Answer to Question 1
The interactions between Earth and its atmosphere are so complex that it is difficult to unequivocally prove that Earth's present warming trend is due entirely to increasing concentrations of greenhouse gases. The problem is that nay human-induced signal of climate change is superimposed on a background of natural climatic variations, called noise. Furthermore, in the temperature observations, it is difficult to separate a signal from the noise of natural climate variability. However, today's more sophisticated climate models are much better at filtering out this noise while at the same time taking into account those forcing agents that are both natural and human-induced.
Answer to Question 2
C
From space earth shows itself as a planet covered mostly by water.
Species of reef-building corals may be able to adapt to warming waters by relying on algae
Mira as seen from the Earth
Geothermal energy and powers Earth’s systems
Foundations of Earth Science, 7th Edition
A current-carrying wire is placed in a uniform magnetic field, as shown below.