IPCC Releases Sixth Assessment Report, Working Group I
9th August 2021
The Intergovernmental Panel on Climate Change (IPCC) has published the Sixth Assessment Report from Working Group 1 on the Physical Science Basis of climate change. The report, stating that it is “…unequivocal that human influence has warmed the atmosphere”, finds that warming of 1.1°C has already occurred. The report also finds that global temperatures are expected to reach 1.5°C – the goal of the Paris Agreement – over the next 20 years, earlier than anticipated in previous reports.
Changes in the climate system, including “…increases in the frequency and intensity of hot extremes, marine heatwaves, and heavy precipitation, agricultural and ecological droughts in some regions, and proportion of intense tropical cyclones, as well as reductions in Arctic sea ice, snow cover and permafrost” are anticipated.
Without delving into mitigation pathways (the remit of Working Group 3, expected in 2022), the report indicates that, following the cessation of emissions, heating will stop and temperatures will stabilise within a couple of decades. This highlights a role for CCS in delivering deep decarbonisation. However, some of the effects of climate change will be irreversible for centuries.
Under the report’s scenarios with increasing CO2, the IPCC projects that ocean and land carbon sinks, such as forests and algae, will be less effective at slowing the accumulation of CO2 in the atmosphere. The report’s Technical Summary stated that “deliberate carbon dioxide removal (CDR) from the atmosphere has the potential to compensate for residual CO2 emissions to reach net zero CO2 emissions or to generate net negative CO2 emissions.”