Introduction
Over the next ten years, society will face unprecedented challenges. The purpose of this paper is to describe the roles that an engineer can play in addressing three of the most significant challenges that face the world in the 21st century. The target audience includes aspiring and experienced engineers, as well as anyone who might be interested in working with an engineer in a collaborative effort to address global challenges. The paper will be divided into sections based on the three challenges that were chosen: developing carbon sequestration methods, preventing nuclear terror, and engineering better medicines. The rationale for the choice of each of these challenges will be provided in each section, and there will also be descriptions of the various roles that an engineer may play in an effort to adequately address them.

Challenge 1: Developing Carbon Sequestration Methods
Global climate change is one of the most significant challenges facing the world today. A majority of scientists agree that global climate change is happening and that the increase in carbon dioxide in the atmosphere is contributing significantly to the phenomenon. However, despite ongoing warnings about global warming, humans around the world have been unwilling or unable to significantly curb carbon emissions and slow the escalation of global warming. In the 2006 documentary An Inconvenient Truth, climate activist Al Gore highlighted the ten warmest years on record, each of which had occurred since 1990. Today, only two of those years are still on the list of the top ten warmest years: the rest have occurred in the years since the film’s release (NOAA, 2017). Because of the lack of success in reducing carbon emissions to reduce global warming, scientists and activists have proposed carbon sequestration as an innovative way to “offset anthropogenic emissions” (Lai, Negassa, & Lorenz, 2015, p. 79). By removing carbon dioxide directly from the atmosphere and transferring it into the earth, it may be possible to reduce the greenhouse effect that is responsible for global warming.

One of the roles that an engineer can play in the development of carbon sequestration methods is as a designer of technologies that support each step of the carbon sequestration process. There are three parts of the carbon sequestration process: capturing the carbon dioxide from the atmosphere, transporting the carbon dioxide to an appropriate location, and storing the carbon dioxide in a secure underground location, such as a depleted oil or gas fields or an underground rock formation (Carbon Capture & Storage Association, 2018). To support effective carbon capture, engineers may design and improve pre-combustion capture systems, post-combustion capture systems, or oxy-fuel combustion systems that make it easier for carbon to be captured after emission (Carbon Capture & Storage Association, 2018). To support carbon transport, engineers may design and improve carbon dioxide pipelines, or they may design new types of road tankers and ships that more efficiently transport carbon dioxide to secure locations. Finally, in the role of a designer, an engineer might design new technologies that make it easier to inject carbon dioxide into the ground, or they may develop security technologies that protect sequestration sites from security threats.

Another role that an engineer can play in the development of carbon sequestration methods is as a project manager for carbon capture and sequestration projects. To make carbon capture a reality, programs will need to be implemented around the world. Not only can each project reduce the emission of carbon dioxide into the atmosphere, but it can also serve as an example that engineers who are acting as designers can use as they design new technologies. In a role as a project manager for a carbon sequestration project, an engineer would have a broad range of duties, including determining staffing and equipment requirements, assessing budgetary requirements, and supervising staff over the course of the project (BLS, 2018). The engineer may play this role on-site at a power plant, or they may manage a project at a non-power-plant site, such as an ethanol production facility or gas processing facility (MIT, 2016).

Challenge 2: Preventing Nuclear Terror
Over the last few years, there has been a growing recognition of the global nuclear threat. As US President Donald Trump and North Korean Leader Kim Jong Un continue to exchange heated words about their nuclear capabilities, some experts worry that a miscalculation could be made on either side, leading to a nuclear attack (Mosher, 2018). There are also concerns that nuclear weapons-grade material may fall into the hands of organized domestic and/or international terrorist organization who can easily find the information they need to create a nuclear weapon (Nuclear Threat Initiative, n.d.). Given these nuclear threats, the Bulletin of Atomic Scientists recently moved its Doomsday Clock forward by 30 seconds, setting the clock at two minutes to midnight, closer than it has been since 1953 (Mosher, 2018). In response to this reality, it is imperative for engineers to develop technologies that can be used to prevent or respond to a nuclear attack.

One role that an engineer might play in the technology development process is in the design of nuclear attack prevention systems. For instance, an engineer could aid in the design of a database that keeps track of all nuclear materials in the world, which would make it easier to stop materials from reaching terrorist organizations (Hecker, 2006). An engineer could also help design sensors for incoming nuclear attacks, since the current technology has produced false alarms on multiple occasions. This will likely require more sensors with enhanced connectivity, which will inevitably lead to more digital vulnerabilities (Tucker, 2018). Therefore, in order to protect a more effective nuclear sensor system, an engineer could help design a cyber infrastructure that is impenetrable to potential hackers (Tucker, 2018).

In a role as a designer, an engineer could also contribute to this challenge by developing future nuclear response and cleanup technologies that can be used in the event of an attack. To do so, an engineer can build on the latest research from scientists studying some of the elements that could be used in nuclear cleanup efforts. For instance, in 2017, a group of chemists reported advances in their understandings of the elements plutonium, californium, and berkelium that could be applied by engineers in the development of nuclear cleanup technologies (Florida State University, 2017).

In an effort to prevent nuclear terror, an engineer could also act as a government consultant. Nuclear terror is an inherently political issue, so it is important for engineers to work closely to work with government officials at the highest levels. An engineer could offer advice about a proposed project, including their analysis of the project’s cost and technical feasibility. If the government decides to undertake a particular project aimed at preventing nuclear terror, an engineer could contract with the government as a project manager, overseeing every step of the project. In this role, an engineer would work with the government to hire competent staff, develop a budget that is within the government’s spending limits, and carry out the project in an efficient, secure manner.

