The Intergovernmental Panel on Climate Change (IPCC), the United Nations body for assessing the science related to climate change, has published its latest assessment of climate change in a report referred to by the UN Secretary-General as a “code red for humanity”.
The previous evaluation was launched eight years ago. Earlier this week, the first of three reports to be corroborated in the IPCC’s sixth evaluation, which is scheduled to appear in a May 2022 summary, were published. That being said, only the other day the contribution of IPCC Working Group I (“Physical Science Base”) came out. The next will be the contribution of Working Group III (“Mitigation of Climate Change”) in September this year. And in October, Working Group II will launch their latest contribution on “Impacts, Adaptation and Vulnerability” to climate change.
Although part of a three-report suite, the WG I report is by no means an easy introduction. On the contrary, it took no less than three years of coordinated work by more than 230 climate researchers to produce 3,949 pages of reports, citing about 14,000 studies that converge in two directions: blaming the human factor for climate change and proclaiming these changes a present reality, not just a prediction. “In past reports, we’ve had to make that statement [about the reality of climate change] more hesitantly. Now it’s a statement of fact,” said Gregory Flato, vice president of the group and a researcher for the Canadian government.
UN Secretary-General António Guterres said the IPCC’s WGI report was the declaration of a “code red for humanity”. “The alarm bells are deafening, and the evidence is irrefutable: greenhouse‑gas emissions from fossil-fuel burning and deforestation are choking our planet and putting billions of people at immediate risk. Global heating is affecting every region on Earth, with many of the changes becoming irreversible,” said the UN chief. The science cannot be ignored. Human induced climate change is real, and continues to affect the global climate.
The first part in the sixth assessment report shows that human activities have already caused global warming by about one degree Celsius, compared to pre-industrial levels. Moreover, scientists say that the global temperature rise will most likely reach 1.5 degrees Celsius between 2030 and 2052 if the current rate of warming is maintained.
Anthropogenic (generated by human activity) greenhouse gas emissions from the pre-industrial period will continue to warm the globe irreversibly in the coming centuries or even millennia, the report’s authors say, which will cause long-term changes in the climate system (including rising sea levels and other consequences following from this).
Climate models that assess the potential impact of projected global warming announce rising average temperatures in most of the dry areas of the globe—and the ocean regions as well—the manifestation of heat extremes in most inhabited regions, the presence of heavy rainfall in some regions, and a high probability of drought in others.
The impact on biodiversity and ecosystems includes the loss by extinction of certain species, but also a serious reduction in the capacity of terrestrial and aquatic (freshwater) ecosystems to serve the interests of its inhabitants. Scientists expect an increase in risks to health and life, food security, a reduction in human access to drinking water, and a decrease in economic growth, as a result of an increase in global temperatures by 1.5 or even 2 degrees Celsius.
Key warnings in the new report refer to the assessment according to which the global surface temperature increased by 1.09 degrees Celsius between 2011 and 2020, compared to the period 1850-1900. Moreover, the last five years have been, on average, the warmest since global temperatures started to be measured in 1850. The rate of sea level rise has now tripled from the rate recorded between 1901 and 1971. There is a 90 per cent probability that human influence has been the main driver of melting glaciers since the 1990s, as well as the declining proportion of ice in the arctic waters. It is “virtually certain,” the report said, that extreme temperatures have become more frequent and intense than they were in the 1950s.
Climate researcher Sonia Seneviratne, who coordinated the chapter on meteorology and climate extremes in the report, said: “There have always been extreme weather events, of course, but evidence of observed changes in extremes has mounted since [the last IPCC assessment report, referred to as AR5]. As global warming increases, these changes will worsen… Terms like ‘a once in a century storm’ will become obsolete.”
How much can we trust the IPCC report?
The IPCC assessments represent the scientific consensus on climate change, obtained through the research and review work of hundreds of experts in the field, delegated by the governments of the 193 UN countries. They are considered the most respectable source of authority in the field of climate change assessment. The IPCC’s scientific findings inform public policymakers around the world and, due to the huge number of experts involved in their formulation, have a high degree of certainty. For example, the three working groups collaborating on the sixth IPCC synthesis total 721 scientists from interconnected but very different fields of research.
IPCC reports are usually scheduled in such a way that they can serve as a foundation for public policy discussions and development at relevant international meetings (see: United Nations Framework Convention on Climate Change, Kyoto Protocol, Paris Agreement). The WGI report precedes the COP26 Summit.
The authors of the IPCC reports come not only from academia but are also representatives of industries, governments, and non-governmental organizations. The process by which they come to sign IPCC contributions is a rigorous selection, and their published research portfolio and international reputation play a very important role.
Each IPCC report goes through a double peer-review process. First, expert editors review it chapter by chapter, and their results are reviewed by government officials and scientific experts. For the WGI report alone, there were 74,849 review comments from hundreds of evaluators representing several disciplines. In addition, the IPCC has an error management protocol which also helps to ensure the accuracy of the information contained in the reports.
A very important aspect is that the involvement of experts delegated by governments only takes place in the review stage, therefore they cannot “dictate” what appears in the reports. According to Rebecca Harris of The Conversation, whether they like the content of the report or not, delegates acknowledge the scientific nature of the evaluation by voting to accept the revisions. Delegates also have a role to play in ensuring that the IPCC assessment “is policy relevant without being policy prescriptive.”
Critical voices claim IPCC reports are politically motivated and one-sided. “But given the many stages at which experts from across the political and scientific spectrum are involved, this is difficult to defend,” Harris notes.
What about the critics?
Despite the massive support from the scientific communities the IPCC reports receive, climate change deniers still exist, and they manage to sow doubt among the population. University professor Jeremiah Bohr, who teaches sociology at Oshkosh University in Wisconsin, said that the narratives of those who challenge climate science oscillate between three mantras: “Climate change is not happening,” “Climate change is happening but humans are not driving it,” and “Climate change is happening but it is nothing to worry about.” The shifting between narratives, the professor said, is the result of a strategic adaptation to their political environment. Bohr also details the economic reasons that drive the refusal to recognize the severity of global warming.
Regarding the political catalysts, the professor considers that those who associate the libertarian policy of defending free markets with the denialist movement on global warming make a mistake in the sense that the real spearheads in the denialist movement are the members of the populist right movements.
Referring to the mix of “corporations in the fossil fuel industry, trade associations, conservative philanthropists, and conservative think tanks” that tend to be against the idea of global warming, the professor draws a parallel with the strategies once used by the tobacco industry, when they could still deny the carcinogenic risks of smoking.
The Conversation made a review of the five most frequently cited reasons for denying global climate change that compete in terms of the clarity of their arguments with this analysis in which they list the psychological reasons for climate change denial.
Starting from the parallel with the tobacco industry, if we look back at how other “denialist campaigns” were treated, for example, those that argued their opposition to the abolition of slavery, or racial segregation in the US, or opposition to women’s right to vote, we can only hope that the truth will finally come to light. However, if we look at the virulence of the anti-vaccine movement and its immediate consequences (visible presently, during the COVID-19 pandemic), we realize that we cannot just sit and quietly wait for the 97-98% of scientists who support the reality of global warming to take care of saving the planet.