Accelerating growth in CO₂ levels in the atmosphere

CO₂ Growth

In 2016, CO₂ levels in the atmosphere grew by 3.36 ppm (parts per million), a new record since 1959 and much higher than the previous record set in 2015.

Worryingly, above graph has a trendline added pointing at a growth rate in CO₂ levels of 6 ppm per year by 2026.

Growth in levels of CO₂ in the atmosphere is accelerating, despite reports that - for the third year in a row - carbon dioxide emissions from fossil fuels and industry (including cement production) had barely grown, as illustrated by the Global Carbon Project image below.

Why is growth in CO₂ levels in the atmosphere accelerating?

So, what makes growth in CO₂ levels in the atmosphere accelerate? As discussed in a previous post, growth in CO₂ levels in the atmosphere is accelerating due to:

• Deforestation and Soil Degradation:
  Agricultural practices such as depleting groundwater and aquifers, plowing, mono-cultures and cutting and burning of trees to raise livestock can significantly reduce the carbon content of soils, along with soil moisture and nutrients levels.
• Climate change and extreme weather events:
  The recent jump in global temperature appears to have severely damaged soils and vegetation. Soil carbon loss and enhanced decomposition of vegetation appear to have occurred both because of the temperature rise and the resulting extreme weather events such as heatwaves, drought, dust-storms and wildfires, and storms, hail, lightning, flooding and the associated erosion, turning parts of what was once a huge land sink into sources of CO₂ emissions.
  Moreover, extreme weather events can also lead to emissions other than CO₂ emissions, such as soot, nitrous oxide, methane and carbon monoxide, which can in turn cause a rise in the levels of ground-level ozone, thus further weakening vegetation and making plants even more vulnerable to pests and infestations.
• Oceans may also be taking up less CO₂ than before:
  Oceans have absorbed some 40% of CO₂ emissions since the start of the industrial era. Up until recently, oceans still took up some 26% of carbon dioxide emitted by people annually. As discussed earlier, oceans are getting warmer, and warm water holds less oxygen than cold water. Furthermore, as the water warms, it tends to form a layer at the surface that does not mix well with cooler, nutrient-rich water below, depriving phytoplankton of some of the nutrients needed in order for phytoplankton to grow. Less phytoplankton in the oceans means that oceans become less able to take up carbon dioxide from the atmosphere. A study by Boyce et al. found a decrease of about 1% per year of phytoplankton in oceans globally. Sergei Petrovskii, co-author of a 2015 study, found that a rise in the water temperature of the world’s oceans of about 6°C could stop oxygen production by phytoplankton by disrupting the process of photosynthesis, adding that “About two-thirds of the planet’s total atmospheric oxygen is produced by ocean phytoplankton – and therefore cessation would result in the depletion of atmospheric oxygen on a global scale. This would likely result in the mass mortality of animals and humans.”

Biomass

Sensitivity

Meanwhile, research including a 2014 study by Franks et al. concludes that the IPCC was too low in its estimates for the upcoming temperature rise locked in for current CO₂ levels. A study by Friedrich et al. updates IPCC estimates for sensitivity to CO₂ rise, concluding that temperatures could rise by as much as 7.36°C by 2100 as a result of rising CO₂ levels.

When also taking further elements than CO₂ more fully into account, we could face an even larger temperature rise, i.e. a rise of 10°C (or 18°F) by 2026 (compared to pre-industrial), as further described at the extinction page that specifies the different elements of such a rise, including a 0.5°C rise due to CO₂ emissions from 2016 to 2026. The CO₂ growth discussed in this post appears to be in line with such a rise and in line with the associated loss of carbon sinks and rising vulnerability of carbon pools.

The situation looks particularly threatening in the Arctic where many of the most vulnerable carbon pools are located, where temperatures are rising fastest and where CO₂ levels have recently risen rapidly (see image below with CO₂ readings at Barrow, Alaska).

[ click on images to enlarge ] 

Also note the recent rise in methane readings at Barrow (image below).

[ click on images to enlarge ] 

Action is needed!

