We are here to face the environmental challenges. Waste Management is driven towards Zero Waste policies. End-of Waste criteria must be influencing all the aspects of Waste MGT projects. According to Article 11 of the Waste Framework Directive (2008/98/EC), Member States must take measures to promote the re-use of products and preparing for re-use activities as well as to promote high quality recycling and set up separate collections of waste to meet the necessary quality standards for the relevant recycling sectors. By 2015, separate collection must be realized for at least paper, metal, plastic and glass. By 2020, the preparing for re-use and the recycling of waste materials such as at least paper, metal, plastic and glass from households and possibly from other origins as far as these waste streams are similar to waste from households, must be increased to a minimum of overall 50% by weight.
Municipal Solid Waste (MSW) management in EU and particularly Greece still remains a big challenge. Waste disposal to landfills is still the predominant method for managing MSW, as 81.1% of the total MSW generated in Greece in 2009 was disposed to landfills and only 18.9% was recycled. The same year in the EU-27, 37.4% of the MSW generated was disposed to landfills, 19.8 was incinerated and 40.6% was recycled. In Attica prefecture which gathers more than 4.5 million inhabitants (Greece) the problem is intense. The majority of solid waste produced in the prefecture is collected in mixed waste trash containers (green bins) and transferred to a central Mechanical Treatment Plant where they are separated in order for a fraction of recyclables to be recovered. Recycling policy in Greece focuses on the maximization of material recovery through the implementation and extension of recycling programs with source separation in large municipalities at specific curbside bins where the recyclable materials are collected separately from the mixed waste (blue bins) and their further separation in the different recyclable streams and treatment in the Material Recovery Facilities (MRF). For example the Center for management of recyclable materials (Κ.Δ.Α.Υ.) in Aspropirgos serves 847.913 inhabitants and collects recyclable materials from 12.738 blue bins. Total recovery for 2012 was around 30.689 tons. The fraction recovered is relatively small and it is often contaminated with impurities and is of low quality. Mixed waste is also disposed in "blue bins" due to the insufficiency in the number of “green bins” (lack of available space in curbsides) and due to lack of residents' awareness on recycling. The rest are disposed to the near-by landfill, which is already overloaded, as well as in many other uncontrolled landfill sites, provoking significant pollution, such as GHG emissions and contamination of underground waters. At the same time, in other European countries the landfills are designated only for the disposal of residues generated after the treatment/recycling of waste. The distance to be covered is huge.
In 2000, approximately 4.6 million tons of MSW was generated in Greece, which is an increase of 50% compared to 1990. In the period 2000-2009, the MSW generation continued to increase, with a lower rate though (16%). According to the National Waste Management Planning, MSW in 2000 consisted of:
- 47.0% organic material,
- 20.0% paper,
- 8.5% plastic,
- 4.5% glass and
- 15.5% other waste (National & Regional Solid Waste Planning, 2003).
In a more recent research carried out by the Hellenic Technical Chamber, MSW in 2007 consisted of:
- 40% organic material,
- 29% paper,
- 14% plastic,
- 3% metal,
- 3% glass,
- 11% other waste.
This shows a significant reduction in the generation of organic material and, in parallel, increase in the recyclable materials included in the MSW. The quantity of MSW recyclable materials generated in 2007, based on the aforementioned MSW synthesis, accounts to 49% by weight of the total MSW, that is 2.5 million tons. However, only 37% of the MSW recyclable materials (0.9 million tons) was recycled that year in Greece (Eurostat, 2011). As a result, the rest 63% remained unexploited and disposed to landfills untreated.
Considering the Waste Framework Directive (2008/98/EC) in Greece, during 2009, 457 kg per capita of municipal solid waste were generated (Eurostat) and from that paper, metal and plastic waste constitute 46% of the MSW (Hellenic Technical Chamber, 2007). The Joint Ministerial Decision 9268/469/2007 revised quantitative national targets for recovery and recycling of packaging waste, set in Law 2931/2001 on packaging and recycling of packaging and other products (as required by the Directive 2004/12/EC) states that until 31 December 2011 at least 60% by weight of the total amount of packaging waste must be recovered or incinerated with energy recovery. 55-80% by weight of the total amount of packaging waste must be recycled. Specific recycling targets per packaging stream are:
- 60% by weight for glass,
- 60% by weight of paper & cardboard,
- 50% by weight of metal,
- 22.5% by weight of plastic and
- 15 % by weight of wood.
