Sir David King, the Foreign Office's adviser on climate change, has commissioned a report into the effects of climate change on food security. There's a monster team of authors featuring among others Tim Benton, a population ecologist and the "UK Champion for Global Food Security", and Rob Bailey, a former executive at Oxfam who now works at Chatham House.
The underlying study is a mega-hypothesis of course - it's computer models all the way down, you might say - so it's of no practical use, but with the project led by someone like Sir David, one can be reasonably sure that it will at least provide some entertainment.
The report is undoubtedly a mixed bag - a heady blend of the trivial and the deceptive. On the trivial front We learn for example that there is "very extensive and convincing evidence" that the climate is changing. Evidence that the sun rises is overwhelming too, or so I am led to believe. But we also learn that there is "good evidence that extreme weather events, from intense storms to droughts and heatwaves, are increasing in frequency and severity at a considerable rate".
The citation is as follows (links added):
See Hansen (op. cit.) and for a brief review COUMOU, D. & S. RAHMSTORF (2012) “A decade of weather extremes” Nature Climate Change DOI 10.1038/NCLIMATE1452 and IPCC (2012) A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change (IPCC). Cambridge University Press, Cambridge, UK, and New York, NY, USA; CHALLINOR, A., et al. 2014. A meta-analysis of crop yield under climate change and adaptation. Nature Climate Change, 4, 287-291.
There is medium confidence that some regions of the world have experienced more intense and longer droughts, in particular in southern Europe and West Africa, but in some regions droughts have become less frequent, less intense, or shorter, for example, in central North America and northwestern Australia. [3.5.1]
There is low confidence in any observed long-term (i.e., 40 years or more) increases in tropical cyclone activity (i.e., intensity, frequency, duration), after accounting for past changes in observing capabilities.
...and about heatwaves:
In many (but not all) regions over the globe with sufficient data, there is medium confidence that the length or number of warm spells or heat waves has increased.
So, all in all, the literature cited by the author team provides virtually no support for the claims they make. They are just sexing things up a bit.