Human-induced climate change is causing dangerous and widespread disruption in nature and already affecting the lives of 3.3 billion people out of today’s global population of 7.9 billion – despite greater efforts to reduce risks.
People and ecosystems least able to cope are already being hardest hit, while their vulnerability is set to increase if global temperatures and carbon emissions are allowed increase above 1.5 degrees, according to the latest Intergovernmental Panel on Climate Change (IPCC) report released on Monday.
"This report is a dire warning about the consequences of inaction," said IPCC chair Dr Hoesung Lee. "It shows climate change is a grave and mounting threat to our wellbeing and a healthy planet. Our actions today will shape how people adapt and nature responds to increasing climate risks."
The rise in weather and climate extremes driven by human activities including use of fossil fuels “has led to some irreversible impacts as natural and human systems are pushed beyond their ability to adapt”, the IPCC concludes. Farmers across the tropics are reaching their limits of adaptation to current climate impacts.
“Approximately 3.3 to 3.6 billion people live in contexts that are highly vulnerable to climate change”, with large cities on coastlines most in danger, it adds, while some measures to prepare for inevitable impacts are actually heightening risk.
Maintaining the resilience of biodiversity and “ecosystem services” – provided by nature – at a global scale “depends on effective and equitable conservation of approximately 30-50 per cent of Earth’s land, freshwater and ocean areas, including currently near-natural ecosystems”, the report by 270 leading scientists finds.
The summary for policymakers of the IPCC Working Group 2 (WG2) report, was approved on Sunday by 195 member governments of the IPCC, including Ireland, at the conclusion of a two-week virtual approval session.
The world faces unavoidable multiple climate hazards over the next two decades even if it somehow manages to contain global warming of 1.5 degrees, it warns. Even temporarily exceeding this warming level will result in additional severe impacts, some of which will be irreversible, it predicts. Risks for society will increase, “including to infrastructure and low-lying coastal settlements”.
Weather extremes
Increased heatwaves, droughts and floods are already exceeding tolerance thresholds for plants and animals, driving mass mortalities in species such as trees and coral reefs, it says. “These weather extremes are occurring simultaneously, causing cascading impacts that are increasingly difficult to manage.”
They have exposed millions of people to acute food and water insecurity, especially in Africa, Asia, Central and South America, the Arctic and on small islands of the Pacific, Indian Ocean and Caribbean.
“To avoid mounting loss of life, biodiversity and infrastructure, ambitious, accelerated action is required to adapt to climate change, at the same time as making rapid, deep cuts in greenhouse gas emissions,” it recommends.
So far, however, progress on adaptation is uneven and there are increasing gaps between action taken and what is needed to deal with the increasing risks, the report says – gaps are largest among lower-income populations.
The report provides regional assessments but not country-by-country evaluations. Europe’s greatest risk will come from heat, notably a combination of heatwaves and droughts, resulting in severe impacts on agriculture and increased water scarcity. Separately, extreme flooding will become more evident in its major rivers and along its coasts.
WG2 is the second instalment of the IPCC’s sixth global assessment, which will be completed this year.
“This report recognises the interdependence of climate, biodiversity and people and integrates natural, social and economic sciences more strongly than earlier IPCC assessments,” Dr Lee added. “It emphasises the urgency of immediate and more ambitious action to address climate risks. Half measures are no longer an option.”
It set out options to adapt to a changing climate and provides new insights into nature’s potential not only to reduce climate risks but also to improve people’s lives. Safeguarding and strengthening nature is key to securing a liveable future it, it says – not just reducing emissions while decarbonising the global economy.
“Healthy ecosystems are more resilient to climate change and provide life-critical services such as food and clean water,” underlined WG2 co-chair Hans-Otto Pörtner.
“By restoring degraded ecosystems and effectively and equitably conserving 30 to 50 per cent 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,” he added.
IPCC scientists highlight growing risk of climate disruption “interacting with global trends such as unsustainable use of natural resources, growing urbanisation, social inequalities, losses and damages from extreme events and a pandemic, jeopardising future development.”
"Our assessment clearly shows that tackling all these different challenges involves everyone – governments, the private sector, civil society – working together to prioritise risk reduction, as well as equity and justice, in decision-making and investment," said co-chair Prof Debra Roberts.
“In this way, different interests, values and world views can be reconciled. By bringing together scientific and technological know-how as well as Indigenous and local knowledge, solutions will be more effective. Failure to achieve climate resilient and sustainable development will result in a suboptimal future for people and nature,” she warned.
Assessment
This report provides detailed assessment of climate change impacts, risks and adaptation in cities, where more than half the world’s population lives – urbanisation is set to rapidly increase over coming decades.
People’s health, lives and livelihoods, as well as property and critical infrastructure, including energy and transportation systems, “are being increasingly adversely affected by hazards from heatwaves, storms, drought and flooding as well as slow-onset changes, including sea-level rise”.
Cities are “hotspots of impacts and risks” yet crucial to solutions, the IPCC notes.
“Together, growing urbanisation 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,” Prof Roberts said.
“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,” she said.
The report details increasing evidence of adaptation that has caused unintended consequences, such as destroying nature, putting peoples’ lives at risk or increasing greenhouse gas emissions. “This can be avoided by involving everyone in planning, attention to equity and justice, and drawing on indigenous and local knowledge,” she added.
Challenging
Climate change is a global challenge that requires local solutions, the report underlines. It outlines extensive regional information to enable climate-resilient development, a process of implementing emission reductions and adaptation measures "to support sustainable development for all".
But pursuing this is already challenging at current warming levels and will become more limited if global warming exceeds 1.5 degrees above pre-industrial levels, it finds. In some regions it will be impossible if global warming exceeds 2 degrees.
“This key finding underlines the urgency for climate action, focusing on equity and justice. Adequate funding, technology transfer, political commitment and partnership lead to more effective climate change adaptation and emissions reductions,” Prof Pörtner said.
“The scientific evidence is unequivocal: climate change is a threat to human wellbeing 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.”
