Showing posts with label climate. Show all posts
Showing posts with label climate. Show all posts

Thursday, February 23, 2017

Estimating Greenhouse Gas Emissions for 100 Cities in the USA

Per capita anthropogenic greenhouse gas emissi...
Per capita anthropogenic greenhouse gas emissions by country for the year 2000 including land-use change. (Photo credit: Wikipedia)
An integrated approach for estimating greenhouse gas emissions from 100 U.S. metropolitan areas (12 page pdf, Samuel A Markolf, H Scott Matthews, Inês L Azevedo and Chris Hendrickson, Environmental Research Letters, Jan. 25, 2017)

Today we review an approach to estimate the emissions for a large number of cities in the USA which has advantages over the traditional bottom-up approach as well as likely being more accurate because it includes production as well as consumption of carbon emissions and fuels. Emissions from individual cities ranged from 5 metric tons per person in Tucson to 65 meteric tons per person in New Orleans. In gross terms, the average emission for the 100 cities examined was 27 million metric tons per year.

Key Quotes:

“over 80% of the United States’ population lives in metropolitan areas and roughly 75% of the earth’s natural resources are consumed in urban areas”

“bottom-up emission estimates for five sectors within a given city:
  1. use of electricity by the community,
  2. fuel use in residential, commercial, and industrial buildings (e.g.natural gas or fuel oil),
  3. fuel use for on-road passenger and freight motor vehicle travel,
  4. energy use in the treatment and distribution of potable water and waste water, and 5) emissions from the collection and degradation of solid waste generated by the community”
“the use of publically available national datasets to form metropolitan emission estimates significantly reduces the time, funding, and human capital that would otherwise be required for a traditional ‘bottom-up’ inventory”

“We find that total 2014 metropolitan CO2 emissions range from 4.1 million metric tons in Lancaster, Pennsylvania to nearly 170 million metric tons in the Houston, Texas; with an overall average of 27 million metric tons.”

“Per capita emissions also show a wide variation: from 5 metric tons per person in the Tucson, Arizona to 65 metric tons per person in the Baton Rouge, Louisiana”

“cities might consider conducting inventories about every 5 years and shift a greater portion of their time and energy toward mitigation efforts in the interim.”

Tuesday, January 24, 2017

How Are Weather Extremes Linked to Climate Change?

Extreme event attribution: the climate versus weather blame game (Rebecca Lindsey, NOAA Climate, Dec. 15, 2016)

 Today we review a paper that describes the statistical process of attributing short term weather extreme events to the longer term changes underway as a result of climate change, whether that is due to natural or man-made burning of carbon fuels. It is important to understand the meaning of return periods. While the probability of a 100 year flood in a given year is 1%, the probability of the same flood over a period of 50 years is 40%. The blaming of an event on climate change depends on how good the observations of past events are, how well climate models can simulate the specific event and how well the physical processes are known and their association with climate change. Extended heat or cold events are more attributable than short term convective storms where the cross links are not as well understood.

 extreme-events  

Key Quotes:

“What is extreme event attribution?

“What can extreme event attribution tell us?

  • whether global warming made (or will make) an event more likely than it would have been without the rise in greenhouse gases from burning fossil fuels.
  • It can tell us if the average number of years between similar events is shorter or longer than it used to be.
  • It can tell us what the risk is for a given extreme weather event and if and how much global warming has increased that risk”
“Sigmas are used to describe the range of natural variability in a given climate or weather characteristic. For most types of climate data, there are many more observations close to the average (within 1 or 2 sigmas) than there are far away. So, if a climate expert describes a heavy rain event as a “5-sigma” event, she is talking about rainfall so extreme that it was 5 standard deviations away from the average high tide water level—way out at the tail end of the range of all values that have been observed.”

“So what does a hundred-year event mean?

  • The risk that a 100-year event will happen this year, or next year, or any single year is low: 1% chance that it will happen, 99% chance that it won’t. But the chance that it will happen within a given 20-year period is 18%. Within any 50-year period, 40%. Within any 100-year period, 63%. By the time 500 years have passed, there’s less than a 1% chance that such an event won’t have happened.”

“Why are some events more difficult than others to connect to global warming?

Attribution analysis depends on ‘three pillars’ of scientific knowledge:
  • The quality of the observational record,
  • The ability of models to simulate a given type of extreme event, and
  • How well we understand the physical processes that create an event and how global warming may influence those processes.
For event types where all three of these pillars are strong, our confidence in the results is higher. If any of the three pillars is weak, it becomes harder to conduct an attribution study, and our confidence in the results is lower. In general, scientists have the highest confidence for heat events because all three of the pillars are strong”

Thursday, January 12, 2017

Are Regional (not Global) Interventions Needed to Reduce Impacts and Mitigate Climate Change?

