After all the talk about the need for climate action, it is time for a reality check. On Monday, the world will receive the UN’s latest climate report. And it’s a big one.
Hundreds of scientists, who form what is known as the Intergovernmental Panel on Climate Change (IPCC), have been hard at work behind the scenes. They have produced a number of reports in the last round, which began in 2015. But on Monday it will all be gathered in what is called the Synthesis Report.
It will explain how the emission of greenhouse gases warms the planet, and then go in depth with the consequences. There is a focus on where we are most vulnerable, as well as efforts to adapt. And then, how we act to reduce emissions and reduce climate change.
Gathering all the evidence, from all corners of the world, is a huge undertaking, let alone reviewing the science to reach a consensus. It is a process that has been repeated several times since it began, more than three decades ago.
This is the sixth round of reports. And it won’t be the last. But this is a crucial moment, because the chance to limit warming and avert dangerous climate change is slipping away.
What is the IPCC and why do we need it?
The IPCC consists of 195 member countries which are responsible for producing comprehensive and objective assessments of scientific evidence for climate change.
The World Economic Forum ranks climate failure as the biggest risk on a global scale over the next decade. And several other top-ten global risks – extreme weather, loss of biodiversity, damage to the human environment and natural resource crises – are made worse by climate change.
Governments, industries and communities are becoming increasingly aware of the need to tackle climate change, especially as predictions become reality.
The scientific effort to understand the causes, effects and solutions is enormous and growing. Tens of thousands of new peer-reviewed scientific studies on climate change are published every year. There must be a way to identify key messages across this vast body of scientific evidence, and use this information to make better decisions. This is what IPCC reports do.
The IPCC process also provides a framework for the scientific community to organize and coordinate their efforts. Each reporting cycle is matched by an international scientific effort, where standardized experiments are run to test the reliability of current climate models.
The experiments include several possible scenarios for how atmospheric greenhouse gas concentrations may change in the future, depending on choices made today. The range of results produced by different models across these experiments helps determine how confident we are about climate change expected in the future.
A key aspect of IPCC reports is that they are co-produced between scientists and authorities. The summary of each report is negotiated and approved line by line, with the consensus of all IPCC member governments. This process ensures that the reports remain true to the underlying scientific evidence, but also extracts the key information that the authorities need.
What can we expect from Monday’s report?
The synthesis report will draw on all six reports issued in the current cycle.
They include three so-called “working group reports” on:
the scientific basis for climate change
impacts, adaptation and vulnerability
In addition, three special reports cut across these working groups and addressed focused themes, where governments called for rapid assessments to help make decisions. They covered:
The headlines from this cycle of IPCC reports have been clearer than ever. They certainly leave no room for disputing man-made warming and the need for urgent reductions in greenhouse gas emissions this decade. We can expect similarly strong and clear headlines from Monday’s report.
How have IPCC reports changed?
Looking back at IPCC reports from the past 33 years shows how our understanding of climate change has improved. The first report in 1990 stated: “the unequivocal detection of the enhanced greenhouse effect from observations is not likely for more than a decade.” Fast forward to 2021 and the corresponding assessment now says: “It is unequivocal that human influence has warmed the atmosphere, sea and land”.
In some cases, the pace of change has dramatically exceeded expectations. In 1990, West Antarctica was an area of concern, but not expected to lose large amounts of ice in the next century. But in 2019, our observations show that glaciers in West Antarctica are retreating rapidly. This has contributed to an accelerating rise in the global sea level.
Concerns are also emerging about the stability of parts of the East Antarctic Ice Sheet that were once thought to be protected from anthropogenic climate warming.
This demonstrates the tendency for IPCC assessments to underestimate the scientific evidence. Climate science is often accused of being alarmist – especially by those trying to delay action on climate change – but in fact the opposite is true.
The production of IPCC reports by consensus with governments means that statements appearing in the report summaries are justified by multiple lines of scientific evidence. This may be behind today’s climate science findings.
What will be next?
Plans are already underway for the next assessment cycle of the IPCC, due to begin in July this year. It is hoped that the next round of reports will be produced in time to inform the Global Stocktake in 2028, where progress towards the Paris Agreement will be assessed.
The current (sixth assessment) cycle has been exhausting. Researchers have increased their commitment to working with authorities to provide the clear and robust information required.
Writing and approving reports in the midst of a global pandemic added to the challenges. So did the inclusion of three special reports in addition to the usual three working group reports.
The evidence for anthropogenic climate change is now unequivocal. This has led to calls for future IPCC reports to more effectively assess rapidly changing areas of science and cut across working groups. This will bring together assessments of causes, effects and solutions for key aspects of climate change in one report, rather than always splitting them into individual working group reports.
The establishment of the IPCC signaled that climate change was an important global problem. Despite this recognition more than three decades ago, and the increasingly worrying reports produced by the IPCC during this time, global greenhouse gas emissions have continued to increase year on year.
However, there is some hope that we can approach the peak in global emissions. By the time the next IPCC reports are released, global climate action may finally have begun to move the world onto a more sustainable path.
Time will tell. Let’s hope policy makers will side with science on the right side of history.
Provided by The Conversation
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Citation: What can we expect from the UN’s final climate report? And what exactly is the IPCC? (2023, March 17) retrieved March 19, 2023 from https://phys.org/news/2023-03-climate-ipcc.html
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