Chapters 8-9 Summary

Manú National Park in Peru is being studied to determine the effects of global warming. Tropical tree species are moving to higher elevations by dispersing seeds. Scientists predict that over the next century, Earth’s temperature will increase 10 times faster than it declined in the last ice age. To survive, species would have to migrate at the same rate. Those that can’t will face extinction. Researchers believe that between 30% and 50% of species risk extinction by 2050.

As global warming continues, some species will benefit, but many others will suffer. As human populations grow and take over more land, species lose their ability to migrate, which lowers reproduction rates, increasing the probability of extinction.

Chapters 8-9 Analysis

In Chapter 8, Kolbert’s research shifts from the oceans to the biodiverse rainforests in Manú National Park, Peru. Her conclusions are largely the same: increasing temperatures are decreasing biodiversity and point to the fact that the Earth is in the midst of a mass extinction caused by humans.

Darwin was correct in his assertion that species will adapt to environmental changes, but once again, time is key. Humans are changing the planet—specifically its temperature—much faster than what occurs naturally. Humans are powerful, and yet, this power could lead to disaster. Kolbert poses a question as to whether species will be able to adapt quickly to the changes humans are imposing on them. The rhetorical answer she suggests is no, even among some of the species that managed to survive the last mass extinction.

As humans develop more land, they increase the probability that species will be unable to survive. This, Kolbert suggests, develops the idea that the human impact on rainforests, similar to that on coral reefs, could have far-reaching implications in the very near future.