## 4 Open Issues for Consideration
### Ethical, Social, and Environmental Issues
#### 4.4.4 Resource/Energy Consumption and Environmental Effects  
Blockchain is the key building block of Web3. Hence, energy consumption and its eventual environmental effects are massive issues for any responsible government. Even though Blockchain provides a lot of great benefits such as machine trust, traceability, and security, putting up with the amount of wasted energy (especially in the case of the Proof-of-Work protocol) makes it quite challenging to proliferate such technologies [89]. The two very popular protocols of Blockchain (Proof-of-Work and Proof-of-Stake) differences have already been discussed in this paper; however, considering that Bitcoin still remains the largest--and the most valuable crypto-asset in the market [90] which uses PoW protocol--that affects any type of Web3 application, either directly, or indirectly.  
Based on a very recent systematic review, the environmental impacts of using cryptocurrencies, and more specifically, the PoW protocol, are as follows [91]:  
* **Resource Consumption**: the mining aspect of such technology is using large amounts of resources in the form of hardware (Electronics, CPUs, GPUs, FPGAs, etc.) to increase computation power and stay competitive. This drains the market from those valuable assets that could have been used more productively elsewhere [92].
* **Electronic Waste**: using a huge amount of electronics means producing a huge amount of waste over time. Electronic waste contains a lot of harmful chemicals and toxic heavy metals. It is a severe threat to the environment that can result in soil, air, and water irreversible pollution [93].
* **Energy Consumption/Waste**: most of the energy consumed by mining activities is wasted just to complete a certain hash and receive a reward [94].
* **Carbon Footprint**: The high energy consumption of blockchain and its related mining activities are tightly correlated with high emissions from non-renewable energy sources [95], which will significantly account for global warming effects on the planet. The emissions related to Bitcoin alone are posing a threat to meeting the goals of the Paris Agreement [95].
* **Environmental-related social aspects**: these aspects can affect and be affected by the security of energy, the global supply chain, human health, and access to products and services [91]. For instance, needing a significant amount of semiconductor manufacturing capacities and producing mining equipment has put a toll on the already weak semiconductor supply chain. It is worsening the global electronic chip shortage. It also can delay or limit access to clean mobility with reasonable pricing for customers who seek to purchase Electronic Vehicles [92].
* **Environmental-related economic aspects**: these aspects can describe how related economic factors such as trading and the price of cryptocurrencies can affect the environment. The cryptocurrencies' rise in price will make mining activities more profitable, thus attracting more people into mining activities [96]. In turn, this will result in more resource and energy consumption, more electronic waste and finally, more carbon footprint [92].