Climate change action must be taken immediately if we want Earth to remain habitable. This is the implication of a grim new report released today by the Intergovernmental Panel on Climate Change (IPCC).
The report states that human-induced climate change is causing dangerous and widespread disruption in nature and affecting the lives of billions of people around the world, despite efforts to reduce the risks.
“The scientific evidence is unequivocal: climate change is a threat to human well-being and the health of the planet. Any further delay in concerted global action will miss a brief and rapidly closing window to secure a liveable future,” said IPCC Working Group II Co-Chair Hans-Otto Pörtner.
“This report is a dire warning about the consequences of inaction,” said Hoesung Lee, Chair of the IPCC. “It shows that climate change is a grave and mounting threat to our well-being and a healthy planet. Our actions today will shape how people adapt and nature responds to increasing climate risks.”
Extreme weather events, including heatwaves, droughts and floods, are happening much more frequently – and often simultaneously. The experts say that the cascading impacts are becoming increasingly difficult to manage.
For example, heat and drought have already driven mass mortality events in species such as trees and corals. Weather extremes have also caused widespread food and water shortages in places like Africa and Asia. The experts say that the people and ecosystems that are least able to cope are already taking the hardest hit.
Reinhard Mechler is the IIASA Systemic Risk and Resilience Research Group Leader and a lead author on Chapter 17 of the report, which focuses on decision-making options for managing risk
“The cumulative scientific evidence of this report is indisputable: climate change is a threat to human well-being and the health of the planet. This report builds on the messages of previous IPCC reports, showing that climate impacts and risks are proliferating at specific levels of global warming,” said Mechler.
“While action on adaptation (and mitigation) is being taken across the world, there are growing gaps with regard to avoiding and reducing risks, as well as dealing with unavoided and unavoidable impacts and risks.”
According to Mechler, adaptation limits will soon be reached in both natural and human systems without urgent action. “The 1.5°C global ambition on climate mitigation is real: beyond this warming level, impacts and risks will become increasingly existential and irreversible.”
The experts emphasized that safeguarding and strengthening nature is key to securing a liveable future. The report provides new insights into nature’s potential to not only reduce climate risks, but to also improve people’s lives.
“Healthy ecosystems are more resilient to climate change and provide life-critical services such as food and clean water,” said Pörtner. “By restoring degraded ecosystems and effectively and equitably conserving 30 to 50 percent of Earth’s land, freshwater and ocean habitats, society can benefit from nature’s capacity to absorb and store carbon, and we can accelerate progress towards sustainable development, but adequate finance and political support are essential.”
The experts note that while cities are hotspots of impacts and risks, they are also a crucial part of the solution.
“Together, growing urbanization and climate change create complex risks, especially for those cities that already experience poorly planned urban growth, high levels of poverty and unemployment, and a lack of basic services,” said IPCC Working Group II Co-Chair Debra Roberts.
“But cities also provide opportunities for climate action – green buildings, reliable supplies of clean water and renewable energy, and sustainable transport systems that connect urban and rural areas can all lead to a more inclusive, fairer society.”
The IPCC report states that building climate resiliency is already challenging at current warming levels, but will become much more limited if global warming exceeds 1.5°C. In some regions, resilience will become impossible if global warming exceeds 2°C. This highlights the urgent need for climate change adaptation and emissions reductions.
“Action on climate change is inextricably linked to action on other global challenges. It is important to note that pursuing climate resilience development pathways will also create opportunities – rapid urban growth, for instance, presents a time-limited opportunity to achieve climate resilient and sustainable development. The benefits would be felt in more rural areas as well through stronger supply chains and financial flows,” said Mechler.
“A healthy planet is fundamental to climate resilient development. Biodiversity and ecosystem services have limited capacity to adapt to increasing global warming levels, which will make climate resilient development progressively harder to achieve beyond 1.5°C warming. Maintaining the resilience of biodiversity and ecosystem services at a global scale depends on effective and equitable conservation of approximately 30 to 50 percent of Earth’s land, freshwater, and ocean areas, including currently near-natural ecosystems.”