Then how are we going to solve climate issue? I don't think there is magic wand that can fix it? What ever policy you introduce there will always be minority of people that are going to suffer. Change is inevitable. Even if they don't face yeild issue today, I think with the advent of climate change and water crisis they are going to face same trouble in future.
How about moving towards sustainable solution with slow changes.
Medical doctors have a maxim "primum non nocere" = "first, do no harm".
Don't assume that the farmers are the only ones hit and that they can be simply waved away as a minority that has to yield to progress. Destabilizing agriculture in food exporting countries is a potential threat to consumers of those calories worldwide.
Humanity consists of 8 billion people, most of them living in countries that are barely self-sufficient in terms of food production or not sufficient at all. Net exporters are an important player in fight against hunger. Canada itself feeds two other Canadas abroad.
If countries like Egypt or Iraq or Nigeria go off the rails because of food insecurity, there will be political instability much worse than during the War on Terror. Canada may be insulated from the consequences, Europe will definitely be not.
And here's a paper [1] corroborating that, at least for Canadian crop yields:
> Canola and wheat yields were projected to increase with global warming, while maize yield was simulated to increase or slightly decrease depending on the characteristics of the currently grown cultivar and differences among the crop models. It appears that future warming accompanied by increased CO2 concentration will remain beneficial to crop yields at the global warming level of 2.0 °C for Canada.
How about moving towards sustainable solution with slow changes.