Answer:
Human activity - Produces greenhouse gasses.
Greenhouse gasses - Cause atmosphere to trap more heat.
Sun's output - Can vary.
Ice age - Peaked 20,000 years ago.
Explanation:
Human activity includes the usage of fossil fuels on a very large scale, and by using them we release huge amounts of greenhouse gasses into the atmosphere.
The greenhouse gasses have the ability to trap the heat that is reflected from the surface of the planet, thus keeping more of it in the atmosphere and causing global temperature rise.
The sun is technically a star, thus an object that produces energy and light, and like every star, it has variations in its activity in accordance with the processes going on on it.
There have been numerous ice ages through the geological past, and the last one of them ended only around 10,000 years ago, with its peak being just 20,000 years ago.
Meld into one nation diverse groups who are peaceful within her borders and have a broader loyalty to the country than the group they belong to. In Canada, (where I live) I like to think that the hatred shown between Muslims and Christians, Hindus and both, Jews and Arabs, is an imported emotion. It's not true of course. We're just much quieter about it.
One of the things that brought tourists to France, was the beautiful scenery and nature
B.rely on wind power rather than electricity
The Earth has an outer solid layer called the crust, a highly viscous layer called the mantle, a liquid layer that is the outer part of the core, called the outer core, and a solid center called the inner core. ... The crust is the outermost layer of the Earth. It is made of solid rocks.