Over and over at the UN climate summit in Glasgow, world leaders have stressed the need     1     (limit) global warming to 1. 5 degrees Celsius. Experts have said crossing the 1. 5 ℃threshold(界限）risks     2     （release) far more severe climate change effects on people, wildlife and ecosystems. Preventing it     3     (require) almost halving global CO₂ emissions(排放) by 2030 from 2010 levels and cutting them to net-zero by 2050.

Already, the world has heated to around 1. 1℃ above pre-industrial levels. Each of the last four decades was     4     (hot) than any decade since 1850. “We never had such a global warming in only a few decades,” said climate     5     (science) Daniela Jacob at the Climate Service Center Germany.

More warming to 1. 5 ℃ and beyond will     6     (worse) such impacts. For example, heatwaves would become both more frequent and more severe. A warmer atmosphere can also hold more moisture(水分), resulting in more extreme rainfall     7     raises flood risks. It also increases evaporation, leading to more intense droughts.

“At 1. 5 ℃, there’s     8     good chance that we can keep most of the Greenland and west Antarctic ice sheet     9     collapsing,” said climate expert Michael Mann at Pennsylvania State University. That would help limit sea level rise to a few     10     (foot) by the end of the century.