Complete the text with the words from the box.

Is human overpopulation killing the planet?

We have changed the planet, and the (1) are grave. Some experts believe (2) temperatures could render Arctic summers ice-free as early as 2018. To put that in perspective, that hasn’t happened to the planet in three million years. If the Arctic ice (3), the ocean and planet will (4) enough to dramatically alter wind flow, global weather patterns, even the jet stream. We’re already experiencing the effects of climate change: (5) weather events are responsible for much of the crop devastation in the last decade or so, including floods in the US, drought in Australia and heat (6) in Russia and Europe. The future seems just as grim: a new Intergovernmental Panel on Climate Change report warns that unchecked climate change will exacerbate food and water (7), and cause further animal extinctions, not to mention human misery and the increased likelihood of war for (8) resources.