Jared Creason

Can Paris pledges avert severe climate change

Reducing risks of severe outcomes and improving chances of limiting warming to 2°C Current international climate negotiations seek to catalyze global emissions reductions through a system of nationally determined country-level emissions reduction targets that would be regularly updated. These “Intended Nationally Determined Contributions” (INDCs) would constitute the core of mitigation commitments under any agreement struck at the upcoming Paris Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) (1). With INDCs now reported from more than 150 countries and covering around 90% of global emissions, we can begin to assess the role of this round of INDCs in facilitating or frustrating achievement of longer-term climate goals. In this context, it is important to understand what these INDCs collectively deliver in terms of two objectives. First, how much do they reduce the probability of the highest levels of global mean surface temperature change? Second, how much do they improve the odds of achieving the international goal of limiting temperature change to under 2°C relative to preindustrial levels (2)? Although much discussion has focused on the latter objective (3–5), the former is equally important when viewing climate mitigation from a risk-management perspective.

The contribution of Paris to limit global warming to 2 °C

The international community has set a goal to limit global warming to 2 °C. Limiting global warming to 2 °C is a challenging goal and will entail a dramatic transformation of the global energy system, largely complete by 2040. As part of the work toward this goal, countries have been submitting their Intended Nationally Determined Contributions (INDCs) to the United Nations Framework Convention on Climate Change, indicating their emissions reduction commitments through 2025 or 2030, in advance of the 21st Conference of the Parties (COP21) in Paris in December 2015. In this paper, we use the Global Change Assessment Model (GCAM) to analyze the near versus long-term energy and economic-cost implications of these INDCs. The INDCs imply near-term actions that reduce the level of mitigation needed in the post-2030 period, particularly when compared with an alternative path in which nations are unable to undertake emissions mitigation until after 2030. We find that the latter case could require up to 2300 GW of premature retirements of fossil fuel power plants and up to 2900 GW of additional low-carbon power capacity installations within a five-year period of 2031–2035. INDCs have the effect of reducing premature retirements and new-capacity installations after 2030 by 50% and 34%, respectively. However, if presently announced INDCs were strengthened to achieve greater near-term emissions mitigation, the 2031–2035 transformation could be tempered to require 84% fewer premature retirements of power generation capacity and 56% fewer new-capacity additions. Our results suggest that the INDCs delivered for COP21 in Paris will have important contributions in reducing the challenges of achieving the goal of limiting global warming to 2 °C.

Global mitigation potential and costs of reducing agricultural non-CO2 greenhouse gas emissions through 2030

Abstract Agricultural emissions account for 53% of 2010 global non-CO2 emissions and are projected to increase substantially over the next 20 years, especially in Asia, Latin America and Africa. While agriculture is a substantial source of emissions, it is also generally considered to be a potential source of cost-effective non-CO2 GHG abatement. Previous “bottom-up” analyses provided marginal abatement cost (MAC) curves for use in modeling these options within economy-wide and global mitigation analyses. In this paper, we utilize updated economic and biophysical data and models developed by the US Environmental Protection Agency (EPA) to investigate regional mitigation potential for major sources of agricultural GHG emissions. In addition, we explore mitigation potential available at costs at or below the estimated benefits of mitigation, as represented by the social cost of carbon. Key enhancements over previous regional assessments include incorporation of additional mitigation options, updated baseline emissions projections, greater spatial disaggregation, and development of MAC curves through 2030. For croplands and rice cultivation, biophysical, process-based models (DAYCENT and DNDC) are used to simulate yields and net GHG emissions under baseline and mitigation scenarios while the livestock sector is modeled by applying key mitigation options to baselines compiled by EPA. MAC curves are generated accounting for net GHG reductions, yield effects, livestock productivity effects, commodity prices, labor requirements, and capital costs where appropriate. MAC curves are developed at the regional level and reveal large potential for non-CO2 GHG mitigation at low carbon prices, especially in Asia.

Electric sector policy, technological change, and U.S. emissions reductions goals: Results from the EMF 32 model intercomparison project

The Energy Modeling Forum (EMF) 32 study compares a range of coordinated scenarios to explore implications of U.S. climate policy options and technological change on the electric power sector. Harmonized policy scenarios (including mass-based emissions limits and various power-sector-only carbon tax trajectories) across 16 models provide comparative assessments of potential impacts on electric sector investment and generation outcomes, emissions reductions, and economic implications. This paper compares results across these policy alternatives, including a variety of technological and natural gas price assumptions, and summarizes robust findings and areas of disagreement across participating models. Under a wide range of policy, technology, and market assumptions, model results suggest that future coal generation will decline relative to current levels while generation from natural gas, wind, and solar will increase, though the pace and extent of these changes vary by policy scenario, technological assumptions, region, and model. Climate policies can amplify trends already under way and make them less susceptible to future market changes. The model results provide useful insights to a range of stakeholders, but future research focused on intersectoral linkages in emission reductions (e.g., the role of electrification), effects of energy storage, and better coverage of bioenergy with carbon capture and storage (BECCS) can improve insights even further.

