The objective of this study is to assess the techno-economic potential of the proposed novel energy system, which allows for negative emissions of carbon dioxide (CO₂). The analyzed system comprises four main subsystems: a biomass-fired combined heat and power plant integrated with a CO₂ capture and compression unit, a CO₂ transport pipeline, a CO₂-enhanced geothermal system, and a supercritical CO₂ Brayton power cycle. For the purpose of the comprehensive techno-economic assessment, the results for the reference biomass-fired combined heat and power plant without CO₂ capture are also presented. Based on the proposed framework for energy and economic assessment, the energy efficiencies, the specific primary energy consumption of CO₂ avoidance, the cost of CO₂ avoidance, and negative CO₂ emissions are evaluated based on the results of process simulations. In addition, an overview of the relevant elements of the whole system is provided, taking into account technological progress and technology readiness levels. The specific primary energy consumption per unit of CO₂ avoided in the analyzed system is equal to 2.17 MJ_LHV/kg CO₂ for biomass only (and 6.22 MJ_LHV/kg CO₂ when geothermal energy is included) and 3.41 MJ_LHV/kg CO₂ excluding the CO₂ utilization in the enhanced geothermal system. Regarding the economic performance of the analyzed system, the levelized cost of electricity and heat are almost two times higher than those of the reference system (239.0 to 127.5 EUR/MWh and 9.4 to 5.0 EUR/GJ), which leads to negative values of the Net Present Value in all analyzed scenarios. The CO₂ avoided cost and CO₂ negative cost in the business as usual economic scenario are equal to 63.0 and 48.2 EUR/t CO₂, respectively, and drop to 27.3 and 20 EUR/t CO₂ in the technological development scenario. The analysis proves the economic feasibility of the proposed CO₂ utilization and storage option in the enhanced geothermal system integrated with the sCO₂ cycle when the cost of CO₂ transport and storage is above 10 EUR/t CO₂ (at a transport distance of 50 km). The technology readiness level of the proposed technology was assessed as TRL4 (technological development), mainly due to the early stage of the CO₂-enhanced geothermal systems development.

Combining biomass-fired power generation with CO₂ capture and storage leads to so-called negative CO₂ emissions. Negative CO₂ emissions can already be obtained when coal is co-fired with biomass in a power plant with CCS technology. The need for bioenergy with CO₂ capture and storage has been identified as one of the key technologies to keep global warming below 2 °C, as this is one of the large-scale technologies that can remove CO₂ from the atmosphere. According to the definition of bioenergy with CO₂ capture and storage, capturing and storing the CO₂ originating from biomass, along with the biomass binding with carbon from the atmosphere as it grows, will result in net removal of CO₂ from the atmosphere. Another technology option for CO₂ removal from the atmosphere is direct air capture. The idea of a net carbon balance for different systems (including bioenergy with CO₂ capture and storage, and direct air capture) has been presented in the literature. This paper gives a background on carbon dioxide removal solutions—with a focus on ecology, economy, and policy-relevant distinctions in technology. As presented in this paper, the bioenergy with CO₂ capture and storage is superior to direct air capture for countries like Poland in terms of ecological impact. This is mainly due to the electricity generation mix structure (highly dependent on fossil fuels), which shifts the CO₂ emissions to upstream processes, and relatively the low environmental burden for biomass acquisition. Nevertheless, the depletion of non-renewable natural resources for newly built bioenergy power plant with CO₂ capture and storage, and direct air capture with surplus wind energy, has a similar impact below 0.5 GJ_3x/t of negative CO₂ emissions. When the economic factors are a concern, the use of bioenergy with CO₂ capture and storage provides an economic justification at current CO₂ emission allowance prices of around 90 EUR/t CO₂. Conversely, for direct air capture to be viable, the cost would need to be from 3 to 4.5 times higher.

There was a huge reaction to the attacks that took place in the Gulf of Oman in May and June 2019 but, in fact, attacks on oil tankers are a century old problem. Oil tankers appear to be easy targets because of their size and cargo. The main objective of this paper is to analyse the effectiveness of different types of attack on oil tankers that have been undertaken since widespread use of oil began. A comparative case-study approach was adopted to evaluate the effectiveness of different types of attack on oil tankers over the long-term, namely the last century. It briefly reviews the destructiveness of three anti-tanker campaigns during the two World Wars. They are subsequently compared with two post-1945 sets of attacks in the Persian Gulf region – the Tanker War of the 1980s and the 2019 attacks. The scale of damages inflicted by attacks on oil tankers is varied. The experience of both World Wars shows their effectiveness. However, post-1945 events do not provide confirmatory evidence. The main difference is the scale of hostile activities. It is not the characteristics of tankers that make them easy targets but political conditions (war/peace state of international system) that enable the application of weapons and tactics that bring about a different scale of destruction.

Climate Change as National Security Threat in the 21st Century as Seen from the US Strategic Documents Perspective The issue of climate change has started to be implemented in official strategic documents of the United States (US) in the first decade of the 21st century. This paper describes briefly the hierarchy of the US national security documents and climate change-related definitions. In the main part it makes an analysis of how climate change-related issues were introduced into the US national security strategic documents by the three 21st century American presidents. The paper comes to a conclusion, that climate change is treated as a national security threat and therefore reflected in a number of the US strategic documents.

Climate change is recognised as one of the greatest challenges facing the international community. For this reason, it has begun to be introduced in defence planning processes. To trace this process this paper applies comparative method to analyse how the issue has been implemented in strategic planning documents of Poland, the US and the UK.

Współczesna gospodarka, oparta na usługach, wymaga od absolwentów szkół wyższych umiejętności sprawnego komunikowania się nie tylko w mowie, lecz także pisemnie. W polskim szkolnictwie wyższym, poza przygotowaniem prac dyplomowych, obszarowi temu poświęca się niewiele zainteresowania. Dla odróżnienia, w wyższym szkolnictwie brytyjskim esej stanowi jedno z podstawowych narzędzi nauczania i sprawdzania wiedzy. W artykule przedstawiono formy wykorzystania eseju w London School of Economics. Następnie przedstawiono problemy, z którymi jest związane jego potencjalne upowszechnienie w Polsce oraz sposoby ich rozwiązania.