Choice of the century: >,2,< °C ?!?

COP21 is happening. UN General secretary has urged all states to work faster and effectively to reduce emission and achieve target of 2°C. He also mentioned that even this target will pose threat in food/water security and economic stability. Scientific communities engaged in climate studies, in another hand, are warning 2 °C would also pose a risk upon earth system and this is political rather science. They add climate projection could not have considered some sudden event or tipping point of forcing like carbon dioxide, which would proliferate the rate of warming. Smaller Island States are demanding for 1.5°C target, which is safer but far too ambitious. In last post of November, I have discussed about the trillion ton carbon, which forces the 2 degree Celsius  and a chunk of it has already been released to atmosphere. As available budget is only left,  it is challenging to remain below the desired level.  Along these different ideas, demand and discussions, almost all nations participating in COP21 seems to agree on agenda to limit global warming by 2°C as compared to pre-industrial level by 2100 AD. IPCC clearly mentions about the range of likely temperature at the end of this century. Clearly, the choice has become an issue of debate. 
An article in The Independent indicate even scientific community are not certain about system behaviour at 2°C and nature of radiative forcing above 400 ppm of carbon dioxide.  Yoshimori et al.(2001) has also showed reduced forcing at different level of concentration. Martı´nez-Bot et al. (2015) discuss about the different extent of radiative forcing of carbon dioxide at for our Pliocene-like future and suggest the current prediction of radiative forcing, an increase of 1.5 K to 4.5 K per doubling of CO2, is more probable to happen.    

From : IPCC AR5 synthesis report .

Tschakert (2015) discuss about how the target of two degree Celsius developed and how good is it. The author describe jump from 1.5 to 2 degree Celsius as move from moderate to close to high risk zone and is an midway. Jaegar & Jaeger (2011) describe different views in 2 °C target. Catastrophe view as move to domain of  safety  from  catastrophic whereas cost benefit view it as optimal efficient, and focal point view as measure to bring a effective coordinated solution which is lacking at present. They argue politician treated the target of 2°C as scientific and scientist as political view. They suggest demonstrative effort can be the right start.    

From: www.Carbonbrieforg

IPCC 2015 press release describe the economics aspect of 2°C target. Some of the condition to meet the target are a) reduce emission by 40-70% by 2010-2050, b) negative emission by 2100, and c) these reduction effort should not effect the economic stability. 

Anderson (2015)  describe the economics aspect of the  2°C and mention it need huge change in trend and reversing the past (reversing rapid emission to negative emission). Author suggest that scientist should communicate their finding clearly and candidly, so that it could be rightly be used by concerned community. This suggest that it is challenging to meet the target. 
COP21 has also clearly mentioned about "Why 2°C. The video explains the crux of choosing it.

Reviewing these ideas, it becomes clear that 1.5°C is definitely better but "How?" hinders to adopt it as global target (also remember the climate denial, which we mentioned in previous post). More than 2°C is simply catastrophic. In this situation limiting at 2°C is a effective way of bringing out collaboration among all state and organization. I was reading a Facebook post where someone was thanking for Uruguay's promising progress in clean energy. My personal idea and urge is to understand 2°C as maximum allowed and work together to bring down as possible and if we all try it is maximum possible. As the choice of 2°C is related with us and whole living system,  this is why I mentioned it as choice of the century.

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