Earmark some days for the history books. March 22, 2016 was one of those days.
I’m sorry that the news is bad. Improved modeling with a paradigm shift away from inherent ice inertia toward CO2 as primary climate control knob finds that huge amounts of ice now melting are likely to wreck the ocean conveyor belt that keeps climate within bounds, and reticently sooner than even the newest models are predicting. Dr. James E. Hansen et al. published their new scientific paper after completing the peer review process. Now everyone in the world can read it in beginning with the journal ACP. Other respected climate scientists, such as Michael E. Mann (of “hockey stick” fame, infamy to a few), express having a hard time accepting the radical paradigm shift this paper posits, but find they cannot disagree with the conclusions. Indeed if the newer models prove correct they have huge implications including storms strengthened up to 1.5 times over those we’ve experienced, and multi-meter rising seas (potentially 1.7 m already by 2060), things we’d not expected humanity would face quite so quickly. Climate science had always assumed a weakening, but never a near-stop, in surface formation of deep ocean water.
This presents still more immediate and adverse consequences for some disproportionately affected, including hundreds of millions of Chinese and Indians who stake their lives on glacier-generated water streams. Such is the reason I originally titled this blog “Houston Climate Justice.” Tremendous questions of equity and equality rush toward us very rapidly now. And something seemingly as simple as ever-rising seas enwraps myriad effects on all nature regarding stronger storms, higher winds, salt water intrusion, lifting aquifers, massive habitat-flooding-wetlands and drainage changes, migrating deserts and pathogens, rapidly oscillating food chains and displaced species that face weakening and extermination, All bets must be considered off approaching 2060, 2080, 2100. And we, which is to say, all of us alive, all who have being, are clearly faced with forcing assertive collective policy action to happen now, and from our perspective maintaining such action forever, if we plan to preserve a humanly supportive planet. We can still do this, but it’s becoming increasingly less certain and it’s certainly getting ever harder to pull off. Please, my friends, begin to run, not walk, toward pricing carbon pollution to drive virtuous market behavior! #CCL #climatechange #sealevelrise #emissionsreduction #carbonfeeandrebate #pricecarbon
Source: http://www.atmos-chem-phys.net/16/3761/2016/ (final publication of peer-reviewed paper)
http://www.columbia.edu/~jeh1/2015/20150704_IceMelt.pdf (original paper pre-peer review)
http://csas.ei.columbia.edu/2016/03/22/abbreviation-of-ice-melt-paper/ (easier 19-page excerpt by Dr. Hansen), includes this short note: Planetary energy imbalance induced by meltwater cooling helps provide the energy required by ice heat of fusion. Ice melt to raise sea level 1 m requires a 10-year Earth energy imbalance 0.9 W/m2 (Table S1, Hansen et al., 2005b). Ed. Note: I must point out that we are within 0.1 W/m2 of this amount of global energy imbalance already, and it is up to you to influence your policy makers to attempt to interrupt global momentum toward and beyond that figure.
About this paper:
Takeaway quote from last 3 paragraphs of the paper:
“Our finding of global cooling from ice melt calls into question whether global temperature is the most fundamental metric for global climate in the 21st century. The first order requirement to stabilize climate is to remove Earth’s energy imbalance, which is now about +0.6 W/m2, more energy coming in than going out. If other forcings are unchanged, removing this imbalance requires reducing atmospheric CO2 from ~400 ppm to ~350 ppm (Hansen et al., 2008, 2013a).
The message that the climate science delivers to policymakers, instead of defining a safe ‘guardrail’, is that fossil fuel CO2 emissions must be reduced as rapidly as practical. Hansen et al. (2013a) conclude that this implies a need for a rising carbon fee or tax, an approach that has the potential to be near-global, as opposed to national caps or goals for emission reductions. Although a carbon fee is the sine qua non for phasing out emissions, the urgency of slowing emissions also implies other needs including widespread technical cooperation in clean energy technologies (Hansen et al., 2013a).
