Question

Which of these processes are capable of producing the significant and long-lived increase in global temperatures of the 20th century? Multiple select question.

A.increases in greenhouse gases
B. La Niña plate tectonics
C. El Niño changes in Earth's
D. orbit volcanic eruptions

Answer 1

The primary cause for the 20th-century global temperature increase is the anthropogenic emission of greenhouse gases, related to activities like the burning of fossil fuels since the Industrial Revolution.

Step-by-step explanation:

The significant and long-lived increase in global temperatures during the 20th century is largely attributed to the increase in greenhouse gases. Since the Industrial Revolution, there has been a steady rise in the burning of fossil fuels, contributing to higher levels of atmospheric greenhouse gases such as carbon dioxide, methane, and nitric oxide. These gases are known to trap infrared radiation, leading to a warming effect known as the greenhouse effect.

While natural factors like volcanic eruptions, changes in the Earth's orbit (Milankovitch cycles), and changes in solar activity do influence the climate, they generally lead to gradual and not rapid changes in temperature. However, the rapid increase observed in the 20th century does not match the patterns expected from these natural processes alone. Therefore, the primary cause of the 20th-century global warming is the anthropogenic increase in greenhouse gas emissions.