Out of energy

Kevin Lewis

July 13, 2016

Retraining Investment for U.S. Transition from Coal to Solar Photovoltaic Employment

Edward Louie & Joshua Pearce

Energy Economics, June 2016, Pages 295–302

Although coal remains the largest source of electricity in the U.S., a combination of factors is driving a decrease in profitability and employment in the coal-sector. Meanwhile, the solar photovoltaic (PV) industry is growing rapidly in the U.S. and generating many jobs that represent employment opportunities for laid off coal workers. In order to determine the viability of a smooth transition from coal to PV-related employment, this paper provides an analysis of the cost to retrain current coal workers for solar photovoltaic industry employment in the U.S. The current coal industry positions are determined, the skill set evaluated and the salaries tabulated. For each type of coal position, the closest equivalent PV position is determined and then the re-training time and investment are quantified. These values are applied on a state-by-state basis for coal producing states employing the bulk of coal workers as a function of time using a reverse seniority retirement program for the current American fleet of coal-powered plants. The results show that a relatively minor investment in retraining would allow the vast majority of coal workers to switch to PV-related positions even in the event of the elimination of the coal industry.


‘Climate value at risk’ of global financial assets

Simon Dietz et al.

Nature Climate Change, July 2016, Pages 676–679

Investors and financial regulators are increasingly aware of climate-change risks. So far, most of the attention has fallen on whether controls on carbon emissions will strand the assets of fossil-fuel companies. However, it is no less important to ask, what might be the impact of climate change itself on asset values? Here we show how a leading integrated assessment model can be used to estimate the impact of twenty-first-century climate change on the present market value of global financial assets. We find that the expected ‘climate value at risk’ (climate VaR) of global financial assets today is 1.8% along a business-as-usual emissions path. Taking a representative estimate of global financial assets, this amounts to US$2.5 trillion. However, much of the risk is in the tail. For example, the 99th percentile climate VaR is 16.9%, or US$24.2 trillion. These estimates would constitute a substantial write-down in the fundamental value of financial assets. Cutting emissions to limit warming to no more than 2 °C reduces the climate VaR by an expected 0.6 percentage points, and the 99th percentile reduction is 7.7 percentage points. Including mitigation costs, the present value of global financial assets is an expected 0.2% higher when warming is limited to no more than 2 °C, compared with business as usual. The 99th percentile is 9.1% higher. Limiting warming to no more than 2 °C makes financial sense to risk-neutral investors — and even more so to the risk averse.


Millions projected to be at risk from sea-level rise in the continental United States

Mathew Hauer, Jason Evans & Deepak Mishra

Nature Climate Change, July 2016, Pages 691–695

Sea-level rise (SLR) is one of the most apparent climate change stressors facing human society. Although it is known that many people at present inhabit areas vulnerable to SLR, few studies have accounted for ongoing population growth when assessing the potential magnitude of future impacts. Here we address this issue by coupling a small-area population projection with a SLR vulnerability assessment across all United States coastal counties. We find that a 2100 SLR of 0.9 m places a land area projected to house 4.2 million people at risk of inundation, whereas 1.8 m affects 13.1 million people — approximately two times larger than indicated by current populations. These results suggest that the absence of protective measures could lead to US population movements of a magnitude similar to the twentieth century Great Migration of southern African-Americans. Furthermore, our population projection approach can be readily adapted to assess other hazards or to model future per capita economic impacts.


Simple reframing unlikely to boost public support for climate policy

Thomas Bernauer & Liam McGrath

Nature Climate Change, July 2016, Pages 680–683

Ambitious policies for limiting climate change require strong public support. However, the public’s appetite for such policies, as observed in most countries, is rather limited. One possibility for enhancing public support could be to shift the main justification in the public policy discourse on greenhouse gas mitigation from benefits of reducing climate change risks (the conventional justification) to other types of benefit. Technological innovation, green jobs, community building and health benefits are widely discussed candidates. The intuition is that reframing greenhouse gas mitigation efforts and their benefits in such terms could make them more personally relevant as well as more emotionally engaging and appealing to citizens. On the basis of results from two survey-embedded experiments (combined N = 1,675), and in contrast to some earlier studies, we conclude that simple reframing of climate policy is unlikely to increase public support, and outline reasons for this finding. As the added value of other justifications remains unclear at best and potentially nil, sticking to climate risk reduction as the dominant justification seems worthwhile.


