earth's surface is considered "young" because there are very few visible impact craters. describe at least three causes/processes responsible for earth having so few impact craters relative to the "older" surface of the moon, despite throughout geological history having been impacted at the same rate.

Earth has so few impact craters compared to the Moon because of erosion, plate tectonics, and volcanoes.

1. Erosion

Weather, running water, and plants all wear down the ground and level it out. The moon has none of these.

2. Plate tectonics

The Earths surface consists of several tectonic plates floating over a liquid core.

As the plates tear apart and crush against each other, new rocks form and older ones disappear.

Over billions of years, all traces of old impact craters have disappeared.

The moon has no moving plates, so tectonics cannot remove lunar craters.  

3. Volcanoes

Volcanic flows cover up impact craters. The Moon has not had active volcanoes for three billion years.

it is very hard for the climatologists to precisely predict how will the global temperatures be changing so there's lots of models, some of which differ significantly, this is due to multiple factors, and probably the most important is the human activity.

humans have been a key factor in climate change around the globe since the start of the industrial revolution, and in the past few decades the consequences are becoming more obvious. there's lots of emission of pollutants in the atmosphere as well as changing the environment on the surface itself, so it's really hard to predict how will that go in the future because there's some countries that are reducing the damage and are going towards green energy, while others are stubbornly continuing with pollution and damages to the environment.