GR with great granddaughter Maricella
I feel a deep sense of dread when I consider the long-term consequences of our CO2 emissions. The atmospheric residence time of CO2 is a tidal wave that few truly comprehend. Let me be blunt: we are locking in catastrophic changes that will continue for centuries, if not millennia.
The stark reality is that even if we stopped all CO2 emissions today, the carbon dioxide already in our atmosphere will continue to warm the planet for hundreds of years (Harde 2017, Mikolajewicz et al. 2007). We’ve set in motion changes that our great-great-grandchildren will still grapple with. This is not alarmism; it’s basic atmospheric chemistry (Cawley 2011).
Given the residence time of CO2, I believe we’ve already committed ourselves to sea level rise that will eventually submerge coastal cities worldwide (Foster and Rohling 2013, Ekwurzel 2017). Venice, Miami, Bangkok – they’re already doomed. It’s not a question of if, but when. And “when” might be sooner than we think.
The long-term acidification of our oceans is another horror show. The seas will continue to absorb CO2 we’ve emitted for centuries, altering marine chemistry (Guinotte and Fabry 2008, Hall-Spencer and Harvey 2019). I expect to see the complete collapse of coral reef ecosystems within my lifetime. The knock-on effects on global fisheries and ocean biodiversity will be apocalyptic.
Climate zones will shift dramatically over the coming centuries because of our current emissions. Entire ecosystems must migrate or face extinction. Many won’t make it. We’re looking at a scale of species loss comparable to the great mass extinctions of Earth’s past (Cahill et al. 2013, Román-Palacios and Wiens 2020).
The most terrifying aspect is the potential for runaway feedback loops (Ripple et al. 2023, Bajželi and Richards 2014). As permafrost melts and releases methane, as forests die and release carbon, we could trigger cascading effects that amplify warming far beyond our current worst-case scenarios. There’s a genuine possibility that the Earth system could shift into a new, much hotter state that’s hostile to human civilization.
Climate tipping points could release the feedback loops. Lenton (2011) and Lento et al. (2019) discuss climate tipping points, and Armstrong McKay et al. (2022) report that exceeding 1.5°C global warming could trigger multiple climate tipping points leading to accelerated changes. We exceeded 1.5°C in 2023 and we might do it again in 2024. Must wait to see if changes do indeed speed up in 2025.
Given the residence time of CO2, our current emissions are an attack on future generations. We’re robbing them of stable climate, biodiversity, and food and water security. We’re bequeathing them a planet that may be unrecognizable and, in many places, uninhabitable (Friedlingstein and Solomon 2005, Hansen et al. 2013).
The inertia in the climate system, coupled with the long atmospheric lifetime of CO2, means that even if we achieve net-zero emissions by mid-century (which looks increasingly unlikely), we’re still in for centuries of rising seas, shifting climate zones, and ecological upheaval.
I fear we’ve already passed critical tipping points. The changes we’ve set in motion will reshape the face of the Earth for longer than human civilization has existed. Our brief fossil fuel binge will echo through geologic time.
Every ton of CO2 we emit now is a burden we’re forcing future Earth to bear. There might be mitigating actions we can take, some brilliant engineering feats that will change all this. I will cover some possibilities in an upcoming post, but based on our track record with climate, I have to say I expect us to fail spectacularly.
References
Each of these references includes many related papers in their bibliographies. Use the links to study the bases for the arguments.
Armstrong McKay, D. I., Staal, A., Abrams, J. F., Winkelmann, R., Srokosz, M. A., Ebi, K. L., Sylla, M. B., Singh, D. B., & Spencer, T. (2022). Exceeding 1.5°C global warming could trigger multiple climate tipping points. Science, 375(6579), 150-153.
Bajželj, B., & Richards, K. S. (2014). The positive feedback loop between the impacts of climate change and agricultural expansion and relocation. Land, 3(3), 898-911.