The most recent data published by Eurostat (2011), showed that in 2008 Greece had recovered/recycled:
- 44% w/w of the total amount of packaging waste and has recycled
- 15% w/w of glass packaging,
- 73.7% w/w of paper packaging,
- 43.8% w/w of metallic packaging,
- 11.9% w/w of plastic packaging and
- 30.8% w/w of wood packaging.
The Landfill Directive 1999/31/EC obliges Member States to reduce the amount of biodegradable waste that is landfilled to 35% of 1995 levels by 2016 (2020 for Greece). According to the Directive, Greece must reduce the quantity of biodegradable waste going to final disposal by around 20% compared with 2000 levels by 2010 and by 50% until 2050 and is currently far from reaching these targets. The key to achieving high re-use and recycling rates and at the same time high diversion rates from landfills appears to be the provision of widespread separate collection facilities, together with the availability of adequate markets for the materials collected. It is recommended that separation of recyclable waste from other waste at source should be considered for inclusion in national strategies. In order to achieve the targets set by the national and European legislation, municipalities and their residents must actively contribute to the national efforts made, by separating materials at home.
Today renewables are seen not only as sources of energy but also as tools to address many other pressing needs, including:
- improving energy security;
- reducing health and environmental impacts associated with fossil and nuclear energy;
- mitigating greenhouse gas emissions;
- improving educational opportunities;
- creating jobs and reducing poverty.
Renewable energy provided an estimated 19% of global final energy consumption in 2012 and continued to grow in 2013. Of this total share in 2012, modern renewables accounted for approximately 10%, with the remainder (estimated at just over 9%) coming from traditional biomass. Heat energy from modern renewable sources accounted for an estimated 4.2% of total final energy use; hydropower made up about 3.8%, and an estimated 2% was provided by power from wind, solar, geothermal, and biomass, as well as by biofuels. The combined modern and traditional renewable energy share remained about level with 2011, even as the share of modern renewables increased. This is because the rapid growth in modern renewable energy is tempered by both a slow migration away from traditional biomass and a continued rise in total global energy demand.
As markets have become more global, renewable energy industries have responded by increasing their flexibility, diversifying their products and developing global supply chains. Several industries had a difficult year, with consolidation continuing, particularly for solar energy and wind power. The picture brightened by the end of 2013, with many solar photovoltaics (PV) and wind turbine manufacturers returning to profitability. The most significant growth occurred in the power sector, with global capacity exceeding 1,560 gigawatts (GW), up more than 8% over 2012. Hydropower rose by 4% to approximately 1,000 GW and other renewables collectively grew nearly 17% to more than 560 GW. For the first time, globally there was added more solar PV than wind power capacity; solar PV and hydropower were essentially tied, each accounting for about one-third of new capacity. Solar PV has continued to expand at a rapid rate, with growth in global capacity averaging almost 55% annually over the past five years. Wind power has added the highest capacity of all renewable technologies over the same period. In 2013, renewables accounted for more than 56% of net additions to global power capacity and represented far higher shares of capacity added in several countries. By the end of 2013, China, the United States, Brazil, Canada, and Germany remained top countries for total installed renewable power capacity; the top countries for non-hydro capacity were again China, the United States and Germany, followed by Spain, Italy, and India. Among the world’s top 20 countries for non-hydro capacity, Denmark had a clear lead for total capacity per capita. Uruguay, Mauritius, and Costa Rica were among the top countries for investment in new renewable power and fuels relative to annual GDP. In contrast to energy production the use of modern renewable technologies for heating and cooling is still limited relative to their vast potential. In the European Union, renewables represented the majority of new electric generating capacity for the sixth consecutive year. The 72% share in 2013 is in stark contrast to a decade earlier, when conventional fossil generation accounted for 80% of new capacity in the EU-27 plus Norway and Switzerland. Even as global investment in solar PV declined nearly 22% relative to 2012, new capacity installations increased by about 32%. China’s new renewable power capacity surpassed new fossil fuel and nuclear capacity for the first time. Variable renewables achieved high levels of penetration in several countries. For example, throughout 2013, wind power met 33.2% of electricity demand in Denmark and 20.9% in Spain; in Italy, solar PV met 7.8% of total annual electricity demand. Wind power was excluded from one of Brazil’s national auctions because it was pricing all other generation sources out of the market.
