In a statement on the Working Group I contribution to the Intergovernmental Panel on Climate Change (IPCC) sixth assessment report, entitled Climate Change 2021: the Physical Science Basis, the UN Climate Change officially welcomes the report
The Working Group I contribution to the IPCC’s Sixth Assessment report confirms that it is indisputable that human influence has warmed the climate system, raising global surface temperature. The report provides an update on the physical science basis of climate change and confirms that there is no going back from some changes that are already affecting the climate system.
Recent changes in the climate are widespread, rapid and intensifying and impacts are affecting every region on Earth, including the oceans. Many weather and climate extremes such as heatwaves, heavy rainfall, droughts and tropical cyclones have become more frequent and severe. The report provides an atlas of regional observed and future impacts, which will allow policy makers and all other stakeholders to better inform climate policies at the regional and local levels.
The report identifies that the level of future emissions will determine the level of future temperature rise and the severity of future climate change and the associated impacts and risks. Not only have CO2 concentrations increased in the Earth’s atmosphere, but the rate of the increase has also sped up. The report shows that greenhouse gas emissions from human activities are responsible for approximately 1.1°C of warming since 1850-1900, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming.
Unless there are rapid, sustained and large-scale reductions of climate change-causing greenhouse gas emissions, including CO2, methane and others, the goal of limiting global warming to 1.5C compared to pre-industrial levels, as enshrined in the Paris Agreement, will be beyond reach.
This assessment of the latest science is a severe warning regarding the well-being of human society and all life on Earth. It is testimony to the fact that efforts to reduce greenhouse gas emissions over the past decades have been wholly insufficient.
With respect to the intergovernmental negotiations on climate change, 2021 marks a crucial year as nations submit their new or updated Nationally Determined Contributions (NDCs), embodying the efforts and actions of each country to respond to climate change and reduce emissions.
An initial synthesis of submitted new or updated NDCs early in 2021 showed that collective efforts fall far short of what is required by science to limit global temperature increases by the end of the century to 2C, let alone the desired objective of less than 1.5C.
Sound policy and action are based on sound science. As the IPCC’s Summary for Policy Makers underscores, limiting warming to 1.5C can only be achieved through immediate and significantly scaled-up reductions. The only way to reach this goal is through the rapid implementation of more ambitious NDCs.
At present, only slightly more than half of all Parties to the Paris Agreement have submitted new or updated NDCs.
All nations that have not yet done so, still have the opportunity to submit ambitious NDCs. Nations that have already submitted new or updated NDCs, still have the opportunity to review and enhance their level of ambition. The collective effort of all submissions will be captured in an updated synthesis report, to be made available later in the year.
Given the latest assessment of the physical science basis of climate change, accepting and rising to the challenge of increasing ambition needs to be the way forward. Pursuing efforts towards 1.5ºC through the implementation of ambitious NDCs is essential for our future and for future generations’ well-being.
