Carbon dioxide rises

 There's more carbon dioxide in the atmosphere today than at any time in the past 800,000 years – 402 parts per million, in measurements earlier this week – according to a report from the mountaintop observatory in Hawaii that measures concentrations of the greenhouse gas.

Carbon dioxide (CO2) the most common and most important of the human-produced greenhouse gases, because it is released from so many sources around the world (like factories, cars, airplanes and power plants) and because it can remain in the atmosphere for centuries, adding to global warming for many human lifetimes.

Carbon dioxide levels passed 400 ppm for the first time in recorded history last May and reached that milestone two months earlier this year, on March 16. They rose just above 402 ppm on April 7, and are projected to remain above 400 ppm for the next couple of months, according to Mashable.

This month's measurements are believed to be the highest in at least 800,000 years – by far the highest since humans have walked on Earth – based on CO2 readings taken from air bubbles in ice cores drilled deep within many glaciers around the world, and from corals taken from deep in the ocean, Mashable notes.

http://www.weather.com/news/science/environment/carbon-dioxide-rises-highest-levels-800000-years-20140410