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Hearst was unique; the Weekly was unique. And newspaper readers of the period liked them both. The decision in 1935 not to allow non-Hearst papers to carry the supplement made its success entirely dependent upon the Hearst style of newspapering.

Scenario analysis clearly indicates that CCS is a critical technology in Paris consistent 'well below 2°C' scenarios. While the optimal deployment of CCS will be debated, the literature is clear that CCS is needed at a large-scale. Scenarios show CCS plays a key role in the power sector and industry, on fossil fuels and bioenergy, and in all world regions. The design of the Paris Agreement around five-yearly cycles to raise ambition is likely to lead to lower and uncertain carbon prices and thereby discourage the deployment of CCS. To ensure that CCS is deployed at the necessary scale, and to make a meaningful contribution to the Paris Agreement's 'well below 2°C' goal, it is likely innovative government support for CCS is necessary to operate in parallel to conventional climate policies. ; publishedVersion

Colophon; Contents ; Summary ; Summary of the key messages ; Response to key questions ; What are the data requirements and possibilities? ; How to use and interpret such estimates and calculations? ; With what degree of certainty and reliability? ; With what validity for illuminating critical environmental goals, targets and boundaries? ; What are the differences between environmental footprint for carbon dioxide emissions and land, water, energy and material use?

Policy makers have called for a 'fair and ambitious' global climate agreement. Scientific constraints, such as the allowable carbon emissions to avoid exceeding a 2 °C global warming limit with 66% probability, can help define ambitious approaches to climate targets. However, fairly sharing the mitigation challenge to meet a global target involves human values rather than just scientific facts. We develop a framework based on cumulative emissions of carbon dioxide to compare the consistency of countries' current emission pledges to the ambition of keeping global temperatures below 2 °C, and, further, compare two alternative methods of sharing the remaining emission allowance. We focus on the recent pledges and other official statements of the EU, USA, and China. The EU and US pledges are close to a 2 °C level of ambition only if the remaining emission allowance is distributed based on current emission shares, which is unlikely to be viewed as 'fair and ambitious' by others who presently emit less. China's stated emissions target also differs from measures of global fairness, owing to emissions that continue to grow into the 2020s. We find that, combined, the EU, US, and Chinese pledges leave little room for other countries to emit CO[subscript 2] if a 2 °C limit is the objective, essentially requiring all other countries to move towards per capita emissions 7 to 14 times lower than the EU, USA, or China by 2030. We argue that a fair and ambitious agreement for a 2 °C limit that would be globally inclusive and effective in the long term will require stronger mitigation than the goals currently proposed. Given such necessary and unprecedented mitigation and the current lack of availability of some key technologies, we suggest a new diplomatic effort directed at ensuring that the necessary technologies become available in the near future.

Greenhouse gas emissions can be addressed at the points of both production and consumption of goods and services. In a world of inhomogeneous climate policy, missing out policies on either production or consumption leaves an important policy area idle, rendering climate policy inefficient and potentially ineffective. While consumption-based emissions accounts have become readily available at the national level, we here show how their more detailed analysis by sectoral destination (which final demand sectors account for them), sectoral source (in which sectors across the globe those emissions are actually occurring) and the geographical location of the latter can inform a complementary consumption-based climate policy approach. For the example of the EU member country Austria, we find that more than 60% of its consumption-based emissions occur outside its borders, and 34% even outside the EU. The top sectors are a very different list under a consumption-based accounting perspective (construction, public administration (including defense, health and education), and wholesale and retail trade) than under a production-based one (electricity, iron and steel, and non-metallic minerals, such as cement). While for some sectors (e.g. electricity) production-based approaches can work well, emission reduction in other sectors (e.g. electronic equipment) is crucially dependent on consumption-based approaches, as a structural path analysis reveals.

Paris Agreement. This study provides a consolidated synthesis of estimates for all anthropogenic and natural sources and sinks of CO2 for the European Union and UK (EU27 + UK), derived from a combination of state-of-the-art bottom-up (BU) and top-down (TD) data sources and models. Given the wide scope of the work and the variety of datasets involved, this study focuses on identifying essential questions which need to be answered to properly understand the differences between various datasets, in particular with regards to the less-well-characterized fluxes from managed ecosystems. The work integrates recent emission inventory data, process-based ecosystem model results, data-driven sector model results and inverse modeling estimates over the period 1990–2018. BU and TD products are compared with European national greenhouse gas inventories (NGHGIs) reported under the UNFCCC in 2019, aiming to assess and understand the differences between approaches. For the uncertainties in NGHGIs, we used the standard deviation obtained by varying parameters of inventory calculations, reported by the member states following the IPCC Guidelines. Variation in estimates produced with other methods, like atmospheric inversion models (TD) or spatially disaggregated inventory datasets (BU), arises from diverse sources including within-model uncertainty related to parameterization as well as structural differences between models. In comparing NGHGIs with other approaches, a key source of uncertainty is that related to different system boundaries and emission categories (CO2 fossil) and the use of different land use definitions for reporting emissions from land use, land use change and forestry (LULUCF) activities (CO2 land). At the EU27 + UK level, the NGHGI (2019) fossil CO2 emissions (including cement production) account for 2624 Tg CO2 in 2014 while all the other seven bottom-up sources are consistent with the NGHGIs and report a mean of 2588 (± 463 Tg CO2). The inversion reports 2700 Tg CO2 (± 480 Tg CO2), which is well in line with the national inventories. Over 2011–2015, the CO2 land sources and sinks from NGHGI estimates report −90 Tg C yr−1 ± 30 Tg C yr−1 while all other BU approaches report a mean sink of −98 Tg C yr−1 (± 362 Tg of C from dynamic global vegetation models only). For the TD model ensemble results, we observe a much larger spread for regional inversions (i.e., mean of 253 Tg C yr−1 ± 400 Tg C yr−1). This concludes that (a) current independent approaches are consistent with NGHGIs and (b) their uncertainty is too large to allow a verification because of model differences and probably also because of the definition of "CO2 flux" obtained from different approaches. The referenced datasets related to figures are visualized at https://doi.org/10.5281/zenodo.4626578 (Petrescu et al., 2020a). ; publishedVersion