Evidence continues to mount that Earth systems processes have passed tipping points or their tipping is foregone without rapid restoration of our climate to within the evolutionary boundary conditions of our former climate. No amount of warming beyond the maximum of our old climate is now safe and we must cool from today to restore those natural conditions. These conditions continue to worsen at an increasing pace, but our global climate mitigation process has now been upended by anti-science leadership in the U.S.
Antarctic Tipping Warning, Australian Antarctic Program… Ongoing changes reveal 1.5 degree C warming may be too warm to prevent irreversible collapse… Abrupt changes across the Antarctic environment are already underway or imminent. Antarctic sea ice extents have abruptly plummeted after slightly increasing for two decades. A significant slowdown in the formation of Antarctic bottom water, similar to the Gulf Stream and Atlantic meridional overturning circulation but stronger already, has been demonstrated in the past to create cascading and amplifying effects to systems worldwide. The tipping point for irreversible ice sheet ice loss will be exceeded under the best-case warming scenarios.
Critical passage in concluding remarks, “The only assured way of reducing the risk of abrupt changes in the Antarctic environment is to make rapid and deep CO2 emission reductions this decade, and achieve true net zero emissions this century within a remaining global carbon budget that allows for as little overshoot of 1.5 °C as possible. Even if this ambitious climate change mitigation is achieved through international cooperation and national to regional-scale implementation, the long-term commitments for Southern Ocean warming mean that climate stabilization between 1.5 °C and 2 °C may not be sufficient to avoid some abrupt and possibly irreversible changes in the Antarctic environment.”
(Abstract) Human-caused climate change worsens with every increment of additional warming, although some impacts can develop abruptly. The potential for abrupt changes is far less understood in the Antarctic compared with the Arctic, but evidence is emerging for rapid, interacting and sometimes self-perpetuating changes in the Antarctic environment. A regime shift has reduced Antarctic sea-ice extent far below its natural variability of past centuries, and in some respects is more abrupt, non-linear and potentially irreversible than Arctic sea-ice loss. A marked slowdown in Antarctic Overturning Circulation is expected to intensify this century and may be faster than the anticipated Atlantic Meridional Overturning Circulation slowdown. The tipping point for unstoppable ice loss from the West Antarctic Ice Sheet could be exceeded even under best-case CO2 emission reduction pathways, potentially initiating global tipping cascades. Regime shifts are occurring in Antarctic and Southern Ocean biological systems through habitat transformation or exceedance of physiological thresholds, and compounding breeding failures are increasing extinction risk. Amplifying feedbacks are common between these abrupt changes in the Antarctic environment, and stabilizing Earth’s climate with minimal overshoot of 1.5 °C will be imperative alongside global adaptation measures to minimise and prepare for the far-reaching impacts of Antarctic and Southern Ocean abrupt changes.
Abram et al., Emerging evidence of abrupt changes in the Antarctic environment, Nature, August 21, 2025.
(Paywall) https://www.nature.com/articles/s41586-025-09349-5
(Press Release) New study confirms “abrupt changes” underway in Antarctica, Australian Antarctic Program, August 21, 2025.
https://www.antarctica.gov.au/news/2025/new-study-confirms-abrupt-changes-underway-in-antarctica/
Earth systems’ sequestration flips into decline, Royal Meteorological Society… Forests degradation from insects and disease across the world, declining ocean and soils absorption and increased permafrost thaw have flipped Earth’s natural greenhouse gas sequestration systems into decline. What this means is that, if our Earth systems were sequestering greenhouse gases at the same rate they did in the 1960s, the annual atmospheric growth rate would have been 1.9 ppm CO2. Instead, the annual growth rate is 2.5 ppm CO2, and this is the 2010 to 2020 average. In 2023 and 2024, the atmospheric growth rate jumped markedly from previous data to nearly 3.5 ppm CO2 growth per year, according to the Mauna Loa CO2 records https://gml.noaa.gov/ccgg/trends/gr.html in Hawai’i (that have been threatened to be discontinued by the fascist dictator in chief.)
(Abstract) The rate of natural sequestration of CO2 from the atmosphere by the terrestrial biosphere peaked in 2008. Atmospheric concentrations will rise more rapidly than previously, in proportion to annual CO2 emissions, as natural sequestration is now declining by 0.25% per year. The current atmospheric increment of +2.5ppm CO2 per year would have been +1.9ppm CO2, if the biosphere had maintained its 1960s growth rate. This effect will accelerate climate change and emphasises the close connection between the climate and nature emergencies. Effort is urgently required to rebuild global biodiversity and to recover its ecosystem services, including natural sequestration.
Curran and Curran, Natural sequestration of carbon dioxide is in decline: climate change will accelerate, Royal Meteorological Society, January 15, 2025
https://doi.org/10.1002/wea.7668
Mega drying regions across the Northern Hemisphere – Unprecedented continental drying, shrinking freshwater availability, and increasing land contributions to sea level rise, Science Advances… Continental drying is so profound that the water loss from land is now the leading factor in sea level rise, surpassing that of ice sheets and other land ice.
(Abstract) Changes in terrestrial water storage (TWS) are a critical indicator of freshwater availability. We use NASA GRACE/GRACE-FO data to show that the continents have undergone unprecedented TWS loss since 2002. Areas experiencing drying increased by twice the size of California annually, creating “mega-drying” regions across the Northern Hemisphere. While most of the world’s dry/wet areas continue to get drier/wetter, dry areas are now drying faster than wet areas are wetting. Changes in TWS are driven by high-latitude water losses, intense Central American/European droughts, and groundwater depletion, which accounts for 68% of TWS loss over non-glaciated continental regions. “Continental drying” is having profound global impacts. Since 2002, 75% of the population lives in 101 countries that have been losing freshwater water. Furthermore, the continents now contribute more freshwater to sea level rise than the ice sheets, and drying regions now contribute more than land glaciers and ice caps. Urgent action is required to prepare for the major impacts of results presented.
Chandanpurkar et al., Unprecedented continental drying, shrinking freshwater availability, and increasing land contributions to sea level rise, Science Advances, July 25, 2025.
https://www.science.org/doi/10.1126/sciadv.adx0298