Carbon lock-in through capital stock inertia associated with weak near-term climate policies

Stringent long-term climate targets necessitate a limit on cumulative emissions in this century for which sufficient policy signals are lacking. Using nine energy-economy models, we explore how policies pursued during the next two decades impact long-term transformation pathways towards stringent long-term climate targets. Less stringent near-term policies (i.e., those with larger emissions) consume more of the long-term cumulative emissions budget in the 2010–2030 period, which increases the likelihood of overshooting the budget and the urgency of reducing GHG emissions after 2030. Furthermore, the larger near-term GHG emissions associated with less stringent policies are generated primarily by additional coal-based electricity generation. Therefore, to be successful in meeting the long-term target despite near-term emissions reductions that are weaker than those implied by cost-optimal mitigation pathways, models must prematurely retire significant coal capacity while rapidly ramping up low-carbon technologies between 2030 and 2050 and remove large quantities of CO2 from the atmosphere in the latter half of the century. While increased energy efficiency lowers mitigation costs considerably, even with weak near-term policies, it does not substantially reduce the short-term reliance on coal electricity. However, increased energy efficiency does allow the energy system more flexibility in mitigating emissions and, thus, facilitates the post-2030 transition

Locked into Copenhagen pledges - Implications of short-term emission targets for the cost and feasibility of long-term climate goals

This paper provides an overview of the AMPERE modeling comparison project with focus on the implications of near-term policies for the costs and attainability of long-term climate objectives. Nine modeling teams participated in the project to explore the consequences of global emissions following the proposed policy stringency of the national pledges from the Copenhagen Accord and Cancún Agreements to 2030. Specific features compared to earlier assessments are the explicit consideration of near-term 2030 emission targets as well as the systematic sensitivity analysis for the availability and potential of mitigation technologies. Our estimates show that a 2030 mitigation effort comparable to the pledges would result in a further “lock-in” of the energy system into fossil fuels and thus impede the required energy transformation to reach low greenhouse-gas stabilization levels (450 ppm CO2e). Major implications include significant increases in mitigation costs, increased risk that low stabilization targets become unattainable, and reduced chances of staying below the proposed temperature change target of 2 °C in case of overshoot. With respect to technologies, we find that following the pledge pathways to 2030 would narrow policy choices, and increases the risks that some currently optional technologies, such as carbon capture and storage (CCS) or the large-scale deployment of bioenergy, will become “a must” by 2030

Adaptation in integrated assessment modeling: where do we stand?

Adaptation is an important element on the climate change policy agenda. Integrated assessment models, which are key tools to assess climate change policies, have begun to address adaptation, either by including it implicitly in damage cost estimates, or by making it an explicit control variable. We analyze how modelers have chosen to describe adaptation within an integrated framework, and suggest many ways they could improve the treatment of adaptation by considering more of its bottom-up characteristics. Until this happens, we suggest, models may be too optimistic about the net benefits adaptation can provide, and therefore may underestimate the amount of mitigation they judge to be socially optimal. Under some conditions, better modeling of adaptation costs and benefits could have important implications for defining mitigation targets. © Springer Science+Business Media B.V. 2009

Modeling global residential sector energy demand for heating and air conditioning in the context of climate change

In this article, we assess the potential development of energy use for future residential heating and air conditioning in the context of climate change. In a reference scenario, global energy demand for heating is projected to increase until 2030 and then stabilize. In contrast, energy demand for air conditioning is projected to increase rapidly over the whole 2000-2100 period, mostly driven by income growth. The associated CO2 emissions for both heating and cooling increase from 0.8 Gt C in 2000 to 2.2 Gt C in 2100, i.e. about 12% of total CO2 emissions from energy use (the strongest increase occurs in Asia). The net effect of climate change on global energy use and emissions is relatively small as decreases in heating are compensated for by increases in cooling. However, impacts on heating and cooling individually are considerable in this scenario, with heating energy demand decreased by 34% worldwide by 2100 as a result of climate change, and air-conditioning energy demand increased by 72%. At the regional scale considerable impacts can be seen, particularly in South Asia, where energy demand for residential air conditioning could increase by around 50% due to climate change, compared with the situation without climate change.Residential energy demand Cooling Heating

Scenarios as the basis for assessment of mitigation and adaptation

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Exploring IMAGE model scenarios that keep greenhouse gas radiative forcing below 3 W/m2 in 2100

