The next century could witness the rise of severe localized famines, leading to food riots, vulnerability to pandemics, and other problems. A leaked intergovernmental report suggests that famine is a likely scenario for the near future.

Several journalists, including the New York Times' Andrew Revkin, have posted a leaked version of a report from the Intergovernmental Panel on Climate Change, which looks at the impact that changing temperatures will have on vulnerable populations — and offers suggestions for adaptation.

Here is a section from the leaked draft, looking at how one of the major impacts of a temperature increase will be famine:

Without adaptation, local temperature increases of 1 °C or more above pre-industrial levels are projected to negatively impact yields for the major crops (wheat, rice, and maize) in tropical and temperate regions, although individual locations may benefit (medium confidence). With or without adaptation, climate change will reduce median yields by 0 to 2% per decade for the rest of the century, as compared to a baseline without climate change. These projected impacts will occur in the context of rising crop demand, projected to increase by about 14% per decade until 2050…. Risks are greatest for tropical countries, given projected impacts that exceed adaptive capacity and higher poverty rates compared with temperate regions. Climate change will progressively increase inter-annual variability of crop yields in many regions.

The chart below, also from the report, highlights the benefits of emissions reduction (at left, the chart shows temperatures with and without reducing emissions) — and shows the likely risks of unchecked temperature rise.

The coming food riots of the twenty-first centuryS

Read more on Revkin's Dot Earth blog