Denmark banned the use of fossil fuel-fired boilers in new buildings as of 2013 and aims for renewables to provide almost 40% of total heat supply by 2020. Growing numbers of cities, states, regions seek to transition to 100% renewable energy in either individual sectors or economy-wide. For example, Djibouti, Scotland, and the small-island state of Tuvalu aim to derive 100% of their electricity from renewable sources by 2020. Among those who have already achieved their goals are about 20 million Germans who live in so-called 100% renewable energy regions. The impacts of these developments on employment numbers in the renewable energy sector have varied by country and technology but globally the number of people working in renewable industries has continued to rise. An estimated 6.5 million people worldwide work directly or indirectly in the sector. By early 2014, at least 144 countries had renewable energy targets and 138 countries had renewable energy support policies in place.
Biomass demand continued to grow steadily in the heat, power and transport sectors. Total primary energy consumption of biomass reached approximately 57 exajoules (EJ) in 2013, of which almost 60% was traditional biomass while the remainder was modern bioenergy (solid, gaseous, and liquid fuels). Concerning modern bioenergy, the variable forms of energy carriers produced from a variety of biomass resources—including organic wastes, purpose-grown energy crops and algae—can provide a range of useful energy services such as lighting, communication, heating, cooling and mobility. The ability of solid, liquid or gaseous biomass resource to act as a store of chemical energy for future use, can be employed to balance variable electricity generation from wind and solar systems when integrated into mini-grids or an existing main grid.
Global hydropower generation during 2013 was an estimated 3,750 TWh. About 40 GW of new hydropower capacity was commissioned in 2013, increasing total global capacity by around 4% to approximately 1,000 GW. By far the most capacity was installed in China (29 GW).
GEOTHERMAL POWER AND HEAT
About 530 MW of new geothermal generating capacity came on line in 2013. Accounting for replacements, net increase was about 455 MW, bringing total global capacity to 12 GW.
Ocean energy capacity, mostly tidal power generation, was about 530 MW by the end of 2013. In preparation for anticipated commercial projects, a handful of pilot installations were deployed during the year for ongoing tests
SOLAR PHOTOVOLTAICS (PV)
Solar PV market had a record year, adding more than 39 GW in 2013, for a total exceeding 139 GW.
SOLAR THERMAL HEATING AND COOLING
Solar water and air collector capacity exceeded 283 GWth in 2012 and reached an estimated 330 GWth by the end of 2013.
CONCENTRATING SOLAR THERMAL POWER (CSP)
Global CSP capacity was up nearly 0.9 GW (36%) in 2013 to reach 3.4 GW.
More than 35 GW of wind power capacity was added in 2013, for a total above 318 GW. However, following several record years, the market was down nearly 10 GW compared to 2012, reflecting primarily a steep drop in the U.S. market. As renewable energy industries and markets mature, they increasingly face new and different challenges—as well as a wide range of opportunities. In Europe, a growing number of countries reduced, sometimes retroactively, financial support for renewables at a rate that exceeds the decline in technology costs. Such actions have been driven, in part, by the ongoing economic crisis in some member states, by related electricity over-capacity and by rising competition with fossil fuels. Policy uncertainty has increased the cost of capital—making it more difficult to finance projects—and reduced investment. During 2013, Europe continued to see a significant loss of start-up companies (especially solar PV), resulting in widespread financial losses. Share of renewables in gross final energy consumption in the European Union, reached an estimated 14.1% in 2012, up from 8.3% in 2004.
All products and services have environmental impacts, from the extraction of raw materials for their production to their manufacturing, distribution, use and disposal. These include energy and resource use, soil, air and water pollution and the greenhouse gases emission. Life-cycle thinking involves looking at all stages of a product’s life to find out where improvements can be made to reduce environmental impacts and use of resources. A key goal is to avoid actions that shift negative impacts from one stage to another.
Life-cycle analysis has shown for example that it is often better for the environment to replace an old washing machine,despite the waste generated, than to continue to use an older machine which is less energy efficient. This is because a washing machine’s greatest environmental impact is during its use phase. Buying an energy-efficient machine and using low temperature detergent reduce environmental impacts that contribute to climate change, acidification ozone layer deterioration.
