Are we heading towards 4-degrees warming? And if yes, should we be concerned?

[OKIsItJustMe]

http://www.hzg.de/mw/earthleague/036338/index_0036338.html

[font face=Serif]16-Sept-2013
[font size=5]Are we heading towards 4-degrees warming? And if yes, should we be concerned?[/font]
[font size=4]By The Earth League members Johan Rockström, Hans Joachim Schellnhuber, Mario Molina, Brian Hoskins, Guy Brasseur, Carlos Nobre, Peter Schlosser, Veerabhadran Ramanathan, Nebojsa Nakicenovic, Youba Sokona, Leena Srivastava, Jennifer Morgan[/font]

[font size=3]The body of scientific evidence indicating that our civilization has already caused significant global warming is overwhelming: Of the almost 14 000 peer-reviewed climate-change articles from the last two decades, analyzed recently by the geologist James Powell, only 24 deny the warming or its human cause. Also, research keeps piling up studies demonstrating that even bigger modifications of the world’s environment can be expected if the release of heat-trapping gases from industry, agriculture, transportation and settlements is not curbed immediately: New projections from the Coupled Model Intercomparison Project (CMIP5) result in up to 6°C higher planetary temperatures by 2100 (as compared to pre-industrial levels) under the assumption of no mitigation. Finally, a disturbing picture of the negative impacts and dramatic risks accompanying unbridled warming of the Earth is emerging: According to a model calibrated with data from the past millennium, a warming by “only” 2°C would generate, by 2300, a sea-level rise of 2.7m above the current value - to name just one dire consequence.

In response to these alarming facts and figures, crucial political institutions (such as the UN Security Council), international agencies (such as the IMF) and business associations (such as the WBCSD) conclude that the long-term prosperity of the human enterprise is challenged. Therefore, these eminent stakeholders call for aggressive climate stabilization, regardless of residual cognitive uncertainties that may never be entirely eliminated. Global institutions have recognized that science speaks effectively with one voice about the reality of climate change. A recent flagship report by the World Bank epitomizes this new dynamics. The document is based on a commissioned review of the latest scientific literature, performed by the Potsdam Institute (PIK) and Climate Analytics (CA), both based in Germany. The World Bank was particularly interested in the most evident consequences that nature and civilization would have to face in a 4°C warmer world. And the Bank wanted to learn how such a change in the planetary environment might impinge on their strategies for world-wide human development and poverty reduction.

PIK and CA fulfilled their task similarly to how the IPCC performs its assessments: The entire body of pertinent studies was searched by about 15 experts, with a strong focus on the peer-reviewed literature in the best international journals. Thus, the report drew upon the inputs from about 1500 international scholars. In order to double-check the scientific quality of the collected information, the resulting piece in turn was peer-reviewed by 13 renowned scientists nominated by the World Bank. This procedure provided the best possible reflection of the relevant state of the climate-change art. Let us now turn to the second overarching question raised in the title. Is a 4-degrees warming a problem? The answer reads, with marginal uncertainty, “yes”. In fact, such a future can only be responsibly described as confronting the world with a potentially disastrous, and thus unacceptable, prospect. This environmental sea-change would most likely cause massive stresses and disruptions in numerous natural and socioeconomic systems across the world. Some of these impacts would neither be acceptable nor manageable for the people directly affected, most of them living in the tropics and sub-tropics. The World Bank report lists several of the most deleterious effects projected and explains why the poor countries would be hit hardest. Much of this has to do with what scientists call “variability”.

In order to appreciate the argument, let us take a long look back on the making of our civilization. This happened over the past 10 000 years, a period of unprecedented stable and temperate climate conditions, which allowed our ancestors to settle down for good. During that unique window of cultural opportunity, the planetary mean surface temperature oscillated only plus/minus one degree around a value of approximately 14 °C, so the global population could grow from a few millions to 7 billion at present.

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[phantom power]

1. concern

[CRH]

2. Yes we are headed for 4*C, ...

and no we should not be concerned, we should be terrified. If a person can't see this with the present disruptions at .8*C, then they are not paying attention, they are not informed, or they have vested interest in enjoying the status quo at the expense of their children.

[Nihil]

3. Rhetorical questions are rhetorical.

It's an interesting article but anyone who is awake already knows the answers
to both questions and anyone who isn't awake will continue to blithely ignore
the facts that have been trumpeted far & wide for years.

Ah well, maybe if each good article changes a mind in the right direction
then ... we need a lot of good articles ...

[kristopher]

4. "A recent flagship report by the World Bank epitomizes this(sic) new dynamics"

When you have agencies like the World Bank sounding the alarm in the manner noted, you are reaching a totally new audience from a totally new stage.

I think (hope) we are at a tipping point where the resistance to action is starting to crumble. Don't forget that action was initiated in 1992 and had momentum until the the fossil fuel industries' organized opposition began to return them benefits in the early 2000s.

IMO, much of their success was possible because the fledgling economic state of the technologies required to address climate change. Considering the current economic capabilities of the energy efficiency and renewable industries, unless they have a new bag of tricks, I don't think they can delay successfully any longer. FF's will continue to make noise and fight, but the ability of renewable technologies to continue their manufacturing capacity growth is now outside the sphere of the areas where the fossil fuel industries are able to exercise political and economic control.

[Nihil]

5. Fair point.

> When you have agencies like the World Bank sounding the alarm in the manner noted,
> you are reaching a totally new audience from a totally new stage.