Biofuels done the wrong way are certainly a bad thing for the poor and for the environment (see Biofuel revolution threatens food security for the poor). That does not mean that all biofuel production scenarios fit into that mould.
Climate change driven by greenhouse gas emissions will also most immediately affect the poor who depend on subsistence agriculture.
There is a balance here. Food and biofuel production have a global element, but there is also a very strong regional component. Growing Miscanthus grasses for cellulosic biofuel in the American southeast, which is a highly inefficient place to grow corn, is not really a threat to food for the poor elsewhere; export-oriented expansion of palm oil production in Indonesia that takes out natural vegetation or food-producing land is.
In reality, there are good and bad biofuels, both from an environmental and a social perspective. They should not be lumped into one bin.