Converting large areas of land for farming to boost food supplies increases planet-heating emissions and places a greater burden on poorer nations already bearing the brunt of climate change, researchers warned yesterday. A study led by Arizona State University (ASU) analysed about 1,500 large land deals totalling 37 million hectares (91 million acres) - across Southeast Asia, Latin America, Africa and eastern Europe - showed that clearing the land for farming may have emitted about 2.3 gigatonnes of carbon emissions.