NEW DELHI: A US-developed weapon system that strikes the atmosphere with a focussed electromagnetic beam may cause global warming , the government today said and acknowledged that climate change is likely to reduce the yield of major crops like wheat and maize in India."The US has developed a type of weapon called High Frequency Active Auroral Research Programme. HAARP strikes the upper atmosphere with a focussed and steerable electromagnetic beam," Environment Minister Anil Madhav Dave told the Rajya Sabha in a written reply."HAARP is an advanced model of a super powerful ionospheric heater which may cause the globe to warm and have global warming effect," he said.Dave was replying to a question on whether the government is aware of HAARP, capable of effecting devastating impact on the world's climate including that of India and resulting in destabilisation of agricultural and ecological systems.He said a study conducted by Indian Council of Agricultural Research has projected the impact of climate change to be adverse in terms of reduction of yield of major crops including wheat, maize, mustard, potato and sorghum.Recognising the adverse impact of climate change, the minister said that the government launched the National Action Plan on Climate Change (NAPCC) in June 2008 to deal with climate change-related issues.NAPCC comprises eight missions in areas of solar energy, enhanced energy efficiency, habitat, water, sustaining Himalayan ecosystems, forestry, agriculture and strategic knowledge of climate change.It also addresses the issues relating to mitigation of greenhouse gases and adaptation to the adverse impacts of climate change on environment, forest, habitat, water resources and agriculture.Dave said 32 states and UTs have also prepared a State Action Plan on Climate Change (SAPCC).