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
http://arctic-news.blogspot.com/p/climateplan.html

• Extinction
http://arctic-news.blogspot.com/p/extinction.html

• Monthly CO₂ not under 400 ppm in 2016
http://arctic-news.blogspot.com/2016/11/monthly-co-not-under-400-ppm-in-2016.html

• Oxygenating the Arctic
http://arctic-news.blogspot.com/p/oxygenating-arctic.html

• How much warming have humans caused?
http://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• Warning of mass extinction of species, including humans, within one decade
http://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

• Global phytoplankton decline over the past century, by Daniel G. Boyce, Marlon R. Lewis & Boris Worm
http://www.nature.com/nature/journal/v466/n7306/abs/nature09268.html

• Mathematical Modelling of Plankton–Oxygen Dynamics Under the Climate Change, by Yadigar Sekerci and Sergei Petrovskii
https://link.springer.com/article/10.1007%2Fs11538-015-0126-0

• Global warming disaster could suffocate life on planet Earth, research shows
http://www2.le.ac.uk/offices/press/press-releases/2015/december/global-warming-disaster-could-suffocate-life-on-planet-earth-research-shows

Climate Change Accelerating

Methane levels as high as 2562 ppb were recorded on October 9, 2014, as illustrated by the image below.

Many grey areas show up in the image where QC (quality control) failed, as it was too hard to read methane levels in the respective area, apparently due to high moisture levels (i.e. snow, rain or water vapor) in the atmosphere.

As above image illustrates, cloud cover is high over the Arctic, while there is also precipatation in the form of snowfall.

In other words, high levels of methane (above 1950 ppb, colored yellow) could be present over a much larger part of the Arctic Ocean, while methane in these grey areas could be even higher than the measured peak level of 2456 ppb.

This appears to be confirmed by persistent high methane levels over vast areas across the Arctic Ocean both in the morning (top part of the image further above) and in the afternoon (bottom part of image) on 9 October 2014.

Methane levels are this high over the Arctic Ocean for the number of reasons, including:

• The Gulf Stream keeps pushing warm water into the Arctic Ocean.
• The resulting eruptions of methane from the seafloor of the Arctic Ocean constitute a feedback that accelerates warming in the Arctic. 
• As the Arctic warms up more rapidly than the rest of Earth, the Arctic's ice and snow cover will decline, further accelerating warming in the Arctic.
• As the Arctic warms up more rapidly than the rest of Earth, the speed at which jet streams circumnavigates the Northern Hemisphere will weaken, making it meander more, resulting in a greater frequency and intensity of extreme weather events, such as heat waves, droughts and wildfires. 

Here's an example of intense warming. Look at what is currently happening on Greenland.

As the image above right shows, sea surface temperature anomalies as high as +1.89°C hit the North Atlantic (on October 8, 2014). 

Furthermore, high cloud cover over the Arctic (image further above) makes it hard for the heat there to radiate out into space, further contributing to high temperature anomalies.

The image on the right shows high temperature anomalies over Greenland and parts of the Arctic Ocean on October 11, 2014. Note that anomalies are averaged out over the course of the day (and night).

The image below (right) shows anomalies at the top end of the scale hitting large parts of Greenland at a specific time during this day. The left part of the image below shows how this could happen, i.e. jet streams curling around Greenland trapping warm air inflow from the North Atlantic.

As said, as the Arctic warms up more rapidly than the rest of Earth, the speed at which jet streams circumnavigate the Northern Hemisphere will weaken, making the jets meander more and creating patterns that can trap heat (or cold) for a number of days over a given area. Due to the height of its mountains, Greenland is particularly prone to be increasingly hit by heatwaves resulting from such blocking patterns. Warming changes the texture of snow and ice, making it more slushy and darker, which also makes that it absorbs more of the sunlight's heat, further accelerating melting.

As Paul Beckwith warns in an earlier post, melt rates on Greenland have doubled in the last 4 to 5 years, and melt rates on the Antarctica Peninsula have increased even faster. Based on the last several decades, melt rates have had a doubling period of around 7 years or so. If this trend continues, we can expect a sea level rise approaching 7 meters by 2070.

From: More than 2.5 m sea level rise by 2040

These are all indications that the pace of climate change is accelerating in many ways, the most dangerous one being ever larger methane eruptions from the Arctic Ocean's seafloor. As the image below shows, sea surface temperature anomalies are very high in the Arctic Ocean, indicating very high temperatures under the surface.

U.S. Secretary of State John Kerry recently said: “There are now – right now – serious food shortages taking place in places like Central America because regions are battling the worst droughts in decades, not 100-year events in terms of floods, in terms of fires, in terms of droughts – 500-year events, something unheard of in our measurement of weather.” Warning about looming catastrophe, Kerry adds: “Life as you know it on Earth ends. Seven degrees increase Fahrenheit (3.9°C), and we can't sustain crops, water, life under those circumstances.”

The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.

Post by Sam Carana.