Overview
The IPCC was established in 1988 by the UN Environment Programme and the World Meteorological Organization. Its job is to assess the state of knowledge on climate change, not produce original research. When the IPCC publishes a report, it is summarising and evaluating thousands of peer-reviewed studies from scientists around the world, the most authoritative distillation of what humanity currently understands about the climate.
Structurally, the IPCC is organised into three working groups. Working Group I covers the physical science of climate change, temperatures, sea levels, atmospheric concentrations. Working Group II addresses impacts, adaptation, and vulnerability, who gets hurt, how badly, and what can be done about it. Working Group III focuses on mitigation, the policy options and strategies for reducing emissions. Together, the three groups produce Assessment Reports roughly every six to seven years.
For communications professionals, the IPCC is the primary citation anchor for any serious climate claim. When a company, government, or NGO invokes a temperature scenario or talks about The 1.5°C Threshold, they are almost certainly drawing on IPCC findings. Understanding how IPCC reports are structured, and the difference between a Working Group summary and a Summary for Policymakers, is essential for navigating how those claims get made and contested.
Assessment Reports and Key Publications
The IPCC’s Assessment Reports are the flagship product. The Sixth Assessment Report (AR6) was completed in 2023, with contributions across all three working groups. These reports take years to produce and carry enormous institutional weight, they set the scientific baseline for negotiations under the UNFCCC and COP.
The 2018 Special Report on Global Warming of 1.5°C was particularly consequential. It was commissioned following the Paris Agreement and concluded that keeping warming to 1.5°C would require rapid, far-reaching transitions across energy, land use, transport, and industry. That report gave the 1.5°C target scientific teeth and directly shaped the ambition of subsequent COP negotiations.
Summaries for Policymakers (SPMs) are the condensed, politically negotiated distillations of each working group report. Every line of an SPM is agreed upon by government delegates, which means they represent a floor of consensus, sometimes watered down from the underlying science. Communications specialists should know the difference between what scientists wrote and what governments approved.
The IPCC’s Role in Finance and Risk
The IPCC does not directly regulate markets or corporations, but its findings underpin the entire architecture of Climate Finance. Risk frameworks like TCFD and disclosure standards like IFRS S1 and S2 require companies to assess physical and transition climate risks, and those risk assessments ultimately trace back to IPCC climate scenarios.
The concept of Physical Risks, the direct damage from extreme weather, sea-level rise, and shifting temperatures, is defined and quantified largely through IPCC Working Group II outputs. When investors, insurers, or banks model climate exposure, they are feeding IPCC scenarios into their models. The IPCC is, in that sense, the upstream source for an enormous amount of downstream financial decision-making.