Question

how do you know that climate change is occurring? (10x 2)

Answer 1

Answer:

Multiple independent data sets show that the Earth’s average surface temperature has warmed by about 1.0°C since the start of the Industrial Revolution in 1850. This historic trend of global warming is a clear signal that human emissions of greenhouse gases are changing the planet’s climate. But why exactly is this happening?

This section explains what the greenhouse gas effect is and what it tells us about the impact of human emissions on the planet; how scientists know natural phenomena such as the sun or the El Niño cycle cannot explain climate change; and why humans are causing atmospheric CO2 to reach higher levels than at any point in the last several million years.