Message from the Director: Green Chemistry and Climate Change

[ACSGCI]

“It is unequivocal that human influence has warmed the atmosphere, ocean and land.  Widespread and rapid changes in the atmosphere, cryosphere and biosphere have occurred.”  This is how the current state of the climate was described in last month’s Intergovernmental Panel on Climate Change (IPCC) report.  This is the sixth climate change assessment report by the IPCC, the United Nations body that provides regular scientific assessments on climate change, along with options to mitigate and adapt to climate change.  

The report addresses the imperative of limiting climate change, stating “From a physical science perspective, limiting human-induced global warming to a specific level requires limiting cumulative CO₂ emissions, reaching at least net zero CO₂ emissions, along with strong reductions in other greenhouse gas emissions.”  Green chemistry and engineering can make important contributions to this goal by minimizing the energy needed to effect chemical transformations and separations, designing new materials needed for alternative energy sources, shifting from petroleum-based feedstocks to biobased starting materials, and converting captured CO₂ into value-added products.  A few examples will help to illustrate each of these areas, but the benefits of green chemistry and engineering are not limited to these areas in combatting climate change.

Catalysts are key to reducing energy requirements for chemical reactions, but we must not forget the energy needed for other processes, such as separations, which are estimated to consume 10-15% of the total energy used in the U.S.  In 2019, the ACS GCI Chemical Manufacturers Roundtable published a report on Sustainable Separation Processes and the National Academies released A Research Agenda for Transforming Separation Science.  Both reports cite the need to move away from distillation to less energy-intensive separation technologies, such as membranes.

Transitioning from our carbon-based economy to one that does not rely on fossil fuels will require new materials for alternate energy technologies, such as batteries and solar cells.  A recent review in Green Chemistry, for example, described advances in designing more sustainable dye-sensitized solar cells, emphasizing the need to select materials that are non-toxic, readily available, low cost, and easily recyclable.

Since we will continue to rely on fossil fuels in the near term, carbon capture, utilization, and storage efforts have been accelerated across the globe.  While most carbon capture technologies focus on point-source emissions, the world’s largest facility to pull carbon dioxide out of the air opened in Iceland earlier this month.  The captured CO₂ is mixed with water and pumped into underground caverns, effectively removing carbon dioxide from the atmosphere.  A research opportunity for green chemists and engineers is to turn this captured carbon dioxide into useful products.      

Finally, replacing petroleum-based starting materials with biobased feedstocks is not always straightforward, and life cycle analysis is an important tool in comparing the environmental impact of biobased starting materials to petroleum-based feedstocks.  Monomers derived from biomass are playing an increasingly important role in polymer synthesis, and such technologies have been recognized with the EPA Green Chemistry Challenge Awards.  We are thrilled that the climate change category is included in the 2022 Green Chemistry Challenge Awards competition.  Nominations for the 2022 program are due to EPA by December 10, 2021.  Please visit www.epa.gov/greenchemistry for information on the awards program and the nomination package.    

Climate Action (#13) is one of the 17 U.N. Sustainable Development Goals (SDGs) and is inextricably linked to the remaining goals, most notably Affordable and Clean Energy (#7) because of the enormous contribution to climate change from burning fossil fuels.  ACS continues to promote chemistry’s role in achieving the SDGs and specifically addresses climate change through its public policy statements, its platinum LEED-certified buildings in Washington, DC, and its efforts to makes ACS National Meetings more sustainable.  Green chemistry and engineering are poised to significantly reduce greenhouse gas emissions through the careful design of products and processes across their life cycle.  The choices we make in our laboratories, as well as in our personal lives, will contribute to a more sustainable energy future.