The new Waste Framework Directive has introduced the concept of life-cycle thinking into waste policies. This approach gives a broader view of all environmental aspects and ensures any action has an overall benefit compared to other options. It also means actions to deal with waste should be compatible with other environmental initiatives.
The airtight conditions of landfill sites mean that materials, in particular biodegradable waste cannot decompose fully and in the absence of oxygen, give-off methane, a dangerous greenhouse gas. Methane produced by an average municipal landfill site, if it was converted to energy, could provide electricity to approximately 20,000 households for a year. An average municipal landfill site can produce up to 150 m³ of leachate a day, which equates to the amount of fresh water that an average household consumes in a year.
It is estimated that materials sent to landfill could have an annual commercial value of around €5.25 billion. Bio-waste (garden, kitchen and food waste) accounts for about one third of the waste we throw away at home – that is around 88 million tones across Europe each year. On average, 40% of bio-waste in the EU goes into landfills. However, bio-waste holds considerable promise as a renewable source of energy and recycled compost. Energy recovered in the form of bio-gas or thermal energy can help in the fight against climate change. According to estimates, about one-third of the EU’s 2020 target for renewable energy in transport could be met by using bio-gas produced from bio-waste, while around 2% of the EU’s overall renewable energy target could be met if all bio-waste was turned into energy. Compost made from bio-waste can also improve the quality of our soils, replacing non-renewable fertilizers. In 1995, more than 13 million tones of municipal waste was composted by Member States. By 2008, this had reached an estimated 43.5 million tones, accounting for 17% of municipal waste. It will be a crucial task in the future to move all Member States up the waste hierarchy to achieve the EU’s goal of becoming a recycling society. This is a unique economic opportunity. Solid-waste management and recycling industries currently have a turnover of around €137 billion which is just over 1.1% of the EU’s Gross Domestic Product. Together, these areas create over 2 million jobs. Overall, municipal waste recycling increased from 19% to 38% between 1998 and 2007. If Member States recycled 70% of their waste, it could create at least half a million new jobs across EU.
Zero Waste is a goal that is ethical, economical, efficient and visionary, to guide people in changing their lifestyles and practices to emulate sustainable natural cycles, where all discarded materials are designed to become resources for others to use. Zero Waste means designing and managing products and processes to systematically avoid and eliminate the volume and toxicity of waste and materials, conserve and recover all resources, and not burn or bury them. Implementing Zero Waste will eliminate all discharges to land, water or air that are a threat to planetary, human, animal or plant health.
Successful strategies and projects
The National Industrial Symbiosis Program has created a market which puts together those producing waste with those who can use it and are willing to pay the most for it. By turning pastry waste into electricity, converting fatty acids into biodiesel and so on, the whole program has boosted UK’s economy by as much as €3 billion. Dry food sold in bulk through dispensers at Italian supermarkets reduces packaging and allows customers to buy the amount they want. This is not only good for the environment but saves shoppers money – between 10 and 70% compared to the price of packaged goods. The 30 Eco-points in Italy and Switzerland prevent the use of an estimated 1 million packages per year. The focus is on spending public money on green products and services (green public procurement), helping small firms become more eco-efficient, the promotion of re-use and repair of goods, and awareness-raising for cultural services. As a result, citizens can buy and sell used appliances through an online flea market, preventing around 1,000 tones of waste annually. Around 400 tones of appliances are repaired annually at local repair and service centres, while eco-efficiency advice has helped save businesses around €34 million since 1998 and prevented over 100,000 tones of waste. The pioneering Menu Dose Certa or Right-Sized Menu project aims to support restaurants in creating menus that generate less food waste. Porto’s waste management organisation LIPOR aims to reduce food waste by 48.5 kilos per year per restaurant client by 2011, by promoting a balanced diet raising awareness of food waste. That means changing attitudes and behavior to eating and encouraging restaurants to cut portion sizes and serve better-balanced meals. Kringloop Re-use Centres extend the useful life of discarded clothes, appliances, kitchenware, furniture, books, records and bicycles. Almost 50,000 tons of discarded items were collected in 2008, a 10% increase on 2007. Launched in 1992, the long-term aim is to achieve an annual re-use volume of 5 kg per inhabitant. The U.S. Zero Waste Business Council (USZWBC) announced March 4, 2013, that it is launching the first Zero Waste business certification program in the country. The announcement coincides with the organization’s issuance of the first Zero Waste certifications to three Whole Foods Market stores in San Diego County. The goal of businesses participating in the Zero Waste Certification program is to divert all end-use material from the landfill, incineration and the environment, while achieving a minimum of 90 percent diversion based on the standards set by the Zero Waste International Alliance (ZWIA). The USZWBC audited the waste diversion processes at Whole Foods Market’s stores in La Jolla, Hillcrest and Encinitas and found that all three stores are successfully reducing, reusing, recycling, and composting. Each of the Whole Foods Market stores received a bronze level Zero Waste certificate for better than 90% diversion.
