human beings do limit global warming by two degree Celsius. But if we contain average warming to 1.5 degrees, this will be limited to about one-tenth, sparing two-third of the land projected to dry under two degree Celsius. Accomplishing 1.5 degrees would be a meaningful action for reducing the likelihood of aridification and related impacts, as per a study published in “Nature Climate Change”. Incidentally, the Paris Deal adopted by 195 countries in 2015 aims to limit global warming to 1.5 degree Celsius, considering pre-industrial level as the baseline. Aridification is a major threat, hastening land degradation and desertification and loss of plants and trees crucial for absorbing the earth-warming CO2. It also boosts droughts and wildfires and affects water quality for farming and drinking. As per NOAA, NASA, a warming climate can exacerbate the frequency and severity of certain kinds of storms, including hurricanes, fires and floods.

Climate is changing

Events in the last year reminded the world that the climate is changing. The temperature in the Arctics, warming about twice as fast as other parts of the planet, soared again during parts of 2017 and the region continued to lose sea ice and permafrost. Arctic Resilience Report warned that the accelerated warmings of Arctic could trigger tipping points which, in turn, lead to catastrophic and uncontrollable climate changes. 

For India, that has a vast coastline, the implications are enormous.

In 2016, the country reported the highest number of deaths due to extreme weather (2119 fatalities) and suffered losses more than $ 21 billion in property damage. This is almost one percent of India's GDP. The IMF data shows increasing evidence for the link between global warming and extreme El-Nino events which affect the monsoon in India. The occurrences of such events would double in the future due to climate change as per The Risk Index report by Munich Re Nat Cat Service.

In India, a decline in monsoon rainfall since the 1950s have already been observed. The frequency of heavy rainfall events has also increased. An abrupt change in the monsoon could precipitate a major crisis, triggering more frequent droughts as well as greater flooding in large parts of India. Analysing a trend of rising temperature and declining rainfall during 1970-2015, the economic survey 2018/19 observed that during the years when rainfall levels drop 100mm below average, farmer incomes would fall by 15 percent during the kharif and seven percent during the rabi crops seasons. The survey points out that climate change could reduce annual agricultural incomes in the range of 15 percent to 18 percent on an average and up to 20-25 percent for unirrigated areas. It stresses that climate change will increase farmer uncertainty and called for effective crop insurance and the use of technology to make farming resilient. 

The survey suggests minimising susceptibility to climate change require drastically extending irrigation via efficient drip and sprinkler technologies. At present, about 45 percent of farmland is under irrigation. The Indo-Gangetic plain and parts of Gujarat and MP are well irrigated. But parts of Karnataka, Maharashtra, MP, Rajasthan, Chhattisgarh and Jharkhand are extremely vulnerable to climate change for not being well irrigated.

The year 2017 has been the warmest winter and with almost no rainfall. Recent occurrences of hailstorm during winter in parts of Maharashtra, MP, Rajasthan, etc have caused severe damages to standing crops whereas shortfall in rainfall has made some major rivers water stressed. The IMD's forecast of hotter summer in the year 2018 would worsen the country’s water situation.  

Water disappears from river basins

India has about 20 river basins. Due to increasing demand for domestic, industrial and agriculture use, most river basins are water stressed. This is further accentuated by the fact that water demand is unevenly distributed across the country. Increasing demand from a growing population, coupled with economic activity, adds pressure on the already stressed water resources. With the country already experiencing water stress, there is a need to augment both water supply in water-rich regions lacking infrastructure and manage water demand in water-scarce regions.

Groundwater plays an important part in India’s economy. It caters to about 85 percent of rural demand, 50 percent urban requirements and more than 60 percent of our irrigation needs. Unregulated groundwater extraction has led to its overuse in many parts of the country, causing the groundwater table to plummet, drying springs and aquifers. According to the CWG Report 2011, the annual groundwater draft is 245 BCM, which accounts for about 62 percent of the net water available. Of this, 91 percent was used for irrigation. However, the effects on groundwater in different regions of the country have not been uniform. The situation is alarming in regions where groundwater exploitation exceeds replenishment. States like Haryana, Punjab and Rajasthan now draw more water than is annually replenished. Several places in Rajasthan and Haryana have a high salt concentration in groundwater, which makes it not potable.

Agriculture sector consumes the largest amount (over 85 percent) of India’s water. The consumption of water would escalate further with pressure from industrialisation and urbanisation. Events like droughts, heavy rains, unseasonal rains, hail storms, floods, etc are on the rise due to climate change and have impacted Indian economy adversely. 

Demands for water are steadily rising. With growing pressures due to climate change, migration and population growth, creative and imaginative governance is needed to manage this precious resource. Incidentally, our country is endowed with vast seawater resources covering large parts for over a dozen of states and union territories. Ensuring purified seawater supply to dedicated network would help people immensely. A few establishments have come up in states like Tamil Nadu, Puducherry, AP, Gujara t,etc. However, the country needs a development strategy utilising seawater in the coastal region to be formulated quickly. The solar and wind energy available in abundance in the region should form as alternative sources of fuel for the purpose and falling prices will considerably reduce the production cost. The financing of setting up purification plants in the region may be shared by the central government, state governments, local bodies and private operators.

The author is former advisor, Planning Commission, ex-Chief Executive Haryana Environmental Management Society. 

Disclaimer: The views and opinions expressed in this article are those of the author/s and do not necessarily reflect the policy or position of India Water Portal.