What’s powering wind? The effect of the U.S. state renewable energy policies on wind capacity (1994–2012)

Karen Maguire

Applied Economics, forthcoming

As of 2012, 29 states had enacted a Renewable Portfolio Standard (RPS), while 37 states had at least one utility offering Green Power Purchasing (GPP) to their customers. The goal of both policies is to promote the adoption of clean, renewable energy. This article examines the influence of these polices on wind capacity across the United States from 1994–2012, a period of significant expansion of the wind generation market. The analysis focuses on wind because as compared with other modern renewable energy sources, wind is the only renewable energy source to make significant inroads into the U.S. electricity generation market. My findings indicate that while there have been significant increases in commercial scale wind generation capacity, neither RPS nor GPP programmes had a significant influence on within state wind capacity additions.


Evidence for climate change in the satellite cloud record

Joel Norris et al.

Nature, forthcoming

Clouds substantially affect Earth’s energy budget by reflecting solar radiation back to space and by restricting emission of thermal radiation to space. They are perhaps the largest uncertainty in our understanding of climate change, owing to disagreement among climate models and observational datasets over what cloud changes have occurred during recent decades and will occur in response to global warming. This is because observational systems originally designed for monitoring weather have lacked sufficient stability to detect cloud changes reliably over decades unless they have been corrected to remove artefacts. Here we show that several independent, empirically corrected satellite records exhibit large-scale patterns of cloud change between the 1980s and the 2000s that are similar to those produced by model simulations of climate with recent historical external radiative forcing. Observed and simulated cloud change patterns are consistent with poleward retreat of mid-latitude storm tracks, expansion of subtropical dry zones, and increasing height of the highest cloud tops at all latitudes. The primary drivers of these cloud changes appear to be increasing greenhouse gas concentrations and a recovery from volcanic radiative cooling. These results indicate that the cloud changes most consistently predicted by global climate models are currently occurring in nature.


Strongly increasing heat extremes in the Middle East and North Africa (MENA) in the 21st century

J. Lelieveld et al.

Climatic Change, July 2016, Pages 245-260

The ensemble results of CMIP5 climate models that applied the RCP4.5 and RCP8.5 scenarios have been used to investigate climate change and temperature extremes in the Middle East and North Africa (MENA). Uncertainty evaluation of climate projections indicates good model agreement for temperature but much less for precipitation. Results imply that climate warming in the MENA is strongest in summer while elsewhere it is typically stronger in winter. The summertime warming extends the thermal low at the surface from South Asia across the Middle East over North Africa, as the hot desert climate intensifies and becomes more extreme. Observations and model calculations of the recent past consistently show increasing heat extremes, which are projected to accelerate in future. The number of warm days and nights may increase sharply. On average in the MENA, the maximum temperature during the hottest days in the recent past was about 43 °C, which could increase to about 46 °C by the middle of the century and reach almost 50 °C by the end of the century, the latter according to the RCP8.5 (business-as-usual) scenario. This will have important consequences for human health and society.


Offshore CCS and ocean acidification: A global long-term probabilistic cost-benefit analysis of climate change mitigation