National Industrial Symbiosis Programme (UK)
Eco-point initiative (Italy)
Vienna waste prevention program (Austria)
Menu Dose Certa (Portugal)
Kringloop Re-use Centres (Belgium)
Whole Foods Market’s stores in La Jolla, Hillcrest and Encinitas (Corona del mar)
The National Industrial Symbiosis Program has created a market which puts together those producing waste with those who can use it and are willing to pay the most for it. By turning pastry waste into electricity, converting fatty acids into biodiesel and so on, the whole program has boosted UK’s economy by as much as €3 billion.
Dry food sold in bulk through dispensers at Italian supermarkets reduces packaging and allows customers to buy the amount they want. This is not only good for the environment but saves shoppers money – between 10 and 70% compared to the price of packaged goods. The 30 Eco-points in Italy and Switzerland prevent the use of an estimated 1 million packages per year.
The focus is on spending public money on green products and services (green public procurement), helping small firms become more eco-efficient, the promotion of re-use and repair of goods, and awareness-raising for cultural services. As a result, citizens can buy and sell used appliances through an online flea market, preventing around 1,000 tones of waste annually. Around 400 tones of appliances are repaired annually at local repair and service centres, while eco-efficiency advice has helped save businesses around €34 million since 1998 and prevented over 100,000 tones of waste.
The pioneering Menu Dose Certa or Right-Sized Menu project aims to support restaurants in creating menus that generate less food waste. Porto’s waste management organisation LIPOR aims to reduce food waste by 48.5 kilos per year per restaurant client by 2011, by promoting a balanced diet raising awareness of food waste. That means changing attitudes and behavior to eating and encouraging restaurants to cut portion sizes and serve better-balanced meals.
Kringloop Re-use Centres extend the useful life of discarded clothes, appliances, kitchenware, furniture, books, records and bicycles. Almost 50,000 tons of discarded items were collected in 2008, a 10% increase on 2007. Launched in 1992, the long-term aim is to achieve an annual re-use volume of 5 kg per inhabitant.
The U.S. Zero Waste Business Council (USZWBC) announced March 4, 2013, that it is launching the first Zero Waste business certification program in the country. The announcement coincides with the organization’s issuance of the first Zero Waste certifications to three Whole Foods Market stores in San Diego County. The goal of businesses participating in the Zero Waste Certification program is to divert all end-use material from the landfill, incineration and the environment, while achieving a minimum of 90 percent diversion based on the standards set by the Zero Waste International Alliance (ZWIA). The USZWBC audited the waste diversion processes at Whole Foods Market’s stores in La Jolla, Hillcrest and Encinitas and found that all three stores are successfully reducing, reusing, recycling, and composting. Each of the Whole Foods Market stores received a bronze level Zero Waste certificate for better than 90% diversion.
Since the beginning of the Industrial Revolution (taken as the year 1750), the burning of fossil fuels and extensive clearing of native forests has contributed to a 40% increase in the atmospheric concentration of carbon dioxide, from 280 ppm in 1750 to 392.6 ppm in 2012. It has now reached 400 ppm in the northern hemisphere. This increase has occurred despite the uptake of a large portion of the emissions by various natural "sinks" involved in the carbon cycle.
The 2007 Fourth Assessment Report https://www.ipcc.ch/report/ar4 compiled by the IPCC (AR4) noted that "changes in atmospheric concentrations of greenhouse gases and aerosols, land cover and solar radiation alter the energy balance of the climate system", and concluded that "increases in anthropogenic greenhouse gas concentrations is very likely to have caused most of the increases in global average temperatures since the mid-20th century.”
