The first priority of the modern computing system is to limit the utilization of power and it was started in 1992 by U.S. Environmental Protection Agency. They introduced a voluntary labeling program called as “Energy Star” which was designed to recognize as well as help the wellorganized energy products to minimize the gas released to the environment by the various products and the topmost products are the computers as well as its monitors. The adoption of sleep mode was introduced as a result of this problem. The concept of “Green Computing” was established to introduce the energy-efficient computers (Lakshmi et al., 2012).

The process of learning and application of calculating, building, utilizing and destroying of computers along with its servers, the peripherals, all types of storage devices, all the networking and systems, systematically and successfully with no effect on the environment is known as Green computing. The proper use of power in the form of energy to recycle the wastage and lower the use of risky as well as the materials that can pollute the environment is the main aim of using green computing. But power is the main obstruction of upgrading the system execution (Saho et al., 2010).

The recent revolution in Information and Communication Technologies (ICT), despite all its benefits for our way of life, has reinforced our dependence on energy. The increasing use of electronic media and devices throughout the world is affecting the power consumption on a daily basis. Green computing can be linked with green data centers as data centers are the vital part of the cloud computing. As internet has penetrated into our daily lives, cloud computing has emerged a new kind of “utility” that gets delivered through wired or wireless networks (Pandya, 2014).

It has been a challenge to find a new strategy to minimize the consumption of energy in cloud computing by using different approaches of virtual machines (Diouani & Medromi, 2018).

This study focuses on saving the environment by controlling the pollution level for protecting natural resources. Our work is to develop a sustainable solution to save our Mother Earth from the hazardous gases produced by the data centers or the large servers used for cloud computing.

Data centers are one of the most unpleasant way in terms of price and environment due to its power consumption cost and large amount of carbon discharge. Different companies around the world generate huge amount of energy as well as consume large amount of power for the cloud computing process and the data center storages (3Ahmed, 2015).

Table 1 has been given which shows the comparison of the rate of energy generation and power consumption of different companies for cloud data centers.

Table 1. Comparison of Significant Cloud Datacenters (Garg & Buyya, 2012)

However, concerns about the energy consumption and carbon footprints intensified recently. In 2007, only cloud infrastructure including telecom sector consumed approximately 623 terawatt-hours of energy and it has been estimated that the consumption will increase to 1963.74 terawatt-hours by 2020 (Saxena & Saxena, 2016). On the other hand, the carbon footprint of IT infrastructure was equivalent to the aviation industry such that 227.5 metric tonne in 2007, (Saxena & Saxena, 2016). Due to the large consumption of power and huge emission of carbon particles, a new technology is needed to be focused for the benefit of human being as well as the environment.

Finally, we also propose and recommend a Green Cloud framework for reducing its carbon footprint in wholesome manner without sacrificing the quality of service (performance, responsiveness and availability) offered by the multiple Cloud providers (Garg & Buyya, 2012). The Green Cloud framework is proposed to provide the environment friendly as well as to save electricity.

Cloud computing is the on-demand availability of computer system resources, especially data storage and computing power, without direct active management by the user (Cloud Computing, 2017). Cloud computing, is an arising technology with remarkable doubts about its environmental behavior. It is a service where resources such as hardware, applications, operating system, software, storage are being shared on demand and accessed using internet (Usvub et al., 2017).

Theoretically, the economical advantages of this technology have been surveyed extensively, but still the energy effectiveness has not been examined in practical use. Cloud Computing can save the energy levels by use of substantial virtual data centers and the cloud services can increase the congestion in the network but gradually enlarging the information database could decrease the effect of saving the energy level. Therefore, Cloud computing investigates the atmospheric sustainability by scanning different methods to reach its objective. According to National Institute of Standards and Technology (NIST) – “the major objective of cloud computing is to maximize the shared resources and at the same time the disadvantage is its high infrastructure cost and unnecessary power consumption” (Atrey et al., 2013).

Cloud computing model offers a claiming assistance as well as beneficial adapted IT services to the users. It permits in organizing the applications from consumer, various research in science and business areas. A large amount of heat and energy is released by cloud computing, supplying very large functioning area of carbon emitted particles to the eco-system.