Cahill, A. E., Aiello-Lammens, M. E., Fisher-Reid, M. C., Hua, X., Karanewsky, C. J., Ryu, H. Y., Sbeglia, G. C., Spagnolo, F., Waldron, J. B., Warsi, O., & Wiens, J. J. (2013). How does climate change cause extinction? Proceedings of the Royal Society B: Biological Sciences, 280(1751), 20121890.
Cawley, G. C. (2011). On the atmospheric residence time of anthropogenically sourced carbon dioxide. Energy & Fuels, 25(11), 5531–5535.
Ekwurzel, B., Boneham, J., Dalton, M. W., Heede, R., Mera, R., Mueller, M. T., & Zimmerle, D. J. (2017). The rise in global atmospheric CO2, surface temperature, and sea level from emissions traced to major carbon producers. Climatic Change, 144(4), 699-723.
Foster, G. L., & Rohling, E. J. (2013). Relationship between sea level and climate forcing by CO2 on geological timescales. Proceedings of the National Academy of Sciences, 110(4), 1209-1214.
Friedlingstein, P., & Solomon, S. (2005). Contributions of past and present human generations to committed warming caused by carbon dioxide. Proceedings of the National Academy of Sciences, 102(31), 10832-10836.
García Hernández, A. L., & Lucatello, S. (2022). Climate policy integration: Taking advantage of policy windows? An analysis of the energy and environment sectors in Mexico (1997–2018). Journal of Environmental Policy & Planning, 1-17.
Guinotte, J. M., & Fabry, V. J. (2008). Ocean acidification and its potential effects on marine ecosystems. Annals of the New York Academy of Sciences, 1134, 320-342.
Hall-Spencer, J. M., & Harvey, B. P. (2019). Ocean acidification impacts on coastal ecosystem services due to habitat degradation. Emerging Topics in Life Sciences, 3(2), 197-206.
Hansen, J., Kharecha, P., Sato, M., Masson-Delmotte, V., Ackerman, F., Beerling, D. J., Hearty, P. J., Hoegh-Guldberg, O., Hsu, S. L., Parmesan, C., Rockstrom, J., Rohling, E. J., Sachs, J., Smith, P., Steffen, K., Van Sustren, L., von Schuckmann, K., & Zachos, J. C. (2013). Assessing “dangerous climate change”: Required reduction of carbon emissions to protect young people, future generations and nature. PLoS one, 8(12), e81648.
Harde, H. (2017). Scrutinizing the carbon cycle and CO2 residence time in the atmosphere. Global and Planetary Change, 158, 114-124.
Lenton, T. M. (2011). Early warning of climate tipping points. Nature Climate Change, 1(4), 201-209.
Lenton, T. M., Rockström, J., Gaffney, O., Rahmstorf, S., Zickfeld, K., Meinshausen, M., Scheffran, J., Schellnhuber, H. J., & Nicoll, K. C. (2019). Climate tipping points—too risky to bet against. Nature, 575(7781), 42-50.
Mikolajewicz, U., Gröger, M., Maier-Reimer, E., Schurgers, G., & Vizcaino, M. (2007). Long-term effects of anthropogenic CO2 emissions simulated with a complex earth system model. Climate Dynamics, 28(6), 599-631.
Pfeifer, L., & Otto, I. M. (2023). Changing seasonal temperature offers a window of opportunity for stricter climate policy. Environmental Science & Policy, 133, 112-119.
Ripple, W. J., Wolf, C., Lenton, T. M., Gregg, J. S., Rockström, J., Smith, P., Huber, H., Porfirio da Silva, M., Lawrence, M., & Scheffran, J. (2023). Many risky feedback loops amplify the need for climate action. One Earth, 6(1), 33-44.
Román-Palacios, C., & Wiens, J. J. (2020). Recent responses to climate change reveal the drivers of species extinction and survival. Proceedings of the National Academy of Sciences, 117(21), 11371-11377.
Yang, X., Li, N., Mu, H., Pang, H., & Zhao, F. (2021). Study on the long-term impact of economic globalization and population aging on CO2 emissions in OECD countries. Science of The Total Environment, 751, 141978.