Refer to the graph below.The Keeling curve,shown here,provides us with more than a half-century of precise measurements of atmospheric CO₂ concentrations over Mauna Loa,Hawaii.Do these data show a trend,and if so,what is the trend? A) No;the data appear random. B) No;the data show constant variability,not a definite trend. C) Yes;the data show a slight,but insignificant,upward trend. D) Yes;the data show an upward trend,but variability makes it invalid. E) Yes;the data show a definite upward trend with predictable seasonal variations.

Question

Quizplus · Accepted Answer

The Keeling curve shows a definite upward trend with predictable seasonal variations. It shows an overall increase in atmospheric CO2 concentrations, with the highest concentrations occurring in the Northern Hemisphere winter and the lowest concentrations in the Northern Hemisphere summer. This trend is significant and has been attributed to human activities, primarily the burning of fossil fuels.

Refer to the Graph Below