Scientists call for immediate, rapid and more ambitious plans to limit warming
Limiting global warming to close to 1.5°C or even 2°C will be beyond reach without immediate, rapid and large-scale reductions in greenhouse gas emissions, a new report from the Intergovernmental Panel on Climate Change (IPCC) said Monday.
Averaged over the next 20 years, the global temperature is expected to reach or exceed 1.5°C of warming in the most ambitious emissions pathway by overshooting to 1.6°C with temperatures dropping down to 1.4°C at the end of the century.
As the report found that governments needed to halve emissions by 2030 to give the best chance of limiting temperature rise to 1.5℃, it said climate plans must be more ambitious and net-zero roadmaps must put rapid emissions reduction at the heart of their plans.
According to the IPCC’s Sixth Assessment Cycle report entitled Climate Change 2021: the Physical Science Basis, scientists say it is unequivocal that climate change is caused by human activities.
Emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900.
Rapid and widespread changes have occurred in the planet’s climate and some impacts are now locked in.
The report said the last decade saw Arctic sea ice at its lowest level since 1850 and that the global sea-level rise has risen faster since 1900 than any other time over the last 3,000 years.
As marine heatwaves have doubled in frequency since the 1980s, human influence has very likely contributed the most to these since at least 2006.
Scientists predict that sea levels will continue to rise for hundreds to thousands of years even in the most ambitious climate pathways. They forecast that the global mean sea level will rise above the likely range by up to 2 meters in 2100 and by 5 meters by 2150.
- Changing climate systems, increasing fires and floods
The report said that most of the planet is already weathering hot extremes, with heatwaves in North America, Europe, Australia, large parts of Latin America, west and east Southern Africa, Siberia, Russia, and across Asia.
Some of these recent hot extremes would have been extremely unlikely to occur without human influence, the IPCC said.
Although less is known about drought, the report said that there is enough evidence to show that North Eastern South Africa, the Mediterranean, Southern Australia, the West Coast of North America are dealing with increased droughts.
The report emphasized that any small increment in warming matters, as projected changes in extremes are larger in frequency with every additional increment of global warming.
- Climate change brings multiple different changes
According to the report, in the coming decades, climate changes will increase in all regions.
For 1.5°C of global warming, the report showed there will be increasing heatwaves, longer warm seasons and shorter cold seasons, while at 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health.
“But it is not just about temperature. Climate change is bringing multiple different changes in different regions which will all increase with further warming. These include changes to wet and dryness, to winds, snow and ice, coastal areas and oceans,” the IPCC said.
“The further we go past 1.5°C, the more we build unpredictable and serious risk into our world,” the report warned.
With the current climate pledges and nationally determined contributions, the global warming increase could climb to 2.7°C by 2100.
“This report is yet another reminder that we need to accelerate global efforts to ditch fossil fuels and shift to a cleaner, greener growth model. We have a plan, the Paris Agreement,” Christiana Figueres, founding partner of Global Optimism and former executive secretary at UN Climate Change Convention, was quoted as saying.
“Everything we need to avoid the exponential impacts of climate change is doable. But it depends on solutions moving exponentially faster than impacts, and getting on track to halving global emissions by 2030. COP26 will be the moment of truth,” she said.
- Need to tackle greenhouse gases
Scientists are clear on the need to tackle greenhouse gases other than carbon emissions in the near term, and methane emissions as a powerful greenhouse gas are of particular concern, the report uncovered.
Atmospheric carbon emissions concentrations were higher than at any time in at least 2 million years and concentrations of methane and nitrous oxide were higher than at any time in at least 800,000 years.
“The IPCC’s assessment is critical to understanding the scale of the climate crisis, and the policy and strategic responses required to address it. The ambition of these policies, business and financing decisions must be based on the science, including the reality of the world’s rapidly diminishing carbon budget and the fast increasing physical risks to people and planet,” Mark Carney, UN special envoy for Climate Action and Finance, said.