Energy modellers should explore extremes more systematically in scenarios

Scenarios are the primary tool for examining how current decisions shape the future, but the future is affected as much by out-of-ordinary extremes as by generally expected trends. Energy modellers can study extremes both by incorporating them directly within models and by using complementary off-model analyses

Opening out and closing down: The treatment of uncertainty in transport planning’s forecasting paradigm

© 2019, The Author(s). Since the 1960s, development of the transport system has been framed by the notion of forecasting future demand. Yet the past decade or more appears to signal some significant changes to the role of travel in society which are having a material impact on how much people travel (and may travel in the future). Coupled with the potential for major technological changes and a range of climate adaptation scenarios, the future of mobility presents today’s decision making on transport strategy and investment with a broader set of uncertainties than has previously been considered. This paper examines current mainstream practice for incorporating uncertainty into decision-making, through an illustrative case study of the highly codified approaches of the Department for Transport in England. It deconstructs the issue by first focussing on different ways in which there is an opening out or acceptance of new uncertainties and how this creates a (wider) set of potential futures. It then turns to consider how this set of futures is used, or not, in decision-making, i.e. the process of closing down uncertainty to arrive at or at least inform a decision. We demonstrate that, because the range of uncertainties has broadened in scope and scale, the traditional technocratic approach of closing down decisions through sensitivity testing is at odds with the greater breadth now being called for at the opening out stage. We conclude that transport decision-making would benefit from a rebalancing of technical depth with analytical breadth. The paper outlines a plausible new approach to opening out and closing down that is starting to be applied in practice. This approach must be accompanied by an opening up of the processes by which technical advice for decisions are reached and how uncertainties are understood and negotiated

Overschatting economische groei in WLO referentiescenario's

NL: Scenario’s zijn belangrijk bij het evalueren van infrastructuur beleid, maar helaas zijn er gegronde redenen om te twijfelen aan de gangbare veronderstellingen ten aanzien van economische groei zoals gehanteerd in vrijwel alle officiële scenariostudies. Dit artikel bespreekt de in de Nederlandse "WLO referentiescenario's" gehanteerde aannamen ten aanzien van arbeidsproductiviteit en arbeidsparticipatie. Het maakt aannemelijk dat er goede redenen zijn om uit te gaan van een lagere economische groei. De huidige scenario's zouden het bruto binnenlands product (BBP) in 2050 wel eens met zo'n 10% tot 40% kunnen overschatten. EN: Scenarios are important for the evaluation of infrastructure policies, but unfortunately there are good reasons to question the mainstream assumptions on economic growth that are applied in virtually all official scenario studies. This paper addresses the assumptions on labour productivity and labour participation in the Dutch "WLO scenario's". It shows there are good reasons to expect lower economic growth and indicates that the present scenario's for the year 2050 may be some 10% to 40% too high.Hydraulic EngineeringCivil Engineering and Geoscience