Low terrestrial carbon storage at the Last Glacial Maximum: constraints from multi-proxy data

Past changes in the inventory of carbon stored in vegetation and soils remain uncertain. Earlier studies inferred the increase in the land carbon inventory (Δland) between the Last Glacial Maximum (LGM) and the preindustrial period (PI) based on marine and atmospheric stable carbon isotope reconstructions, with recent estimates yielding 300–400&thinsp;GtC. Surprisingly, however, earlier studies considered a mass balance for the ocean–atmosphere–land biosphere system only. Notably, these studies neglect carbon exchange with marine sediments, weathering–burial flux imbalances, and the influence of the transient deglacial reorganization on the isotopic budgets. We show this simplification to significantly reduce Δland in simulations using the Bern3D Earth System Model of Intermediate Complexity v.2.0s. We constrain Δland to ∼850&thinsp;GtC (median estimate; 450 to 1250&thinsp;GtC ±1SD) by using reconstructed changes in atmospheric δ13C, marine δ13C, deep Pacific carbonate ion concentration, and atmospheric CO2 as observational targets in a Monte Carlo ensemble with half a million members. It is highly unlikely that the land carbon inventory was larger at LGM than PI. Sensitivities of the target variables to changes in individual deglacial carbon cycle processes are established from transient factorial simulations with the Bern3D model. These are used in the Monte Carlo ensemble and provide forcing–response relationships for future model–model and model–data comparisons. Our study demonstrates the importance of ocean–sediment interactions and burial as well as weathering fluxes involving marine organic matter to explain deglacial change and suggests a major upward revision of earlier isotope-based estimates of Δland.</p

PaCTS 1.0: a crowdsourced reporting standard for paleoclimate data

The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on the data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big Data advances in the field. Building upon recent efforts to standardize the format and terminology of paleoclimate data, this article describes the Paleoclimate Community reporTing Standard (PaCTS), a crowdsourced reporting standard for such data. PaCTS captures which information should be included when reporting paleoclimate data, with the goal of maximizing the reuse value of paleoclimate datasets, particularly for synthesis work and comparison to climate model simulations. Initiated by the LinkedEarth project, the process to elicit a reporting standard involved an international workshop in 2016, various forms of digital community engagement over the next few years, and grassroots working groups. Participants in this process identified important properties across paleoclimate archives, in addition to the reporting of uncertainties and chronologies; they also identified archive-specific properties and distinguished reporting standards for new vs. legacy datasets. This work shows that at least 135 respondents overwhelmingly support a drastic increase in the amount of metadata accompanying paleoclimate datasets. Since such goals are at odds with present practices, we discuss a transparent path towards implementing or revising these recommendations in the near future, using both bottom-up and top-down approaches

The Iso2k database: a global compilation of paleo-δ18O and δ2H records to aid understanding of common era climate

Reconstructions of global hydroclimate during the Common Era (CE; the past ~2,000 years) are important for providing context for current and future global environmental change. Stable isotope ratios in water are quantitative indicators of hydroclimate on regional to global scales, and these signals are encoded in a wide range of natural geologic archives. Here we present the Iso2k database, a global compilation of previously published datasets from a variety of natural archives that record the stable oxygen (δ18O) or hydrogen (δ²H) isotopic composition of environmental waters, which reflect hydroclimate changes over the CE. The Iso2k database contains 756 isotope records from the terrestrial and marine realms, including: glacier and ground ice (205); speleothems (68); corals, sclerosponges, and mollusks (145); wood (81); lake sediments and other terrestrial sediments (e.g., loess) (158); and marine sediments (99). Individual datasets have temporal resolutions ranging from sub-annual to centennial, and include chronological data where available. A fundamental feature of the database is its comprehensive metadata, which will assist both experts and non-experts in the interpretation of each record and in data synthesis. Key metadata fields have standardized vocabularies to facilitate comparisons across diverse archives and with climate model simulated fields. This is the first global-scale collection of water isotope proxy records from multiple types of geological and biological archives. It is suitable for evaluating hydroclimate processes through time and space using large-scale synthesis, model-data intercomparison and (paleo)data assimilation. The Iso2k database is available for download at: https://doi.org/10.25921/57j8-vs18 (Konecky and McKay, 2020) and is also accessible via through the NOAA/WDS Paleo Data landing page: https://www.ncdc.noaa.gov/paleo/study/29593

Editorial

The objective of the new international financial architecture, as defined by the G 7 and the IMF, is to master international financial instability by improving the transparency and the supervision of financial markets, and by arousing a greatest sense of responsibility in the prevention and management of crises, of both private and public actors. However, the project of financial architecture can be analysed as a pragmatic compromise whose application remains at present unfulfilled and which cannot be considered as a full reply to the challenges of international financial instability. Meanwhile, in 2001, we are witnessing the outbreak of new financial crises in Turkey, in Argentina… This Special Issue examines five dimensions of international financial architecture. Andre CARTAPANIS and Michel HERLAND (Systemic Risk and New International Financial Architecture: Reconciling KEYNES and Neo-Liberalism ?) replace the new architecture in the context of systemic crises of the 90’s and show that it isn’t the revenge of KEYNES and keynesian foundations, but rather a neo-liberal compromise with procedural and pragmatic rules. Patrick ARTUS (What Exchange-Rate System for Emerging Countries?) compares dollarisation, currency boards and exchange rate flexibility from the external debt dynamics point of view. Alfred STEINHERR (Financial Crises in 1997–2001: Shortcomings of the International Financial Architecture) draws the lessons from the systemic crises in 1997-2001, especially about the IMF’s role. Jerome STEIN (The Equilibrium Value of the Euro-Dollar US Exchange Rate: an Evaluation of Research) examines the equilibrium value of the Euro-Dollar exchange rate and estimates the misalignment of the Euro. Finally, Vincent DROPSY (Emerging Stock Market Liberalization, and Currency Crises) analyses the integration of emerging stock markets and investigates the relationship between stock returns and currency crises in the 1990’s.

Systemic Risk and New International Financial Architecture: Reconciling KEYNES and Neo-Liberalism?

Facing the systemic crisis which originated in Mexico and in Asia, and spread to all financial centers, the objective of the new international financial architecture is to master the international financial instability; this means improving the transparency and the regulation of markets, as well as arousing a greater responsibility of public and private actors in the prevention and management of crises. But many interrogations subsist concerning the contours of the new architecture. Does it simply mean improving the transparency of information in order to prompt better practices? Or is it desirable to introduce new constraining rules as far as the international mobility of capital is concerned? Does it call for allocating new responsibilities, and therefore new resources, to the International Monetary Fund, or should the Bank for International Settlements, or a central banks club, be entrusted with such a mission? In fact, these questions arise mainly because there is no theoretical consensus among economists and official experts. Paradoxically this leads us to revisit the thought and theoretical inheritance of KEYNES. The growing importance, in current debates, of concepts such as confidence, liquidity, imperfection of financial markets, mimetic contagions, is striking in that respect. Furthermore, discussions about the international financial institutions remind debates that KEYNES started, in his Treatise on Money as well as during the preparation of the conference of Bretton Woods. In a nutshell, cannot one see in this new international financial architecture the revenge of KEYNES? In section 1, one replaces the project of international financial architecture in the context of systemic crisis of the 90’s. The basic principles of this architecture, as they appear in reports of the G 22 and the G7, are then reminded, in section 2. In section 3, one sheds a light on the keynesian foundations on which, according to us, this project partially rests, and draws some consequences on the responsibilities assigned to the International Financial Institutions.International Financial Architecture; Keynes; neo-liberalism; financial crises.