Two people on the shore of the Pacific Ocean
The Rationale for Accelerating Regionally Focused Climate Intervention Research (17 page pdf, Michael C. MacCracken, Earth's Future, Nov. 14, 2016)

Today we review a proposal to focus on particular regions where effort to reduce climate impacts would be more effective and likely have fewer unintended negative consequences than efforts aimed at the globe as a whole. Included in the potential approaches are modifying arctic warming by injecting sulfate aerosols directly into the Arctic atmosphere, moderate the intensity of tropical cyclones by brightening cloud albedoes, slowing the melting of Greenland and Antarctic ice sheets by blocking ice streams, and compensate for the reduced cooling from SO2 emissions in Asia by brightening the Pacific Ocean.

Key Quotes:

“Global-scale climate intervention is seen as a potential emergency backstop, even though the impacts from initiating melting of the polar ice sheets and biodiversity loss may well be irreversible and even undertaking testing steps in the intervention process outside the laboratory are controversial, at best”

 “model-based simulations ..… project global average temperature to increase to 3-4ºC above its preindustrial level by 2100 “

“surface-based approaches to altering energy flows as a means for moderating adverse regional impacts might well pose less difficult governance challenges and more regionally constrained evaluations of intended outcomes and unintended consequences. “ “near-term reductions in positive radiative forcing could most rapidly be achieved by reducing the atmospheric loadings of short-lived species (particularly methane, black carbon, and tropospheric ozone). “

 “The potential for moderating amplified Arctic warming:
  • high-latitude injection of sulfate aerosols into the stratosphere not only cooled the Arctic, but also, due to their roughly one-year half-life, spread to sub-Arctic latitudes and depressed the summer monsoon.
  • Potential approaches ....include brightening land, ocean, and clear and/or cloudy skies during the sunlit season .. reversing the warming influence caused by reducing air pollutant emissions flowing into the region … and, during the fall and winter seasons, cirrus thinning … bypassing the thermal barrier created by the sea ice ..and ice thickening by pumping sea water up onto existing sea ice.”
“The potential for moderating ocean warming in the tropical cyclone intensification zones:
* moderate the intensification effect of warmer ocean waters in only a few specific regions, so the amount of sea salt and/or sulfate aerosols needed to brighten clouds in only a few regions might well remain within reasonable bounds”

“The potential for slowing mass loss from the Greenland and Antarctic Ice Sheets:
*In addition to approaches involving physically blocking the exits of ice streams that may well be unworkable, approaches to consider might include cloud brightening, injection of reflective bubbles, and vertical mixing to lower the temperature of the waters that are observed to be inducing melting at the faces of ice streams. “

“The potential for a regional replacement for the loss of global sulfate cooling:
  • the centroid of the 0.5-1.0ºC cooling influence resulting from SO2 emissions has moved from the North Atlantic basin to southern and eastern Asia, a region where the per-ton-of-emission influence of SO2 emissions is likely larger due to the higher amounts of incoming solar radiation
  • inducing modest clear and cloudy sky brightening in the troposphere over the vast Pacific Ocean that would cause changes in the global energy balance comparable to those induced by the present highly concentrated, health-damaging sulfate loading presently centered over China, India, and downwind would seem to be possible as an alternative global-scale climate intervention”

Thursday, December 29, 2016

What is Important for Coastal Areas Facing Sea-Level Rise - A Literature Review

Resilience of Infrastructure Systems to Sea-Level Rise in Coastal Areas: Impacts, Adaptation Measures, and Implementation Challenges (28 page pdf, Beatriz Azevedo de Almeida and Ali Mostafavi, Sustainability, Nov. 1, 2016)

Today we summarize a literature review of research papers examining the impacts of sea level rise on coastal areas of the world which include flooding, coastal erosion, land subsidence and saltwater intrusion. A rise of only ½ a meter in the next 50 years puts at risk 150 million people and $35 trillion of assets in 20 of the world’s most vulnerable port cities. Any success in reducing carbon emissions and the associated increase via climate change in temperature, precipitation and sea level rise would allow for 30% less impact on infrastructure systems such as power stations, oil and gas refineries and wastewater treatment plants.

 sea-level-rise-impacts  

Key Quotes:

“Expansive areas of low elevation in many densely populated coastal areas are at elevated risk of storm surges and flooding due to torrential precipitation, as a result of sea level rise.”

