Your assumptions that the world is headed for a climate and poverty crisis is in itself pessimistic. One could also define optimism as the belief that we are currently making significant inroads on climate change and global poverty.
Now, before someone shouts “Denier!”, let me say that I’m not asserting that there is no climate change or widespread world poverty. I’m just saying that optimism, pessimism, and realism are relative, not absolute, measures.
Your optimism is another’s pessimism, and realism depends largely on the assumption that your perception of reality is correct.