Dear Editor: The latest study on the climate crisis by 200 climate scientists indicates that the Earth is perilously close to several “tipping points.” These are moments when the Earth has warmed beyond 1.5 degrees Celsius, causing the Earth to be warmed so much that certain side effects become irreversible. The study looks at 26 different systems and points especially to five of them: 1. Melting of the Greenland ice sheet. 2. Melting of the Antarctic ice sheets. 3. The dying off of the warm-water coral reefs. 4. The thawing of permafrost. 5. Impacts to a North Atlantic Ocean current.