The Working Group II report is freshly out, and a lot is being written about it. This IPCC Working Group II report which has so much gloom and doom in it,Dr. Richard Tol (one of the lead authors) asked to have his name removed from it because it is too alarmist for what data is in evidence.
It would be understandable if the gloom and doom had an iota basis in science to give it some credibility, but it doesn't.
From: IPCC WGII AR5 Summary for Policymakers (pdf)
Based on many studies covering a wide range of regions and crops, negative impacts of climate change on crop yields have been more common than positive impacts (high
confidence). The smaller number of studies showing positive impacts relate mainly to highlatitude regions, though it is not yet clear whether the balance of impacts has been negative or positive in these regions (high confidence). Climate change has negatively affected wheat and maize yields for many regions and in the global aggregate (medium confidence).
Note the past tense "has" negatively affected wheat and maize (corn) yields. Also conveniently left unknown are the "wide range of regions," and "clarity of whether the balance of impacts has been negative or positive." Still, in spite of the uncertainty they give it a level of "high confidence." Well as the United States is a huge producer of corn and wheat, it would be derelict to not include it. The IPCC claim about corn and wheat is false for the world, and also the USA. Lets see what the USDA says about yeilds.
Source: USDA Data
Gee. It looks very un-alarming!
Well, maybe because temperatures in the US Corn belt are not rising at all. However we know that the IPCC models are, and they prefer model output over reality. Unfortunately this isn't April Foolery, but what passes for science.
Source: USHCN data NOAA, CMIP5 model data plotted by Roy Spencer
The IPCC and alarmists should spend more time in reality and less time with models that are setup to model their hearts desire.