It is widely recognised that the process of formulating their reports the Intergovernmental Panel on Climate Change has pressurised the scientists involved to
be complicit in allowing their natural scientific caution (for avoiding overstating
the extent of any risks that the science is suggesting) to be used by the political
representatives of government involved to ensure any reports ended up
reporting the minimum level of risk the scientists could agree to.
In the latest report by the IPCC WG3, reference is frequently made to the level of
CO2-equivalent concentration of greenhouse gases (CO2e) of 450ppm
corresponding to a 2 degrees C global average temperature increase. The report
effectively argues that cutting the emissions of CO2, the dominant greenhouse
gas today, leaves the world with a chance of holding the rise in temperatures to 2
degrees, assuming that the present level of atmospheric CO2 is 400ppm.
Yet there is ample evidence that we have already exceeded the threshold of
450ppm when one takes into account all of the other greenhouse gases in
addition to CO2, such as methane, nitrous oxide and CFCs [1], so that there
effectively is no further ‘carbon budget’. And further, the 450ppm target has
been called into question by measurements suggesting that climate sensitivity
(the final temperature increase for a given increase in climate forcing) is higher
than originally thought [2],[3], so we must aim for a lower atmospheric
greenhouse gas concentration if we want to reach the same limit in temperature
rise.
Most importantly of all, as sea ice in the Arctic Ocean declines at an accelerating
rate, field studies previously reported by the scientists Maria Shakhova and Igor
Semelitov confirm a rapid increase in methane emissions from thawing
permafrost deposits on the ocean floor and onshore permafrost regions. The
same scientists have warned that a sudden release of 50 Giga-Tonne (Gt) of
methane from the ocean sources is possible at any time. Because methane is 84
times more powerful than CO2 in the short term (20 year time scale), we are
therefore faced with the risk of abrupt, catastrophic global warming as a result of
the loss of Arctic sea ice, which is predicted to occur in the summertime in a
matter of years.
There is no mention of the Arctic and methane emissions resulting from it by the
IPCC. Many prominent climate scientists have attempted to downplay the risk of
sudden methane release, advancing the view that permafrost melting is a slow
process, or arguing that the danger is reduced by the short lifetime of methane in
the atmosphere. But the data suggests that methane from the Arctic is
concentrating in the Arctic, increasing it’s effective lifetime adding to warming of
the Arctic and continually increasing the risk of large emissions- a runaway
situation developing.
The surest way of reducing the risk is to tackle the root cause of these emissions
by cooling the Arctic, in order to save it’s snow and sea ice cover, which would be
achieved by the addition of sunlight reflective particles in the Arctic atmosphere
in the short term, replaced as much as possible by the more reliable technique of
marine cloud brightening (MCB) to increase the Arctic albedo, in the longer term.
This would be a short term solution to buy the time for making large reductions
in carbon emissions and drawing down CO2 from the atmosphere to halt global
climate change.
In summary, AMEG has undertaken serious investigations of the latest scientific
observations and evidence and have come to the following extremely pertinent
conclusions:
1. Observations and best models show that the sea ice is on an exponential
downward trend (e.g. towards there being very little sea ice left at the end of
summer 2016), demonstrating that the sea ice is already beyond the tipping
point.
2. We are heading inexorably towards a complete and catastrophic meltdown
of the Arctic ice cap, including the Greenland Ice Sheet and permafrost.
3. There appears to be no natural mechanism in the Earth System to stop this
happening, therefore active intervention will be required to cool the Arctic and
prevent further decline in the sea ice, melting of the Greenland Ice Sheet, and
thawing of permafrost.
4. Permafrost is releasing vast quantities of the potent greenhouse gas,
methane, at an exponentially growing rate, so suppression of this gas is
needed.
5. Methane is 84 times more potent than CO2 over 20 years, whereas the
carbon budget set by AR5 assumed a potency of around 20 times over 100
years. With this higher figure, we have already run out of carbon budget and
are committed to a dangerous level of global warming this century, even if the
Arctic is cooled quickly.
6. Ocean acidification is already affecting the marine food chain and there is
extreme risk in allowing acidification to worsen for further decades.
7. Therefore there has to be active intervention to remove CO2 from the
atmosphere (where we propose a combination of methods such as forest
management, soil improvement with biochar, rock crushing with weathering,
and aquaculture with diatoms).
8. Arctic cooling is relatively inexpensive; we need to ramp up public awareness
towards a global agreement recognizing the great threat represented by losing the
seaice and the need for governments to commit funding to save the situation, which is
clearly in the interests of all of humanity.
[1] http://oceans.mit.edu/featured-stories/5-questions-mits-ron-prinn-400ppm-threshold
[2] http://www.apollo-gaia.org/CoR%20Keynote.pdf
[3] http://m.rsta.royalsocietypublishing.org/content/371/2001/20120294.full