How does human activity affect large-scale climate change?
Answers
The Earth’s climate is changing rapidly. Scientists trying to find out what’s causing climate change work like detectives, gathering evidence to rule out some suspects and to ascertain just who is responsible. It’s clear, based on over a century of scientific investigation, that humans are responsible for most of the climate change we’ve seen over the last 150 years.
Humans are not the only suspects. The climate has changed throughout the Earth’s history, well before humans evolved. The Sun is the primary driver of the climate. Roughly speaking, global temperatures rise when more energy from the Sun enters the atmosphere than returns to space through the atmosphere. The climate cools any time more energy returns to space than comes in from the Sun. While humans can influence that balance, other factors, from continental drift and changes in the shape of the Earth’s orbit to variations in the Sun’s activity and phenomena like El Niño, can all influence the climate. Considering the pace of climate change today, scientists can rule out most of those suspects: some happen too slowly to explain current climate change, while others move in small cycles, not long trends, and others only influence the climate in part of the planet. Scientists know about these factors and can account for them when assessing human-caused climate change.
Humans affect the environment to a greater extent. Climate depends on several factors. Human activities like burning gas, oil and coal in power plants and cars, deforestation affect the Earth's albedo. Atmospheric CO2 is increased by the fossil fuel burning it leads to temperature rise and results in warming of the earth. Compared to other sources the emission of carbon from fossil fuel is high which affects the atmosphere to a greater extent. Scientists agree that the increase in average surface temperature is a key climate change indicator.