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Emissions of CO2 from the EU can be estimated using different system boundaries, depending on the policy question. We analyze and compare the trends in territorial emissions (1990–2016) and consumption-based emissions and emissions embodied in trade (1990–2014). We find the Global Financial Crisis (GFC) in 2008 was an important turning point. Territorial emissions were roughly stable in the years before the GFC but have since declined. Consumption-based emissions rose from 2000 to the GFC but then declined in concert with territorial emissions. A Kaya identity decomposition suggests that the main factor pushing the EU’s territorial emissions up before the GFC was a growth in GDP, balanced by constant improvements in energy and carbon intensity. The large increase in consumption-based emissions up to the GFC was mainly due to emissions from the production of imported manufactured goods, particularly from China. After the GFC, the Kaya identity decomposition suggests that lower GDP growth facilitated a sustained decrease in territorial emissions. The decline in consumption-based emissions since the GFC was partly due to decreasing territorial emissions but accelerated due to a decrease in the emissions from the production of imported products from China. Preliminary data indicates that EU CO2 emissions have increased from 2014 to 2017, with the Kaya identity decomposition suggesting the increase is due to a return to stronger GDP growth.

Climate policy is generally concerned with the mitigation of well-mixed greenhouse gases, allocated to the country where the emissions occur, and with different emissions weighted together with the Global Warming Potential (GWP) using a 100 year time horizon. This perspective is not unique. Recent research has considered the inclusion of Short-Lived Climate Forcers (SCLFs), allocated emissions to the consumption of goods and services, and used alternative emissions metrics. Here, for the first time, we combine these alternative perspectives to explore the potential policy implications of three alternative framings: 1) using the Global Temperature change Potential (GTP) to directly link current emissions to temperature change, 2) including SLCFs that have both warming and cooling effects on climate, and 3) allocating emissions to consuming sectors and regions. Collectively, we use these three aspects to allocate the future temperature response to the consumption of goods and services in a given year. We show, in order of importance, that the method of allocating emissions to economic sectors is the most important, followed by the emission metric (including time-horizon), and then the mix of short-lived and well-mixed climate forcers. The consumption perspective reallocates emissions from electricity and manufacturing to service sectors, which suggests different policy options for demand and supply. The net effect of multiple pollutants and GTP significantly change the importance of the sectors compared to when only considering CO2 or when using the GWP. We argue that a focus on only one accounting system and framing in climate policy can potentially limit consideration of mitigation options to a reduced set of activities, and thereby missing significant opportunities for mitigation in other aspects.

Brazil’s economic development has been underpinned by a diverse and – in a global comparison – unusual set of energy carriers, notably hydroelectricity and ethanol from sugar cane. Its energy mix makes Brazil one of the least energy-related carbon-intensive economies worldwide. Given that the country is fast becoming one of the world’s economic powerhouses, decision-makers need to understand the drivers underlying past and current carbon dioxide emissions trends. We therefore investigate a) which key long-term drivers have led to Brazil’s unique emissions profile, and b) the implications of these drivers for Brazil’s national policies. We show that Brazil’s emissions are growing mainly due to increasing individual standards of living, exports and population size, and that this growth is so far unchallenged by technological and structural improvements toward lower emissions intensities and more efficient production structures. As these trends are likely to continue amidst growing international pressure on key economies to reduce their carbon emissions, a decoupling of drivers from emissions is needed to simultaneously meet development and environmental goals.

Emissions and resources are typically allocated to national territories. There has been increased interest in allocating environmental flows to the final consumption of goods and services. The resu ...

Pricing carbon is one of the most important tools to reduce emissions and mitigate climate change. Already, about 40 nations have implemented explicit or implicit carbon prices, and a carbon price was explicitly stated as a mitigation strategy by many nations in their emission pledges submitted to the Paris Agreement. The coverage of carbon prices varies significantly between nations though, often only covering a subset of sectors in the economy. We investigate the propagation of carbon prices along the global supply-chain when the carbon price is applied at the point where carbon is removed from the ground (extraction), is combusted (production), or where goods and services are consumed (consumption). We consider both the regional and sectoral effects, and compare the carbon price income and costs relative to economic output. We find that implementation using different accounting systems makes a significant difference to revenues and increased expenditure, and that domestic and global trade plays a significant role in spreading the carbon price between sectors and countries. A few single sectors experience the largest relative price increases (especially electricity and transport), but most of the carbon price is ultimately paid by households for goods and services due to the large expenditure and indirect supply chain impacts. We finally show that a global carbon price will generate a larger share of revenue relative to GDP in non-OECD nations than OECD nations, independent on the point of implementation.

Several studies have connected emissions of greenhouse gases to economic and trade data to quantify the causal chain from consumption to emissions and climate change. These studies usually combine data and models originating from different sources, making it difficult to estimate uncertainties along the entire causal chain. We estimate uncertainties in economic data, multi-pollutant emission statistics, and metric parameters, and use Monte Carlo analysis to quantify contributions to uncertainty and to determine how uncertainty propagates to estimates of global temperature change from regional and sectoral territorial- and consumption-based emissions for the year 2007. We find that the uncertainties are sensitive to the emission allocations, mix of pollutants included, the metric and its time horizon, and the level of aggregation of the results. Uncertainties in the final results are largely dominated by the climate sensitivity and the parameters associated with the warming effects of CO2. Based on our assumptions, which exclude correlations in the economic data, the uncertainty in the economic data appears to have a relatively small impact on uncertainty at the national level in comparison to emissions and metric uncertainty. Much higher uncertainties are found at the sectoral level. Our results suggest that consumption-based national emissions are not significantly more uncertain than the corresponding production-based emissions since the largest uncertainties are due to metric and emissions which affect both perspectives equally. The two perspectives exhibit different sectoral uncertainties, due to changes of pollutant compositions. We find global sectoral consumption uncertainties in the range of ±10 to ±27 % using the Global Temperature Potential with a 50-year time horizon, with metric uncertainties dominating. National-level uncertainties are similar in both perspectives due to the dominance of CO2 over other pollutants. The consumption emissions of the top 10 emitting regions have a broad uncertainty range of ±9 to ±25 %, with metric and emission uncertainties contributing similarly. The absolute global temperature potential (AGTP) with a 50-year time horizon has much higher uncertainties, with considerable uncertainty overlap for regions and sectors, indicating that the ranking of countries is uncertain.

Expanding high elevation and high latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically-based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase of summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land use history. In the future scenarios, forest cover increased from 12 to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high latitude and high elevation expanding mountain forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. Climate warming feedback from mountain birch forest expansion: Reduced albedo dominates carbon uptake

This study focuses on evaluating image correlation methods for deriving surface velocity fields of glaciers, ice shelves, rockglaciers and landslides from both repeat optical and synthetic aperture radar (SAR) images. Firstly we show that low resolution MODIS images (250m spatial resolution) can in fact be used for determining displacements on Antarctic ice shelves. In this particular case, orientation correlation operated in the frequency domain and using only the phase part of the signal performs better than normalized cross-correlation operated in the spatial domain. Secondly we demonstrate that for determining subpixel displacement when using normalized cross- correlation, image intensity interpolation before the matching process outperforms interpolation of the correlation peak after the matching. We also study methods for adaptively varying the matching template size in order to create the most reliable and accurate matches. The last part of the work shows some application studies of glacier flow from optical and SAR images, rockglacier creep and land sliding.