Challenge 3: Engineering Better Medicines
As the global population continues to expand, more people are in need of access to adequate healthcare. Also, as climate change escalates, researchers predict that there will be an increase in the “burden of vectorborne and waterborne infectious diseases” (Shuman, 2010, p. 1061). There are also concerns that the thawing of the permafrost in the Arctic will release diseases that humans have not needed to contend with for centuries (Stierwalt, 2017). At the same time, recent advances in genetics and biological data collection methods have opened up unprecedented opportunities for exploration and development in personalized medicine. In order to combat threats and take advantage of opportunities, engineers can take the lead in addressing the challenge of developing better medicines.

One role that an engineer may play is in the design of drugs and vaccines. For instance, an engineer might develop a vaccine that has a longer shelf-life so that it can be transported to remote locations in developing countries to populations that need it. An engineer might also redesign a drug for cancer in order to improve its chemical specificity for cellular targets. With efforts like these, an engineer who takes on a role as a designer can find ways to make it easier for a drug to reach a broader population and ensure that it is effect for the patients who need it.

An engineer who is focused on supporting improvements in the field of medicine can also contribute by serving as a materials researcher for composite materials that could be used more effective medical devices and internal medication delivery systems. For instance, a materials researcher could help develop a material for a limb replacement that is less likely to be rejected by the immune system. Materials researchers could also engage in efforts to create insulin delivery systems for patients with diabetes that are free of electronic and rely instead on the properties of innovative materials (Matsumoto et al., 2017).

Conclusion
In conclusion, the world is facing serious challenges that can be addressed by engineers over the next ten years. One of the most important is global climate change, which is broadly recognized as a serious threat, but which has yet to be adequately addressed. An engineer can take on this challenge by acting as designers for carbon sequestration-related systems or by acting as project managers to oversee carbon sequestration projects. Nuclear terror also presents a growing threat, which must be addressed on both the scientific and political levels. Engineers can design systems and strategies for nuclear attack prevention and response, and they can also work closely with government leaders to create and implement projects that meet global security needs. Finally, in the field of healthcare, engineers have the chance to take advantage of revolutionary technologies to advance medicine and address the threats to health that derive from population growth and global climate change. Through contributions to medication design and delivery projects, an engineer can support significant improvements for patients all over the world. Engineers focused on materials research can also enhance existing medical devices and delivery systems. Overall, these findings support the broader conclusion that the world is facing significant threats, but engineers can do a great deal to support the development of solutions for the future.

Recommendations
Based on the findings of this paper, it is recommended that engineers embrace their opportunities to contribute to global solutions. For aspiring engineers who are still in training, it is also important to recognize the most significant threats that the world faces and tailor their studies to ensure that they have the technical knowledge they need to address these threats and are well-prepared to take on one of the key roles that an engineer can take to help tackle the issue. Finally, individuals who are not in the field of engineering should recognize what engineers have to offer when it comes to finding solutions to today’s global problems. If engineers work together with government officials, business leaders, healthcare providers, and concerned citizens, each group’s expertise can contribute to comprehensive, long-lasting solutions.

References
• Architectural and engineering managers. (2018). BLS. Retrieved from https://www.bls.gov/ooh/management/architectural-and-engineering-managers.htm#tab-2
• Carbon capture & sequestration technologies. (2016). MIT. Retrieved from https://sequestration.mit.edu/tools/projects/storage_only.html
• Florida State University. (2017). New plutonium discovery lights way to clean up. Phys.org. Retrieved from https://phys.org/news/2017-05-plutonium-discovery-nuclear.html
• Global climate report – Annual 2017. (2017). NOAA. Retrieved from https://www.ncdc.noaa.gov/sotc/global/201713
• Gore, A. (2006). An Inconvenient Truth. Lawrence Bender Productions.
• Hecker, S.S. (2006). Toward a comprehensive safeguards system: Keeping fissile materials out of terrorists’ hands. The Annals of American Academy of Political and Social Science, 607, 121-32.
• Lai, R., Negassa, W., & Lorenz, K. (2015). Carbon sequestration in soil. Current Opinion in Environmental Sustainability, 15, 79-86.
• Matsumoto, A., Tanaka, M., Matsumoto, H., Ochi, K., Moro-Oka, Y. Kuwata, H….Suganami, T. (2017). Synthetic “smart gel” provides glucose-responsive insulin delivery in diabetic mice. Science Advances, 3(11).
• Mosher, D. (2018). North Korea and Donald Trump may be a recipe for accidental nuclear war – here’s how it could happen. Business Insider. Retrieved from http://www.businessinsider.com/north-korea-nuclear-weapons-miscalculation-preemptive-strike-trump-2018-1
• Nuclear terrorism. (n.d.). Nuclear Threat Initiative. Retrieved from http://www.nti.org/about/nuclear-terrorism/
• Shurman, E.K. (2010). Global climate change and infectious diseases. New England Journal of Medicine, 362, 1061-3.
• Stierwalt, S. (2017). Will the thawing of Arctic ice release diseases? Scientific American. Retrieved from https://www.scientificamerican.com/article/will-the-thawing-of-arctic-ice-release-diseases/
• Tucker, P. (2018). As America’s nukes and sensors get more connected, the risk of cyber attack is growing. Defense One. Retrieved from http://www.defenseone.com/technology/2018/01/americas-nukes-and-sensors-get-more-connected-risk-cyber-attack-growing/145229/
• What is CCS? (2018). Carbon Capture & Storage Association. Retrieved from http://www.ccsassociation.org/what-is-ccs/