CICERO Research Archive (CICERO Senter for klimaforskning)
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Modeling Global Carbon Costs of Plant Nitrogen and Phosphorus Acquisition
Get PDFMost Earth system models (ESMs) do not explicitly represent the carbon (C) costs of plant nutrient acquisition, which leads to uncertainty in predictions of the current and future constraints to the land C sink. We integrate a plant productivity-optimizing nitrogen (N) and phosphorus (P) acquisition model (fixation & uptake of nutrients, FUN) into the energy exascale Earth system (E3SM) land model (ELM). Global plant N and P uptake are dynamically simulated by ELM-FUN based on the C costs of nutrient acquisition from mycorrhizae, direct root uptake, retranslocation from senescing leaves, and biological N fixation. We benchmarked ELM-FUN with three classes of products: ILAMB, a remotely sensed nutrient limitation product, and CMIP6 models; we found significant improvements in C cycle variables, although the lack of more observed nutrient data prevents a comprehensive level of benchmarking. Overall, we found N and P co-limitation for 80% of land area, with the remaining 20% being either predominantly N or P limited. Globally, the new model predicts that plants invested 4.1 Pg C yr−1 to acquire 841.8 Tg N yr−1 and 48.1 Tg P yr−1 (1994–2005), leading to significant downregulation of global net primary production (NPP). Global NPP is reduced by 20% with C costs of N and 50% with C costs of NP. Modeled and observed nutrient limitation agreement increases when N and P are considered together (r2 from 0.73 to 0.83).publishedVersio
Climate cooperation in the shadow of solar geoengineering: an experimental investigation of the moral hazard conjecture
Get PDFAs international efforts to mitigate greenhouse gases continue to fall short of global targets, the scientific community increasingly debates the role of solar geoengineering in climate policy. Given the infancy of these technologies, the debate is not yet whether to deploy solar geoengineering but whether solar geoengineering deserves consideration and research funding. Looming large over this discussion is the moral hazard conjecture – normalizing solar geoengineering will decrease mitigation efforts. Using a controlled experiment of a collective-risk social dilemma that simulates the strategic decisions of heterogeneous groups to mitigate emissions and deploy solar geoengineering, we find no evidence for the moral hazard conjecture. On the contrary, when people in the experiment are given the option to deploy solar geoengineering, average investment in mitigation increases.publishedVersio
Evaluating global and regional land warming trends in the past decades with both MODIS and ERA5-Land land surface temperature data
Get PDFGlobal surface temperature has been setting new record highs in the recent decades, imposing increasing environmental challenges for societies and ecosystems worldwide. Global warming rates of the 20th century have been documented by a number of studies, nevertheless, the warming rates in the most recent decades in the 21st century are of particular interest for understanding the ongoing climate change. Analyzing temperature trends demands data with high spatial resolution and broad geographical coverage to allow for analyzing trends and changes on a regional scale. Land Surface Temperature data from NASA MODIS with global resolution of 0.05° and Skin Temperature data from European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5-Land reanalysis with global resolution of 0.1° fulfill these demands. In this study, we analyze the remote-sensing-based MODIS data to estimate land surface temperature change rates over the period 2001–2020 in global, continental, and pixel-wise scales with statistical significance indicated. The model-based ERA5-Land data are also analyzed in parallel, extending the period of analysis back to 1981. These two independently-sourced datasets, one from satellites above the atmosphere and one from combining surface modeling and observations, are shown to produce highly consistent results. It is revealed that the trends in the shorter period 2001–2020 are spatially conforming to the trends in the longer period 1981–2020 despite the shorter time length. For the period 2001–2020, we show that the global average land surface temperature rate of change was 0.26 °C-0.34 °C per decade, with substantially different warming rates in different regions. The Arctic, Europe, and Russia show statistically significant warming in both datasets. The Arctic, in particular, warmed at a rate 2.5–2.8 times the global average, and data in the 40-year period 1981–2020 suggest that warming is accelerating in almost all the continents or large regions. Most noticeably, the two independent datasets both indicate that Arctic permafrost regions had the world's highest warming rate at the onset of the 21st century, reaching >2 °C per decade in some areas.publishedVersio
