Carbon dioxide levels have increased by 31 percent over the past 250 years, reaching a concentration unseen on the planet in 420,000 years and perhaps as far back as 20 million years, the report said.
(Carbon dioxide levels; reaching; a concentration unseen on the planet; T:in 420,000 years and perhaps as far back as 20 million years) (Carbon dioxide levels have increased by 31 percent over the past 250 years; said; the report) Context(Carbon dioxide levels have increased by 31 percent over the past 250 years said,List([0, 199))):(Carbon dioxide levels; have increased; by 31 percent; T:over the past 250 years)
Carbon dioxide levels have increased by 31 percent over the past 250 years said,List([0, 199))
Carbon dioxide levels Carbon dioxide levels have increased by 31 percent over the past 250 years Carbon dioxide levels
reaching said have increased
a concentration unseen on the planet T:in 420,000 years and perhaps as far back as 20 million years
the report
by 31 percent T:over the past 250 years