Summary of the IPCC Sixth Assessment Report (AR6)

Key Points:

  • The Intergovernmental Panel on Climate Change has summarized over 8500 pages of content in its Sixth Assessment Report.
  • The IPCC sent two important documents out into the world on March 20, 2023: a long, heavily cited document written by scientists summarizing the sixth assessment cycle, and a shorter, summary for policymakers that summarizes the text line by line. The summary says that human activity has warmed the planet by 1.1 degrees Celsius.
  • Although the public is demanding action, we’re still putting more greenhouse gases in the atmosphere and not even meeting the emissions reductions targets set out under the Paris Agreement. This increases the likelihood of warming-charged disasters.
  • The IPCC report makes it clear that we need to cut greenhouse gas emissions by around 42% by 2030, 60% by 2035, and be near goals of elimination by 2050 to keep warming to 1.5 degrees Celsius.
  • Climate policy is already working, and we have a host of climate change solutions which are available, cheap, and popular. The costs of solar, wind and batteries are all plummeting.
  • The report uses the phrase “increment of global warming” half a dozen times and argues that even if we do overshoot our limits, there are still many benefits to accelerating climate action, like reduced air pollution, walkable cities, better and tastier produce, and increased food security.
  • The IPCC’s seventh assessment report is scheduled to be released at the end of the decade – let’s hope we’re still not having the same conversations then.

Summary of the IPCC Sixth Assessment Report (AR6) – The Synthesis Report

Here, we will attempt to summarize the summary of the summary of the summary of everything we know about climate change and its impacts on everything we know and care about.

The Intergovernmental Panel on Climate Change (IPCC) on March 20th, 2023, released the final piece of the Sixth Assessment Report. They’ve had the daunting task of summarizing everything that has been published in the three working group reports and three special reports – over 8500 pages of content.

The IPCC sent two important documents out into the world on the 20th. The first is the Synthesis Report, which is a long, heavily cited document written by scientists summarizing the sixth assessment cycle. The second, which may be of more interest to readers, is the summary for policymakers, a much shorter document that is easier for interested parties, such as corporations, NGOs, and regulators, to digest. The summary for policymakers, or SPM, as it’s often called, is agreed on line-by-line by governments party to the IPCC, which is a very long process of scrutinizing the text until consensus is reached. In the end, you have a document that 195 countries have endorsed, and it says – much to the surprise of everyone reading – human activity, predominantly from burning fossil fuels, has warmed the planet by 1.1 degrees Celsius, and this warming has and will continue harming people and places, where those who have contributed the least experiencing the greatest negative impacts. In a few places we’ve been responding to the increasing risks effectively. But most everywhere else our adaptation strategies are a mess. They’re unequally distributed, too incremental and often maladaptive, meaning they’re doing more harm than good.

“In 2018, IPCC highlighted the unprecedented scale of the challenge required to keep warming to 1.5°C. Five years later, that challenge has become even greater due to a continued increase in greenhouse gas emissions. The pace and scale of what has been done so far, and current plans, are insufficient to tackle climate change…More than a century of burning fossil fuels as well as unequal and unsustainable energy and land use has led to global warming of 1.1°C above pre-industrial levels. This has resulted in more frequent and more intense extreme weather events that have caused increasingly dangerous impacts on nature and people in every region of the world.” – IPCC Press Release

When it comes to actions that we’ve collectively utilized to mitigate the effects of climate change, results have varied. Some things are working, and renewables are cheaper than they’ve ever been. But even though the public is demanding action more and more, we’re still putting more greenhouse gases in the atmosphere and not yet meeting the emissions reductions targets set out under the Paris Agreement, as we’ve written about extensively in the past. And with those temperature increases, it increases the likelihood of warming-charged disasters and compounding and cascading extreme events, which is pretty bad news, considering most of the world is already at its limits contending with disasters today. Everything becomes worse and harder, the warmer it gets – the effects are incremental in nature.

