Thursday, May 19, 2016

Modelling the Best Way to Reduce Global Carbon Emissions

English: Carbon flow schematic of different en...
English: Carbon flow schematic of different energy source, including systems with carbon capture and storage (Photo credit: Wikipedia)
2 °C and SDGs: united they stand, divided they fall? (16 page pdf, Christoph von Stechow, Jan C Minx, Keywan Riahi, Jessica Jewell, David L McCollum, Max W Callaghan, Christoph Bertram, Gunnar Luderer and Giovanni Baiocchi, Environmental Research Letters, Mar. 16, 2016)

Also discussed here: Short-sighted climate policy jeopardizes other UN sustainable development goals (International Institute for Applied Systems Analysis News, Mar. 16, 2016)

 Today we review the results from 7 “integrated” models which were used to assess 20 scenarios for each decade out to 2050 while considering the 17 Sustainable Development Goals (SDGs) and 169 targets and the agreement to limit global climate warming to 2 deg C, set out in the recent COP 21 conference in Paris. Some carbon emission reduction strategies have emphasized economic impacts alone, failing to take into account wider social and environmental implications.

Application of carbon pricing to transportation, for example, has a greater potential for lowering emissions in the near term because of the short turn-around needed for technological improvements (e.g. electric vehicles) and the quick responsiveness of users to fuel price changes. On the other hand, a major increase in energy prices can have major impacts on the poor in developing countries, unless their concerns are accommodated in some way.

Another significant finding from this research is the impact of delaying the reduction of energy while waiting for potential non carbon energy technologies to become cost effective and widely used, such as BioEnergy(BE), Carbon Capture and Storage (CCS) and Low Energy Nuclear Reaction (LENR). The modelling indicates that delaying climate mitigation in the short term, to give time for these technologies to emerge, leads to more risk and costs in the long term if the 2 deg goal is to be met. 
 

 Key Quotes:

“some 2 °C pathways could, if not designed properly, undermine SD in non-climate dimensions. For example, pathways with a limited short-term ambition like the current INDCs may have higher SD risks than more ambitious ones…Such broader SD implications could delegitimize some 2 °C pathways or even the 2 °C target itself”

“Since the transport sector is characterized by faster capital turnover rates (at least with regard to the vehicle fleet) .. it can react more quickly to carbon price changes, compensating for higher emissions from sectors that are less flexible.”

“a 20%–30% increase in energy prices may have a much more immediate, adverse effect on the poor in many countries than a 4-7-fold increase in maximum decadal upscaling of variable renewable energy sources, which is primarily a technological and institutional challenge for infrastructure provision.”

“delaying stringent mitigation in the near term leads to a significant increase in mitigation risk levels in the medium term compared to optimal 2 °C pathways. With more GHG emissions before 2030, subsequent reductions are more expensive”

 “assuming lower energy demand growth entails mitigation risk reductions relative to optimal 2 °C pathways ..As each unit of energy not produced is free of pervasive supply-side risks, reducing energy demand by promoting energy efficiency in end-use sectors,… lifestyle changes .. and structural changes in the economy …is an important strategy both for mitigation and other sustainable energy objectives"

 “the absence of CCS seriously questions the achievability of the 2 °C target in a world with delayed climate action and therefore threatens the climate SDG itself” “SD considerations are central for determining socially acceptable climate policies and that the prospects of meeting other SDGs need not dwindle and can even be enhanced for some goals if appropriate climate policy choices are made.”

“limiting the availability of key mitigation technologies yields some co-benefits and decreases risks specific to these technologies but greatly increases many others”

Tuesday, May 17, 2016

How is Air Pollution Linked to Diabetes and Insulin Sensitivity?

English: idealized curves of human blood gluco...
English: idealized curves of human blood glucose and insulin concentrations during the course of a day containing three meals; in addition, effect of sugar-rich meal is highlighted; (Photo credit: Wikipedia)
Ambient Air Pollutants Have Adverse Effects on Insulin and Glucose Homeostasis in Mexican Americans (Abstract, Zhanghua Chen, Muhammad T. Salam, Claudia Toledo-Corral, Richard M. Watanabe, Anny H. Xiang, Thomas A. Buchanan, Rima Habre, Theresa M. Bastain, Fred Lurmann, John P. Wilson, Enrique Trigo and Frank D. Gilliland, Diabetes Care, Mar.29, 2016)

Today we review research conducted in Mexico that examined the links between air pollution and insulin sensitivity. Results indicated that short term (under 2 months) exposure to fine particulates (PM2.5) was linked to lower insulin sensitivity and higher cholesterol and this effect was highest with obese patients.  