Индустрия переработки твердых коммунальных отходов на пути к «зеленому» росту
Get PDFВ статье анализируется национальная (Российская Федерация) и региональная (Мурманская область) политика в сфере обращения с отходами с позиции концепции «зеленого роста» и дается экологическая и экономическая оценка её будущих эффектов. Исследование выполнено на примере Мурманской области, Арктическом регионе с развитой инфраструктурой по переработке отходов. В регионе уже действуют мусоросжигательный завод и мусоросортировочный комплекс. Экстраполяция полученных для Мурманской области результатов на уровень Российской Федерации позволила сделать вывод о том, что в случае утилизации ТКО, размещенных на свалках в 2020 г., Россия могла бы сократить выбросы парниковых газов (в СО2 – эквиваленте) на величину, сопоставимую с объемом выбросов такой страны, как Алжир. Установлено, что основным препятствием на пути к полной переработке ТКО в Мурманской области является отсутствие прибыльных рынков для сбыта вторичного сырья. При этом высокие затраты в создание новой системы обращения с отходами, направленной на увеличение доли переработки ТКО, привели к росту коммунальных платежей. Для снижения эксплуатационных расходов и повышения рентабельности создаваемой системы рекомендовано осуществлять сортировку отходов непосредственно у источника их образования.Solid Municipal Waste Recycling Industry on the Track to Green GrowthИндустрия переработки твердых коммунальных отходов на пути к «зеленому» ростуpublishedVersio
Cities as public agents: A typology of co-creational leadership for urban climate transformation
Get PDFThis article develops a typology of co-creational leadership for urban climate transformation. The typology is constructed from a combination of governance theory and empirical observations of co-creational leadership in four global, climate-ambitious cities. By applying a framework that differentiates between authority (multilevel or polycentric) and purpose (policy design or implementation) as key dimensions and categories that structure and condition cities’ performance of co-creational leadership, the typology draws out four unique yet interdependent ideal types of leadership. The typology serves two aims. First, it allows a more nuanced understanding of the ways in which contextual features present distinct types of challenges and condition co-creational leadership by cities. Second, it provides a framework for investigating what is required by city officials as leaders of co-creation. The typology underlines how co-creation is an intrinsic element of hybrid city climate governance.publishedVersio
Uncertainty in land carbon budget simulated by terrestrial biosphere models: the role of atmospheric forcing
Get PDFGlobal estimates of the land carbon sink are often based on simulations by terrestrial biosphere models (TBMs). The use of a large number of models that differ in their underlying hypotheses, structure and parameters is one way to assess the uncertainty in the historical land carbon sink. Here we show that the atmospheric forcing datasets used to drive these TBMs represent a significant source of uncertainty that is currently not systematically accounted for in land carbon cycle evaluations. We present results from three TBMs each forced with three different historical atmospheric forcing reconstructions over the period 1850–2015. We perform an analysis of variance to quantify the relative uncertainty in carbon fluxes arising from the models themselves, atmospheric forcing, and model-forcing interactions. We find that atmospheric forcing in this set of simulations plays a dominant role on uncertainties in global gross primary productivity (GPP) (75% of variability) and autotrophic respiration (90%), and a significant but reduced role on net primary productivity and heterotrophic respiration (30%). Atmospheric forcing is the dominant driver (52%) of variability for the net ecosystem exchange flux, defined as the difference between GPP and respiration (both autotrophic and heterotrophic respiration). In contrast, for wildfire-driven carbon emissions model uncertainties dominate and, as a result, model uncertainties dominate for net ecosystem productivity. At regional scales, the contribution of atmospheric forcing to uncertainty shows a very heterogeneous pattern and is smaller on average than at the global scale. We find that this difference in the relative importance of forcing uncertainty between global and regional scales is related to large differences in regional model flux estimates, which partially offset each other when integrated globally, while the flux differences driven by forcing are mainly consistent across the world and therefore add up to a larger fractional contribution to global uncertainty.publishedVersio