A high probability of limiting temperature increase to 2 °C requires a radiative forcing below 3 W/m2, around the end of this century, according to current knowledge. This paper identifies conditions under which achieving such low radiative forcing levels is feasible. Calculations here show that such targets could be achieved, based on technical and physical considerations, provided some key conditions are met. These key conditions include early participation by major sectors and regions in sufficiently stringent policy regimes, and a wide portfolio of mitigation options. Bio-energy and carbon capture and storage (CCS) play an important role in achieving low stabilisation targets. This would require optimistic assumptions with respect to the expansion of the area needed for food production, to allow space for bio-energy crops, and a significant increase in the efficiency of second-generation biofuels. The sensitivity analysis shows that if certain technologies are removed from the available portfolio, low targets -- especially the 2.6 W/m2 target -- are no longer within reach.Scenarios Integrated assessment Concentration targets

Comparison of different climate regimes: the impact of broadening participation

So-far, most climate mitigation studies look at climate policy strategies in a so-called first-best world, i.e. using the least expensive emission reduction options in all world regions and sectors. To explore the impact of limited participation of countries, we have run a set of scenarios that explore the impact of introducing a carbon tax in OECD, the BRIC countries (Brazil Russia, India and China) and the rest of the world. The results show that carbon taxes can effectively reduce greenhouse gas emissions. However, if low greenhouse gas concentration levels are to be achieved, early participation (in some form) of large developing countries is important to increase reduction potential. It should be noted that global carbon taxes (without additional assumptions) lead to relatively high costs in low-income regions. Cap-and-trade regimes have more flexibility to create a comparable distribution of costs amongst countries.Climate policy Global carbon tax Broadening participation

Reaching the 2°C Target: Technological Requirements, Economic Costs and Policies. CEPS Policy Briefs No. 188, 15 May 2009

This policy brief builds on results arising from the mitigation and policy appraisal research domains of the ADAM project (Adaptation and Mitigation Strategies: Supporting European Climate Policy). Funded by the European Commission and coordinated by the Tyndall Centre for Climate Change Research in the UK, ADAM is an integrated research project running from 2006 to 2009 that will lead to a better understanding of the trade-offs and conflicts that exist between adaptation and mitigation policies. This multi-authored report addresses questions surrounding the European Union’s proclaimed goal to stabilise the global mean temperature at less than 2°C above pre-industrial levels

RCP2.6: exploring the possibility to keep global mean temperature increase below 2°C

The RCP2.6 emission and concentration pathway is representative of the literature on mitigation scenarios aiming to limit the increase of global mean temperature to 2°C. These scenarios form the low end of the scenario literature in terms of emissions and radiative forcing. They often show negative emissions from energy use in the second half of the 21st century. The RCP2. 6 scenario is shown to be technically feasible in the IMAGE integrated assessment modeling framework from a medium emission baseline scenario, assuming full participation of all countries. Cumulative emissions of greenhouse gases from 2010 to 2100 need to be reduced by 70% compared to a baseline scenario, requiring substantial changes in energy use and emissions of non-CO2 gases. These measures (specifically the use of bio-energy and reforestation measures) also have clear consequences for global land use. Based on the RCP2. 6 scenario, recommendations for further research on low emission scenarios have been formulated. These include the response of the climate system to a radiative forcing peak, the ability of society to achieve the required emission reduction rates given political and social inertia and the possibilities to further reduce emissions of non-CO2 gases. © 2011 The Author(s)

Impact of fragmented emission reduction regimes on the energy market and on CO2 emissions related to land use: A case study with China and the European Union as first movers

In recent years, an approach based on voluntary pledges by individual regions has attracted interest of policy-makers and consequently also climate policy research. In this paper, we analyze scenarios in which the EU and China act as early-movers in international climate policy. Such a situation risks leakage between regions with ambitious emission reduction targets and those with less ambitious targets via fossil-fuel markets, displacement of heavy industry and land-use consequences. We examine some of these factors using the IMAGE model. While IMAGE does not include all mechanisms, we find the leakage rate to be relatively small, about 5% of the emission reductions in the EU and China. The far majority occurs via the energy market channel and the remainder through land-use change. Reduced oil prices due to less depletion forms the key reason for this leakage impact