Mankind's treatment of the Earth as well as its contribution to the planet's weakening weather structure will become evident this month as concentrations of trapped carbon dioxide in the atmosphere reach 400 parts per million (ppm), or maybe even more.

"I wish it weren't true, but it looks like the world is going to blow through the 400-ppm level without losing a beat," Ralph Keeling, a geologist at the Scripps Institution of Oceanography at UC San Diego that operates the Hawaiian observatory Mauna Loa station.

"At this pace we'll hit 450ppm within a few decades."

The new record in a nutshell translate to a hotter planet and rising sea levels. "Our dumping of heat and CO2 into the ocean is like making investments in a pollution bank."

Scientists reported that daily average readings of CO2 at Mauna Loa showed that as of April 25 it had reached 399.72ppm. The readings from the Mauna Loa station are considered the gold standard since it is located at 3,400m and far away from major pollution sources in the Pacific Ocean. It has been monitoring atmospheric CO2 readings by the hour for more than 50 years.

Although hitting the 400 ppm mark does not translate to an immediate or instant end of days or doomsday scenario like the movie 2012, it however must not be taken lightly.

"This is another global emissions target that we've blown past without doing anything," Jim Butler, director of global monitoring at NOAA's Earth System Research Laboratory, told InsideClimate News. "Stronger storms, droughts, rising seas. We are already seeing the impacts of increased CO2 in the atmosphere... How much further can we really go?"

Essentially, the greenhouse emissions symbolic milestone underscores the global governments inaction on global warming.

What's more, the last time the Earth experienced its CO2 level hitting 400 ppm was between three million and five million years ago during the Pliocene epoch.

"The current increase is a direct consequence of how much our society relies on fossil fuels for energy," Mr Keeling said.

"The 400-ppm threshold is a sobering milestone, and should serve as a wake up call for all of us to support clean energy technology and reduce emissions of greenhouse gases, before it's too late for our children and grandchildren," Tim Lueker, an oceanographer and carbon cycle researcher, said in a statement.