Michel den Elzen

Towards an equitable global climate change regime: compatibility with Article 2 of the Climate Change Convention and the link with sustainable development

In this paper we argue that the discussion on how to get to an equitable global climate change regime requires a long-term context. Some key dimensions of this discussion are responsibility, capability and development needs. Each of these, separately or in combination, has been used in designing schemes for differentiation of commitments to limit or reduce greenhouse gas emissions. Many implementation problems of these proposals are often side-stepped. In particular, some proposals may be incompatible with Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC), i.e. they are unlikely to keep the option open of long-term stabilisation of atmospheric greenhouse gas concentrations at relatively low levels. We present some evidence that shifting the emphasis from emission reduction to sustainable development needs can contribute significantly to relieving the threat of human-induced climate change.

Meeting the EU 2°C climate target: global and regional emission implications

Abstract This article presents a set of multi-gas emission pathways for different CO2-equivalent concentration stabilization levels, i.e. 400, 450, 500 and 550 ppm CO2-equivalent, along with an analysis of their global and regional reduction implications and implied probability of achieving the EU climate target of 2°C. For achieving the 2°C target with a probability of more than 60%, greenhouse gas concentrations need to be stabilized at 450 ppm CO2-equivalent or below, if the 90% uncertainty range for climate sensitivity is believed to be 1.5–4.5°C. A stabilization at 450 ppm CO2-equivalent or below (400 ppm) requires global emissions to peak around 2015, followed by substantial overall reductions of as much as 25% (45% for 400 ppm) compared to 1990 levels in 2050. In 2020, Annex I emissions need to be approximately 15% (30%) below 1990 levels, and non-Annex I emissions also need to be reduced by 15–20% compared to their baseline emissions. A further delay in peaking of global emissions by 10 years doubles maximum reduction rates to about 5% per year, and very probably leads to high costs. In order to keep the option open of stabilizing at 400 and 450 ppm CO2-equivalent, the USA and major advanced non-Annex I countries will have to participate in the reductions within the next 10–15 years.

Peaking profiles for achieving long-term temperature targets with more likelihood at lower costs

How can dangerous interference with the climate system be avoided? Science can help decision-makers answer this political question. Earlier publications have focused on the probability of keeping global mean temperature change below certain thresholds by stabilizing greenhouse gas concentrations at particular levels. We compare the results of such “stabilization profiles” with a set of “peaking profiles” that reduce emissions further after stabilization and thus result in a concentration peak. Given the inertia in the climate system, stabilization profiles lead to ongoing warming beyond 2100 until the temperature reaches equilibrium. This warming partly can be prevented for peaking profiles. In this way, these profiles can increase the likelihood of achieving temperature thresholds by 10–20% compared with the likelihood for the associated stabilization profiles. Because the additional mitigation efforts and thus costs for peaking profiles lie mainly beyond 2100, peaking profiles achieving temperature thresholds with the same likelihood as the original stabilization profile, but at considerably lower cost (up to 40%), can be identified. The magnitude of the cost reductions depends on the assumptions on discounting. Peaking profiles and overshoot profiles with a limited overshoot may, in particular, play an important role in making more ambitious climate targets feasible.

Responsibility for Past and Future Global Warming: Uncertainties in Attributing Anthropogenic Climate Change

During the negotiations on the Kyoto Protocol, Brazil proposed a methodology to link the relative contribution of Annex I Parties to emission reductions with the relative contributions of Parties to the global-mean temperature increase. The proposal was not adopted during the negotiations but referred to the Subsidiary Body for Scientific and Technological Advice for consideration of its methodological aspects. In this context we analyze the impact of model uncertainties and methodological choices on the regionally attributed global-mean temperature increase. A climate assessment model has been developed to calculate changes in greenhouse gas concentrations, global-mean temperature and sea-level rise attributable to individual regions. The analysis shows the impact of the different choices in methodological aspects to be as important as the impact of model uncertainties on a regions contribution to present and future global temperature increases. Choices may be the inclusion of the anthropogenic non-CO2 greenhouse gas emissions and/or theCO2 emissions associated with land-use changes. When responsibility to global temperature change is attributed to all emitting Parties, the impacts of modeling uncertainties and methodological choices on contributions of individual Parties are considerable. However, if relative contributions are calculated only within the group of Annex I countries, the results are less sensitive to the uncertainty aspects considered here.

