Question

Q4.11. Attribution studies focus on determining whether or not Earth's climate has changed in a statistical sense. True/False?

Q4.12. While variation in solar output explains some of the increase in mean global temperature over the past 150 years, it is not nearly as important as the climate forcing resulting from human activities. True/False?

Q4.13. Which of the following statements about changes in greenhouse gases is NOT true? Check all that apply:

A. Based on observations made on Mauna Loa, climatologists have demonstrated that CO2 has increased dramatically since the 1950s.

B. Based on observations made on Mauna Loa, climatologists have demonstrated that CO2 concentrations go up and down each year, increasing during the Northern hemisphere's winter and decreasing during its summer.

C. Based on data from ice cores, climatologists have demonstrated that CO2 concentrations have varied dramatically over the past 600,000 years, and were frequently well in excess of recent values.

Q4.14. Even if the composition of the atmosphere did not change from its present state, Earth's climate would continue to warm for the next century. True/False?

Answer 1

11) true. Over the years scientists have been studying the earth's climatic changes and measuring various parameters like temperature, humidity, wind and water currents, precipitation, atmospheric composition, etc. globally as well as locally. All reports suggest a substantial variation from what existed at the time when the human race began.

12) true. The solar output has increased without any doubt but the levels of CO2 has shot up alarmingly resulting in trapping of the heat hence being the more grave and important reason behind the global warming.

13) b and c are false. The mauna kea observations say that CO2 levels have consistently increased with an average of 1.4% for some yrs now. They havnt and should not exceed 400ppm. But we are approaching these levels which is alarming

14) true. Because the sun's output would increase even though it is minimal