 “A 100-year storm surge, which is expected to begin occurring every 3–20 years, could cost billions of dollars in direct damages after 1 foot of sea-level rise” “Salt water intrusion into groundwater aquifers is one of the major impacts of sea-level rise.”

“there are 136 major port cities with more than one million inhabitants each, 13 of which are among the top 20 most populated cities in the world.”

 “Many of the world’s infrastructure facilities such as power generation facilities, refineries stations, water and wastewater treatment plants, and transportation networks are located along coastlines. As sea levels rise and coastlines erode, infrastructures are more exposed to the forces of nature and becoming structurally unstable.”

“groundwater inundation caused by sea level rise reduces the drainage capacity of storm water systems, and thus, could affect drainage and runoff infiltration…. during Hurricane Sandy in 2012, sewage backup led to the overflow of 11 billion gallons of raw sewage into the streets, rivers, and coastal waters”

 “In the U.S., a great number of coastal energy facilities are located in areas exposed to 4 feet sea-level rise. An analysis …identified 287 energy facilities at risk of flooding, spreading throughout 22 coastal states. These facilities include natural gas infrastructures, electric power plants, and oil and gas refineries.”

 “Global climate models suggest that global average sea level might rise 18–59 cm by 2100, if ice sheets continue to melt at the rate observed from 1993 to 2003. If the rate increases at the same trend as global temperatures warm, total sea level rise by 2100 might be 10–20 cm greater than the average projections.”

Tuesday, December 20, 2016

How Can The US Transportation Become Carbon Free by 2050?


Also discussed here: Report: Global Warming Solutions (Environment America Research & Policy Center, Oct. 24, 2016)

Today we review a report that recommends 50 steps aimed at state and federal program and policies that could make the USA’s transportation system carbon free by 2050. The steps include making carbon reduction strategies a key priority by exploiting the growth of electric vehicles, autonomous vehicles and the sharing of cars and bicycles, adding more effective public transit, employing smart pricing policies and phasing out carbon intensive vehicles and fuels.

 co2-emissions-by-country  
Key Quotes:

“Efficient electric vehicles that can be powered by clean, renewable electricity are entering the marketplace faster than the hybrid cars of a decade ago “

“An explosion of technology-enabled services – from carsharing to bikesharing to Lyft and Uber – has begun to revolutionize transportation in many cities. “

 “Public transportation reduces vehicle travel (and greenhouse gas emissions) by about 10 percent in U.S. cities, and cities across the country are considering bold plans to expand access to high-quality transit.”

“Cities around the world have shown that smart pricing policies can reduce congestion and encourage the use of low-carbon modes of travel.”

 “autonomous vehicles can be deployed in ways that can support efforts to reduce greenhouse gas emissions – especially if they facilitate the use of shared mobility services, vehicle electrification and smart pricing, and if public policy limits any increases in vehicle travel resulting from automation.”

 “Principles:
  • Climate concerns should inform every transportation policy decision…Only seven states have enforceable, economy-wide limits on carbon pollution, and, as of 2012, the vast majority of states and metropolitan planning organizations did not even consider greenhouse gas emissions in agency planning processes.
  • Low-carbon transportation should be at the front of the line for public funding … Between 1956 and 2014, 79 percent of all government capital expenditures on transportation went toward highways,
  • People should be rewarded for making low-carbon transportation choices….income tax exclusion for commuter parking subsidizes rush hour driving to the tune of more than $7 billion per year.
  • Carbon-intensive vehicles and fuels should be phased out…Federal policies have failed to tap the potential of lower-carbon fuels, with the federal Renewable Fuels Standard currently serving largely to encourage the use of corn ethanol
  • Public policy should encourage climate-friendly communities…some localities have begun to lift mandatory minimum parking requirements that add to the cost of new housing development and consume precious and limited urban space.
  • Public policy should foster innovation…Key state and federal policies hamper innovation by failing to account for changing circumstances such as the emergence of shared mobility services or growing demand for urban living, or by locking officials into spending or policy practices more attuned to the needs of a previous generation.”

Thursday, December 15, 2016

What Factors are Important for Coastal Cities Facing Sea-Level Rise - A Literature Review

Resilience of Infrastructure Systems to Sea-Level Rise in Coastal Areas: Impacts, Adaptation Measures, and Implementation Challenges (28 page pdf, Beatriz Azevedo de Almeida and Ali Mostafavi, Sustainability, Nov. 1, 2016)

Today we summarize a literature review of research papers examining the impacts of sea level rise on coastal areas of the world which include flooding, coastal erosion, land subsidence and saltwater intrusion. A rise of only ½ a meter in the next 50 years puts at risk 150 million people and $35 trillion of assets in 20 of the world’s most vulnerable port cities. Any success in reducing carbon emissions and the associated increase via climate change in temperature, precipitation and sea level rise would allow for 30% less impact on infrastructure systems such as power stations, oil and gas refineries and wastewater treatment plants.

 sea-level-rise-impacts  

Key Quotes:

 “Expansive areas of low elevation in many densely populated coastal areas are at elevated risk of storm surges and flooding due to torrential precipitation, as a result of sea level rise.”