 Key Quotes:

“Ambient air pollutant concentrations (NO2, O3, and PM2.5) for short- and long-term periods were assigned by spatial interpolation (maximum interpolation radius of 50 km) of data from air quality monitors. Traffic-related air pollution from freeways (TRAP) was estimated using the dispersion model as NOx”  

“Short-term (up to 58 days cumulative lagged averages) exposure to PM2.5 was associated with lower insulin sensitivity and HDL-to-LDL cholesterol ratio and higher fasting glucose and insulin, HOMA-IR, total cholesterol, and LDL cholesterol (LDL-C)”

“The effects of short-term PM2.5 exposure on insulin sensitivity were largest among obese participants.” “Exposure to ambient air pollutants adversely affects glucose tolerance, insulin sensitivity, and blood lipid concentrations.”

Thursday, May 12, 2016

The Anthropocene and the Future

The Anthropocene: a conspicuous stratigraphical signal of anthropogenic changes in production and consumption across the biosphere (20 page pdf, MarkWilliams, Jan Zalasiewicz, Colin N.Waters, Matt Edgeworth, Carys Bennett, Anthony D.Barnosky, Erle C. Ellis, Michael A. Ellis, Alejandro Cearreta, Peter K. Haff, Juliana A. Ivar do Sul, Reinhold Leinfelder, John R. McNeill, Eric Odada, Naomi Oreskes, Andrew Revkin, Daniel deB Richter,Will Steffen, Colin Summerhayes, James P. Syvitski, Davor Vidas, Michael Wagreich, Scott L.Wing, Alexander P.Wolfe, and An Zhisheng, AGU Publications - Earth’s Future, Mar. 14, 2016)

Also discussed here: Human impact forms 'striking new pattern' in Earth's global energy flow (ScienceDaily, Mar. 23, 2016)

Today we review a geophysical history of the earth from the days when carbon and biological life were not present, through the evolution of the biosphere over 4 Billion years and photosynthesis to the advent of animal and plant life some 460 million years ago, modern humans 195, 000 years ago to the farming of land 10,000 years ago and the build-up of carbon dioxide in the atmosphere and the beginning of a new geological epoch, the Anthropocene. This history not only puts the significance of global climate change into context but it also shows the ways that man has literally changed the world.

 anthrocene future  

Key Quotes:

  “The impact humans have made on Earth in terms of how we produce and consume resources has formed a 'striking new pattern' in the planet's global energy flow”

"Scale and process in the Earth’s biological-consumption system can be measured in a number of ways: a common one is Net Primary Production (NPP)—a measure of the net flux of carbon from the atmosphere into plants for a given time.”

 “Currently, humans appropriate between 25 and 38% of NPP [dependent on different estimates… they liberate considerable additional energy from fossil NPP [hydrocarbons such as coal, oil and gas;..and, increasingly, produce energy from sources such as hydropower, solar radiation, wind, waves, geothermal sources, and nuclear reactors.”

 “the team identified that human patterns of production and consumption are a key factor characterizing the epoch, and when measured against the billion-year old patterns of planet Earth, they form a striking new pattern.”

"Very big changes in our planet's pattern of biological production and consumption do not happen very often. The appearance of photosynthesis was one, about two and a half billion years ago. Then, a little over half a billion years ago, animals like trilobites appeared, to add scavengers and predators into a food web of increasing complexity.”

"It is without precedent to have a single species appropriating something like one quarter of the net primary biological production of the planet and to become effectively the top predator both on land and at sea."

“a biosphere state that is characterized by a geologically unprecedented pattern of global energy flow that is now pervasively influenced and mediated by humans, and which is necessary for maintaining the complexity of modern human societies.”

Tuesday, May 10, 2016

What is the Local Environmental Impact of Fracking?

Investigating the traffic-related environmental impacts of hydraulic-fracturing (fracking) operations (13 page pdf, Paul S. Goodman, Fabio Galatioto, Neil Thorpe, Anil K. Namdeo, Richard J. Davies, Roger N. Bird, Environment International, Feb. 1, 2016)

Today we review an aspect of fracking, not often investigated: the impact of local fracking wells which is a combination of the air pollution emissions from the fracking itself and the removal of waste water by tanker trucks which adds vehicle emissions and noise. There is a requirement for 9,000 to 29,000 cubic metres per well, or 54,000 to 174,000 cubic metres for a six-well pad. Total CO2 emissions associated with extraction of shale gas from a well were small (0.2–2.9%) compared to the combustion of the gas from the well. Modelling of NOx emissions showed increases reaching 30% over non-fracking periods and noise levels doubling.

  fracking traffic  

Key Quotes:

 “relatively high population densities in many countries and the potential negative environmental impacts that may be associated with fracking operations has stimulated …significant public debate regarding if and where fracking should be permitted. Road traffic generated by fracking operations is one possible source of environmental impact whose significance has, until now, been largely neglected in the available literature.”

