The world's largest-ever climate change report has been released – and the conclusions are, well, pretty damn scary. However, while the seriousness of the findings shouldn’t be understated, there is a glimmer of hope.
The report is by the Intergovernmental Panel on Climate Change (IPCC), the United Nations body for assessing the science of the climate crisis. For this latest installment, the IPCC report involved an international team of 234 authors and 517 contributing authors who used 14,000 cited references, providing the latest information available on the state of the world’s changing climate.
“The IPCC report gives a comprehensive update on the 'knowns' of climate change over the present century, and it makes for grim reading,” commented Andrew Watson FRS, Royal Society Research Professor at the University of Exeter.
The main findings are: greenhouse gases from human activities have already created at least 1.1°C (1.98°F) warming (as of 2019) since the 19th century – and we can expect global temperatures to reach or exceed 1.5°C (2.7°F) of warming within the next 20 years unless there are immediate, rapid, and large-scale reductions in greenhouse gas emissions.
This milestone is especially significant because the Paris Agreement set the goal of ideally limiting global warming to 1.5°C (2.7°F) – we're currently speeding towards that benchmark at a dizzying pace.
In a world that’s 1.5°C (2.7°F) warmer, we’ll experience increasingly more worrying changes to our planet’s climate, namely increasing heat waves, longer warm seasons, and shorter cold seasons.
If 2°C (3.6F) of global warming is reached – possible within this century unless major changes occur – then Earth would see catastrophic changes. Heat extremes would reach critical tolerance thresholds for agriculture and health more often. There would also be profound damage to ecosystems. For instance, a world with 2°C (3.6°F) of warming may lose coral reefs.
Many irreversible changes, however, are already set in motion and will intensify as temperatures creep up. This includes permafrost thawing, loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic sea ice. We can also expect more intense rainfall and associated flooding, plus more intense droughts in many regions. On top of this, coastal areas will see continued sea-level rise throughout the 21st century, resulting in more frequent and severe coastal flooding in many parts of the world.
“Climate change is happening before our very eyes. Recent events across the world only emphasise that – from devastating wildfires in California, Greece and Turkey, to floods in England, Belgium and Germany, to heatwaves in Siberia and Canada. This report reminds us of what we already know – that these kinds of events will only become more frequent and hard-hitting with ongoing warming,” remarked Dr Ella Gilbert, post-doctoral research assistant at the University of Reading.
“Every IPCC report comes with stronger evidence for the damage we are doing to our planet. This time is no different,” Dr Gilbert added.
The report contained some vaguely optimistic findings. Since humans are driving these changes, we hold the power to stop them. The report argues that if robust and prompt action is taken by governments and policymakers, it’s possible the planet will avoid some of the more disastrous consequences of global warming.
However, that window is quickly closing.
“This report is a scientific and political wake-up call for all governments of the world to take climate change seriously. It acts as a reminder of the urgency of the climate crisis,” noted Mark Maslin, Professor of Earth System Science at University College London.