A void in Central Asia research: climate change
Get PDFThis article assesses the extent to which the academic community engaged with climate change in Central Asia between 1991 and 2021. The article finds that climate change has been neglected in the field of Central Asia area studies. Out of a total 13,488 journal articles in eight key journals for Central Asia research, only 33 articles (0.24%) were on climate change or a related topic. Climate change has been similarly neglected at the events of 17 Central Asia area studies associations. Out of 1305 conference panels, none was focused on climate change. Out of 10,249 individual presentations, only two (0.02%) were focused on climate change. The very same scholars who have been most active in the securitization of Central Asia have ignored the severe security threats that climate change poses to the region. The article contributes to the field of Central Asian studies by drawing attention to severe knowledge gaps that hinder the Central Asian countries from adapting to climate change. It concludes with six recommendations.publishedVersio
Barrierer for klimatilpasning på lokalt og regionalt nivå
Get PDFPå oppdrag fra Miljødirektoratet har CICERO, Vestlandsforskning og Nordlandsforskning gjennomført en studie av barrierer for klimatilpasning på lokalt og regionalt nivå. Studien består av en kunnskapssammenstilling om barrierer for klimatilpasning, fem dialogseminarer med klimatilpasningsaktører fra ulike forvaltningsnivå, og en caseanalyse av Hamar kommune. Rapporten viser at det er en manglende politisk oppslutning rundt klimatilpasning i kommunene, ressurser er fremdeles en hovedbarriere, oversettelsen av kunnskap mellom statlig og lokalt nivå bør forbedres, fokus på sammensatte barrierer blir viktig for framtidige barrierestudier, og at utviklingen på klimatilpasningsfeltet gir behov for nye typer nettverk.publishedVersio
Anthropogenic sulfate aerosol pollution in South and East Asia induces increased summer precipitation over arid Central Asia
Get PDFPrecipitation has increased across the arid Central Asia region over recent decades. However, the underlying mechanisms of this trend are poorly understood. Here, we analyze multi-model simulations from the Precipitation Driver and Response Model Intercomparison Project (PDRMIP) to investigate potential drivers of the observed precipitation trend. We find that anthropogenic sulfate aerosols over remote polluted regions in South and East Asia lead to increased summer precipitation, especially convective and extreme precipitation, in arid Central Asia. Elevated concentrations of sulfate aerosols over remote polluted Asia cause an equatorward shift of the Asian Westerly Jet Stream through a fast response to cooling of the local atmosphere at mid-latitudes. This shift favours moisture supply from low-latitudes and moisture flux convergence over arid Central Asia, which is confirmed by a moisture budget analysis. High levels of absorbing black carbon lead to opposing changes in the Asian Westerly Jet Stream and reduced local precipitation, which can mask the impact of sulfate aerosols. This teleconnection between arid Central Asia precipitation and anthropogenic aerosols in remote Asian polluted regions highlights long-range impacts of anthropogenic aerosols on atmospheric circulations and the hydrological cycle.publishedVersio
A new halocarbon absorption model based on HITRAN cross-section data and new estimates of halocarbon instantaneous clear-sky radiative forcing
Get PDFThe article describes a new practical model for the infrared absorption of chlorofluorocarbons and other gases with dense spectra, based on high-resolution transmission molecular absorption database (HITRAN) absorption cross-sections. The model is very simple, consisting of frequency-dependent polynomial coefficients describing the pressure and temperature dependence of absorption. Currently it is implemented for the halocarbon species required by the Radiative Forcing Model Intercomparison Project. In cases where cross-section data is available at a range of different temperatures and pressures, this approach offers practical advantages compared to previously available options, and is traceable, since the polynomial coefficients follow directly from the laboratory spectra. The new model is freely available and has several important applications, notably in remote sensing and in developing advanced radiation schemes for global circulation models that include halocarbon absorption. For demonstration, the model is applied to the problem of computing instantaneous clear-sky halocarbon radiative efficiencies and present day radiative forcing. Results are in reasonable agreement with earlier assessments that were carried out with the less explicit Pinnock method, and thus broadly validate that method.publishedVersio