The final installment of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) is due for release on November 2. The Synthesis Report serves as the capstone aiming to distill, synthesise and integrate the findings of the working group contributions released over this past year.

The reports of the three Working Groups over the past year covered the physical science of climate change (Working Group 1), vulnerability to climate impacts and adaptation (Working Group 2), and mitigation strategies to tackle climate change (Working Group 3).

Essentially through these reports the IPCC has shown that:

  • Climate change is here, man-made and already having dangerous impacts across all continents and the ocean;
  • Global warming can still be kept below the politically agreed limit of 2 degrees Celsius compared to preindustrial levels;
  • Securing a safe climate future is possible and economically viable if immediate action taken.

Below is a more detailed overview of the 10 most important findings from these three reports:

1. Climate change is primarily caused by humans. Working Group I found with 95% certainty that humans have caused most of the observed warming since 1951


2. Climate change in acceleration. Many indicators of climate change are accelerating: Ice sheet melt, glacial melt, and sea level rise have all accelerated faster than previously predicted. 


3. Climate change is impacting extreme weather. Increases in the frequency and intensity of some types of extreme weather have been detected today, and other types are projected to increase in the future.


4. Nobody is going to be untouched by the impacts of climate change. People everywhere are vulnerable to extreme climate and weather events as adaptation and preparation remains low, which could result in severe consequences as impacts rise.


5. Climate change is already harming agricultural yields, and this will worsen.


6. Further delay = temperature targets to be exceeded.  2ºC target agreed upon by world leaders will soon be out of reach if no further action is taken. Governments must restrict emissions from additional fossil-fuel burning, which means  leaving the vast majority of the world’s reserves of fossil fuels in the ground. If greenhouse gas emissions continue rising at current rates, average projected global temperature will be  2.6-4.8ºC warmer by the end of the century. 



7. Solution is renewables in transitioning to a low-carbon economy. Renewable energy will need to triple or quadruple by 2050 to meet temperature targets. Meanwhile, carbon dioxide from fossil fuels and industry has accounted for about ¾ of greenhouse gas pollution since 1970.


8. Restricting warming to 2ºC is practical and affordable. The cost of renewable energy is falling and deforestation rates have declined.


9. Economic growth will be HIGHER if we invest in clean energy, and it will be LOWER if we decline to ramp up investments in clean energy. The IPCC is clear that impacts on the conventional fossil-fuel path will be catastrophic.  To meet targets, scenarios show a $30 billion/year decline in fossil fuel investment, a $147 billion/year increase in low-carbon energy investment, and a $100 billion/year increase in energy efficiency investments. Investments in long-lived fossil fuel infrastructure will be difficult and costly to change


10. We are at a crucial cross-roads: We can go down the clean energy path on which economic growth is strong or continue in the fossil fuel dependent path where economic growth is derailed by climate change.



For additional  analysis: Climate Nexus IPCC orientation