Cape Town - Climate change is threatening food security and pushing up food prices, Water and Environmental Affairs Minister Edna Molewa warned on Wednesday.Speaking during debate in the National Assembly on last week's State of the Nation address, she said there was also a risk of malaria and waterborne diseases spreading to new areas."The effects of climate change continue to impact negatively on our food security. The recent food price increases are mainly as a result of... climate change."Molewa said changes in climate patterns might also, over time, cause major damage to the agriculture and fishing sectors, as well as to urban and rural infrastructure.Climate change was responsible for the fires over the past decade in the Western Cape being more prevalent and damaging than ever before."The rooibos farmers in the province have had to change the way they cultivate tea because of changes in weather patterns."The communities living along the Limpopo River basin... have experienced a degree of flooding and disruption to their farming."Changes in ocean temperatures and currents have also affected our marine resources, and there has been a southward shift in some of our fish stocks, including the West Coast rock lobster."There was also a risk of malaria and other waterborne diseases spreading to new areas and putting more people at risk, she said.