Bob van der Zwaan & Reyer Gerlagh

Climatic Change, July 2016, Pages 157-170

Public fear over environmental and health impacts of CO2 storage, or over potential leakage of CO2 from geological reservoirs, is among the reasons why over the past decade CCS has not yet been deployed on a scale large enough so as to meaningfully contribute to mitigate climate change. Storage of CO2 under the seabed moves this climate mitigation option away from inhabited areas and could thereby take away some of the opposition towards this technology. Given that in the event of CO2 leakage through the overburden in the case of sub-seabed CCS, the ocean could function as buffer for receiving this greenhouse gas, instead of it directly being emitted into the atmosphere, offshore CCS could also address concerns over the climatic impacts of CO2 seepage. We point out that recent geological studies provide evidence that to date CO2 has been safely stored under the seabed. Leakage for individual offshore CCS operations could thus be unlikely from a technical point of view, if storage sites are well chosen, well managed and well monitored. But we argue that on a global longterm scale, for an ensemble of thousands or millions of storage sites, leakage of CO2 could take place in certain cases and/or countries for e.g. economic, institutional, legal or safety-cultural reasons. In this paper we investigate what the impact could be in terms of temperature increase and ocean acidification if leakage occurs at a global level, and address the question what the relative roles could be of on- and offshore CCS if mankind desires to divert the damages resulting from climate change. For this purpose, we constructed a top-down energy-environment-economy model, with which we performed a probabilistic Monte-Carlo cost-benefit analysis of climate change mitigation with on- and offshore CCS as specific CO2 abatement options. One of our main conclusions is that, even under conditions with non-zero (permille/year) leakage for CCS activity globally, both onshore and offshore CCS should probably – on economic grounds at least - still account for anywhere between 20 % and 80 % of all future CO2 abatement efforts under a broad range of CCS cost assumptions.


Anthropogenic forcing dominates global mean sea-level rise since 1970

Aimée Slangen et al.

Nature Climate Change, July 2016, Pages 701–705

Sea-level change is an important consequence of anthropogenic climate change, as higher sea levels increase the frequency of sea-level extremes and the impact of coastal flooding and erosion on the coastal environment, infrastructure and coastal communities. Although individual attribution studies have been done for ocean thermal expansion and glacier mass loss, two of the largest contributors to twentieth-century sea-level rise, this has not been done for the other contributors or total global mean sea-level change (GMSLC). Here, we evaluate the influence of greenhouse gases (GHGs), anthropogenic aerosols, natural radiative forcings and internal climate variability on sea-level contributions of ocean thermal expansion, glaciers, ice-sheet surface mass balance and total GMSLC. For each contribution, dedicated models are forced with results from the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate model archive. The sum of all included contributions explains 74 ± 22% (±2σ) of the observed GMSLC over the period 1900–2005. The natural radiative forcing makes essentially zero contribution over the twentieth century (2 ± 15% over the period 1900–2005), but combined with the response to past climatic variations explains 67 ± 23% of the observed rise before 1950 and only 9 ± 18% after 1970 (38 ± 12% over the period 1900–2005). In contrast, the anthropogenic forcing (primarily a balance between a positive sea-level contribution from GHGs and a partially offsetting component from anthropogenic aerosols) explains only 15 ± 55% of the observations before 1950, but increases to become the dominant contribution to sea-level rise after 1970 (69 ± 31%), reaching 72 ± 39% in 2000 (37 ± 38% over the period 1900–2005).


Human-induced greening of the northern extratropical land surface

Jiafu Mao et al.

Nature Climate Change, forthcoming

Significant land greening in the northern extratropical latitudes (NEL) has been documented through satellite observations during the past three decades. This enhanced vegetation growth has broad implications for surface energy, water and carbon budgets, and ecosystem services across multiple scales. Discernible human impacts on the Earth’s climate system have been revealed by using statistical frameworks of detection–attribution. These impacts, however, were not previously identified on the NEL greening signal, owing to the lack of long-term observational records, possible bias of satellite data, different algorithms used to calculate vegetation greenness, and the lack of suitable simulations from coupled Earth system models (ESMs). Here we have overcome these challenges to attribute recent changes in NEL vegetation activity. We used two 30-year-long remote-sensing-based leaf area index (LAI) data sets, simulations from 19 coupled ESMs with interactive vegetation, and a formal detection and attribution algorithm. Our findings reveal that the observed greening record is consistent with an assumption of anthropogenic forcings, where greenhouse gases play a dominant role, but is not consistent with simulations that include only natural forcings and internal climate variability. These results provide the first clear evidence of a discernible human fingerprint on physiological vegetation changes other than phenology and range shifts.


