IPCC — Climate Change 2014 (AR5 Synthesis Report)
PDF · 139 pages · 6 MB
What this document is
‘Climate Change 2014: Synthesis Report’ is the concluding volume of the Intergovernmental Panel on Climate Change’s Fifth Assessment Report, known as AR5. The IPCC is the United Nations body that periodically reviews the state of climate science; it does not carry out new research itself but assesses the published literature and summarises where the evidence stands.
AR5 was released in stages. Three working groups each produced a major volume: one on the physical science of the climate system, one on impacts, adaptation and vulnerability, and one on mitigation. The Synthesis Report is the document that pulls all three together into a single, integrated assessment aimed at policymakers and the general reader.
This page is a summary for readers who reached a broken link to the original PDF. It describes the report honestly and generally; for exact wording, figures and confidence statements you should always consult the primary source published by the IPCC.
What it covers
The Synthesis Report is organised around a small number of overarching themes that recur throughout the wider assessment. In broad terms it addresses the following areas.
- Observed changes in the climate system, including warming of the atmosphere and oceans and reductions in snow and ice;
- The human influence on the climate, principally through greenhouse gas emissions from burning fossil fuels;
- Projected future changes under different emission pathways, and the risks associated with each;
- Options for reducing emissions (mitigation) and for adapting to changes that are already unavoidable;
- The concept that limiting warming requires cumulative emissions to be kept within a finite budget.
A hallmark of IPCC reporting is its careful language of confidence and likelihood: findings are qualified according to the strength of the underlying evidence. That measured tone is part of why the assessment is treated as an authoritative reference point.
Why it matters
AR5 and its Synthesis Report were the scientific backdrop to the 2015 United Nations climate conference in Paris. The evidence they assembled underpinned the case for the Paris Agreement and its goal of holding global warming well below 2 °C above pre-industrial levels, while pursuing efforts to limit it to 1.5 °C.
Because it was the most comprehensive stocktake of climate science of its era, the report is cited extensively by governments, researchers, journalists and campaigners. Many external articles that once linked to the original PDF now hit a dead link, which is why a stable summary such as this one is useful.
How it relates to UK energy
The single biggest lever the report identifies for cutting emissions is the way we produce and use energy. That connects directly to decisions UK households face, from switching to greener electricity to insulating homes and electrifying heat and transport.
If you want to see how these global conclusions play out closer to home, our guide to renewable energy explains where low-carbon electricity comes from, and our broader environment guides cover carbon, climate policy and low-carbon living in a UK context.
You can read the original assessment on the IPCC’s official AR5 Synthesis Report page.
Frequently asked questions
Who wrote the Climate Change 2014 Synthesis Report?
It was produced by the Intergovernmental Panel on Climate Change (IPCC), the United Nations body that assesses the science of climate change. The synthesis draws together the work of the panel’s three working groups and hundreds of volunteer scientists, and its Summary for Policymakers is approved line by line by member governments.
What is the difference between AR5 and the Synthesis Report?
AR5 is the Fifth Assessment Report as a whole, published across 2013 and 2014 in three main working-group volumes covering the physical science, impacts and adaptation, and mitigation. The Synthesis Report is the final, integrating volume that distils those three into one accessible document for decision-makers.
Why was this report important?
It was the most comprehensive assessment of climate science available at the time and fed directly into the negotiations that produced the 2015 Paris Agreement. It is one of the most cited climate documents ever published.
Where can I read the original document?
The full report and its Summary for Policymakers are published openly by the IPCC. This page links to the IPCC’s official AR5 pages so you can consult the primary source directly.