<span>c.) decrease in the overall world population </span>
Tropical places are hot because the humidity coming from the moisture of the plants and water are heated by the sun on the top layer of the tropical zone. The climate varies little in rain forest. There are five layers in the tropic trees so it's so thick that barely any light come through. This is also why vines grow up the trees so they can reach the sunlight to get nutrients. Also, the tropics are near the equator and that also causes the heat. The polars are cold because they barely get any sun heat to melt the snow or warm it up. The polars are melting due to certain chemicals and gasses in the atmosphere. also known as global warming. Hope that was helpful!
I would think that it is true bit in not sure
<span>In terms of matter and resources, the Earth is essentially a closed system, because matter and resources are fixed.
</span>In terms of energy, the Earth is an open system, because there is a balanced transfer of energy. (The energy<span> radiates into the </span>Earth's system<span>, from the Sun and</span><span> then it is radiated back into space from the </span>Earth. The<span> flows of energy are regulated by the </span>Earth's<span> atmosphere and ozone layer.)</span>