Saturday, March 9, 2019

Global CH4 up 8.4 ppb in November 2018

According to the NOAA ESRL latest monthly data release, November, 2018 saw the planet experience a global methane mean of 1867.2 ppb, an increase of 8.4 ppb over 2017.

During the past five years we have experienced an increase of 46.8 ppb, and in the last 10 years, a 69.8 ppb increase.

As recently reported, the science community is still determining the mix of sources driving this increase since 2007, and the acceleration since 2014. What has been proposed are changes in biological sources such as emissions from cattle, a drop in hydroxyls in the atmosphere which impact the length of time before methane breaks down, or agricultural production that is increasing methane emissions, particularly from rice production. A final source suggested is an increase in methane released by new natural gas and oil production. 

Of significant concern is that natural feedbacks may begin or increase. If this occurs - despite cuts in human emissions - natural sources will offset our cuts and lead to future climate change.

Global CO2 December 2018 - On Track for 410+ ppm in March/April 2019

Global CO2: December 2018

In December, 2018, NOAA/ESRL reported global carbon dioxide at 409.36 ppm, or 2.83 ppm above December, 2017. That annual change was the highest since those associated with the 2015-2016 El Nino, when the world experienced increases above 3 ppm for 12 consecutive months. 


This month continues the unbroken CO2 concentration rise observed at Mauna Loa since 1959, then globally since 1980.

Five and Ten Year Increases

When December, 2018 is compared to 2013, global carbon dioxide has increased 12.71 ppm, the highest five year change since July, 2017 when we experienced a five year increase of 13.09 ppm. 

The last three months have experienced a decadal change above 23 ppm, with December having the highest at 23.32 ppm. The five and ten year rates continue trends which reflect ever increasing global emissions at increasing rates of change.

Passing 410 ppm

The world is on track to pass 410 ppm in 2019. It is possible this will be reached in February, quite probable in March, and almost certain in April, 2019. It is also probable that the global concentration will exceed 411 ppm in April or May 2019, given historical changes of 2+ ppm between December and April/May in recent previous years.

Quicker Milestones

Of greater concern is reaching 10 ppm increases in shorter times. If we pass 410 ppm in March, 2019, it will be only 48 months after passing 400 ppm in March, 2015. To increase from 320 to 330 ppm took 12 years (May 1960 to May 1972). We are now blowing through these 10 ppm milestones in 1/3 the time. 

The Future Trend?

If we stabilize carbon dioxide concentration increases for each future 10 ppm at 48 months, the planet will experience a doubling of CO2 compared to pre-industrial by 2080 and over 610 ppm by 2100. However, given that emissions are not slowing, combined with potential environmental system feedbacks, we may reach 560 ppm sooner, with less ability to influence the trend with decreasing emissions. More on this in another post.