Another month, another carbon dioxide record. This  time  the record  extends  beyond the  rocky  slopes of  Mauna Loa, Hawaii, home to the most storied carbon dioxide record, and includes 39 other sites around the globe to paint a troubling picture of a greenhouse gas rise with no signs of slowing down.

For the first time since record  keeping began, carbon  dioxide levels  have  surpassed  400  parts  per million (ppm) globally, according to newly published data for March. CO₂ emissions are the  main driver of  climate  change and have risen more than 120  ppm  since  pre-industrial  times. The planet  has  warmed 1.6°F over that period as well. This isn’t the first time 400  ppm has made news. In May 2013, CO₂ measurements taken at Mauna Loa surpassed 400 ppm for the first time. Measurements have been taken continuously at the site since 1958 and present the longest running record of atmospheric CO₂ on the planet.

Tropical Forests Gulp CO₂, Slowing Climate Change

In April of last year, 12 observatories in the northern hemisphere, including Mauna Loa, averaged 400 ppm for thefirst time on record. And Mauna Loa rang in 2015 by registering a 400 ppm measurement, the earliest occurrence on record for the site.But what makes the new record more profound is that 400 ppm is officially part of the global record. Concentrations will likely remain above that mark until May when blooming plants in the northern hemisphere start to suck CO₂ out of the air.The reason it has taken a bit longer for the global measurement to catch up with the northern hemisphere record is due to a handful of factors. The main reason is because southern hemisphere CO₂ measurements lag behind their northern counterparts because there are more sources of human CO₂ emissions in the northern half of the globe. Though CO₂ moves around in the atmosphere, it takes time to spread.

Source:- News.discovery.com