Click on "People living with HIV" on the left side of this map: http://aidsinfo. unaids. org/ Then select "People living with HIV - All ages." Move the timeline at the bottom to 2015 and hover over South Africa to view the amount of people living with HIV in 2015. Then select the year 1990 on the timeline on the bottom, and hover over South Africa again. How does the prevalence of the HIV virus in South Africa in 1990 compare to the prevalence in 2015? What does this suggest about South Africa’s AIDS prevention measures over that time span?

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.