additionally the spillover of using productivityenhancing technologies for particular crops may reduce their prices globally thereby increasing food affordability although on a limited scale the widespread adoption of crop varieties that are resistant to the projected new climate conditions significantly reduces projected food prices in compared to the climate change baseline similarly increasing the efficiency of irrigation systems or expanding irrigation infrastructure where appropriate can significantly reduce water stress and make farming practices more resilient to climate change these costs depend strongly on the projected adaptation level and the marginal costs must always be evaluated against the marginal benefits they deliver due to the lack of common metrics to measure the effectiveness of adaptation it is impossible to determine optimal adaptation strategies under the assumptions used in this study the potential additional costs in rd and in improved irrigation technologies are estimated to reach usd to billion per year by for oecd countries