Eleven of the twelve years in the period (1995–2006) rank among the top 12 warmest years in the instrumental record (since 1880). Warming in the last 100 years has caused about a 0.74 °C increase in global average temperature. This is up from the 0.6 °C increase in the 100 years prior to the Third Assessment Report.
Mountain glaciers and snow cover have declined on average in both hemispheres. Losses from the land-based ice sheets of Greenland and Antarctica have very likely (>90%) contributed to sea level rise between 1993 and 2003. Ocean warming causes seawater to expand and contributes to sea level rising. It is likely that anthropogenic (i.e., human-induced) warming, such as that due to elevated greenhouse gas levels, has had a discernible influence on many physical and biological systems. Future warming is projected to have a range of impacts, including sea level rise, increased frequencies and severities of some extreme weather events, loss of biodiversity, and regional changes in agricultural productivity.
Predictions from the Fifth Assessment Report https://www.ipcc.ch/index.htm are:
- Further warming will continue if emissions of greenhouse gases continue.
- The global surface temperature increase by the end of the 21st century is likely to exceed 1.5 °C relative to the 1850 to 1900 period for most scenarios, and is likely to exceed 2.0 °C for many scenarios
- The global water cycle will change, with increases in disparity between wet and dry regions, as well as wet and dry seasons, with some regional exceptions.
- The oceans will continue to warm, with heat extending to the deep ocean, affecting circulation patterns.
- Decreases are very likely in Arctic sea ice cover, Northern Hemisphere spring snow cover, and global glacier volume
- Global mean sea level will continue to rise at a rate very likely to exceed the rate of the past four decades
- Changes in climate will cause an increase in the rate of CO2 production. Increased uptake by the oceans will increase the acidification of the oceans.
- Future surface temperatures will be largely determined by cumulative CO2, which means climate change will continue even if CO2 emissions are stopped.
In 2012, direct industrial greenhouse gas emissions accounted for approximately 20% of total U.S. greenhouse gas emissions, making it the third largest contributor to U.S. greenhouse gas emissions, after the Electricity and Transportation sectors. If both direct and indirect emissions associated with electricity use are included, industry's share of total U.S. greenhouse gas emissions in 2012 was 28%, making it the second largest contributor of greenhouse gases of any sector, just after transportation. Greenhouse gas emissions from industry have declined by almost 17% since 1990, while emissions from most other sectors have increased.
There are several strategies of lowering the industry’s impact on GHG emissions.
- Upgrading to more efficient industrial technology. Identifying the ways that manufacturers can use less energy to light and heat factories or to run equipment.
- Switching to fuels that result in less CO2 emissions but the same amount of energy, when combusted. Upgrading to more efficient industrial technology. Recycling. Producing industrial products from materials that are recycled or renewable, rather than producing new products from raw materials. Using scrap steel and scrap aluminum as opposed to smelting new aluminum or forging new steel.
- Training and Awareness Making companies and workers aware of the steps to reduce or prevent emissions leaks from equipment.
- Instituting handling policies and procedures for perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF6) that reduce occurrences accidental releases and leaks from containers and equipment.
Carbon dioxide (CO2) makes up the vast majority of greenhouse gas emissions from the sector of electricity, but smaller amounts of methane (CH4) and nitrous oxide (N2O) are also emitted. In 2012, the electricity sector was the largest source of U.S. greenhouse gas emissions, accounting for about 32% of the U.S. total. Greenhouse gas emissions from electricity have increased by about 11% since 1990 as electricity demand has grown and fossil fuels have remained the dominant source for generation. Coal combustion is generally more carbon intensive than burning natural gas or petroleum for electricity. Although coal accounts for about 75% of CO2 emissions from the sector, it represents about 39% of the electricity generated in the US.
The majority of greenhouse gas emissions from transportation are CO2 emissions. Greenhouse gas emissions from transportation have increased by about 18% since 1990. This historical increase is largely due to increased demand for travel and the limited gains in fuel efficiency across the U.S. vehicle fleet. The number of vehicle miles traveled by passenger cars and light-duty trucks increased 35% from 1990 to 2012. The increase in travel miles is attributed to several factors, including population growth, economic growth, urban sprawl, and low fuel prices during the beginning of this period.
There are several strategies of lowering transportations’ impact on GHG emissions.