Climate change is a threat to human wellbeing and planetary health “with a rapidly closing window of opportunity to secure a liveable and sustainable future for all”, according to the latest verdict of the Intergovernmental Panel on Climate Change (IPCC) issued on Monday.
“The choices and actions implemented in this decade will have impacts now and for thousands of years,” warn leading climate scientists who are part of the UN body.
They conclude, however, that there are “multiple, feasible and effective options” immediately available to reduce greenhouse gas emissions and to adapt to human-caused climate change by enhancing climate resilience, especially in the developing world.
But without sustained cuts to emissions throughout the current decade, it adds, “the world will see catastrophic levels of global warming”. And in a stark message, it says failure to address climate issues will make most of the UN sustainable development goals much harder to achieve.
How a hotter world is affecting Ireland in five graphics
It’s fishmas time again as aquariums deck the tanks and embrace scuba Santa
A year of devastating climate firsts, a dispiriting outcome to Cop29 and elections where climate was off the radar
Why Ireland may face a €20 billion bill if we fail to meet climate goals
Known as the “synthesis report”, it evaluates six major reports issued since 2018 and is the culmination of a global review known as AR6. It is aimed at policymakers, especially government and key decision-makers on climate action.
“Last year’s IPCC report... clearly confirmed that with ‘rapid and substantial reductions’ we can still limit global warming,” it concludes.
“Today’s impact report spells out the consequences if we fail to make these changes – and they are severe.”
It adds: “This report could not be more explicit: leaders of all nations must rapidly phase out fossil fuels and transition to clean, renewable energy.”
UN secretary general António Guterres said, “The climate time-bomb is ticking,” in response to the report, which confirms the rate of temperature rise in the last half-century is the highest in 2,000 years while concentrations of carbon dioxide are at their highest in at least two million years.
“But today’s IPCC report is a how-to guide to defuse the climate time-bomb. It is a survival guide for humanity. As it shows, the 1.5-degree limit is achievable. But it will take a quantum leap in climate action,” he added.
In 2018, IPCC highlighted the unprecedented scale of the challenge required to keep warming to 1.5 degrees – a key target under the Paris Agreement.
“Five years later, that challenge has become even greater due to a continued increase in greenhouse gas emissions. The pace and scale of what has been done so far, and current plans, are insufficient to tackle climate change,” the synthesis report finds.
Irish climate scientist Prof Peter Thorne, a core author of the report, said it focused uniquely on near-term actions and the need for governments, industry, communities and individuals to grapple with climate actions immediately; “if not, the consequences will reverberate for thousands of years”.
While there was a need to start to take actions to avoid a 2 degree-plus world caused by human activities, it was critical that people recognised “a message of opportunity... this is eminently fixable”, but it meant people had to “stop treating the earth’s atmosphere as a massive dustbin”.
He confirmed the report indicates 1.5 degrees is likely to be breached in any given year over the coming decade but that did not necessarily mean a long-term rise. Immediate action could help pull that rise back through immediate actions and this could stop temperatures exceeding 2 degrees in the 2030s.
More than a century of burning fossil fuels as well as unequal and unsustainable energy and land use has led to global warming of 1.1 degrees above pre-industrial levels, the climate scientists confirm. “This has resulted in more frequent and more intense extreme weather events that have caused increasingly dangerous impacts on nature and people in every region of the world.”
Worldwide “climate-resilient development is more urgent than previously assessed in AR5” – the previous assessment concluded in 2014.
The report underlines that climate, ecosystems and society are highly interconnected, and “effective and equitable conservation” of 30-50 per cent of the Earth’s land, freshwater and oceans is essential to ensure a healthy planet.
Every increment of warming results in rapidly escalating hazards, it says. More intense heatwaves, heavier rainfall and other weather extremes further increase risks for human health and ecosystems. In every region, people are dying from extreme heat, while climate-driven food and water insecurity is predicted to increase with increased warming.
“When the risks combine with other adverse events, such as pandemics or conflicts, they become even more difficult to manage,” it notes.
