Stochastic National Income

Abstract: How can national income be adjusted to indicate welfare improvement if the future is uncertain? The present paper extends the definition of national income to stochastic settings on the basis of discounted utilitarian welfare function. Real interest rate of consumption is redefined so that real national income can be interpreted as the expected present value of real interest on future national consumption. A stochastic one-good model is used to illustrate the application of the stochastic real national income. It turns out that under uncertainty real national income may be decreasing even though captial stock is constant or increasing over time

The Effects on Energy Markets of Achieving a 1.5 °C Scenario

Net zero emission scenarios are aligned with the criteria for the Paris Agreement to keep global warming below 1.5 °C. By soft-linking an energy model with a macroeconomic model, we create a similar pathway to the net zero emission scenario from the International Energy Agency (IEA) to 2050 both of demand for fossil fuels and total CO2 emissions. Soft-linking entails that we insert endogenous variables from one model into the other model. We implement measures such as CO2 taxes, improved energy efficiency, more renewables in electricity production and other sectors, easier substitution between electricity and fossil fuels for final users, and drastically limiting future production of oil, gas and coal. Our conclusion is that net zero is possible by introducing very strict measures, e.g., a high rate of energy efficiency improvement, far above what has been achieved in the past. While our partial equilibrium energy model, similar to the IEA model, overlooks the potential rebound effects, i.e., more energy used by consumers due to lower prices caused by energy efficiency improvement, our macroeconomic model does capture the rebound effects and has to implement stricter supply-side measures to reduce fossil fuel use to achieve the 1.5 °C scenario.The Effects on Energy Markets of Achieving a 1.5 °C ScenariopublishedVersio

A Comment on the Copenhagen Accord- Feasibility and Cost

The Copenhagen Accord has been followed up by national pledges of greenhouse gas emissions reductions in the year 2020 without specifying measures to enforce actions. As a consequence, the capacity of parties to fulfil their obligations is of basic interest. This article outlines the effects of full compliance with pledges on greenhouse gas emissions, economic growth, and trade. The study is based on the global computable general equilibrium model GRACE distinguishing between fossil and non-fossil energy use. Global emissions from fossil fuels in 2020 turn out to be 15% lower than in a business as usual (BAU) scenario and 3% below the global emissions from fossil fuels in 2005. China and India increase their emissions in 2020 to 1 and 5 per cent above BAU levels in 2020, respectively. We find some carbon leakage towards India, China and Russia within the energy intensive industries steel and cement.

Farvel til en fossil æra? IEAs Net Zero by 2050-scenario

Norge har sluttet seg til Parisavtalen og 1,5°C-målet, som innebærer at verden må nå netto null utslipp av CO2 innen midten av dette århundret. Norsk økonomi lener seg fortsatt tungt på olje- og gassinntekter med et betydelig innslag av ressursrente. Dermed blir det et viktig spørsmål for Norge hvor raskt det grønne skiftet snevrer inn etterspørselen etter olje og gass, og om det vil bli rom for å opprettholde noe produksjon av petroleum omgjort til lavutslipps energi ved hjelp av karbonfangst og -lagring. På grunn av sin rolle som observatør og analytiker av energimarkeder og teknologi på global basis er IEAs scenarioer ofte tydeligere enn andre når det gjelder næringsspesifikke særtrekk og teknologivalg. Det gjør IEAs netto null-utslippsscenario som kan lede til 1,5 °C-målet til et nyttig utgangspunkt for å diskutere realismen i og utsikter for det grønne skiftet. Denne artikkelen gir en oversikt over IEAs netto null-utslippsscenario, med forutsetninger om bruk av virkemidler, teknologisk utvikling, økonomisk vekst og energibruk langs utviklingsbanen. Perspektivet er globalt, men vi peker på noen muligheter som åpner seg for Norge på veien til 1,5°C- målet.Farvel til en fossil æra? IEAs Net Zero by 2050-scenariopublishedVersio

Stress-testing the Norwegian economy: The effects of the 1.5°C scenario on global energy markets and the Norwegian economy developing a baseline scenario by soft-linking three models

