An Even Sterner Review: Introducing Relative Prices into the Discounting Debate

The Stern Review has had a major influence on the policy discussion on climate change. One reason is that the report has raised the estimated cost of unmitigated climate damages by an order of magnitude compared to most earlier estimates, leading to a call for strong and urgent action on climate change. Not surprisingly, severe criticism has been levied against the report by authors who think that these results hinge mainly on the use of a discount rate that is too low. Here we discuss the Ramsey rule for the discount rates and its implications for the economics of climate change. While we find no strong objections to the discounting assumptions adopted in the Stern Review, our main point is that the conclusions reached in the review can be justified on other grounds than by using a low discount rate. We argue that nonmarket damages from climate change are probably underestimated and that future scarcities that will be induced by the changing composition of the economy and climate change should lead to rising relative prices for certain goods and services, raising the estimated damage of climate change and counteracting the effect of discounting. We build our analysis on earlier research (Hoel and Sterner 2007) that has shown that the Ramsey discounting formula is somewhat modified in a two-sector economy with differential growth rates. Most importantly, such a model is characterized by changing relative prices, something that has major implications for a correct valuation of future climate damages. We introduce these results into a slightly modified version of the DICE model (Nordhaus 1994) and find that taking relative prices into account can have as large an effect on economically warranted abatement levels as can a low discount rate.discounting, relative prices, Ramsey, climate damage

Nonequilibrium dynamical mean-field theory for bosonic lattice models

We develop the nonequilibrium extension of bosonic dynamical mean field theory (BDMFT) and a Nambu real-time strong-coupling perturbative impurity solver. In contrast to Gutzwiller mean-field theory and strong coupling perturbative approaches, nonequilibrium BDMFT captures not only dynamical transitions, but also damping and thermalization effects at finite temperature. We apply the formalism to quenches in the Bose-Hubbard model, starting both from the normal and Bose-condensed phases. Depending on the parameter regime, one observes qualitatively different dynamical properties, such as rapid thermalization, trapping in metastable superfluid or normal states, as well as long-lived or strongly damped amplitude oscillations. We summarize our results in non-equilibrium "phase diagrams" which map out the different dynamical regimes.Comment: 18 pages, 8 figure

The Energy of n Identical Bosons in a Finite Volume at O(L^{-7})

The volume dependence of the ground-state energy of n identical bosons with short-range interactions in a periodic spatial volume with sides of length L is calculated at order L^{-7} in the large volume expansion. This result will enable a refined determination of the pi^+ pi^+ pi^+ interaction from lattice QCD calculations.Comment: 3 page

Optical phase cloaking of 700-nm light waves in the far field by a three-dimensional carpet cloak

Transformation optics is a design tool that connects geometry of space and propagation of light. Invisibility cloaking is a corresponding benchmark example. Recent experiments at optical frequencies have demonstrated cloaking for the light amplitude ("ray cloaking"). In this Letter, we demonstrate far-field cloaking of the light phase ("wave cloaking") by interferometric microscope-imaging experiments on the previously introduced three-dimensional carpet cloak at 700-nm wavelength and for arbitrary polarization of light

Palliative care for people with non-malignant lung disease: summary of current evidence and future direction

Background: The physical and psychosocial needs of patients with chronic non-malignant lung disease are comparable to those with lung cancer. This article will focus on chronic obstructive pulmonary disease, interstitial lung disease and cystic fibrosis as examples of life-limiting, non-curable and non-malignant lung diseases. The need for supportive and palliative care: Recent national guidance has demanded that palliative care is inclusive of all patients with life-limiting disease, irrespective of diagnosis, and that specialist palliative care teams are involved in the management of patients on a basis of need rather than prognosis. What is known: Despite medical therapy, most patients with moderate to severe chronic obstructive pulmonary disease, interstitial lung disease and cystic fibrosis experience pain, fatigue and dyspnoea, with the majority not getting relief from dyspnoea towards the end of life. Furthermore, dyspnoea causes social isolation and difficulty performing activities of daily living and impairs quality of life. There is an increasing evidence base for the assessment of supportive and palliative care needs, symptom interventions, prognostication, models of service delivery and implications of these for clinical practice and research in non-malignant lung diseases. What is unknown: Despite advances, much still remains unknown regarding assessment, management and prognostication in individual chronic non-malignant lung diseases. Although different service models are being used in clinical practice, the optimal model(s) of service delivery remain unknown. Implication for future research, policy and practice: We describe key areas for further research, which include the need for large, high-quality trials of pharmacological and non-pharmacological interventions and their combinations as well as evaluation of the efficacy and cost-effectiveness of models of care. As access to palliative care is poor for these patients, the barriers to referral need to be understood and reduced, which along with effective working between palliative care teams, with respiratory services backup, should optimise delivery of care in patients with life-limiting non-malignant lung disease

Rotational cooling of trapped polyatomic molecules

Controlling the internal degrees of freedom is a key challenge for applications of cold and ultracold molecules. Here, we demonstrate rotational-state cooling of trapped methyl fluoride molecules (CH3F) by optically pumping the population of 16 M-sublevels in the rotational states J=3,4,5, and 6 into a single level. By combining rotational-state cooling with motional cooling, we increase the relative number of molecules in the state J=4, K=3, M=4 from a few percent to over 70%, thereby generating a translationally cold (~30mK) and nearly pure state ensemble of about 10^6 molecules. Our scheme is extendable to larger sets of initial states, other final states and a variety of molecule species, thus paving the way for internal-state control of ever larger molecules