[ Our choices as consumers will determine how much greenhouse gas emissions occurOpens in new window ]
The report, approved during weeklong negotiations in Interlaken Switzerland between climate scientists and almost 200 countries – signatories of the Paris Agreement – brings into sharp focus losses and damages already being experienced, hitting the most vulnerable people and ecosystems especially hard. Yet, “taking the right action now could result in the transformational change essential for a sustainable, equitable world”.
“Mainstreaming effective and equitable climate action will not only reduce losses and damages for nature and people, it will also provide wider benefits,” said IPCC chairman Prof Hoesung Lee. “This synthesis report underscores the urgency of taking more ambitious action and shows that, if we act now, we can still secure a liveable sustainable future for all.”
Dr Aditi Mukherji, one of the 93 main authors, said: “Climate justice is crucial because those who have contributed least to climate change are being disproportionately affected.
“Almost half of the world’s population lives in regions that are highly vulnerable to climate change. In the last decade, deaths from floods, droughts and storms were 15 times higher in highly vulnerable regions,” she added.
In this decade, accelerated action to adapt to climate change is essential to close the gap between existing adaptation and what is needed. Meanwhile, keeping warming to 1.5 degrees above pre-industrial levels requires deep, rapid and sustained emissions reductions in all sectors. “Emissions should be decreasing by now and will need to be cut by almost half by 2030, if warming is to be limited to 1.5 degrees,” the report says.
It highlights the importance of “climate-resilient development” in providing a solution. “This involves integrating measures to adapt to climate change with actions to reduce or avoid greenhouse gas emissions in ways that provide wider benefits.”
Access to clean energy and technologies and low-carbon electrification, walking, cycling and public transport enhance air quality, improve health, employment opportunities and deliver equity. “The economic benefits for people’s health from air quality improvements alone would be roughly the same, or possibly even larger than the costs of reducing or avoiding emissions.”
Climate-resilient development, however, will become progressively more challenging with every increment of warming, it warns. “This is why the choices made in the next few years will play a critical role in deciding our future and that of generations to come.”
Author Christopher Trisos said: “The greatest gains in wellbeing could come from prioritising climate risk reduction for low-income and marginalised communities, including people living in informal settlements.”
He highlighted a financing deficit as “accelerated climate action will only come about if there is a manyfold increase in finance. Insufficient and misaligned finance is holding back progress.”
There is sufficient global capital to rapidly reduce emissions if existing barriers are reduced, the report says. “Governments, through public funding and clear signals to investors, are key in reducing these barriers. Investors, central banks and financial regulators can also play their part.”
Political commitment, co-ordinated policies, international co-operation, ecosystem stewardship and inclusive governance are all important for effective and equitable climate action.
“If technology, know-how and suitable policy measures are shared, and adequate finance is made available now, every community can reduce or avoid carbon-intensive consumption. Combined with significant investment in adaptation, we can avert rising risks, especially for vulnerable groups and regions,” the IPCC says.
Changes in the food sector, electricity, transport, industry, buildings and land-use can reduce emissions and make it easier for people to lead low-carbon lifestyles, which will also improve health and wellbeing. “A better understanding of the consequences of overconsumption can help people make more informed choices,” it says.
“Transformational changes are more likely to succeed where there is trust, where everyone works together to prioritise risk reduction, and where benefits and burdens are shared equitably,” Prof Lee said.
“We live in a diverse world in which everyone has different responsibilities and different opportunities to bring about change. Some can do a lot while others will need support to help them manage the change.”
The report highlights how many low-cost solutions already exist for “the necessary economywide transformation”, especially with the cost of renewables like wind and solar having dropped in price by up to 85 per cent over the past decade – in contrast to the cost of oil and gas which have come with price volatility.
The IPCC says the case for widespread electrification is unanswerable – which is especially crucial for enabling the decarbonisation of road transport, industry, mining and manufacturing, and must be powered by renewable sources. In addition, energy efficiency and conservation are central to achieving “a greener, safer future”.