“the local impacts of a single well pad may be short duration but large magnitude… whilst single digit percentile increases in emissions of CO2, NOx and PM are estimated for the period from start of construction to pad completion.. excess emissions of NOx on individual days of peak activity can reach 30% over baseline”

 “A production well pad could include 12 or more wells, which may be re-fracked several times, once production has declined. It subsequently becomes necessary to remove flowback water from those sites both during and after fracturing. If this transportation is done by road, as has typically been the case in the US and Canada, then considerable volumes of HDV (i.e. tanker) traffic may be generated, albeit for relatively short periods (i.e. weeks) of time. “

"The production of CO2 from traffic emissions due to shale gas exploitation has been previously examined …with on-road emissions estimated at 38 t–59 t CO2 per well… total CO2 emissions associated with extraction of shale gas from a well were small (0.2–2.9%) compared to total emissions from combustion of the gas produced by the well”

“each stage of a fracking operation for a single well will require between 1100 and 2200 m3 of water, leading to a total demand of 9000 to 29000 m3 per well, or 54,000 to 174,000 m3 for a six-well pad.”

“Total daily NOx emissions increase by 18%–20% (low scenario), and 27%–30% (high scenario) depending on access policy…the best policy for diurnal total emissions is overnight access, which creates negligible conflict with baseline traffic, though the relative emissions in the overnight period increase by a factor of 2–2.6.”

"Modelling of NOx emissions showed increases reaching 30% over non-fracking periods and noise levels doubling (+3.4 dBA), dependent on access policy implemented to the site, potentially exacerbating existing environmental issues.”

Thursday, May 5, 2016

Literature Review on the Impacts of Climate Change on Infectious Diseases

Impact of climate change on human infectious diseases: Empirical evidence and human adaptation (10 page pdf, Xiaoxu Wu, Yongmei Lu, Sen Zhou, Lifan Chen, Bing Xu, Environment International, Jan. 2016)

Today we review an analysis of literature concerning the links between weather and climate and the spread of infectious diseases which need three ingredients: a pathogen or source, a vector or host and a transmission environment. Climate change can change the geographical and seasonal distribution of diseases while weather (especially extreme weather events) affects the timing and intensity of disease outbreaks. Shifts in precipitation patterns can have impacts on water-borne pathogens while stronger wind patterns can extend the spatial distribution of mosquitoes and the spread of diseases such as malaria.

 infectious diseases and ck ch  

Key Quotes:

 “Three components are essential for most infectious diseases: an agent (or pathogen), a host (or vector) and transmission environment” “long-term climate warming tends to favor the geographic expansion of several infectious diseases … and that extreme weather events may help create the opportunities for more clustered disease outbreaks or outbreaks at non-traditional places and time “

“Overall, climate conditions constrain the geographic and seasonal distributions of infectious diseases, and weather affects the timing and intensity of disease outbreaks” “Pathogen refers to a wide range of disease agents, including virus, bacterium, parasite germ, and fungi. The impact of climate change on pathogens can be direct, through influencing the survival, reproduction, and life cycle of pathogens, or indirect, through influencing the habitat, environment, or competitors of pathogens.”

 “Climate change may cause shifts in precipitation, which affects the dissemination of water-borne pathogens. Rainfall plays an important role in the development of water-borne disease pathogens. Rainy season is related to the increase of fecal pathogens as heavy rain may stir up sediments in water, leading to the accumulation of fecal microorganisms”

 “some vector-borne human infectious diseases, including malaria, African trypanosomiasis, Lyme disease, tick-borne encephalitis, yellow fever, plague, and dengue have distributed to a wider range”

 “Wind may affect the malaria cycle both negatively and positively. Strong wind can reduce the biting opportunities for mosquitoes, but can extend their flight distance. During a monsoon season, wind is able to change the spatial distribution of mosquitoes”

“The following adaptation measures are recommended:
  1. to go beyond empirical observations of the association between climate change and infectious diseases and develop more scientific explanations,
  2. to improve the prediction of spatial–temporal process of climate change and the associated shifts in infectious diseases at various spatial and temporal scales, and
  3. to establish locally effective early warning systems for the health effects of predicated climate change.”

Tuesday, May 3, 2016

Can Extreme Weather Events be Attributed to Climate Change?

