State of the planet: 7 eye-opening facts for Earth Day

Earth recently hit several remarkable records — but not in a good way.

The amount of carbon dioxide gas, a global warming pollutant, has risen to the highest level in at least 800,000 years. Monthly average Arctic sea ice extent in March was the lowest in the satellite record. So far, 2015 has seen the warmest start of the year in at least 136 years.

For the 45th annual Earth Day on Wednesday, we compiled seven facts about the current state of our planet — indicators of the Earth under stress, largely due to humanity's own footprint

In the video above and list below, learn how manmade climate change has drastically altered our world. Read more...