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 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