That explains where we are today – decidedly negative – but the report also has a lot to say about where we could go. For starters, it includes a table that plainly lays out what we need to do to limit warming to 1.5 degrees Celsius – clearly showing, despite even our own doubts, that the international community still sees this as a viable goal. Global greenhouse gas emissions must be cut by around 42% by 2030, 60% by 2035, and be near the goal of elimination by 2050. The IPCC’s frequently used phrase “rapidly narrowing or closing window of opportunity” has never been truer. When scientists modeled what the future climate could look like, all the scenarios that keep us below 1.5 have global emissions peaking before 2025, which is less than two years away. But the report also makes it clear that this is doable.

“Mainstreaming effective and equitable climate action will not only reduce losses and damages for nature and people, it will also provide wider benefits,” said IPCC Chair Hoesung Lee. “This Synthesis Report underscores the urgency of taking more ambitious action and shows that, if we act now, we can still secure a liveable sustainable future for all.” – IPCC Press Release

It’s important to note first, although this does not often seem to be true, climate policy is already working. It can be easy to get the idea that all these years of negotiations and deals have achieved nothing, but the report spells out that policies have led to several billion tons of avoided emissions per year, indicating that we are starting to turn the tide and shift towards decarbonization. This isn’t enough progress, but it’s not nothing. We now have a host of climate change solutions which are available, cheap, and popular. The report mentions everything from solar panels to avoiding food waste in a single sentence, and the technology to ensure viability for these activities is getting cheap. The costs of solar, wind and batteries are all plummeting. This all might seem irrelevant given that we’re risking overshooting 1.5 or two degrees, but the report makes clear that there’s no point at which we get to give up – echoing the sentiment that we saw from COP27 and the publication of ISO’s Net Zero Guidelines, which, despite us clearly missing the mark, double down on the 1.5 target set with the Paris Agreement.

“There are multiple, feasible and effective options to reduce greenhouse gas emissions and adapt to human-caused climate change, and they are available now.” – IPCC Press Release

When considering extreme weather, for example, with every additional increment of global warming, extreme weather gets worse. Conversely, every increment of global warming that we can avoid means avoiding people dying of these disasters. In fact, this idea that climate change is mostly incremental is so important that the report uses the phrase “increment of global warming” half a dozen times. So even if we do overshoot our limits, there’s still the world to fight for, and avoiding as many increments of global warming as possible is something we can continue to do, regardless of how overwhelming and impossible the task at hand seems to be.

We’re at the point where we’ve got all the tools we need and are working to be able to utilize them at scale – if all the projected risks of increasing global temperatures aren’t enough to promote immediate action, there are many non-climate benefits of accelerated climate action – like reduced air pollution, walkable cities, better and tastier produce, and increased food security, all not to mention the economic benefits. Just consider air pollution alone – the cost of reducing emissions is less than the economic benefits of the improved health and well-being of people living with clean air.  The ICPP makes this clear when it says, “The solution lies in climate resilient development. This involves integrating measures to adapt to climate change with actions to reduce or avoid greenhouse gas emissions in ways that provide wider benefits…access to clean energy and technologies improves health, especially for women and children; low-carbon electrification, walking, cycling, and public transport enhance air quality, improve health, employment opportunities and deliver equity. The economic benefits for people’s health from air quality improvements alone would be roughly the same, or possibly even larger than the costs of reducing or avoiding emissions.”

“Every increment of warming results in rapidly escalating hazards. More intense heatwaves, heavier rainfall and other weather extremes further increase risks for human health and ecosystems. In every region, people are dying from extreme heat. Climate-driven food and water insecurity is expected to increase with increased warming. When the risks combine with other adverse events, such as pandemics or conflicts, they become even more difficult to manage.” – IPCC Press Release

Anything but reducing emissions and building risk resilience as fast and as equitably as we can is going to harm more people and places and cost us billions of dollars.

This synthesis is the last major report the IPCC is scheduled to release for at least the next five years. When the seventh assessment report starts coming out at the end of the decade, hopefully we’re still not having the same conversations. So, let’s let the end of this assessment cycle be the start, or really the continuation of imagining better futures and demanding from our governments and the people in power the future we all deserve.  To learn more, you can read the entire March 20th press release here, or to learn more about the IPCC and all of the reports that they’ve generated, visit their official website.