Business

Impact of climate change imminent in Kerala

KOCHI: Dry spell during the monsoon season and heavy rains in the summer seasons are not unfamiliar to the land mass in Kerala. These phenomena are part of the climate changes taking place across the world. The WTO Cell of Department of Agriculture and Kerala Agricultural University undertook a study on the impact of the climate change in Kerala. The team had based its studies on the findings of various scientific bodies in the past, apart from conducting their own research.

Kerala experienced decline in annual and monsoon rainfall and an increase in temperature during the past decades. The mean annual maximum temperature over Kerala has risen by 0.8 degree centigrade, the minimum temperature by 0.2 degree Celsius and the average by 0.5 degree centigrade between 1961 and 2003 as per the study taken up by the India Meteorological Department. The maximum temperature shot up to 40 degree centigrade in Palakkad during February and March 2004 and the highest of 41 degree centigrade was noticed on April 26, 1950. The year 1987 was the warmest year over Kerala, according to the study.

The 1990s were the warmest years over the globe while 1981-90 was the driest decade over Kerala. The monsoon behaviour in 2007 was totally different from previous years. Heavy rains were noticed from June to September and it led to floods in low lying areas. In contrast, severe summer droughts were noticed in 1983 and 2004 during which the surface water resources became scarce, led to hydrological drought and the State’s economy was hit very badly.

The wetlands or paddy lands in Kerala are the rich water source during summer and act as sink during the rainy season. Such wetlands have been declining very fast. It was 7.53 lakh hectare in Kerala in 1961-62 and 2.76 lakh hectares in 2005-06. The decrease in wetlands might be one of the reasons for frequent floods and droughts in recent years. The drought during summer 2004 over Kerala led to increase in maximum temperature of 1-3 degree Celsius during February and March and thermo-sensitive crops such as black pepper, cocoa and cardamom across the high ranges and several other perennial crops in the State suffered to a large extent.

The groundwater is found to be depleting at a faster rate than that of its recharge mainly owing to decline in rainfall, overuse of water for irrigation, deforestation, riverbed sand-mining, decline in wetland area and disappearance of lakes and ponds in recent times.

Some of the above factors also led to the drying up of open and surface wells. Silting over a period of time also led to less water storage capacity in existing major reservoirs and surface wells. These factors lead to impending disaster in the form of severe water scarcity and saline water intrusion along the coastal areas. The saline water intrusion was not there when traditional fresh water lakes were built in wetlands. Destruction of fresh water lakes or conversion of wetlands aggravated the scarcity of fresh water, especially in deficit rainfall years during the summer in places such as Kuttanad and Palakkad.

The forest cover over Kerala declined from 70 per cent to 24 per cent over a period of 150 years. The main causes of forest fires are lightning, self-combustion and man-made. Out of these, lightning is the major cause of forest fires.

The National Biodiversity Strategy and Action Plan reported that India has lost over half of its forest cover, 40 per cent of its mangroves and a significant part of its wetlands in the last couple of centuries.

© Copyright 2000 - 2009 The Hindu