The task of achieving a reduction of atmospheric CO2 is formidable, but not impossible. Rapid transition to abundant affordable carbon-free electricity is the core requirement, as that would also permit production of net-zero-carbon liquid fuels from electricity. The rate at which CO2 emissions must be reduced is about 6%/year to reach 350 ppm atmospheric CO2 by about 2100, under the assumption that improved agricultural and forestry practices could sequester 100 GtC (Hansen et al., 2013a). The amount of CO2 fossil fuel emissions taken up by the ocean, soil and biosphere has continued to increase (Fig. S23), thus providing hope that it may be possible to sequester more than 100 GtC. Improved understanding of the carbon cycle and non-CO2 forcings are needed, but it is clear that the essential requirement is to begin to phase down fossil fuel CO2 emissions rapidly. It is also clear that continued high emissions are likely to lock-in continued global energy imbalance, ocean warming, ice sheet disintegration, and large sea level rise, which young people and future generations would not be able to avoid. Given the inertia of the climate and energy systems, and the grave threat posed by continued high emissions, the matter is urgent and calls for emergency cooperation among nations.” (p. 43-44, Hansen et. al. “Icemelt” draft discussion paper. 2015.)
(Paper after peer review complete:)
“The United Nations Framework Convention on Climate Change (UNFCCC, 1992) states the following:
The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.
‘Dangerous’ is not further defined by the UNFCCC. Our present paper has several implications with regard to the concerns that the UNFCCC is meant to address.
First, our conclusions suggest that a target of limiting global warming to 2°C, which has sometimes been discussed, does not provide safety. We cannot be certain that multi-meter sea level rise will occur if we allow global warming of 2 C. However, we know the warming would remain present for many centuries, if we allow it to occur (Solomon et al., 2010), a period exceeding the ice sheet response time implied by paleoclimate data. Sea level reached 6–9 m in the Eemian, a time that we have concluded was probably no more than a few tenths of a degree warmer than today. We observe accelerating mass losses from the Greenland and Antarctic ice sheets, and we have identified amplifying feedbacks that will increase the rates of change. We also observe changes occurring in the North Atlantic and Southern oceans, changes that we can attribute to ongoing warming and ice melt, which imply that this human-driven climate change seems poised to affect these most powerful overturning ocean circulation systems, systems that we know have had huge effects on the planetary environment in the past. We conclude that, in the common meaning of the word danger, 2°C global warming is dangerous.
Second, our study suggests that global surface air temperature, although an important diagnostic, is a flawed metric of planetary ‘health’, because faster ice melt has a cooling effect for a substantial period. Earth’s energy imbalance is in some sense a more fundamental climate diagnostic. Stabilizing climate, to first order, requires restoring planetary energy balance. The UNFCCC never mentions temperature – instead it mentions stabilization of greenhouse gas concentrations at a level to avoid danger. It has been shown that the dominant climate forcing, CO2, must be reduced to no more than 350 ppm to restore planetary energy balance (Hansen et al., 2008) and keep climate near the Holocene level, if other forcings remain unchanged. Rapid phasedown of fossil fuel emissions is the crucial need, because of the millennial timescale of this carbon in the climate system. Improved understanding of the carbon cycle is needed to determine the most effective complementary actions. It may be feasible to restore planetary energy balance via improved agricultural and forestry practices and other actions to draw down atmospheric CO2 amount, if fossil fuel emissions are rapidly phased out.
Third, not only do we see evidence of changes beginning to happen in the climate system, as discussed above, but we have also associated these changes with amplifying feedback processes. We understand that in a system that is out of equilibrium, a system in which the equilibrium is difficult to restore rapidly, a system in which major components such as the ocean and ice sheets have great inertia but are beginning to change, the existence of such amplifying feedbacks presents a situation of great concern. There is a possibility, a real danger, that we will hand young people and future generations a climate system that is practically out of their control.
We conclude that the message our climate science delivers to society, policymakers, and the public alike is this: we have a global emergency. Fossil fuel CO2 emissions should be reduced as rapidly as practical.” (