BAMOS October 2021
12 Article
This is the most sobering report card yet on climate change and Earth ’ s future . Here ’ s what you need to know
Pep Canadell1 , Joëlle Gergis2 , Malte Meinshausen3 , Mark Hemer1 , Michael Grose4
1 CSIRO Oceans and Atmosphere 2 Australian National University 3 Australian-German College of Climate & Energy Transitions at The University of Melbourne 4 CSIRO Climate Science Centre
Photo by Genaro Servín from
Pexels .
Earth has warmed 1.09oC since pre-industrial times and many changes such as sea-level rise and glacier melt are now virtually irreversible , according to the most sobering report yet by the Intergovernmental Panel on Climate Change ( IPCC ).
The report also found escape from human-caused climate change is no longer possible . Climate change is now affecting every continent , region and ocean on Earth , and every facet of the weather .
The long-awaited report is the sixth assessment of its kind since the panel was
formed in 1988 . It will give world leaders the most timely , accurate information about climate change ahead of a crucial international summit in Glasgow , Scotland in November .
The IPCC is the peak climate science body of the United Nations and the World Meteorological Organization . It is the global authority on the state of Earth ’ s climate and how human activities affect it . We are authors of the latest IPCC report and have drawn from the work of thousands of scientists from around the world to produce this new assessment .
Sadly , there is hardly any good news in the 3,900 pages of text released today . But there is still time to avert the worst damage , if humanity chooses to .
It ’ s unequivocal : humans are warming the planet
For the first time , the IPCC states unequivocally — leaving absolutely no room for doubt — humans are responsible for the observed warming of the atmosphere , lands and oceans .
The IPCC finds Earth ’ s global surface temperature warmed 1.09oC between 1850 – 1900 and the last decade . This is 0.29oC warmer than in the
previous IPCC report in 2013 . ( It should be noted that 0.1oC of the increase is due to data improvements ).
The IPCC recognises the role of natural changes to the Earth ’ s climate . However , it finds 1.07oC of the 1.09oC warming is due to greenhouse gases associated with human activities . In other words , pretty much all global warming is due to humans .
Global surface temperature has warmed faster since 1970 than in any other 50-year period over at least the last 2,000 years , with the warming also reaching ocean depths below 2,000 metres .
The IPCC says human activities have also affected global precipitation ( rain and snow ). Since 1950 , total global precipitation has increased , but while some regions have become wetter , others have become drier .
The frequency and intensity of heavy precipitation events have increased over most land areas . This is because the warmer atmosphere is able to hold more moisture —
about 7 % more for each additional degree of temperature — which makes wet seasons and rainfall events wetter .
Higher concentrations of CO₂ , growing faster
Present-day global concentrations of atmospheric carbon dioxide ( CO₂ ) are higher and rising faster than at any time in at least the past two million years .