"Since the 1970's, temperatures at the earth's surface have warmed, Arctic sea ice has decreased in thickness, and now we know that the average temperature of the world's oceans has increased during this same time period."
(Arctic sea ice; has decreased; in thickness) Context(Arctic sea ice has decreased,List([68, 96))):(temperatures at the earth's surface; have warmed; T:Since the 1970's) (we; know; that the average temperature of the world's oceans has increased during this same time period; T:now) Context(we know,List([119, 126))):(the average temperature of the world's oceans; has increased; T:during this same time period)
Arctic sea ice has decreased,List([68, 96)) we know,List([119, 126))
Arctic sea ice temperatures at the earth's surface we the average temperature of the world's oceans
has decreased have warmed know has increased
in thickness
T:Since the 1970's
that the average temperature of the world's oceans has increased during this same time period T:now
T:during this same time period