IPCC Report on Climate Change

Source:Brisbane 4EB Sri Lankan Newsletter – Dæhæna – September 2021

The UN’s climate science body has published a major report on the physical changes happening and projected to occur as a result of human activity, from devastating floods to destructive wildfires. It is the first scientific review since 2013 when the Intergovernmental Panel on Climate Change (IPCC) started its last round of assessment reports, AR5.
Assessment reports come in groups of three. This first one outlines the projected impacts of five global emissions scenarios, ranging from
global emissions doubling by 2050 and 2100 compared to current levels, to emissions falling to net zero around 2050 and becoming negative after that.The second and third reports, due in early 2022, will look at how to adapt to these impacts and how to prevent the worst case scenarios. Here are a few key messages from this landmark report.

1. Human influence has warmed the climate at a rate that is unprecedented in at least the last 2000 years.

2. Observed warming is driven by emissions from human activities, with greenhouse gas warming partly masked by aerosol cooling.

3. Climate change is already affecting every inhabited region across the globe with human influence contributing to many observed changes in weather and climate extremes.

4. Future emissions cause future additional warming, with total warming dominated by past and future CO₂ emissions.

5. With every increment of global warming, changes get larger in regional mean temperature, precipitation and soil moisture.

6. Projected changes in extremes are larger in frequency and intensity with every additional increment of global warming.

7. Human activities affect all the major climate system components, with some responding over decades and others over centuries.

8. Every tonne of CO₂ emissions adds to global warming.