There are many who consider a 2°C limit for global temperature rise to be an unacceptable climate risk. For them it’s «1.5°C to stay alive,» and the new IPCC report shows that they have a serious point.
The IPCC’s newly updated «Reasons for Concern» indicators (sometimes called «the burning embers,» refers to a chart showing increasing risk for the key indicators in yellow, orange and red colors) show that 2 or even 3 out of 5 key risks would could be at dangerous levels with 2°C warming.
The risks play out most at a regional scale, so let’s have a look at what could happen with just 2°C warming globally (recognising that warming also varies by region):
For Africa, of 9 key regional risks, 8 pose medium or higher risk with 2°C warming, even with high levels of adaptation. We’re talking fundamentals like water stress, reduced food production and the spread of diseases.
For Small Island States, highly vulnerable to sea-level rise and high-water events, and dependent on ocean ecosystems, 2°C would be a disaster.
For Asia, risks of catastrophic flooding and lethal heatwaves would be in the medium or high range even with high levels of adaptation.
For Europe, there would be medium risks related to freshwater availability and extreme heat events even, again, with high levels of adaptation.
For Australasia, 2°C really wouldn’t leave much hope for coral ecosystems, or the fish, tourism, and communities that depend on them.
For North America, 2°C would imply high or very high risks related to wildfires and droughts.
For Central and South America, 2°C with high levels of adaptation would imply high risks of flooding and landslides caused by heavy rains, and big problems for water availability in semi-arid and glacier melt-dependent regions.
For the oceans, risks related to 2°C look particularly devastating: risks are very high for «reduced biodiversity, fisheries abundance and coastal protection by coral reefs due to heat-induced mass coral bleaching and mortality increases, exacerbated by ocean acidification».
You don’t even need to look into the future. Today, with less than 1°C warming, we are already witnessing:
- Greenland Ice Sheet losing ice 6 times faster (!) in 2002-2011 than just a decade earlier.
- Unprecedented high-impact climate extremes during the 2001-2010 decade (according to WMO).
- The newest findings of the fast-moving research on the West Antarctic Ice Sheet, coming in after AR5 but further refining the assessment, strongly suggests that key glaciers are crossing a point of no return, making at least 1.2 meter sea-level rise inevitable and possibly triggering the collapse of the rest of the WAIS.
What this means is that every new ton of carbon in the atmosphere is making our lives worse. And the further we drift upward from 1.5°C warming, the bigger the necessity for adaptation and compensation for loss and damage.
The conclusion is quite clear: we must act on the science and head for 1.5°C maximum warming instead of 2°C.