Communicating Science (2020w109)

Have you heard concerns regarding climate change in the past few years? I think almost everyone has, which goes to show how serious this global issue really is.  One of the main causes of climate change is the release of excess carbon dioxide into the atmosphere, due to the burning of fossil fuels. If we could somehow reduce these greenhouse gas emissions, climate change would pose less of a threat to humanity. 

A solution to climate change

One solution that scientists have proposed in order to reduce the amount of atmospheric carbon dioxide is to capture carbon dioxide in the air and use the captured carbon dioxide as a source of chemical carbon for other processes. This process is known as “carbon capture and utilization” (CCU). Although the potential benefits of CCU are very promising, changing the carbon dioxide into a different form and using it in other chemical processes has been proven to be difficult. Although CCU has gained major traction over the past few years, it will still require a lot of time before it can be used industrially worldwide. Scientists are currently in the process of trying to find the least costly, and most efficient means of capturing carbon emissions to reduce climate change. 

Image: Carbon Capture and Utilization Process                          Source: Wikimedia Commons                                                           Relevance: Shows path of CO2 in this process

Carbon capture methods

One of the carbon capturing methods that has been showing promise in recent scientific studies, is the adsorption of carbon dioxide through the use of solid sorbents. Adsorption is the adhesion or the clinging of gas molecules onto a surface. In this case, the carbon dioxide molecules will stick to the solid surface of the sorbent, which leads to successful carbon capturing. The solid sorbents used in this method can be made of “porous carbonaceous materials, zeolites, alumina, silica, (or) metal-organic frameworks.” Adsorption of carbon dioxide can be categorized into two variations; physical and chemical adsorption. In physical adsorption, the transfer of carbon dioxide into the solid sorbent occurs due to the Van der Waals interactions (attraction between neutral molecules) between the sorbent and the carbon dioxide. The issue with these physical sorbents is that they have “poor selectivity for CO2 and low CO2 adsorption capacities.” A means of improving both the carbon dioxide selectivity and the carbon dioxide adsorption capacities of these sorbents is by adding basic groups to the sorbent surface, which can strengthen its interactions with the acidic carbon dioxide. Although carbon dioxide adsorption via solid sorbents is very promising, more scientific work needs to be done to improve the adsorption capabilities of sorbents.

                                                      Video: Carbon Capture Plant in Squamish, BC

Although CCU has gained major traction over the past few years, it will still require a lot of time before it is used industrially worldwide, and this timeline is uncertain. Moving forward, scientists must also be wary of the energy consumption of these carbon capture mechanisms, as they could use “a quarter of global energy in 2100”.

– Yoshinao Matsubara

Image from: Pattaya Mail

There are some things in the world that you know are bad for you, and that you can see, but air pollution is a different story. Ultrafine particulate matter, which are smaller than a strand of human hair, is known as PM 2.5. Because of its size, it can easily penetrate the natural barriers of your mucus and nostrils and directly access the bloodstream. These particulates are considered a major environmental risk and can contribute to a host of illnesses such as an increased risk of stroke, heart attacks, and both chronic and acute respiratory disease. As well, these particulates can exist as dust, fossil fuels emissions, and even indoor cooking smoke! So now you’re probably thinking, I should try to avoid and limit my exposure to PM2.5  as much as possible, but even that might not be enough.

Relative small size of PM2.5 compared to other objects.

Image from: USA EPA

The Environmental Protection Agency (EPA) recommends that the annual exposure to PM2.5 does not exceed 12 micrograms per meter cubed. However, a recent study showed that even stricter guidelines should be implemented. The study found that 99% of PM2.5 associated deaths occurred at PM2.5 levels below the current EPA guidelines. In the study, they compared 4.5 million veterans with annual levels of ultra-fine particulates where they lived, and the results showed that the average particulate levels were lower than 12 micrograms. So, this begs the question, are our current air pollution laws good enough to prevent the health consequences? Ziyad al-Aly, the co-author of the study says that “there’s not a whole lot a person can do other than really participate in the discussion”.

So what can you do then as an individual who cares about the wellbeing of people and the planet? Demand action by local, regional, and national level policy-makers working in sectors like transport, energy and urban planning. According to the World Health Organization (WHO), one way to reduce PM2.5 levels is by shifting to electric vehicles from diesel engines. A successful example is the Californian Diesel Risk Reduction plan, where the government implemented tighter diesel emission standards for car manufacturers and lowered PM2.5 concentrations.

It is unfortunate to learn that even the lowest levels of particulate matter can affect our health in the long-run, however it also encourages us to take action immediately. By reaching out to policy makers and becoming an active voice in the community, perhaps we can make progress towards cleaning our air.

– Michael Ge