Veteran actress Jane Fonda is urging families to consider having just one child in a bid to conserve the world's diminishing natural resources. The MONSTER-IN-LAW star is terrified that if serious measures aren't taken to sustain fuel and energy, it will soon have detrimental effects on the planet. She says, "The amount we consume scares me. At my ranch, everything is solar. I conserve water. My daughter's Mercedes runs on vegetable oil. "I remember back in the Fifties when there were 4 billion less of us. I think parents now should make a conscious decision to have only one child."