Statements about climate researchers’ carbon footprints affect their credibility and the impact of their advice

Shahzeen Attari, David Krantz & Elke Weber

Climatic Change, forthcoming

Would you follow advice about personal energy conservation from a climate specialist with a large carbon footprint? Many climate researchers report anecdotes in which their sincerity was challenged based on their alleged failure to reduce carbon emissions. Here, we report the results of two large online surveys that measure the perceived credibility of a climate researcher who provides advice on how to reduce energy use (by flying less, conserving home energy, and taking public transportation), as a function of that researcher’s personal carbon footprint description. Across the two studies, we randomly assigned participants to one of 18 vignettes about a climate scientist. We show that alleged large carbon footprints can greatly reduce the researcher’s credibility compared to low footprints. We also show that these differences in perceived credibility strongly affect participants’ reported intentions to change personal energy consumption. These effects are large, both for participants who believe climate change is important and for those who do not. Participants’ politics do affect their attitudes toward researchers, and have an extra effect on reported intentions to use public transportation (but not on intentions to fly less or conserve home energy). Credibility effects are similar for male and female climate scientists.


Enhanced economic connectivity to foster heat stress–related losses

Leonie Wenz & Anders Levermann

Science Advances, June 2016

Assessing global impacts of unexpected meteorological events in an increasingly connected world economy is important for estimating the costs of climate change. We show that since the beginning of the 21st century, the structural evolution of the global supply network has been such as to foster an increase of climate-related production losses. We compute first- and higher-order losses from heat stress–induced reductions in productivity under changing economic and climatic conditions between 1991 and 2011. Since 2001, the economic connectivity has augmented in such a way as to facilitate the cascading of production loss. The influence of this structural change has dominated over the effect of the comparably weak climate warming during this decade. Thus, particularly under future warming, the intensification of international trade has the potential to amplify climate losses if no adaptation measures are taken.


The downside risk of climate change in California’s Central Valley agricultural sector

Michael Hanemann, Susan Stratton Sayre & Larry Dale

Climatic Change, July 2016, Pages 15-27

Downscaled climate change projections for California, when translated into changes in irrigation water delivery and then into profit from agriculture in the Central Valley, show an increase in conventional measures of variability such as the variance. However, these increases are modest and mask a more pronounced increase in downside risk, defined as the probability of unfavorable outcomes of water supply or profit. This paper describes the concept of downside risk and measures it as it applies to outcomes for Central Valley agriculture projected under four climate change scenarios. We compare the effect of downside risk aversion versus conventional risk aversion or risk neutrality when assessing the impact of climate change on the profitability of Central Valley agriculture. We find that, when downside risk is considered, the assessment of losses due to climate change increases substantially.


From Urban to National Heat Island: The effect of anthropogenic heat output on climate change in high population industrial countries

John Murray & Douglas Heggie

Earth's Future, forthcoming

The project presented here sought to determine whether changes in anthropogenic thermal emission can have a measurable effect on temperature at the national level, taking Japan & Great Britain as type examples. Using energy consumption as a proxy for thermal emission, strong correlations (mean r2 = 0.90 & 0.89 respectively) are found between national equivalent heat output HO and temperature above background levels ∆t averaged over 5 to 8 year periods between 1965 and 2013, as opposed to weaker correlations for CMIP5 model temperatures above background levels ∆mt (mean r2 = 0.52 & 0.10). It is clear that the fluctuations in ∆t are better explained by energy consumption than by present climate models, and that energy consumption can contribute to climate change at the national level on these timescales.


Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions

Juerg Matter et al.

Science, 10 June 2016, Pages 1312-1314

Carbon capture and storage (CCS) provides a solution toward decarbonization of the global economy. The success of this solution depends on the ability to safely and permanently store CO2. This study demonstrates for the first time the permanent disposal of CO2 as environmentally benign carbonate minerals in basaltic rocks. We find that over 95% of the CO2 injected into the CarbFix site in Iceland was mineralized to carbonate minerals in less than 2 years. This result contrasts with the common view that the immobilization of CO2 as carbonate minerals within geologic reservoirs takes several hundreds to thousands of years. Our results, therefore, demonstrate that the safe long-term storage of anthropogenic CO2 emissions through mineralization can be far faster than previously postulated.


