The global temperature is about to overshoot the 1.5°C benchmark.
At this point, any fraction of a degree more of warming intensifies the risk of reaching irreversible climate tipping points which have horrifying impacts on human — and all life — on Earth.
This was according to the latest report from the UN Environmental Programme (Unep), which said that at the present rate of human-generated emissions, the temperature was likely to peak at more than 2°C of warming since pre-industrial levels.
At the release of the report in Nairobi on September 2, Unep said the 1.5°C overshoot would happen “within the next few years, pushing climate risks and impacts to increasingly dangerous heights”.
The report warns that the tipping points would include the destabilisation of major ice sheets, degradation of the Amazon rainforest and disruption of the Atlantic Meridional Overturning Circulation (Amoc).
This is a massive system of currents that moves warm surface water north and cold deep water south, playing a key role in regulating the climate.
“Some impacts may emerge abruptly,” Unep said, “while others will accumulate over time.”
UN secretary-general Antonio Guterres said: “This summer’s scorching heat, raging wildfires and deadly floods are a warning of what lies ahead.
“We must make the overshoot above 1.5 degrees as small and short as possible. That demands an overshoot of ambition”.
He called for immediate and sustained cuts to greenhouse gas emissions, including methane, to bring emissions down to zero through the “carefully governed process of carbon dioxide removal [CDR] from the air and storing it through afforestation or other means”.
Unep executive director Inger Andersen said: “There are no good outcomes if we remain above 1.5°C.
“Across the globe, extreme heatwaves are already proving that climate impacts will strike faster, hit harder, and last longer, costing more lives and causing deeper disruption.
“Now is the time we must double down on climate action.
Australian climate change and energy minister Chris Bowen said: “Our Pacific family is standing on the frontlines.
“The recent energy crisis has reminded the world of the need to reduce our dependence on fossil fuels, accelerate the transition to renewable energy and bolster climate co-operation.”
Unep said devastating impacts of the overshoot would be “intensified extreme weather, ecosystem loss, and submersion of small island states and low-lying coastal cities.
“Severe damage to human health, food security, water supplies, nature, cities, infrastructure and economies”.
It said the most optimistic scenario was a peak of 1.8°C but “most other scenarios predict higher peaks”.
Moving away from fossil fuels to renewable energy would improve air quality and public health.
But this would require “strong political will and multilateralism, effective policies, inclusive governance and finances”.
“Equity and justice must underpin all responses.”
In this new scenario, issues of justice, power and political legitimacy would require new, inclusive governance.
Big polluter countries had to act faster and with more ambition.
Unep said mitigation and adaptation actions were mutually reinforcing and must advance together.
One combination was nature-based cooling, and this was a priority.
It said some overshoot impacts would be permanent even if there was a return to 1.5°C — “many communities may be forced to relocate or change livelihoods”.
“An overshoot, peak and decline pathway is a next generation climate frontier, but one which cannot be left unattended to for the next generation to tackle. Immediate action is required.”
Daily Dispatch