Final answer:
The attitude of humans on Earth, as described in paragraph one, can be best described as a mix of pessimism and optimism.
Step-by-step explanation:
The attitude of humans on Earth, as described in paragraph one of the excerpt, can be best described as a mix of pessimism and optimism. The writer acknowledges that human activities are threatening the integrity of the biosphere and that ecological collapse is inevitable if these activities continue unabated. However, the writer also notes the human capacity to wonder about the planet and the universe, suggesting that through humans, the universe becomes aware of itself.