By Anders Lorenzen

Just months before the crucial UN climate summit, COP26 kicks off in Glasgow, UK in November the Intergovernmental Panel on Climate Change (IPCC) has issued one of its starkest reports stating that governments have taken too long to take action and we are now paying the price.

The latest IPCC climate report, Climate Change: The Physical Science Basis is the first instalment of the Sixth Assessment Report (AR6), with the remaining three reports to be released during 2022.

Unprecedented

The comprehensive report leaves no one in doubt that every corner of the Earth is now impacted by climate change, the change caused by the burning of fossil fuels and other human activities. It finds that many of the changes observed in the climate are unprecedented in thousands if not hundreds of thousands of years. Some of those predicted changes are already happening such as continued sea level rise which is now irreversible over a time span of hundreds to thousands of years.

However, its authors leave a glimmer of hope in what could be a nod to governments ahead of COP26, that strong and sustained CO2 emissions reductions, as well as cuts to other planet-warming greenhouse gasses (GHG), would limit climate change. If that were to happen global temperatures could stabilise within a time frame of 20-30 years, according to the IPCC Working Group who worked on the report.

Commenting on the release of the report, Hoesung Lee, Chair of the IPCC said: “This report reflects extraordinary efforts under exceptional circumstances. The innovations in this report, and advances in climate science that it reflects, provide invaluable input into climate negotiations and decision-making.”

Almost beyond reach

In the report, researchers set out new estimates for the chances of crossing the 1.5 degrees C threshold in the next decades which countries had agreed as the desirable target in 2015’s Paris Agreement. They found that unless there are immediate, rapid and large-scale reductions to the agreed limits of warming to 1.5 degrees or even 2 degrees C, which must not be crossed, reversal will be beyond reach. 

The report details that so far human-driven emissions are responsible for approximately 1.1 degrees C of warming since 1850-1900 and that, averaged over the next 20 years, global temperatures are expected to reach or exceed 1.5 degrees C. Co-Chair of the working group Valérie Masson-Delmotte said “This report is a reality check. We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”

Not evenly distributed

The report also explains that the warming the planet is and will experience is not evenly distributed. For instance, warming over land is higher than the global average, and in the Arctic, it is more than twice as high. “Climate change is already affecting every region on Earth, in multiple ways. The changes we experience will increase with additional warming” explained Panmao Zhai, also CO-Chair of the working group.

In the coming decades, the changes in the climate will be felt in all regions across the planet. A warming of 1.5 degrees C will cause increasing heatwaves, longer warm seasons and shorter cold seasons. At 2 degrees C of warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health.  The report states that a warming climate does not just impact temperatures but other settled weather patterns in different  regions such as changes to wetness and dryness, to winds, snow and ice, coastal areas and oceans.

What’s to come

The authors highlight a series of examples that present and future warming will bring such as intensifying water cycles – meaning more intense rainfall, a change in rainfall patterns and flooding resulting in more intense drought in many regions. And coastal areas will continue to be at the forefront of the battle due to continued sea-level rise throughout the 21st century – contributing to more frequent and severe flooding in low-lying areas as well as in coastal erosion. And by the end of this century, extreme sea-level events which previously occurred every 100 years could happen every year. 

In the Arctic, further warming will increase the thawing of permafrost and the loss of seasonal cover and speed up the melting of glaciers, ice sheets and the loss of summer Arctic Sea ice. Changes to the ocean including warming, frequent marine heatwaves, ocean acidification and reduced oxygen levels will continue throughout at least the rest of the century. In some cities, the risks of heatwaves and serious flooding will increase.

Though a majority of the public has long been convinced that the science of climate change is settled then this report brings ever more evidence and clarity, and concludes that the Earth’s climate is changing due to human activity and this fact is undisputed.

Responding to the report, Dr Stephen Cornelius, Chief Adviser on Climate Change and WWF lead on the IPCC, said: “This is a stark assessment of the frightening future that awaits us if we fail to act. With the world on the brink of irreversible harm, every fraction of a degree of warming matters to limit the dangers of climate change. It is clear that keeping global warming to 1.5°C is hugely challenging and can only be done if urgent action is taken globally to reduce greenhouse gas emissions and protect and restore nature.” 

And the UN Secretary-General Antonio Guterres was in a sombre mood, saying: “Today’s IPCC report is a code red for humanity. The alarm bells are deafening, and the evidence is irrefutable: greenhouse gas emissions from fossil fuel burning and deforestation are choking our planet and putting billions of people at immediate risk. Global heating is affecting every region on Earth, with many of the changes becoming irreversible.”