Question

The main cause of recent increased global temperatures is?

1) CO₂ from factories, power plants, and automobiles
2) Earth's orbital eccentricities
3) variations in the sun's output
4) water vapor

Answer 1

The primary cause of increased global temperatures is CO₂ emissions from human activities, especially the burning of fossil fuels, leading to an enhanced greenhouse effect.

Step-by-step explanation:

The main cause of recent increased global temperatures is CO₂ from factories, power plants, and automobiles. This has led to a substantial increase in greenhouse gases such as carbon dioxide and methane in the atmosphere, contributing to the enhanced greenhouse effect. Since the Industrial Revolution, human activities such as the burning of fossil fuels and deforestation have resulted in a significant rise in these gases. Greenhouse gases raise air temperatures by absorbing infrared radiation, creating a 'blanket' that traps heat on Earth's surface. This has led to a measurable increase in Earth's average surface temperature, particularly since 1980, indicating a clear trend of global warming.