With the new feedback that have been introduced recently which range from the albedo flip from the lack of snow and ice in the Arctic, to the record methane in the atmosphere (see: Arctic News: Record Methane in Arctic early March 2013) which have had very negative effects on agriculture in the main bread baskets of the world, for example America: With drought season off to a bad start, scientists forecast another bleak year | Nation/World | ADN.com, which has some serious implications for the world.
What is concerning about the increase in drought in certain areas is the decrease in Agricultural Output as areas that depend on imports will lose out and there is the risk of a large proportion of the population of the world starving with conflicts over resources which are little in availability and thus with the recent new developments such as the Arctic's record melt and the recent fracture event: Arctic freezing season ends with a loud crack - Arctic Sea Ice, will likely cause more positive feedbacks and Agricultural Output to tank even further.
This brings us to the man question which is about the main impacts of these new developments. Either we could experience societal collapse, global starvation, nuclear war and cannibalism becoming the main regime in the very near future or the process might be even more gradual.