Effects of technology assumptions on US power sector capacity, generation and emissions projections: Results from the EMF 32 Model Intercomparison Project

This paper is one of two syntheses in this special issue of the results of the EMF 32 power sector study. This paper focuses on the effects of technology and market assumptions with projections out to 2050. A total of 15 models contributed projections based on a set of standardized scenarios. The scenarios include a range of assumptions about the price of natural gas, costs of end-use energy efficiency, retirements of nuclear power, the cost of renewable electricity, and overall electricity demand. The range of models and scenarios represent similarities and differences across a broad spectrum of analytical methods. One similarity across almost all results from all models and scenarios is that the share of electricity generation and capacity fueled by coal shrinks over time, although the rate at which coal capacity is retired depends on the price of natural gas and the amount of electricity that is demanded. Another similarity is that the models project average increases in natural gas power generating capacity in every scenario over the 2020-2050 period, but at lower average annual rates than those that prevailed during the 2000-2015 period. The projections also include higher gas capacity utilization rates in the 2035-2050 period compared to the 2020-2050 period in every scenario, except the high gas price sensitivity. Renewables capacity is also projected to increase in every scenario, although the annual new capacity varies from modest rates below the observed 2000-2015 wind and solar average to rates more than 3 times that high. Model estimates of CO2 emissions largely follow from the trends in generation. Low renewables cost and low gas prices both result in lower overall CO2 emission rates relative to the 2020-2035 and 2035-2050 reference. Both limited nuclear lifetimes and higher demand result in increased CO2 emissions.

Global mitigation of non-CO2 greenhouse gases: marginal abatement costs curves and abatement potential through 2030

Abstract Greenhouse gases (GHGs) other than carbon dioxide (CO2) play an important role in the effort to understand and address global climate change. Approximately 25% of Global warming potential-weighted GHG emissions in the year 2005 comprise the non-CO2 GHGs. The report, Global Mitigation of Non-CO2 Greenhouse Gases: 2010–2030 provides a comprehensive global analysis and resulting data-set of marginal abatement cost curves that illustrate the abatement potential of non-CO2 GHGs by sector and by region. The basic methodology – a bottom-up, engineering cost approach – builds on the baseline non-CO2 emissions projections published by EPA, applying abatement options to the emissions baseline in each sector. The results of the analysis are MAC curves that reflect aggregated breakeven prices for implementing abatement options in a given sector and region. Among the key findings of the report is that significant, cost-effective abatement exists from non-CO2 sources with abatement options that are available today. Without a price signal (i.e. at

Structural change as a key component for agricultural non-CO2 mitigation efforts

0/tCO2e), the global abatement potential is greater than 1800 million metric tons of CO2 equivalent. Globally, the energy and agriculture sectors have the greatest potential for abatement. Among the non-CO2 GHGs, methane has the largest abatement potential. Despite the potential for project level cost savings and environmental benefits, barriers to mitigating non-CO2 emissions continue to exist. This paper will provide an overview of the methods and key findings of the report.

Evaluating the effects of climate change on US agricultural systems: sensitivity to regional impact and trade expansion scenarios

Agriculture is the single largest source of anthropogenic non-carbon dioxide (non-CO2) emissions. Reaching the climate target of the Paris Agreement will require significant emission reductions across sectors by 2030 and continued efforts thereafter. Here we show that the economic potential of non-CO2 emissions reductions from agriculture is up to four times as high as previously estimated. In fact, we find that agriculture could achieve already at a carbon price of 25 

Impacts of rising air temperatures and emissions mitigation on electricity demand and supply in the United States: a multi-model comparison

/tCO2eq non-CO2 reductions of around 1 GtCO2eq/year by 2030 mainly through the adoption of technical and structural mitigation options. At 100 

Projected climate change impacts on skiing and snowmobiling: A case study of the United States

/tCO2eq agriculture could even provide non-CO2 reductions of 2.6 GtCO2eq/year in 2050 including demand side efforts. Immediate action to favor the widespread adoption of technical options in developed countries together with productivity increases through structural changes in developing countries is needed to move agriculture on track with a 2 °C climate stabilization pathway.To achieve the climate target of the Paris Agreement substantial emission reductions will be required across economic sectors. Here the authors show that agriculture can make a significant contribution to non-CO2 mitigation efforts through structural change in the livestock sector and the deployment of technical options.