What was done
The authors used the validated potato model LPOTCO to project future European potato (Solanum tuberosum cv. Maris Piper) yields under various climate change scenarios, including those with elevated atmospheric CO2 and ozone concentrations.  Projected yields were assessed under conditions of natural rainfall and did not include any accounting for supplemental irrigation.

What was learned
Averaged across three study sites in France, Italy and the UK, twice-ambient CO2 concentrations were predicted to increase potato tuber yields by 26%.  In addition, the negative effects of elevated ozone on tuber production were reduced by atmospheric CO2 enrichment.  Moreover, when projecting yields under two climate change scenarios that incorporated the effects of increased greenhouse gasses on climate (i.e. increased air temperature and reduced precipitation), the model generated increases in tuber production ranging from 1,000 to 3,000 kg of dry matter per hectare across Europe.  Furthermore, climate change did not significantly impact any of the risks associated with potato production.

What it means
As the CO2 content of the air increases, potato production in Europe will likely increase right along with it, even if air temperatures and atmospheric ozone concentrations rise and precipitation declines.