Harald Winkler

Paris Agreement climate proposals need a boost to keep warming well below 2 °C

The Paris climate agreement aims at holding global warming to well below 2 degrees Celsius and to “pursue efforts” to limit it to 1.5 degrees Celsius. To accomplish this, countries have submitted Intended Nationally Determined Contributions (INDCs) outlining their post-2020 climate action. Here we assess the effect of current INDCs on reducing aggregate greenhouse gas emissions, its implications for achieving the temperature objective of the Paris climate agreement, and potential options for overachievement. The INDCs collectively lower greenhouse gas emissions compared to where current policies stand, but still imply a median warming of 2.6–3.1 degrees Celsius by 2100. More can be achieved, because the agreement stipulates that targets for reducing greenhouse gas emissions are strengthened over time, both in ambition and scope. Substantial enhancement or over-delivery on current INDCs by additional national, sub-national and non-state actions is required to maintain a reasonable chance of meeting the target of keeping warming well below 2 degrees Celsius.

A new scenario framework for Climate Change Research: scenario matrix architecture

This paper describes the scenario matrix architecture that underlies a framework for developing new scenarios for climate change research. The matrix architecture facilitates addressing key questions related to current climate research and policy-making: identifying the effectiveness of different adaptation and mitigation strategies (in terms of their costs, risks and other consequences) and the possible trade-offs and synergies. The two main axes of the matrix are: 1) the level of radiative forcing of the climate system (as characterised by the representative concentration pathways) and 2) a set of alternative plausible trajectories of future global development (described as shared socio-economic pathways). The matrix can be used to guide scenario development at different scales. It can also be used as a heuristic tool for classifying new and existing scenarios for assessment. Key elements of the architecture, in particular the shared socio-economic pathways and shared policy assumptions (devices for incorporating explicit mitigation and adaptation policies), are elaborated in other papers in this special issue.

Renewable energy policy in South Africa: Policy options for renewable electricity

Investment in renewable energy and energy efficiency is important to reduce the negative economic, social and environmental impacts of energy production and consumption in South Africa. Currently, renewable energy contributes relatively little to primary energy and even less to the consumption of commercial energy. This article examines policy options for promoting renewable electricity. Feed-in tariffs guarantee prices for developers, but lack certainty on the amount of renewable electricity such laws would deliver under local conditions. Portfolio standards set a fixed quantity, which would guarantee diversity of supply. The question is whether the incremental upfront cost to be paid by society may be unacceptably high, compared to future health and environmental benefits. A renewables obligation combines the setting of a target with a tendering process, but may be bureaucratic to administer. Neither setting targets or regulating prices alone, however, will be sufficient. Power purchase agreements, access to the grid and creating markets for green electricity are some supporting activities that should be considered. Given that renewable electricity technologies have to compete with relatively low electricity tariffs, funding will be needed. Possible sources, both locally and internationally, are identified. The extent to which these are utilised will determine the future mix of renewable energy in South Africa.

A new scenario framework for climate change research: background, process, and future directions

The scientific community is developing new global, regional, and sectoral scenarios to facilitate interdisciplinary research and assessment to explore the range of possible future climates and related physical changes that could pose risks to human and natural systems; how these changes could interact with social, economic, and environmental development pathways; the degree to which mitigation and adaptation policies can avoid and reduce risks; the costs and benefits of various policy mixes; and the relationship of future climate change adaptation and mitigation policy responses with sustainable development. This paper provides the background to and process of developing the conceptual framework for these scenarios, as described in the three subsequent papers in this Special Issue (Van Vuuren et al., 2013; O’Neill et al., 2013; Kriegler et al., Submitted for publication in this special issue). The paper also discusses research needs to further develop, apply, and revise this framework in an iterative and open-ended process. A key goal of the framework design and its future development is to facilitate the collaboration of climate change researchers from a broad range of perspectives and disciplines to develop policy- and decision-relevant scenarios and explore the challenges and opportunities human and natural systems could face with additional climate change.

Energy policies for sustainable development in South Africa

This paper summarises the results of a study that analysed ways of making South Africas future energy development more sustainable. The South African economy is comparatively energy-intensive, with total primary energy supply of 11.7 MJ per US

A new scenario framework for climate change research: the concept of shared climate policy assumptions

of GDP on a purchasing power parity basis, compared to 7.9 MJ/

Changing development paths: From an energy-intensive to low-carbon economy in South Africa

for Asia and 6.7 MJ/

Comparing developing countries under potential carbon allocation schemes

for Latin America. Moreover, the high dependence on coal makes the country also very carbon-intensive, with energy related CO 2 emissions of 6.7 tonnes per capita, comparable to the OECD average of about 11 tCO 2 /cap., and far higher than the non-OECD average of 1.7 tCO 2 /cap. Important policy initiatives are already under way to improve energy efficiency as well as the share of renewable energy. The impact of different energy policies, including alternative technologies for both supply and demand up to 2025, were analysed using the Markal model, a least-cost optimising tool. The reference case is close to the governments Integrated Energy Plan, with CO 2 emissions increasing from 337 million tonnes (Mt) in 2001 to 591 Mt in 2025. A cost-effective renewable energy policy scenario would increase the renewable electricity generation from 2,000 GWh in 2001 to almost 18,000 GWh in 2025, with significant contribution from solar thermal and biomass cogeneration technologies. Energy efficiency can make a substantial contribution, especially in industry. The combination of measures would reduce total energy system costs by 16 billion rands (

Energy and the World Summit on Sustainable Development: what next?

2.2 billion) and CO 2 emissions by 770 Mt, each over a 25-year period. The policies analysed here can therefore contribute both to sustainable development and to climate change mitigation.

CBDR&RC in a Regime Applicable to All

The new scenario framework facilitates the coupling of multiple socioeconomic reference pathways with climate model products using the representative concentration pathways. This will allow for improved assessment of climate impacts, adaptation and mitigation. Assumptions about climate policy play a major role in linking socioeconomic futures with forcing and climate outcomes. The paper presents the concept of shared climate policy assumptions as an important element of the new scenario framework. Shared climate policy assumptions capture key policy attributes such as the goals, instruments and obstacles of mitigation and adaptation measures, and introduce an important additional dimension to the scenario matrix architecture. They can be used to improve the comparability of scenarios in the scenario matrix. Shared climate policy assumptions should be designed to be policy relevant, and as a set to be broad enough to allow a comprehensive exploration of the climate change scenario space.