Attribution of Extreme Weather Events in the Context of Climate Change (163 page pdf, Committee on Extreme Weather Events and Climate Change Attribution; Board on Atmospheric Sciences and Climate; Division on Earth and Life Studies; National Academies of Sciences, Engineering, and Medicine, Mar. 17, 2016)

 Also discussed here: Global Warming Is Happening FAST, but Is It Causing Extreme Weather Events?(Astrid Caldas, Union of Concerned Scientists, Mar. 11, 2016)

Today we review a major effort to answer the question: how does climate change affect extreme weather events? This was investigated using two well known approaches: the long term statistics of meteorological parameters and through simulations using physical climate models. Although much more research is needed, several conclusions were made including a main one that some types of extreme weather events (such as extreme cold and heat events) are more easily understood and attributable to climate change than others (such as wildfires and severe convective storms and tornadoes) . This, in turn, is linked to the ability of models to simulate and physically represent large scale temperature events covering continents more effectively than those on an urban or smaller scale that involve fine scale precipitation patterns. Another major finding was that it is impossible to absolutely link climate change alone to a single extreme event because of the role that natural variability almost always plays. Attribution-capability-by-type-event  

Key Quotes:

“each extreme event is a consequence of multiple factors under a set of conditions—much like a cookie is the product of various ingredients and conditions. You tweak one ingredient or condition and the result will be slightly different, while still remaining a cookie—or in our case, an extreme event.”

 “Events related to an aspect of temperature (such as warming) are easier to attribute than events that have a variety of other influences….there is high confidence on the capability of attribution and high understanding of the effects of climate change on heat waves and cold waves, but not hurricanes or droughts, which involve a lot more complex interactions both physical and human-induced.”

“If one is able find out whether an event had climate change as a major component, then one can estimate if similar events will be more likely in the future, and plan for risk reduction and adaptation strategies”

“Confidence in attribution findings of anthropogenic influence is greatest for those extreme events that are related to an aspect of temperature, such as the observed long-term warming of the regional or global climate, where there is little doubt that human activities have caused an observed change.”

“Confidence in attribution analyses of specific extreme events is highest for extreme heat and cold events, followed by hydrological drought and heavy precipitation. There is little or no confidence in the attribution of severe convective storms and extratropical cyclones.”

“A definitive answer to the commonly asked question of whether climate change “caused” a particular event to occur cannot usually be provided in a deterministic sense because natural variability almost always plays a role.”

Thursday, April 28, 2016

What are the Overall Benefits of Road Pricing beyond Revenue Generation and Congestion Management?

Next Generations of Road Pricing: Social Welfare Enhancing (15 page pdf, Omid M. Rouhani, Sustainability, Mar.11, 2016)

Today we review a paper that looks beyond the two factors often used to justify road pricing: raising cash and reducing traffic congestion. Some of those factors are public acceptability, equity and the fact that only 26% of the important factors are generic- much depends on local factors that differ from one location to another – which perhaps explains why congestion pricing (and carbon taxes for that matter) are overwhelmingly accepted in places such as Stockholm and British Columbia but vigorously rejected by the public in many US and Canadian cities.

Some of the implementation decisions involve the spillover of traffic from a tolled road to its neighbours (which supports the notion of tolling existing roads and not just new ones) and then need for alternatives to road use (i.e. walking, cycling, public transit) for those who need to travel and the need for flexibility in terms of the rate to be charged and finally the need to make clear at the onset the overall benefits or welfare to the travelling public.

 road pricing welfare  

Key Quotes:

“the actual adoption of RPs has been very limited … Several barriers constrain their implementation. The most important is politics. A strong and devoted political champion is required for such new policies. Politicians are often not willing to risk their election prospects for a system where success is not guaranteed.”

“Two major goals drive the road pricing decision: revenue generation and congestion management.…other objectives are pursued as well, including transportation-related emissions reduction .. public transportation use or mode shift encouragement .. land use management .. and social welfare maximization”

 “time-based pricing provides the greatest social benefits, followed by distance-based, congestion (zonal) pricing, and cordon pricing.”

“only 26 percent of factors affecting implementation of RPs are generic, and that dominant factors are those factors, such as public acceptability.. and equity .. that result from particular features of the case study. This is the major reason why various models are required for predicting the outcomes of a scheme both before and after its implementation”

 “To support a more sustainable and welfare-enhancing transportation system, RP schemes should be implemented where high quality travel alternatives such as public transportation, biking lanes, walking facilities, ridesharing and other services are available”

“Tolls on few roads, especially with unlimited (high) profit-maximizing rates, could increase total travel costs for a transportation system as a whole because of spillover effects to un-tolled sections .. suggests creating and applying congestion pricing on existing roads, not only on (limited) new facilities.”

“The important factors:
  • take profits from road pricing into account, contrary to economists’ approach
  • examine the impacts of pricing on transport systems as a whole not only the priced facility or the charge zone
  • consider the demand risk (uncertain future demand) in the analysis, using a scenario analysis
  • include the disutility resulting from travel discomfort of road pricing
  • improve public transport systems to provide/encourage an environmentally-friendly alternative to driving
  • provide the vision to users and residents why road pricing increases welfare
  • explore equity implications
  • offer a flexible, but capped, tolling/pricing system that allows tolls to vary temporally
  • include impacts on sectors outside transportation"