I dette prosjektet myklinker vi tre modeller; GRACE, FRISBEE og KVARTS for å studere effektene på norsk økonomi av å nå 1,5°C-målet om global oppvarming. Vi utvikler en strategi for hvordan vi kan konstruere et konsistent basisscenario frem til 2050 for alle tre modellene. GRACE er en generell likevektsmodell av verdensøkonomien, FRISBEE er en delvis likevektsmodell av de globale energimarkedene, mens KVARTS er en modell av norsk økonomi. For FRISBEE og GRACE vil vi innrette oss etter den regionale energiutviklingen av grunnscenarioet i IEAs World Energy Outlook fra 2019, men streber ikke etter et perfekt treff. Hvis den simulerte etterspørselen til de ulike energivarene i de ulike regionene er langt unna målene i henhold til IEA, vil vi justere relevante parameterverdier. Videre, på grunn av mangel på data, utfører vi ulike estimater angående BNP-vekstrater og CO 2-priser i ulike regioner. Denne rapporten viser en strategi for å studere effektene på økonomien i Norge i et referansescenario. De viktigste variablene som skal implementeres fra FRISBEE og GRACE i KVARTS-modellen er olje- og gasspriser, samt investerings- og produksjonsprofiler for olje og gass. Selv om referansebanen er i fokus i denne rapporten, beskriver vi også flyten av variabler mellom modellene i policyscenarioene

Low-angle dunes in the Changjiang (Yangtze) Estuary: Flow and sediment dynamics under tidal influence

It has long been highlighted that important feedbacks exist between river bed morphology, sediment transport and the turbulent flow field and that these feedbacks change in response to forcing mechanisms. However, our current understanding of bedform dynamics is largely based on studies of steady flow environments and cohesionless bed conditions. Few investigations have been made under rapidly changing flows. Here, we examine flow and sediment dynamics over low-angle dunes in unsteady flows in the Changjiang (Yangtze) Estuary, China. Topography, flow and sediment data were collected over a reach ca 1.8 km long through a semi-diurnal tidal cycle in a moderate tide of flood season. The results show that: (1) roughness length derived from the upper flow changes little with the flow reversing and displays the same value on both the ebb and flood tide. Moreover, the variability of individual bedform features plays an important role in roughness length variation. (2) Shear stress over the crest of low-angle dunes roughly represents the total spatially averaged stress over dunes in this study area, which has significant implications for advancing numerical models. (3) Changes in morphology, flow and sediment dynamics over dunes through time reveal how low-angle dunes evolve within a tidal cycle. (4) The clockwise hysteresis loops between flow dynamics and bedform features (height and aspect ratio) are also observed. The combination of suspended sediment transport and bedload transport on dune transformation and migration attributes to the clockwise hysteresis. The specific sediment composition of the riverbed, in some extent, affects the mechanism of sediment transport related to the exchange between suspended sediment and riverbed, but further investigation is needed to figure out the mechanism behind this for extended series of tides, such as spring/neap tide and tides in flooding and dry season

On the causes of pulsing in continuous turbidity currents

Velocity pulsing has previously been observed in continuous turbidity currents in lakes and reservoirs, even though the input flow is steady. Several different mechanisms have been ascribed to the generation of these fluctuations, including Rayleigh‐Taylor (RT) instabilities that are related to surface lobes along the plunge line where the river enters the receiving water body and interfacial waves such as Kelvin‐Helmholtz instabilities. However, the understanding of velocity pulsing in turbidity currents remains limited. Herein we undertake a stability analysis for inclined flows and compare it against laboratory experiments, direct numerical simulations, and field data from Lillooet Lake, Canada, and Xiaolangdi Reservoir, China, thus enabling an improved understanding of the formative mechanisms for velocity pulsing. Both RT and Kelvin‐Helmholtz instabilities are shown to be prevalent in turbidity currents depending on initial conditions and topography, with plunge line lobes and higher bulk Richardson numbers favoring RT instabilities. Other interfacial wave instabilities (Holmboe and Taylor‐Caulfield) may also be present. While this is the most detailed analysis of velocity pulsing conducted to date, the differences in spatial scales between field, direct numerical simulations, and experiments and the potential complexity of multiple processes acting in field examples indicate that further work is required. In particular, there is a need for simultaneous field measurements at multiple locations within a given system to quantify the spatiotemporal evolution of such pulsing