Question

Global average air temperatures worldwide _______.

1) have appeared to stabilize after a century of increase
2) are being influenced by human-induced changes in the greenhouse effect
3) are at present demonstrating no apparent trend one way or another
4) are generally lower than 20 years ago

Answer 1

Global average air temperatures are increasing due to human activity, especially from greenhouse gas emissions, with the most pronounced warming occurring over land and in the Arctic. Option 2 is correct.

Step-by-step explanation:

The question addresses the trend of global average air temperatures worldwide. Based on the information provided, the correct statement is that global average air temperatures are being influenced by human-induced changes in the greenhouse effect.

Climate models predict a rise in global surface temperature due to increased levels of greenhouse gases from human activities primarily from fossil-fuel burning.

This rise has been more pronounced over land and especially in the Arctic. Additionally, the number of warm days and nights has increased, while the number of cold days and nights has decreased. Therefore, please select option 2 as the correct answer to the question.