Green Computing is also known as “Green IT” due to its ability to minimize the carbon particles from the environment by using efficient number of resources to operate on various activities of Information Technology. Another reason to call Green Computing as “Green IT” is due to its minimal power utilization which leads to a sustainable Cloud Computing in the future. This technology mainly focuses on promoting eco-friendly Information Technology by producing, utilizing and after that discarding the computers and its related hardware or other peripheral devices. Green data centers, where energy efficiency is maximized and CO emissions and e-waste 2 are minimized, not only for ICT equipment, but for all environmental aspects (building, lightning, cooling, etc.) are the basis for actual and future green cloud computing (Radu, 2017) .

The solutions are proposed for green cloud computing models (Agarwal, 2014).

4.1 Recycle and Reuse

Computers should not be thrown away in junkyards, instead, they should be recycled for other use or they can be reused by some non-profitable organizations if the computers are still usable (Agarwal et al., 2013).

4.2 Purchase Products which are Environmentally Green and Sound

It should be advised to the consumers to buy green or eco friendly technical products so that the power consumption and hazardous gas emission can be reduced and as a result, it can provide a better environment towards the green society.

4.3 Minimizing Consumption of Paper Paper

work is always advised to be reduced to save the trees. Therefore some alternative methods are introduced like online messaging, e-mail, social media circulations, etc.

4.4 Conservation of Energy

The energy consumption by electronic equipments should be reduced.

4.5 Green Procurement and Asset Management

Factory waste management programs should be introduced and circulated in the organizations using huge number of electronic equipments for environment friendly system.

4.6 Technology-based Solutions

It focuses on the technology that reduces employees to travel far for official tour or seminars. Instead the use of video conferencing or any other technological equipments, the solutions should be focused.

Green computing is considered to be an enhanced part of cloud computing and therefore it includes all the benefits of cloud computing technology. Along with those benefits, it also has some of its own benefits and they are,

• Green Computing has the most important benefit which allows less energy consumption.
• This technology also has the benefit to reduce the cost of labor as there will not be any concept of servers to repair, that causes the absence of hardware to upgrade and no software to install (Atrey et al., 2013).

In the current situation of data center, there are primary as well as secondary devices available in the system. The secondary devices start their work whenever the primary fails. These devices are in working state endlessly and as a result they releases harmful gases in the environment.

It is proposed that the secondary devices should be in standby mode whenever the primary devices start working. As the main devices face any kind of problem, from that moment onwards the secondary devices start its working. It minimizes the power consumption and as a result it controls the release of dangerous gas in the eco-system.

The main challenge of Green Computing Model on clouds is to build a model which is environment friendly and an eco-friendly system that plays a very important role in this area. The green cloud computing design has mainly two types of problems: one is technical and the other one is non-technical.

One of the technical challenge includes software design which can enhance the power consumption and resource utilization by designing dynamic applications which should be adequately structured. It is the main problem for the future research to build a design to be efficient enough.

Another type of challenge is the Virtual Machine allocation design to upgrade the relocation of workload between machines for topographically separated data centers. This design could produce a result of less power consumption by reducing the execution time and cost.

The last type of technical challenge is the Thermal Awareness management system that mainly focuses on the heating problem that produces the hazardous gases and therefore it is one of the major research areas in our near future to observe the temperature of all types of machines used. To control the heating effect, a schedule of workload has to be performed on the basis of temperature that reaches an optimum level.

The non-technical challenges include the aspects for standards that uses some internal policies as well as some strategies to control the Green Cloud Computing Models. One of the major non-technical aspects is the security issues and various rules and regulations in different countries around the world for the cloud. Some of the counties provide very strict rules and regulations in this area to protect environment whereas some countries are not that much concerned for pollution free environment.

Another type of non-technical challenge is the high price of green cloud computing where the cloud customers will buy the products from cloud providers and as a result the cost of the service will be increased.

The Quality of Services (QoS) and Cloud Computing Security are two of the major part of research area. The QoS focuses on customer review based on their satisfaction level and the second is the environment security in terms of protection. The customer satisfaction level will be reached based on the optimum efficiency of the products with maximum energy saving ideas. The environmental protection is also related to energy saving technology. Therefore it is suggested for the future research to design a sustainable model that consume less power and releases less heat in a low cost so that the world can work with that type of devices to save our environment.

In this era of computing, cloud computing is playing a major role with the current generation. But this technology can cause a huge extension of the data center framework that can lead to infinite amount of power consumption and as a result it releases a huge quantity of carbondioxide in the environment. The energy efficient solution of cloud computing has resulted in less number of emission of carbon particles in the air and as a result this points on achieving a green computing technology.