The main difficulties people had with the growing process was related to the lack of knowledge about what a plant needs to grow like how much water to use or which nutrients does it needs,
and also about some natural conditions like the quality of water, quality of soil, insects, and parasites. When we were talking about the difficulties they had in Barcelona, they talked about the weather, the seasons, the soil and the water.
When we were talking about how they think they could adapt the plants they grow or the growing process depending on the climate, they said things like Genetic Modifications, creating new kinds/species of plants, greenhouses, watering systems, methodologies that could reproduce/simulate climates or bringing plants that already work on the other future climates. But the most interesting answer I got was about keeping the seeds that already survived extreme weather so that in some sort of way do a natural adaptation. So if you already know it survived, you save It for next year and grow it again, and so on, so that the seed gets stronger.