February 16, 2020 preprint on Biorxiv: “The environmental impacts of palm oil and its alternatives” investigates how the environmental impacts of palm oil compare to other crops, Palm oil has a very high yield per unit of land, compared to rapeseed, soybean and sunflower but is connected to large scale loss of tropical rainforest and peatlands in Africa, Indonesia.
The authors conclude: “We find that oil palm has the lowest carbon loss and species richness loss per-tonne-oil, but has a larger impact on range-restricted species than sunflower and rapeseed.”
Moreover: “We go on to identify global areas for oil crop expansion that will minimise future carbon and biodiversity impacts, and argue that closing current yield gaps and optimising the location of future growing areas will be much more effective at reducing future environmental impacts of global vegetable oil production than substituting any one crop for another.”
i.o.w. picking the right location for crops is more effective than substituting one for another. How closing yield gaps is factored in is not entirely clear, but one of the studies referenced suggests “increases in global crop productivity will be much more effective in saving forests, including those at risk from oil palm expansion in Indonesia and Malaysia” (PDF). This would require strong policies that favour productivity increase over land conversion (my take).