Humanity has reached a pivotal moment as global warming means we are accelerating towards tipping points that will trigger irreversible environmental changes, according to a new report.
The most comprehensive assessment of its kind, conducted by an international team of more than 200 researchers, says Earth system tipping points likely to be triggered include the collapse of major ice sheets and widespread mortality of warm-water coral reefs. As other tipping points are reached, there is a risk of catastrophic, global-scale loss of capacity to grow staple crops, resulting in mass displacement of people, political instability and financial collapse.
UKCEH freshwater scientists Professor Bryan Spears and Dr Amy Pickard contributed to a chapter in the report that assessed the likelihood of sudden large-scale changes in lakes. This work drew on UKCEH’s large scale, long-term environmental monitoring, which is vital in providing the essential early warning of sudden changes in ecosystem behaviour in the UK and overseas.
Prof Spears explains: “Freshwaters are essential for life on earth. The report highlights that climate change and other pressures including nutrient pollution from agriculture and wastewater are increasing the likelihood of mass tipping point events across lakes and reservoirs. If left unchecked, these events may cause sudden species loss, water quality impairment leading to increased human health risks, and increased greenhouse gas emissions from polluted water bodies.”
Based on an assessment of 26 negative Earth system tipping points, the report concludes that “business as usual” is no longer acceptable, with rapid changes to nature and societies already happening, and more coming.
The report’s authors warn that damage to the natural world will leave societies overwhelmed unless world leaders, who are meeting at COP28, take urgent action to halt the climate and biodiversity crises and steer us towards positive tipping points. The latter would include the phasing out of fossil fuels towards electric vehicles and renewable energy, the transition from large-scale meat and dairy consumption to more plant-based diets; and shift from widespread tree felling to forest restoration.
The Global Tipping Points Report makes six key recommendations:
- Phase out fossil fuels and land-use emissions well before 2050.
- Strengthen adaptation and “loss and damage” governance, recognising inequality between and within nations.
- Include tipping points in the Global Stocktake (the world’s climate ‘inventory’) and each country’s efforts to tackle climate change.
- Coordinate policy efforts to trigger positive tipping points.
- Convene an urgent global summit on the issue.
- Deepen knowledge of tipping points including an IPCC Special Report.
The report was coordinated by the University of Exeter, in partnership with Bezos Earth Fund. It is available at global-tipping-points.org
Further information
UKCEH’s large scale monitoring projects that identify, and provide evidence, of environmental changes, include:
- UK-SCAPE, which is improving our understanding of the integrated dynamics of our environment
- Our long-term UK lakes monitoring programme
- Our long-term upland waters monitoring programme
- GHG Aqua, which is transforming our capacity to measure, understand and mitigate greenhouse gas emissions from UK inland waters.
- BIOPOLE, investigating how nutrients in polar waters drive the global carbon cycle
- International science for net zero plus, which helps countries, organisations, and companies develop and deliver plans to reduce emissions and increase resilience to climate change.
- On behalf of the World Water Quality Alliance, UKCEH recently published a White Paper setting out priority actions for addressing lake degradation globally. The alliance is coordinated by the United Nations Environment Programme.