Greenhouse gas emissions in an equity-, environment- and service-oriented world: An IMAGE-based scenario for the 21st century

Abstract This article describes a greenhouse gas (GHG) emissions scenario for a world that chooses collectively and effectively to pursue service-oriented economic prosperity while taking into account equity and environmental concerns, but without policies directed at mitigating climate change. After peaking around 2050 at 2.2 times the 1990 level of primary energy use, a number of factors lead to a primary energy use rate at the end of the next century that is only 40% higher than the 1990 rate. Among these factors are a stabilizing (and after 2050, declining) population, convergence in economic productivity, dematerialization and technology transfer, and high-tech innovations in energy use and supply. Land use-related emissions show a similar trend. Total CO 2 emissions peak at 12.8 CtC/yr around 2040, after which they start falling off. Other GHG emissions show a similar trend. The resulting CO 2 -equivalent concentration continues to rise to about 600 ppmv in 2100. Present understanding of climate change impacts suggest that even in this world of high-tech innovations in resource use in combination with effective global governance and concern about equity and environment issues, climate policy is needed if mankind is to avoid dangerous interference with the climate system.

Analyzing the Kyoto Protocol under the Marrakesh Accords: economic efficiency and environmental effectiveness

Abstract This article evaluates the environmental effectiveness and economic implications of the Kyoto Protocol (KP) after the Bonn agreement and the Marrakesh Accords. We will break it down into several components that correspond with major steps in the international process: pre-COP 6 version of the KP, with unrestricted international emissions trading but without sinks; withdrawal of the USA; and decisions on sinks in Bonn and Marrakesh. The Marrakesh Accords bring Annex-I emissions in 2010 without the USA at 0.5% under base-year levels; this corresponds to nearly 2% above the 1990-levels. The US withdrawal has by far the greatest impact in reducing the environmental effectiveness of the KP, whereas the impact of the decision on sinks is comparatively small. The US withdrawal also substantially reduces the permit demand and permit prices will drop dramatically. Hot air becomes increasingly dominant and may threaten the viability of the Kyoto Mechanisms (KM), especially in lower baseline (business-as-usual (BaU)) scenarios. Therefore, banking of hot air is of absolute importance to improve the environmental effectiveness of the protocol at moderately higher costs, while enhancing the development of a viable emission trading market. A strategy of curtailing and banking permit supply is also in the interest of the dominant seller, Russia.

Long-term reductions in costs of controlling regional air pollution in Europe due to climate policy

Abstract This paper examines to what extent climate change policies will alter the effectiveness of agreed-upon or future policies to reduce regional air pollution in Europe and vice versa. And when is it cost-effective to combat regional air pollution with clean technology instead of add-on technology? For this exercise, several extensions were made to the energy model TIMER, to introduce add-on abatement technologies, specified in terms of costs and reduction potentials, in order to be able to calculate cost-effective emission reduction strategies for different scenarios and regions. The results show that add-on technologies to reduce regional air pollution remain necessary throughout the century. The costs to reach the NO x emission reduction targets in Europe are about three times as high as for SO 2 . Mitigation costs averaged over the century by add-on technologies can be reduced by climate measures by 50–70% for SO 2 and around 50% for NO x . The costs of SO 2 and NO x mitigation by add-on technology in a world without climate policy are comparable or in some periods even higher than the costs of an integrated mitigation of SO 2 , NO x and CO 2 emissions if a reduction of specific costs by learning is, in contrast with energy technologies, not assumed for abatement technologies. So, the costs of SO 2 and NO x add-on measures avoided by climate policies can outweigh the costs of these climate measures. The total annual costs are in the order of 1 or 2% of the present GDP, depending on the scenario.

Sharing the burden of adaptation financing: An assessment of the contributions of countries

Climate change may cause most harm to countries that contribute least to greenhouse gas emissions. This paper identifies deontology, solidarity and consequentialism as the principles that can serve as a basis for a fair international burden sharing scheme of adaptation costs. We translate these principles into criteria that can be applied in assigning contributions of individual countries, namely historical responsibility, equality and capacity to pay. Specific political and scientific choices are discussed, highlighting implications for international burden-sharing. Combining historical responsibility and capacity to pay seems a promising starting point for international negotiations on the design of burden-sharing schemes. From the numerical assessment, it is clear that UNFCCC Annex I countries carry the greatest burden under most scenarios, but contributions differ substantially subject to the choice of an indicator for capacity to pay. The total financial contribution by the Annex I countries could be in the range of

Evaluating the Bonn-Marrakesh agreement

55-68 billion annually.

Long-term, consistent scenarios of emissions, deposition, and climate change in Europe

This article evaluates the environmental effectiveness and economic efficiency of the Kyoto Protocol after the Bonn Agreement and the Marrakesh Accords. The US withdrawal has by far the greatest impact in reducing the environmental effectiveness, lowering the price of traded emission permits and reducing Annex I abatement costs. The decisions on sinks imply that the Annex I CO 2 -equivalent emissions without the US will come out at about 1/2% below base-year level, instead of over 4% below base-year level. Without US participation, the emission permit price is estimated to be low. Therefore, banking hot air by Russia and the Ukraine is of absolute importance for the development of a viable emissions trading market, and would also enhance the environmental effectiveness of the Kyoto Protocol.