Future Changes in Convective Storm Days over the Northeastern United States Using Linear Discriminant Analysis Applied to CMIP5 Predictions

Harrison Li & Brian Colle

Journal of Climate, June 2016, Pages 4327–4345

Future changes in the frequency of environmental conditions conducive for convective storm days (“CE days”) are determined for the northeastern United States (NEUS) during the warm seasons (April–September) of the twenty-first century. Statistical relationships between historical runs of seven models in phase 5 of the Coupled Model Intercomparison Project (CMIP5) and radar-classified convective storm days are developed using linear discriminant analysis (LDA), and these relationships are then applied to analyze changes in the convective environment under the high-emissions representative concentration pathway 8.5 (RCP8.5) scenario over the period 2006–99. The 1996–2007 warm seasons are used to train the LDA thresholds using convective precipitation from two reanalysis datasets and radar data, and the 1979–95 and 2008–10 warm seasons are used to verify these thresholds. For the CMIP5 historical period (1979–2005), the frequency of warm season CE days averaged across the CMIP5 models is slightly greater than that derived using reanalysis data, although both methods indicate a slight increasing trend through the historical period. Between 2006 and 2099, warm season CE day frequency is predicted to increase substantially at an average rate of 4–5 days decade−1 (50%–80% increase over the entire period). These changes are mostly attributed to a predicted 30%–40% increase in midlevel precipitable water between the historical period and the last few decades of the twenty-first century. Consistent with previous studies, there is decreasing deep-layer vertical wind shear as a result of a weakening horizontal temperature gradient, but this is outweighed by increases in instability led by the moisture increases.


The Realization of Extreme Tornadic Storm Events under Future Anthropogenic Climate Change

Robert Trapp & Kimberly Hoogewind

Journal of Climate, July 2016, Pages 5251–5265

This research seeks to answer the basic question of how current-day extreme tornadic storm events might be realized under future anthropogenic climate change. The pseudo global warming (PGW) methodology was adapted for this purpose. Three contributions to the CMIP5 archive were used to obtain the mean 3D atmospheric state simulated during May 1990–99 and May 2090–99. The climate change differences (or Δs) in temperature, relative humidity, pressure, and winds were added to NWP analyses of three high-end tornadic storm events, and this modified atmospheric state was then used for initial and boundary conditions for real-data WRF Model simulations of the events at high resolution. Comparison of an ensemble of these simulations with control simulations (CTRL) facilitated assessment of PGW effects. In contrast to the robust development of supercellular convection in each CTRL, the combined effects of increased convective inhibition (CIN) and decreased parcel lifting under PGW led to a failure of convection initiation in many of the experiments. Those experiments that had sufficient matching between the CIN and lifting tended to generate stronger convective updrafts than CTRL, although not in proportion to the projected higher levels of convective available potential energy (CAPE) under PGW. In addition, the experiments with enhanced updrafts also tended to have enhanced vertical rotation. In fact, such supercellular convection was even found in simulations that were driven with PGW-reduced environmental wind shear. Notably, the PGW modifications did not induce a change in the convective morphology in any of the PGW experiments with significant convective storminess.


Cash for Carbon: A Randomized Controlled Trial of Payments for Ecosystem Services to Reduce Deforestation

Seema Jayachandran et al.

NBER Working Paper, June 2016

This paper evaluates a Payments for Ecosystem Services (PES) program in western Uganda that offered forest-owning households cash payments if they conserved their forest. The program was implemented as a randomized trial in 121 villages, 60 of which received the program for two years. The PES program reduced deforestation and forest degradation: Tree cover, measured using high-resolution satellite imagery, declined by 2% to 5% in treatment villages compared to 7% to 10% in control villages during the study period. We find no evidence of shifting of tree-cutting to nearby land. We then use the estimated effect size and the "social cost of carbon" to value the delayed carbon dioxide emissions, and compare this benefit to the program's cost.


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