“A 100-year storm surge, which is expected to begin occurring every 3–20 years, could cost billions of dollars in direct damages after 1 foot of sea-level rise”

 “Salt water intrusion into groundwater aquifers is one of the major impacts of sea-level rise.” “there are 136 major port cities with more than one million inhabitants each, 13 of which are among the top 20 most populated cities in the world.”

“Many of the world’s infrastructure facilities such as power generation facilities, refineries stations, water and wastewater treatment plants, and transportation networks are located along coastlines. As sea levels rise and coastlines erode, infrastructures are more exposed to the forces of nature and becoming structurally unstable.”

“groundwater inundation caused by sea level rise reduces the drainage capacity of storm water systems, and thus, could affect drainage and runoff infiltration…. during Hurricane Sandy in 2012, sewage backup led to the overflow of 11 billion gallons of raw sewage into the streets, rivers, and coastal waters”

“In the U.S., a great number of coastal energy facilities are located in areas exposed to 4 feet sea-level rise. An analysis …identified 287 energy facilities at risk of flooding, spreading throughout 22 coastal states. These facilities include natural gas infrastructures, electric power plants, and oil and gas refineries.”

“Global climate models suggest that global average sea level might rise 18–59 cm by 2100, if ice sheets continue to melt at the rate observed from 1993 to 2003. If the rate increases at the same trend as global temperatures warm, total sea level rise by 2100 might be 10–20 cm greater than the average projections.”

Thursday, December 8, 2016

How Can Transportation in the USA Become Carbon Free by 2050?



Also discussed here: Report: Global Warming Solutions (Environment America Research & Policy Center, Oct. 24, 2016)

Today we review a report that recommends 50 steps aimed at state and federal program and policies that could make the USA’s transportation system carbon free by 2050. The steps include making carbon reduction strategies a key priority by exploiting the growth of electric vehicles, autonomous vehicles and the sharing of cars and bicycles, adding more effective public transit, employing smart pricing policies and phasing out carbon intensive vehicles and fuels. co2-emissions-by-country  

Key Quotes:

“Efficient electric vehicles that can be powered by clean, renewable electricity are entering the marketplace faster than the hybrid cars of a decade ago “

 “An explosion of technology-enabled services – from carsharing to bikesharing to Lyft and Uber – has begun to revolutionize transportation in many cities. “

“Public transportation reduces vehicle travel (and greenhouse gas emissions) by about 10 percent in U.S. cities, and cities across the country are considering bold plans to expand access to high-quality transit.”

“Cities around the world have shown that smart pricing policies can reduce congestion and encourage the use of low-carbon modes of travel.”

 “autonomous vehicles can be deployed in ways that can support efforts to reduce greenhouse gas emissions – especially if they facilitate the use of shared mobility services, vehicle electrification and smart pricing, and if public policy limits any increases in vehicle travel resulting from automation.”

“Principles:
  • Climate concerns should inform every transportation policy decision…Only seven states have enforceable, economy-wide limits on carbon pollution, and, as of 2012, the vast majority of states and metropolitan planning organizations did not even consider greenhouse gas emissions in agency planning processes.
  • Low-carbon transportation should be at the front of the line for public funding … Between 1956 and 2014, 79 percent of all government capital expenditures on transportation went toward highways,
  • People should be rewarded for making low-carbon transportation choices….income tax exclusion for commuter parking subsidizes rush hour driving to the tune of more than $7 billion per year.
  • Carbon-intensive vehicles and fuels should be phased out…Federal policies have failed to tap the potential of lower-carbon fuels, with the federal Renewable Fuels Standard currently serving largely to encourage the use of corn ethanol
  • Public policy should encourage climate-friendly communities…some localities have begun to lift mandatory minimum parking requirements that add to the cost of new housing development and consume precious and limited urban space.
  • Public policy should foster innovation…Key state and federal policies hamper innovation by failing to account for changing circumstances such as the emergence of shared mobility services or growing demand for urban living, or by locking officials into spending or policy practices more attuned to the needs of a previous generation.”