In two-thousand three, American William Ruddiman first proposed that global warming resulted from human activities thousands of years ago.

VOA: special.2011.04.26

Human activities are producing increased amounts of carbon dioxide and other gases.

VOA: special.2010.01.19

Are climate changes real? If so,were human activities mainly to blame?

VOA: special.2010.01.19

However,human activities are threatening the world's coral reefs.

VOA: special.2010.08.10

"The majority of turtles are actually killed out of human activities."

VOA: standard.2010.07.15

They also attract unscrupulous people who engage in nefarious activities, including child labor, human trafficking and abuse of commercial sex workers.

VOA: standard.2010.05.29

"Naturally,one would be concerned because with the likes of prostitutes that will be coming over, so people are bound to be more exposed to such activities such as prostitution and human trafficking."

VOA: standard.2010.05.29