A leaked draft of an Intergovernmental Panel on Climate Change report due in 2014 shows how climate change is already affecting food security around the world.

The report, which a spokesperson for the IPCC described as a "work in progress," is likely to change before it is fully released in March 2014. However, it lays out in concerning detail the conclusions of recent research on how climate change is affecting the world's food supplies today and how it is likely to affect the supply in the future.

The report concludes that the climate is already having an effect on food security and that while rising temperatures may have beneficial effects on agricultural production in limited areas, global productivity is expected to decrease two percent per decade for the rest of the century from what it would be without humanity's influence on the climate.

The IPCC's warning is described in the New York Times as "the sharpest in tone the panel has issued," in contrast to the more hopeful version from 2007 which reported that tropical production losses would most likely be offset by gains at higher latitudes.

Since then, much work has been done on food security around the globe, which is summarized in the report. Of biggest concern is the response of crops to heat waves and how CO 2 fertilizes plant life.

The report also discusses the impact of climate change on ecosystems, with plants and animals fleeing rising temperatures to higher elevations and latitudes, making the species already found in those areas extinct.

The worst effects are expected to be felt in poorer, tropical countries, the report also notes.

Finally, the report notes that while countries have begun to mitigate and adapt to the effects of climate change, these efforts are so far inadequate in comparison with the risks.

This story originally appeared on Wired UK.