Process-evaluation of tropospheric humidity simulated by general circulation models using water vapor isotopic observations: 2. Using isotopic diagnostics to understand the mid and upper tropospheric moist bias in the tropics and subtropics

Evaluating the representation of processes controlling tropical and subtropical tropospheric relative humidity (RH) in atmospheric general circulation models (GCMs) is crucial to assess the credibility of predicted climate changes. GCMs have long exhibited a moist bias in the tropical and subtropical mid and upper troposphere, which could be due to the mis-representation of cloud processes or of the large-scale circulation, or to excessive diffusion during water vapor transport. The goal of this study is to use observations of the water vapor isotopic ratio to understand the cause of this bias. We compare the three-dimensional distribution of the water vapor isotopic ratio measured from space and ground to that simulated by several versions of the isotopic GCM LMDZ. We show that the combined evaluation of RH and of the water vapor isotopic composition makes it possible to discriminate the most likely cause of RH biases. Models characterized either by an excessive vertical diffusion, an excessive convective detrainment or an underestimated in situ cloud condensation will all produce a moist bias in the free troposphere. However, only an excessive vertical diffusion can lead to a reversed seasonality of the free tropospheric isotopic composition in the subtropics compared to observations. Comparing seven isotopic GCMs suggests that the moist bias found in many GCMs in the mid and upper troposphere most frequently results from an excessive diffusion during vertical water vapor transport. This study demonstrates the added value of water vapor isotopic measurements for interpreting shortcomings in the simulation of RH by climate models

Back to the failure: an analytic narrative of the De Lorean debacle

There has been a recent identification of a need for a New Business History. This discussion connects with the analytic narrative approach. By following this approach, the study of business history provides important implications for the conduct and institutional design of contemporary industrial policy. The approach also allows us to solve historical puzzles. The failure of the De Lorean Motor Company Limited is one specific puzzle. Journalistic accounts that focus on John De Lorean's alleged personality defects as an explanation for this failure miss the crucial institutional component. Moreover, distortions in the rewards associated with industrial policy, and the fact that the objectives of the institutions implementing the policy were not solely efficiency-based, led to increased opportunities for rent-seeking. Political economy solves the specific puzzle; by considering institutional dimensions, we can also solve the more general puzzle of why activist industrial policy was relatively unsuccessful in Northern Ireland

Is Earth special?

Peculiar conditions may be required for the origin of life and/or the evolution of complex organisms. Hence, Earth attributes—such as plate-tectonics, oceans, magnetism and a large moon—may be necessary preconditions, for our own existence, that are rare in the general population of planets. The unknown magnitude of this observational bias undermines understanding of our planet. However the discovery and characterization of exoplanets, along with advances in mathematical modelling of Earth systems, now allow this “anthropic selection” effect to be more thoroughly evaluated than before. This paper looks at a number of properties of our Solar System and our planet. It examines their possible benefits for life, whether these properties might be rare, whether they required fine-tuning and whether they have an associated habitability-lifetime. It also discusses additional data likely to become available in the near future.None of the individual properties considered show convincing evidence for anthropic bias. However, the time-scales associated with habitability— in particular, those associated with solar-warming, with axial stability and with planetary-cooling—are surprisingly similar and this provides tentative support for the view that Earth may be special

A tale of two cognitions: The Evolution of Social Constructivism in International Relations

Abstract Constructivism in International Relations (IR) is popular, but constructivists seem disappointed. Allegedly something has been lost. Such criticisms are misplaced. There was never a uniform Constructivism. Since constructivism is socially constructed, to argue that constructivism has evolved “wrongly” is odd. This paper explains the dissatisfaction with constructivism followed by a second reading of its evolution as a tale of two cognitions. These two cognitions distinguish genera in the constructivist “family”. A criticism against one genus based on the cognition of the other is unfair. A focus on cognitions and the use of genera helps in perceiving constructivism’s future evolution

Earth's energy imbalance more than doubled in recent decades

Global warming results from anthropogenic greenhouse gas emissions which upset the delicate balance between the incoming sunlight, and the reflected and emitted radiation from Earth. The imbalance leads to energy accumulation in the atmosphere, oceans and land, and melting of the cryosphere, resulting in increasing temperatures, rising sea levels, and more extreme weather around the globe. Despite the fundamental role of the energy imbalance in regulating the climate system, as known to humanity for more than two centuries, our capacity to observe it is rapidly deteriorating as satellites are being decommissioned

What's at stake in the agent-structure debate?

Recent developments in the philosophy of science, particularly those falling under the rubric of “scientific realism,” have earned growing recognition among theorists of international relations but have failed to generate substantive programs of research. Consequently, the empirical relevance of much philosophical discourse, such as that centering on the agent-structure problem in social theory, remains unestablished. This article attempts to bridge the gap between the philosophy and practice of science by outlining a model of international structure based on the principles of scientific realism and by considering its implications for a structural research program in international relations theory. Appealing to Imre Lakatos's methodology of theorychoice, the article presents an ontological case for adopting a “transformational” model of structure over the “positional” model developed in the work of Kenneth Waltz. The article demonstrates that the positional approach offers no conceptual or explanatory hold on those features of the international structure that are the intended products of state action. In conclusion, the article argues that the stakes in the agent-structure debate include the capacity to generate integrative structural theory and the ability to theorize the possibilities for peaceful change in the international system.</jats:p