An alarming, and probably historic, report on climate change will be released this Monday. The international climate panel IPCC of the United Nations, for the sixth time since its foundation in 1988, is publishing a report on the scientific basis of global warming.
This report is the first of three volumes to be published through early 2022. The other two parts will deal with possible solutions to climate change and the social and economic impacts in specific regions. This first report will provide a broad picture of how the climate is warming due to human activity.
That picture will be grim.
from a preview on the site of the scientific journal Nature, it appears that the internationally agreed target of staying below 1.5 degrees warming is no longer promising. That limit may already be exceeded around 2030, and according to some models earlier.
Also read: How the UN Climate Panel is keeping everyone on their toes
Several climate studies even show that the world is on track to become an average of about 3 degrees warmer in 2100 than before industrialization – unless governments, citizens and companies reduce their greenhouse gas emissions much more strongly.
The climate crisis will ensure that parts of the inhabited world and the ecosystems on earth will change or disappear drastically. The IPCC report will also address whether heat waves, wildfires, floods and droughts will be a more frequent part of life on this planet.
In addition, much scientific literature has recently focused on the irreversibility of certain climate changes, often referred to as tipping points.
“For example, that due to higher temperatures and droughts, parts of the Amazon can no longer survive,” it says in a statement Nature. “These tipping points can also reinforce each other, like falling dominoes.”
The report must be ‘policy-relevant but policy-neutral’. It does not contain any recommendations on greenhouse gas reduction or adaptation measures to prepare countries and ecosystems for the climate crisis. These are decisions that have to be taken in other bodies.
Compiling the report took six years. The studies that jointly support it have been extensively commented and honed by scientists worldwide. According to the IPCC itself, the second version received 51,387 comments from 1,279 experts. In total, more than 14,000 scientific papers are used as a source. Previous IPCC reports are regarded as leading in the formulation of climate policy worldwide.
The new edition will not contain major substantive surprises, because it consists of already published scientific studies. But the coherence between all the individual findings and the broad-based weighting of all those studies together will almost certainly have a major impact.
Models contain uncertainties
It will also look in more detail at the degree of certainty that researchers think they have. Models of highly complex systems such as the climate by definition contain large uncertainties and unpredictability. That sometimes leads to criticism of the veracity of IPCC reports, and skeptics on different sides of the political spectrum will also speak out in the coming days and weeks.
IPCC reports lead the way in formulating climate policy worldwide
But the consequences of climate change are no longer limited to calculation models and predictions for the future. The report comes just after striking extreme weather phenomena such as the floods in Germany and Limburg and a heat wave of more than 50 degrees in Canada in July. Those are events that climate scientists have linked to the greater likelihood of such extreme weather occurring on a warmer planet.
Due to the growing urgency, previous IPCC publications have already noticed a change in tone: it is becoming more and more existential. In the introduction to a previous IPCC publication, there was a poignant quote from French writer Antoine de Saint-Exupéry: “When it comes to the future, it’s not about predicting it – it’s about making it possible.”
The question is what big words will be in the new report today – and how humanity will react to them.
A version of this article also appeared in NRC in the morning of August 9, 2021