It is incumbent upon those with the power to stop degrading the environment to do so. Where the Amazon rainforest is concerned, that's Brazil.

Getting every nation which might want cheap soybeans (all of them, to a first approximation) to agree to stop buying from Brazil is a complex coordination problem with rewards for defection. Getting Brazil to stop cutting down the rainforest for the profit of agribusiness is coordinating the policy of a single nation; still difficult, just not completely intractable.

Brazilian soybeans rely on genetic modification to survive in the sweltering climate. Monsanto is perhaps the best target here.

Something I did not know, and definitely a really important consideration here.