Which of the following statements regarding climate change is true?
Most climate scientists conclude that human activities over the past 100 years have had an effect on the planet’s climate.
Factors Influencing Climate
Which of the following is the best statement regarding the graph of atmospheric CO2 concentrations?
Atmospheric CO2 concentrations have increased by more than 15% over the past 50 years.
Which of the following is the best statement regarding the graph in Step 2 showing atmospheric CO2 and surface temperature changes over the past 50 years?
This data is consistent with the hypothesis that increased atmospheric concentrations of CO2 may be causing an increase in average surface temperatures.
What was the percent change in CO2 emissions for transportation from 1980 to 2005?
Which of the following policy recommendations by the two authors would most directly lower the risk of climate change?
A carbon tax that could reduce greenhouse gas emissions by 25%