The Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for assessing the science related to climate change. The IPCC was created in 1988 by the World Meteorological Organization(WMO) and the United Nations Environment Programme (UNEP), with the objective of providing governments with scientific information that they can use to develop climate policies. They do this by providing assessment reports of the scientific basis of climate change every 6-7 years.
Thousands of leading climate scientists from all over the world contribute to these assessment reports. These scientists volunteer their time to contribute to the IPCC reports by assessing the thousands of scientific papers published each year. As a result, they provide a comprehensive summary of what is known about the drivers of climate change, its impacts, and future risks, and how adaptation and mitigation can reduce those risks.
These assessment reports provide a culmination of years of peer reviewed research, making them particularly valuable to myself: a young scientist and an individual who is interested in the topic of climate change. The report of Working Group I of the IPCC Climate Change 2021: the Physical Science Basis, was virtually approved by 195 member governments of the IPCC, and was published on the 9th of August 2021, consisting of 13 chapters and 3949 pages. This report was compiled by the Working Group I, which addresses the most up-to-date physical understanding of the climate system and climate change. The report is the first part of the IPCC’s 6th Assessment Report which will be completed in 2022, bringing together the latest advances in climate science, and combining multiple lines of evidence from palaeoclimate (past climates), observations, process understanding, and global and regional climate simulations projecting future climates.
Within this comprehensive report are several headline statements from the Summary for Policy Makers. After reading the summary, I had some strong reactions as a climate PhD student and decided to record and share them. The headline statements are found here. I provide my reaction to some of the statements I found particularly important.
Reaction: The use of the word unequivocal is important to me. A Google search of the word unequivocal, “leaving no doubt; unambiguous” demonstrates that there is “no doubt” that human influence has done the warming. Apart from Google, the word unequivocal has a special meaning in the IPCC language: it points directly to how the IPCC quantifies and engages with uncertainty, agreement, confidence, and evidence. One of the most progressive aspects of the IPCC is the use of language and how they quantify and engage with uncertainty. According to the glossary of terms within the report, uncertainty “is a state of incomplete knowledge that can result from a lack of information or from disagreement about what is known or even knowable”. Therefore, the use of unequivocal demonstrates clearly that there is no doubt of our responsibility to warming of global systems. My reaction to the statement is not one of surprise, more of satisfaction that the climate change denialists have no ground on which to stand. Secondary to this, the changes that humans have caused have occurred in all global spheres essential to life on earth, having a complete global influence.
Reaction: The word unprecedented has been used far too often in the recent past. This statement creates a lot of anxiety and uncertainty, leading me to ask many questions of the future. How will humanity cope with unprecedented changes in the climate system when we are currently facing an unprecedented global pandemic? Is the world prepared to face and be able to adapt to the scale of changes across the climate system? Which communities will be most or least affected, and in what areas?
Reaction: This statement makes me fearful towards those who may be affected by these extreme weather events. My fear extends not only for myself and my family, but to millions of people and communities as I imagine that these extreme events will be far reaching. It also points out that extreme events are not that extreme after all, but events that will likely occur more regularly in future. With respect to agriculture, I am worried that the food industry is too reliant weather systems that may become unreliable and unpredictable in future.
With respect to the natural world, the overall (direct) negative human influence on the natural world has been well documented. Issues of climate change caused by humans in the first place will again affect the natural world, just indirectly – through ecological droughts, heat extremes, floods and marine heatwaves as mentioned in the statement. As a solution, both direct and indirect human impacts on the natural world should be addressed.
Reaction: The cycle/system is self-perpetuating, i.e., increases in changes to the climate system will hinder the natural barriers against those changes, leading to further changes. The changes have the power to continue indefinitely. This statement is particularly important for my PhD. I am studying an extensive peatland deposit within the Angolan Highlands. Peatlands are an essential global carbon and methane sink. Within what is currently a self-perpetuating system, the ability of sinks to continue to function naturally becomes greatly diminished. In the case of peatlands, disturbance in the peatland functioning causes the ecosystem to become a greenhouse gas source, releasing both carbon and methane that has been locked away for millennia back into the atmosphere. Release of carbon and methane adds to the greenhouse effect, self-perpetuating the system.
Reaction: This statement highlights again the progression and use of language by the IPCC, including their practices when dealing with levels of uncertainty. In the case of “low-likelihood outcomes”, such phenomena are highly unlikely to occur. This statement also leaves me with a word of caution, it may be the case that some literature should be challenged and that extreme examples such as ice sheet collapses, or abrupt ocean circulation changes are very unlikely to occur, but not impossible. This extends to possible headline statements of imminent catastrophes, and the responsibility of scientists and media to include within their reports and research a level of certainty/ likelihood that this is that event will occur.
Reaction: This statement provides me with hope, the question remains if we can reach such targets quickly enough. The work of the IPCC and climate scientists (and the IPCC) is invaluable, and their work and is becoming more and more a part of the human psyche and behaviour. The changes that have already occurred with such rapid pace during the global pandemic show how quickly humans can adapt and develop new behaviour. The use of the words strong and rapid will hopefully drive decision makers to act in a decisive way. The further we are educated to the benefits of solving this problem, the greater our collective impact will be.
Closing reaction: Reading the summary for policy makers has created a sense of pragmatism within me, I am hopeful that solutions and progress can be made practically without the need for too many more theoretical considerations. The IPCC and the peer-reviewed scientific literature with which they base these statements, are trustworthy. Continued report writing and research needs to be met with effective and practical solutions to this global crisis. If indeed we do not adjust our behaviour, or at least the policies with which we are governed do not change/ develop, the good work of the IPCC and climate change science may be in vain.